Sample records for accelerated seismic release

  1. Accelerated Seismic Release and Related Aspects of Seismicity Patterns on Earthquake Faults

    NASA Astrophysics Data System (ADS)

    Ben-Zion, Y.; Lyakhovsky, V.

    2001-05-01

    Observational studies indicate that large earthquakes are sometimes preceded by phases of accelerated seismic release (ASR) characterized by cumulative Benioff strain following a power law time-to-failure relation with a term (tf - t)m, where tf is the failure time of the large event and observed values of m are close to 0.3. We discuss properties of ASR and related aspects of seismicity patterns associated with several theoretical frameworks, with a focus on models of heterogeneous faults in continuum solids. Using stress and earthquake histories simulated by the model of Ben-Zion (1996) for a discrete fault with quenched heterogeneities in a 3D elastic half space, we show that large model earthquakes are associated with non-repeating cyclical establishment and destruction of long-range stress correlations, accompanied by non-stationary cumulative Benioff strain release. We then analyze results associated with a regional lithospheric model consisting of a seismogenic upper crust governed by the damage rheology of Lyakhovsky et al. (1997) over a viscoelastic substrate. We demonstrate analytically for a simplified 1D case that the employed damage rheology leads to a singular power law equation for strain proportional to (tf - t)-1/3, and a non-singular power law relation for cumulative Benioff strain proportional to (tf - t)1/3. A simple approximate generalization of the latter for regional cumulative Benioff strain is obtained by adding to the result a linear function of time representing a stationary background release. To go beyond the analytical expectations, we examine results generated by various realizations of the regional lithospheric model producing seismicity following the characteristic frequency-size statistics, Gutenberg-Richter power law distribution, and mode switching activity. We find that phases of ASR exist only when the seismicity preceding a given large event has broad frequency-size statistics. In such cases the simulated ASR phases can be

  2. Accelerated Seismic Release and Related Aspects of Seismicity Patterns on Earthquake Faults

    NASA Astrophysics Data System (ADS)

    Ben-Zion, Y.; Lyakhovsky, V.

    Observational studies indicate that large earthquakes are sometimes preceded by phases of accelerated seismic release (ASR) characterized by cumulative Benioff strain following a power law time-to-failure relation with a term (tf-t)m, where tf is the failure time of the large event and observed values of m are close to 0.3. We discuss properties of ASR and related aspects of seismicity patterns associated with several theoretical frameworks. The subcritical crack growth approach developed to describe deformation on a crack prior to the occurrence of dynamic rupture predicts great variability and low asymptotic values of the exponent m that are not compatible with observed ASR phases. Statistical physics studies assuming that system-size failures in a deforming region correspond to critical phase transitions predict establishment of long-range correlations of dynamic variables and power-law statistics before large events. Using stress and earthquake histories simulated by the model of Ben-Zion (1996) for a discrete fault with quenched heterogeneities in a 3-D elastic half space, we show that large model earthquakes are associated with nonrepeating cyclical establishment and destruction of long-range stress correlations, accompanied by nonstationary cumulative Benioff strain release. We then analyze results associated with a regional lithospheric model consisting of a seismogenic upper crust governed by the damage rheology of Lyakhovskyet al. (1997) over a viscoelastic substrate. We demonstrate analytically for a simplified 1-D case that the employed damage rheology leads to a singular power-law equation for strain proportional to (tf-t)-1/3, and a nonsingular power-law relation for cumulative Benioff strain proportional to (tf-t)1/3. A simple approximate generalization of the latter for regional cumulative Benioff strain is obtained by adding to the result a linear function of time representing a stationary background release. To go beyond the analytical

  3. Experimental Evidence of Accelerated Seismic Release without Critical Failure in Acoustic Emissions of Compressed Nanoporous Materials

    NASA Astrophysics Data System (ADS)

    Baró, Jordi; Dahmen, Karin A.; Davidsen, Jörn; Planes, Antoni; Castillo, Pedro O.; Nataf, Guillaume F.; Salje, Ekhard K. H.; Vives, Eduard

    2018-06-01

    The total energy of acoustic emission (AE) events in externally stressed materials diverges when approaching macroscopic failure. Numerical and conceptual models explain this accelerated seismic release (ASR) as the approach to a critical point that coincides with ultimate failure. Here, we report ASR during soft uniaxial compression of three silica-based (SiO2 ) nanoporous materials. Instead of a singular critical point, the distribution of AE energies is stationary, and variations in the activity rate are sufficient to explain the presence of multiple periods of ASR leading to distinct brittle failure events. We propose that critical failure is suppressed in the AE statistics by mechanisms of transient hardening. Some of the critical exponents estimated from the experiments are compatible with mean field models, while others are still open to interpretation in terms of the solution of frictional and fracture avalanche models.

  4. Investigating glide snow avalanche release using seismic monitoring in combination with time-lapse photography

    NASA Astrophysics Data System (ADS)

    van Herwijnen, Alec; Failletaz, Jerome; Berhod, Nicole; Mitterer, Christoph

    2013-04-01

    Glide avalanches occur when the entire snowpack glides over the ground until an avalanche releases. These avalanches are difficult to forecast since the gliding process can take place over a few hours up to several weeks or months. The presence of liquid water at the interface between the snow cover and the ground surface is of primary importance as it reduces frictional support. Glide avalanches are often preceded by the opening of a tensile crack in the snow cover, called a glide crack. Past research has shown that glide crack opening accelerates prior to avalanche release. During the winter of 2012-2013, we monitored glide crack expansion using time-lapse photography in combination with a seismic sensor and two heat flux sensors on a slope with well documented glide avalanche activity in the Eastern Swiss Alps above Davos, Switzerland. To track changes in glide rates, the number of dark pixels in an area around the glide crack is counted in each image. Using this technique, we observed an increase in glide rates prior to avalanche release. Since the field site is located very close to the town of Davos, the seismic data was very noisy. Nevertheless, the accelerated snow gliding observed in the time-lapse images coincided with increased seismic activity. Overall, these results show that a combination of time-lapse photography with seismic monitoring could provide valuable insight into glide avalanche release. Recordings of the heat flux plates show that the energy input from the soil is fairly small and constant throughout the observed period. The results suggest that ground heat flux is a minor contributor to the water production at the snow-soil interface. Instead, the presence of water at the base of the snowpack is probably due to a strong hydraulic pressure gradient at the snow-soil interface.

  5. Artificial seismic acceleration

    USGS Publications Warehouse

    Felzer, Karen R.; Page, Morgan T.; Michael, Andrew J.

    2015-01-01

    In their 2013 paper, Bouchon, Durand, Marsan, Karabulut, 3 and Schmittbuhl (BDMKS) claim to see significant accelerating seismicity before M 6.5 interplate mainshocks, but not before intraplate mainshocks, reflecting a preparatory process before large events. We concur with the finding of BDMKS that their interplate dataset has significantly more fore- shocks than their intraplate dataset; however, we disagree that the foreshocks are predictive of large events in particular. Acceleration in stacked foreshock sequences has been seen before and has been explained by the cascade model, in which earthquakes occasionally trigger aftershocks larger than themselves4. In this model, the time lags between the smaller mainshocks and larger aftershocks follow the inverse power law common to all aftershock sequences, creating an apparent acceleration when stacked (see Supplementary Information).

  6. Seismic rupture and ground accelerations induced by CO 2 injection in the shallow crust

    DOE PAGES

    Cappa, Frédéric; Rutqvist, Jonny

    2012-09-01

    We present that because of the critically stressed nature of the upper crust, the injection of large volumes of carbon dioxide (CO 2) into shallow geological reservoirs can trigger seismicity and induce ground deformations when the injection increases the fluid pressure in the vicinity of potentially seismic faults. The increased fluid pressure reduces the strength against fault slip, allowing the stored elastic energy to be released in seismic events that can produce felt ground accelerations. Here, we seek to explore the likelihood ground motions induced by a CO 2 injection using hydromechanical modelling with multiphase fluid flow and dynamic rupture,more » including fault-frictional weakening. We extend the previous work of Cappa and Rutqvist, in which activation of a normal fault at critical stress may be possible for fast rupture nucleating by localized increase in fluid pressure and large decrease in fault friction. In this paper, we include seismic wave propagation generated by the rupture. For our assumed system and injection rate, simulations show that after a few days of injection, a dynamic fault rupture of few centimetres nucleates at the base of the CO 2 reservoir and grows bilaterally, both toward the top of the reservoir and outside. The rupture is asymmetric and affects a larger zone below the reservoir where the rupture is self-propagating (without any further pressure increase) as a result of fault-strength weakening. The acceleration and deceleration of the rupture generate waves and result in ground accelerations (~0.1–0.6 g) consistent with observed ground motion records. Finally, the maximum ground acceleration is obtained near the fault, and horizontal accelerations are generally markedly higher than vertical accelerations.« less

  7. Micro-seismicity and seismic moment release within the Coso Geothermal Field, California

    USGS Publications Warehouse

    Kaven, Joern; Hickman, Stephen H.; Davatzes, Nicholas C.

    2014-01-01

    We relocate 16 years of seismicity in the Coso Geothermal Field (CGF) using differential travel times and simultaneously invert for seismic velocities to improve our knowledge of the subsurface geologic and hydrologic structure. We expand on our previous results by doubling the number of relocated events from April 1996 through May 2012 using a new field-wide 3-D velocity model. Relocated micro-seismicity sharpens in many portions of the active geothermal reservoir, likely defining large-scale fault zones and fluid pressure compartment boundaries. However, a significant fraction of seismicity remains diffuse and does not cluster into sharply defined structures, suggesting that permeability is maintained within the reservoir through distributed brittle failure. The seismic velocity structure reveals heterogeneous distributions of compressional (Vp) and shear (Vs) wave speed, with Vs generally higher in the Main Field and East Flank and Vp remaining relatively uniform across the CGF, but with significant local variations. The Vp/Vs ratio appears to outline the two main producing compartments of the reservoir at depths below mean ground level of approximately 1 to 2.5 km, with a ridge of relatively high Vp/Vs separating the Main Field from the East Flank. Detailed analyses of spatial and temporal variations in earthquake relocations and cumulative seismic moment release in the East Flank reveal three regions with persistently high rates of seismic activity. Two of these regions exhibit sharp, stationary boundaries at the margins of the East Flank that likely represent barriers to fluid flow and advective heat transport. However, seismicity and moment release in a third region at the northern end of the East Flank spread over time to form an elongated NE to SW structure, roughly parallel both to an elongated cluster of seismicity at the southern end of the East Flank and to regional fault traces mapped at the surface. Our results indicate that high

  8. Tsallis entropy and complexity theory in the understanding of physics of precursory accelerating seismicity.

    NASA Astrophysics Data System (ADS)

    Vallianatos, Filippos; Chatzopoulos, George

    2014-05-01

    Strong observational indications support the hypothesis that many large earthquakes are preceded by accelerating seismic release rates which described by a power law time to failure relation. In the present work, a unified theoretical framework is discussed based on the ideas of non-extensive statistical physics along with fundamental principles of physics such as the energy conservation in a faulted crustal volume undergoing stress loading. We derive the time-to-failure power-law of: a) cumulative number of earthquakes, b) cumulative Benioff strain and c) cumulative energy released in a fault system that obeys a hierarchical distribution law extracted from Tsallis entropy. Considering the analytic conditions near the time of failure, we derive from first principles the time-to-failure power-law and show that a common critical exponent m(q) exists, which is a function of the non-extensive entropic parameter q. We conclude that the cumulative precursory parameters are function of the energy supplied to the system and the size of the precursory volume. In addition the q-exponential distribution which describes the fault system is a crucial factor on the appearance of power-law acceleration in the seismicity. Our results based on Tsallis entropy and the energy conservation gives a new view on the empirical laws derived by other researchers. Examples and applications of this technique to observations of accelerating seismicity will also be presented and discussed. This work was implemented through the project IMPACT-ARC in the framework of action "ARCHIMEDES III-Support of Research Teams at TEI of Crete" (MIS380353) of the Operational Program "Education and Lifelong Learning" and is co-financed by the European Union (European Social Fund) and Greek national funds

  9. Accurate Measurement of Velocity and Acceleration of Seismic Vibrations near Nuclear Power Plants

    NASA Astrophysics Data System (ADS)

    Arif, Syed Javed; Imdadullah; Asghar, Mohammad Syed Jamil

    In spite of all prerequisite geological study based precautions, the sites of nuclear power plants are also susceptible to seismic vibrations and their consequent effects. The effect of the ongoing nuclear tragedy in Japan caused by an earthquake and its consequent tsunami on March 11, 2011 is currently beyond contemplations. It has led to a rethinking on nuclear power stations by various governments around the world. Therefore, the prediction of location and time of large earthquakes has regained a great importance. The earth crust is made up of several wide, thin and rigid plates like blocks which are in constant motion with respect to each other. A series of vibrations on the earth surface are produced by the generation of elastic seismic waves due to sudden rupture within the plates during the release of accumulated strain energy. The range of frequency of seismic vibrations is from 0 to 10 Hz. However, there appears a large variation in magnitude, velocity and acceleration of these vibrations. The response of existing or conventional methods of measurement of seismic vibrations is very slow, which is of the order of tens of seconds. A systematic and high resolution measurement of velocity and acceleration of these vibrations are useful to interpret the pattern of waves and their anomalies more accurately, which are useful for the prediction of an earthquake. In the proposed work, a fast rotating magnetic field (RMF) is used to measure the velocity and acceleration of seismic vibrations in the millisecond range. The broad spectrum of pulses within one second range, measured by proposed method, gives all possible values of instantaneous velocity and instantaneous acceleration of the seismic vibrations. The spectrum of pulses in millisecond range becomes available which is useful to measure the pattern of fore shocks to predict the time and location of large earthquakes more accurately. Moreover, instead of average, the peak values of these quantities are helpful

  10. Seismic Signatures of Brine Release at Blood Falls, Taylor Glacier, Antarctica

    NASA Astrophysics Data System (ADS)

    Carr, C. G.; Pettit, E. C.; Carmichael, J.

    2017-12-01

    Blood Falls is created by the release of subglacially-sourced, iron-rich brine at the surface of Taylor Glacier, McMurdo Dry Valleys, Antarctica. The supraglacial portion of this hydrological feature is episodically active. Englacial liquid brine flow occurs despite ice temperatures of -17°C and we document supraglacial liquid brine release despite ambient air temperatures average -20°C. In this study, we use data from a seismic network, time-lapse cameras, and publicly available weather station data to address the questions: what are the characteristics of seismic events that occur during Blood Falls brine release and how do these compare with seismic events that occur during times of Blood Falls quiescence? How are different processes observable in the time-lapse imagery represented in the seismic record? Time-lapse photography constrains the timing of brine release events during the austral winter of 2014. We use a noise-adaptive digital power detector to identify seismic events and cluster analysis to identify repeating events based on waveform similarity across the network. During the 2014 wintertime brine release, high-energy repeated seismic events occurred proximal to Blood Falls. We investigate the ground motions associated with these clustered events, as well as their spatial distribution. We see evidence of possible tremor during the brine release periods, an indicator of fluid movement. If distinctive seismic signatures are associated with Blood Falls brine release they could be identified based solely on seismic data without any aid from time-lapse cameras. Passive seismologic monitoring has the benefit of continuity during the polar night and other poor visibility conditions, which make time-lapse imagery unusable.

  11. Design and analysis of fractional order seismic transducer for displacement and acceleration measurements

    NASA Astrophysics Data System (ADS)

    Veeraian, Parthasarathi; Gandhi, Uma; Mangalanathan, Umapathy

    2018-04-01

    Seismic transducers are widely used for measurement of displacement, velocity, and acceleration. This paper presents the design of seismic transducer in the fractional domain for the measurement of displacement and acceleration. The fractional order transfer function for seismic displacement and acceleration transducer are derived using Grünwald-Letnikov derivative. Frequency response analysis of fractional order seismic displacement transducer (FOSDT) and fractional order seismic acceleration transducer (FOSAT) are carried out for different damping ratio with the different fractional order, and the maximum dynamic measurement range is identified. The results demonstrate that fractional order seismic transducer has increased dynamic measurement range and less phase distortion as compared to the conventional seismic transducer even with a lower damping ratio. Time response of FOSDT and FOSAT are derived analytically in terms of Mittag-Leffler function, the effect of fractional behavior in the time domain is evaluated from the impulse and step response. The fractional order system is found to have significantly reduced overshoot as compared to the conventional transducer. The fractional order seismic transducer design proposed in this paper is illustrated with a design example for FOSDT and FOSAT. Finally, an electrical equivalent of FOSDT and FOSAT is considered, and its frequency response is found to be in close agreement with the proposed fractional order seismic transducer.

  12. Accelerated in-vitro release testing methods for extended-release parenteral dosage forms.

    PubMed

    Shen, Jie; Burgess, Diane J

    2012-07-01

    This review highlights current methods and strategies for accelerated in-vitro drug release testing of extended-release parenteral dosage forms such as polymeric microparticulate systems, lipid microparticulate systems, in-situ depot-forming systems and implants. Extended-release parenteral dosage forms are typically designed to maintain the effective drug concentration over periods of weeks, months or even years. Consequently, 'real-time' in-vitro release tests for these dosage forms are often run over a long time period. Accelerated in-vitro release methods can provide rapid evaluation and therefore are desirable for quality control purposes. To this end, different accelerated in-vitro release methods using United States Pharmacopeia (USP) apparatus have been developed. Different mechanisms of accelerating drug release from extended-release parenteral dosage forms, along with the accelerated in-vitro release testing methods currently employed are discussed. Accelerated in-vitro release testing methods with good discriminatory ability are critical for quality control of extended-release parenteral products. Methods that can be used in the development of in-vitro-in-vivo correlation (IVIVC) are desirable; however, for complex parenteral products this may not always be achievable. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

  13. Accelerated in vitro release testing methods for extended release parenteral dosage forms

    PubMed Central

    Shen, Jie; Burgess, Diane J.

    2012-01-01

    Objectives This review highlights current methods and strategies for accelerated in vitro drug release testing of extended release parenteral dosage forms such as polymeric microparticulate systems, lipid microparticulate systems, in situ depot-forming systems, and implants. Key findings Extended release parenteral dosage forms are typically designed to maintain the effective drug concentration over periods of weeks, months or even years. Consequently, “real-time” in vitro release tests for these dosage forms are often run over a long time period. Accelerated in vitro release methods can provide rapid evaluation and therefore are desirable for quality control purposes. To this end, different accelerated in vitro release methods using United States Pharmacopoeia (USP) apparatus have been developed. Different mechanisms of accelerating drug release from extended release parenteral dosage forms, along with the accelerated in vitro release testing methods currently employed are discussed. Conclusions Accelerated in vitro release testing methods with good discriminatory ability are critical for quality control of extended release parenteral products. Methods that can be used in the development of in vitro-in vivo correlation (IVIVC) are desirable, however for complex parenteral products this may not always be achievable. PMID:22686344

  14. Dike propagation energy balance from deformation modeling and seismic release

    NASA Astrophysics Data System (ADS)

    Bonaccorso, Alessandro; Aoki, Yosuke; Rivalta, Eleonora

    2017-06-01

    Magma is transported in the crust mainly by dike intrusions. In volcanic areas, dikes can ascend toward the free surface and also move by lateral propagation, eventually feeding flank eruptions. Understanding dike mechanics is a key to forecasting the expected propagation and associated hazard. Several studies have been conducted on dike mechanisms and propagation; however, a less in-depth investigated aspect is the relation between measured dike-induced deformation and the seismicity released during its propagation. We individuated a simple x that can be used as a proxy of the expected mechanical energy released by a propagating dike and is related to its average thickness. For several intrusions around the world (Afar, Japan, and Mount Etna), we correlate such mechanical energy to the seismic moment released by the induced earthquakes. We obtain an empirical law that quantifies the expected seismic energy released before arrest. The proposed approach may be helpful to predict the total seismic moment that will be released by an intrusion and thus to control the energy status during its propagation and the time of dike arrest.Plain Language SummaryDike propagation is a dominant mechanism for magma ascent, transport, and eruptions. Besides being an intriguing physical process, it has critical hazard implications. After the magma intrusion starts, it is difficult to predict when and where a specific horizontal dike is going to halt and what its final length will be. In our study, we singled an equation that can be used as a proxy of the expected mechanical energy to be <span class="hlt">released</span> by the opening dike. We related this expected energy to the <span class="hlt">seismic</span> moment of several eruptive intrusions around the world (Afar region, Japanese volcanoes, and Mount Etna). The proposed novel approach is helpful to estimate the total <span class="hlt">seismic</span> moment to be <span class="hlt">released</span>, therefore allowing potentially predicting when the dike will end its propagation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.2323R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.2323R"><span>Influence of LOD variations on <span class="hlt">seismic</span> energy <span class="hlt">release</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Riguzzi, F.; Krumm, F.; Wang, K.; Kiszely, M.; Varga, P.</p> <p>2009-04-01</p> <p>Tidal friction causes significant time variations of geodynamical parameters, among them geometrical flattening. The axial despinning of the Earth due to tidal friction through the change of flattening generates incremental meridional and azimuthal stresses. The stress pattern in an incompressible elastic upper mantle and crust is symmetric to the equator and has its inflection points at the critical latitude close to ±45°. Consequently the distribution of <span class="hlt">seismic</span> energy <span class="hlt">released</span> by strong, shallow focus earthquakes should have also sharp maxima at this latitude. To investigate the influence of length of day (LOD) variations on earthquake activity an earthquake catalogue of strongest <span class="hlt">seismic</span> events (M>7.0) was completed for the period 1900-2007. It is shown with the use of this catalogue that for the studied time-interval the catalogue is complete and consists of the <span class="hlt">seismic</span> events responsible for more than 90% of <span class="hlt">released</span> <span class="hlt">seismic</span> energy. Study of the catalogue for earthquakes M>7.0 shows that the <span class="hlt">seismic</span> energy discharged by the strongest <span class="hlt">seismic</span> events has significant maxima at ±45°, what renders probably that the <span class="hlt">seismic</span> activity of our planet is influenced by an external component, i.e. by the tidal friction, which acts through the variation of the hydrostatic figure of the Earth caused by it. Distribution along the latitude of earthquake numbers and energies was investigated also for the case of global linear tectonic structures, such as mid ocean ridges and subduction zones. It can be shown that the number of the shallow focus shocks has a repartition along the latitude similar to the distribution of the linear tectonic structures. This means that the position of foci of <span class="hlt">seismic</span> events is mainly controlled by the tectonic activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T33E2979P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T33E2979P"><span>Spectral-element <span class="hlt">Seismic</span> Wave Propagation on CUDA/OpenCL Hardware <span class="hlt">Accelerators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peter, D. B.; Videau, B.; Pouget, K.; Komatitsch, D.</p> <p>2015-12-01</p> <p><span class="hlt">Seismic</span> wave propagation codes are essential tools to investigate a variety of wave phenomena in the Earth. Furthermore, they can now be used for <span class="hlt">seismic</span> full-waveform inversions in regional- and global-scale adjoint tomography. Although these <span class="hlt">seismic</span> wave propagation solvers are crucial ingredients to improve the resolution of tomographic images to answer important questions about the nature of Earth's internal processes and subsurface structure, their practical application is often limited due to high computational costs. They thus need high-performance computing (HPC) facilities to improving the current state of knowledge. At present, numerous large HPC systems embed many-core architectures such as graphics processing units (GPUs) to enhance numerical performance. Such hardware <span class="hlt">accelerators</span> can be programmed using either the CUDA programming environment or the OpenCL language standard. CUDA software development targets NVIDIA graphic cards while OpenCL was adopted by additional hardware <span class="hlt">accelerators</span>, like e.g. AMD graphic cards, ARM-based processors as well as Intel Xeon Phi coprocessors. For <span class="hlt">seismic</span> wave propagation simulations using the open-source spectral-element code package SPECFEM3D_GLOBE, we incorporated an automatic source-to-source code generation tool (BOAST) which allows us to use meta-programming of all computational kernels for forward and adjoint runs. Using our BOAST kernels, we generate optimized source code for both CUDA and OpenCL languages within the source code package. Thus, <span class="hlt">seismic</span> wave simulations are able now to fully utilize CUDA and OpenCL hardware <span class="hlt">accelerators</span>. We show benchmarks of forward <span class="hlt">seismic</span> wave propagation simulations using SPECFEM3D_GLOBE on CUDA/OpenCL GPUs, validating results and comparing performances for different simulations and hardware usages.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1713875P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1713875P"><span>Forward and adjoint spectral-element simulations of <span class="hlt">seismic</span> wave propagation using hardware <span class="hlt">accelerators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peter, Daniel; Videau, Brice; Pouget, Kevin; Komatitsch, Dimitri</p> <p>2015-04-01</p> <p>Improving the resolution of tomographic images is crucial to answer important questions on the nature of Earth's subsurface structure and internal processes. <span class="hlt">Seismic</span> tomography is the most prominent approach where <span class="hlt">seismic</span> signals from ground-motion records are used to infer physical properties of internal structures such as compressional- and shear-wave speeds, anisotropy and attenuation. Recent advances in regional- and global-scale <span class="hlt">seismic</span> inversions move towards full-waveform inversions which require accurate simulations of <span class="hlt">seismic</span> wave propagation in complex 3D media, providing access to the full 3D <span class="hlt">seismic</span> wavefields. However, these numerical simulations are computationally very expensive and need high-performance computing (HPC) facilities for further improving the current state of knowledge. During recent years, many-core architectures such as graphics processing units (GPUs) have been added to available large HPC systems. Such GPU-<span class="hlt">accelerated</span> computing together with advances in multi-core central processing units (CPUs) can greatly <span class="hlt">accelerate</span> scientific applications. There are mainly two possible choices of language support for GPU cards, the CUDA programming environment and OpenCL language standard. CUDA software development targets NVIDIA graphic cards while OpenCL was adopted mainly by AMD graphic cards. In order to employ such hardware <span class="hlt">accelerators</span> for <span class="hlt">seismic</span> wave propagation simulations, we incorporated a code generation tool BOAST into an existing spectral-element code package SPECFEM3D_GLOBE. This allows us to use meta-programming of computational kernels and generate optimized source code for both CUDA and OpenCL languages, running simulations on either CUDA or OpenCL hardware <span class="hlt">accelerators</span>. We show here applications of forward and adjoint <span class="hlt">seismic</span> wave propagation on CUDA/OpenCL GPUs, validating results and comparing performances for different simulations and hardware usages.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70015489','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70015489"><span>Predicting earthquakes by analyzing <span class="hlt">accelerating</span> precursory <span class="hlt">seismic</span> activity</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Varnes, D.J.</p> <p>1989-01-01</p> <p>During 11 sequences of earthquakes that in retrospect can be classed as foreshocks, the <span class="hlt">accelerating</span> rate at which <span class="hlt">seismic</span> moment is <span class="hlt">released</span> follows, at least in part, a simple equation. This equation (1) is {Mathematical expression},where {Mathematical expression} is the cumulative sum until time, t, of the square roots of <span class="hlt">seismic</span> moments of individual foreshocks computed from reported magnitudes;C and n are constants; and tfis a limiting time at which the rate of <span class="hlt">seismic</span> moment accumulation becomes infinite. The possible time of a major foreshock or main shock, tf,is found by the best fit of equation (1), or its integral, to step-like plots of {Mathematical expression} versus time using successive estimates of tfin linearized regressions until the maximum coefficient of determination, r2,is obtained. Analyzed examples include sequences preceding earthquakes at Cremasta, Greece, 2/5/66; Haicheng, China 2/4/75; Oaxaca, Mexico, 11/29/78; Petatlan, Mexico, 3/14/79; and Central Chile, 3/3/85. In 29 estimates of main-shock time, made as the sequences developed, the errors in 20 were less than one-half and in 9 less than one tenth the time remaining between the time of the last data used and the main shock. Some precursory sequences, or parts of them, yield no solution. Two sequences appear to include in their first parts the aftershocks of a previous event; plots using the integral of equation (1) show that the sequences are easily separable into aftershock and foreshock segments. Synthetic <span class="hlt">seismic</span> sequences of shocks at equal time intervals were constructed to follow equation (1), using four values of n. In each series the resulting distributions of magnitudes closely follow the linear Gutenberg-Richter relation log N=a-bM, and the product n times b for each series is the same constant. In various forms and for decades, equation (1) has been used successfully to predict failure times of stressed metals and ceramics, landslides in soil and rock slopes, and volcanic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28153651','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28153651"><span><span class="hlt">Accelerated</span> in vitro <span class="hlt">release</span> testing method for naltrexone loaded PLGA microspheres.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Andhariya, Janki V; Choi, Stephanie; Wang, Yan; Zou, Yuan; Burgess, Diane J; Shen, Jie</p> <p>2017-03-30</p> <p>The objective of the present study was to develop a discriminatory and reproducible <span class="hlt">accelerated</span> <span class="hlt">release</span> testing method for naltrexone loaded parenteral polymeric microspheres. The commercially available naltrexone microsphere product (Vivitrol ® ) was used as the testing formulation in the in vitro <span class="hlt">release</span> method development, and both sample-and-separate and USP apparatus 4 methods were investigated. Following an in vitro drug stability study, frequent media replacement and addition of anti-oxidant in the <span class="hlt">release</span> medium were used to prevent degradation of naltrexone during <span class="hlt">release</span> testing at "real-time" (37°C) and "<span class="hlt">accelerated</span>" (45°C), respectively. The USP apparatus 4 method was more reproducible than the sample-and-separate method. In addition, the <span class="hlt">accelerated</span> <span class="hlt">release</span> profile obtained using USP apparatus 4 had a shortened <span class="hlt">release</span> duration (within seven days), and good correlation with the "real-time" <span class="hlt">release</span> profile. Lastly, the discriminatory ability of the developed <span class="hlt">accelerated</span> <span class="hlt">release</span> method was assessed using compositionally equivalent naltrexone microspheres with different <span class="hlt">release</span> characteristics. The developed <span class="hlt">accelerated</span> USP apparatus 4 <span class="hlt">release</span> method was able to detect differences in the <span class="hlt">release</span> characteristics of the prepared naltrexone microspheres. Moreover, a linear correlation was observed between the "real-time" and <span class="hlt">accelerated</span> <span class="hlt">release</span> profiles of all the formulations investigated, suggesting that the <span class="hlt">release</span> mechanism(s) may be similar under both conditions. These results indicate that the developed <span class="hlt">accelerated</span> USP apparatus 4 method has the potential to be an appropriate fast quality control tool for long-acting naltrexone PLGA microspheres. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GeoJI.195..785G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GeoJI.195..785G"><span>Testing the <span class="hlt">accelerating</span> moment <span class="hlt">release</span> (AMR) hypothesis in areas of high stress</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guilhem, Aurélie; Bürgmann, Roland; Freed, Andrew M.; Ali, Syed Tabrez</p> <p>2013-11-01</p> <p>Several retrospective analyses have proposed that significant increases in moment <span class="hlt">release</span> occurred prior to many large earthquakes of recent times. However, the finding of <span class="hlt">accelerating</span> moment <span class="hlt">release</span> (AMR) strongly depends on the choice of three parameters: (1) magnitude range, (2) area being considered surrounding the events and (3) the time period prior to the large earthquakes. Consequently, the AMR analysis has been criticized as being a posteriori data-fitting exercise with no new predictive power. As AMR has been hypothesized to relate to changes in the state of stress around the eventual epicentre, we compare here AMR results to models of stress accumulation in California. Instead of assuming a complete stress drop on all surrounding fault segments implied by a back-slip stress lobe method, we consider that stress evolves dynamically, punctuated by the occurrence of earthquakes, and governed by the elastic and viscous properties of the lithosphere. We study the <span class="hlt">seismicity</span> of southern California and extract events for AMR calculations following the systematic approach employed in previous studies. We present several sensitivity tests of the method, as well as grid-search analyses over the region between 1955 and 2005 using fixed magnitude range, radius of the search area and period of time. The results are compared to the occurrence of large events and to maps of Coulomb stress changes. The Coulomb stress maps are compiled using the coseismic stress from all M > 7.0 earthquakes since 1812, their subsequent post-<span class="hlt">seismic</span> relaxation, and the interseismic strain accumulation. We find no convincing correlation of <span class="hlt">seismicity</span> rate changes in recent decades with areas of high stress that would support the AMR hypothesis. Furthermore, this indicates limited utility for practical earthquake hazard analysis in southern California, and possibly other regions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li class="active"><span>1</span></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_1 --> <div id="page_2" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="21"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1305883','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1305883"><span>Probabilistic <span class="hlt">Seismic</span> Hazard Assessment for Iraq</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Onur, Tuna; Gok, Rengin; Abdulnaby, Wathiq</p> <p></p> <p>Probabilistic <span class="hlt">Seismic</span> Hazard Assessments (PSHA) form the basis for most contemporary <span class="hlt">seismic</span> provisions in building codes around the world. The current building code of Iraq was published in 1997. An update to this edition is in the process of being <span class="hlt">released</span>. However, there are no national PSHA studies in Iraq for the new building code to refer to for <span class="hlt">seismic</span> loading in terms of spectral <span class="hlt">accelerations</span>. As an interim solution, the new draft building code was considering to refer to PSHA results produced in the late 1990s as part of the Global <span class="hlt">Seismic</span> Hazard Assessment Program (GSHAP; Giardini et al.,more » 1999). However these results are: a) more than 15 years outdated, b) PGA-based only, necessitating rough conversion factors to calculate spectral <span class="hlt">accelerations</span> at 0.3s and 1.0s for <span class="hlt">seismic</span> design, and c) at a probability level of 10% chance of exceedance in 50 years, not the 2% that the building code requires. Hence there is a pressing need for a new, updated PSHA for Iraq.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24597702','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24597702"><span>A novel <span class="hlt">accelerated</span> in vitro <span class="hlt">release</span> method to evaluate the <span class="hlt">release</span> of thymopentin from PLGA microspheres.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xie, Xiangyang; Li, Zhiping; Zhang, Ling; Chi, Qiang; Yang, Yanfang; Zhang, Hui; Yang, Yang; Mei, Xingguo</p> <p>2015-01-01</p> <p>A novel <span class="hlt">accelerated</span> method of good correlations with "real-time" <span class="hlt">release</span> to evaluate in vitro thymopentin <span class="hlt">release</span> from poly (D, L-lactide-co-glycolide) (PLGA) microsphere was developed. Thymopentin-loaded microspheres were made from three types of PLGA, and peptide <span class="hlt">release</span> was studied in various conditions. Incomplete <span class="hlt">release</span> of peptide (<60%) from microspheres was found in <span class="hlt">accelerated</span> testing with two typical <span class="hlt">release</span> media. This problem was circumvented by adding organic solvents to the <span class="hlt">release</span> media and varying the temperature in the media heating process. <span class="hlt">Release</span> media containing three kinds of organic solvents at 50 °C were tested, respectively, and hydro-alcoholic solution was selected for further study. After the surfactant concentration (0.06%, W/V) and ethanol concentration (20%, V/V) were fixed, a gradient heating program, consisting of three stages and each stage with a different temperature, was introduced to enhance the correlations between the short- and long-term <span class="hlt">release</span>. After adjusting the heating time of each stage, a good correlation (R(2) = 9896, formulation 8 K; R(2) = 0.9898, formulation 13 K; R(2) = 0.9886, formulation 28 K) between <span class="hlt">accelerated</span> and "real-time" <span class="hlt">release</span> was obtained. By optimizing the conditions as ethanol concentration and temperature gradients, this <span class="hlt">accelerated</span> method may be appropriate for similar peptide formulations that not well correlate with "real-time" <span class="hlt">release</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28521697','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28521697"><span>An <span class="hlt">Accelerated</span> <span class="hlt">Release</span> Method of Risperidone Loaded PLGA Microspheres with Good IVIVC.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, Xiaoqin; Zhang, Jianwei; Tang, Xuemei; Li, Mingyuan; Ma, Siyu; Liu, Cheng; Gao, Yue; Zhang, Yue; Liu, Yan; Yu, Fanglin; Yang, Yang; Guo, Jia; Li, Zhiping; Mei, Xingguo</p> <p>2018-01-01</p> <p>A long <span class="hlt">release</span> period lasting several days or several weeks is always needed and thereby it is tedious and time consuming to screen formulations of such microspheres with so long <span class="hlt">release</span> period and evaluate their <span class="hlt">release</span> profiles in vitro with conventional long-term or "real-time" <span class="hlt">release</span> method. So, an <span class="hlt">accelerated</span> <span class="hlt">release</span> testing of such system is necessary for formulation design as well as quality control purpose. The purpose of this study is to obtain an <span class="hlt">accelerated</span> <span class="hlt">release</span> method of risperidone loaded poly(lactic-co-glycolic acid) (PLGA) microspheres with good in vitro/in vivo correlation (IVIVC). Two formulations of risperidone loaded PLGA microspheres used for evaluating IVIVC were prepared by O/W method. The <span class="hlt">accelerated</span> <span class="hlt">release</span> condition was optimized by investigating the effect of pH, osmotic pressure, temperature and ethanol concentration on the <span class="hlt">release</span> of risperidone from microspheres and the in vitro <span class="hlt">accelerated</span> <span class="hlt">release</span> profiles of risperidone from PLGA microspheres were obtained under this optimized <span class="hlt">accelerated</span> <span class="hlt">release</span> condition. The plasma concentration of risperidone were also detected after subcutaneous injection of risperidone loaded microspheres to rats. The in vivo cumulative absorption profiles were then calculated using Wagner-Nelson model, Loo- Riegelman model and numerical convolution model, respectively. The correlation between in vitro <span class="hlt">accelerated</span> <span class="hlt">release</span> and in vivo cumulative absorption were finally evaluated with Least Square Method. It was shown that temperature and ethanol concentration significantly affected the <span class="hlt">release</span> of risperidone from the microspheres while pH and osmotic pressure of <span class="hlt">release</span> media slightly affected the <span class="hlt">release</span> behavior of risperidone. The in vitro <span class="hlt">release</span> of risperidone from microspheres were finally undergone in PBS (pH7.0, 300mosm) with 20% (V/V) ethanol at 45°C. The sustained and complete <span class="hlt">release</span> of risperidone was observed in both formulations under the <span class="hlt">accelerated</span> <span class="hlt">release</span> condition although these two <span class="hlt">release</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....8246N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....8246N"><span>Amplification of <span class="hlt">seismic</span> waves beneath active volcanoes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Navon, O.; Lensky, N. G.; Collier, L.; Neuberg, J.; Lyakhovsky, V.</p> <p>2003-04-01</p> <p>Long-period (LP) <span class="hlt">seismic</span> events are typical for many volcanoes and are attributed to energy leaking from waves traveling along the conduit - country-rock interface. While the wave propagation is well understood, their actual trigger mechanism and their energy source are not. Here we test the hypothesis that energy may be supplied by volatile-<span class="hlt">release</span> from a supersaturated melt. If bubbles are initially in equilibrium with the melt in the conduit, and the melt is suddenly decompressed, the transfer of volatiles from the supersaturated melt into the bubbles transforms stored potential energy into expansion work. For example, small dome collapse, opening of a crack or a displacement along the brittle part of the conduit may decompress the magma by a few bars and create the needed supersaturation. This energy is <span class="hlt">released</span> over the timescale of <span class="hlt">accelerated</span> expansion, which is longer than a typical LP event. Following decompression, when the transfer of volatiles into bubbles is fast enough, expansion <span class="hlt">accelerates</span> and the bulk viscosity of the bubbly magma is negative (Lensky et al., 2002). New calculations show that under such conditions a sinusoidal P-wave is amplified. We note that <span class="hlt">seismic</span> waves created by tectonic earthquakes that are not associated with net decompression, do not lead to net <span class="hlt">release</span> of volatiles or to net expansion. In this case, the bulk viscosity is positive and waves traveling through the magma should attenuate. The proposed model explains how weak <span class="hlt">seismic</span> signals may be amplified as they travel through a conduit that contains supersaturated bubbly magma. It provides the general framework for amplifying volcanic <span class="hlt">seismicity</span> such as long-period events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27793758','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27793758"><span>Development and evaluation of <span class="hlt">accelerated</span> drug <span class="hlt">release</span> testing methods for a matrix-type intravaginal ring.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Externbrink, Anna; Eggenreich, Karin; Eder, Simone; Mohr, Stefan; Nickisch, Klaus; Klein, Sandra</p> <p>2017-01-01</p> <p><span class="hlt">Accelerated</span> drug <span class="hlt">release</span> testing is a valuable quality control tool for long-acting non-oral extended <span class="hlt">release</span> formulations. Currently, several intravaginal ring candidates designed for the long-term delivery of steroids or anti-infective drugs are being in the developing pipeline. The present article addresses the demand for <span class="hlt">accelerated</span> drug <span class="hlt">release</span> methods for these formulations. We describe the development and evaluation of <span class="hlt">accelerated</span> <span class="hlt">release</span> methods for a steroid <span class="hlt">releasing</span> matrix-type intravaginal ring. The drug <span class="hlt">release</span> properties of the formulation were evaluated under real-time and <span class="hlt">accelerated</span> test conditions. Under real-time test conditions drug <span class="hlt">release</span> from the intravaginal ring was strongly affected by the steroid solubility in the <span class="hlt">release</span> medium. Under sufficient sink conditions that were provided in <span class="hlt">release</span> media containing surfactants drug <span class="hlt">release</span> was Fickian diffusion driven. Both temperature and hydro-organic dissolution media were successfully employed to <span class="hlt">accelerate</span> drug <span class="hlt">release</span> from the formulation. Drug <span class="hlt">release</span> could be further increased by combining the temperature effect with the application of a hydro-organic <span class="hlt">release</span> medium. The formulation continued to exhibit a diffusion controlled <span class="hlt">release</span> kinetic under the investigated <span class="hlt">accelerated</span> conditions. Moreover, the <span class="hlt">accelerated</span> methods were able to differentiate between different prototypes of the intravaginal ring that exhibited different <span class="hlt">release</span> profiles under real-time test conditions. Overall, the results of the present study indicate that both temperature and hydro-organic <span class="hlt">release</span> media are valid parameters for <span class="hlt">accelerating</span> drug <span class="hlt">release</span> from the intravaginal ring. Variation of either a single or both parameters yielded <span class="hlt">release</span> profiles that correlated well with real-time <span class="hlt">release</span>. Copyright © 2016 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23791685','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23791685"><span>Investigating the feasibility of temperature-controlled <span class="hlt">accelerated</span> drug <span class="hlt">release</span> testing for an intravaginal ring.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Externbrink, Anna; Clark, Meredith R; Friend, David R; Klein, Sandra</p> <p>2013-11-01</p> <p>The objective of the present study was to investigate if temperature can be utilized to <span class="hlt">accelerate</span> drug <span class="hlt">release</span> from Nuvaring®, a reservoir type intravaginal ring based on polyethylene vinyl acetate copolymer that <span class="hlt">releases</span> a constant dose of contraceptive steroids over a duration of 3 weeks. The reciprocating holder apparatus (USP 7) was utilized to determine real-time and <span class="hlt">accelerated</span> etonogestrel <span class="hlt">release</span> from ring segments. It was demonstrated that drug <span class="hlt">release</span> increased with increasing temperature which can be attributed to enhanced drug diffusion. An Arrhenius relationship of the zero-order <span class="hlt">release</span> constants was established, indicating that temperature is a valid parameter to <span class="hlt">accelerate</span> drug <span class="hlt">release</span> from this dosage form and that the <span class="hlt">release</span> mechanism is maintained under these <span class="hlt">accelerated</span> test conditions. <span class="hlt">Accelerated</span> <span class="hlt">release</span> tests are particularly useful for routine quality control to assist during batch <span class="hlt">release</span> of extended <span class="hlt">release</span> formulations that typically <span class="hlt">release</span> the active over several weeks, months or even years, since they can increase the product shelf life. The <span class="hlt">accelerated</span> method should therefore be able to discriminate between formulations with different <span class="hlt">release</span> characteristics that can result from normal manufacturing variance. In the case of Nuvaring®, it is well known that the process parameters during the extrusion process strongly influence the polymeric structure. These changes in the polymeric structure can affect the permeability which, in turn, is reflected in the <span class="hlt">release</span> properties. Results from this study indicate that changes in the polymeric structure can lead to a different temperature dependence of the <span class="hlt">release</span> rate, and as a consequence, the <span class="hlt">accelerated</span> method can become less sensitive to detect changes in the <span class="hlt">release</span> properties. When the <span class="hlt">accelerated</span> method is utilized during batch <span class="hlt">release</span>, it is therefore important to take this possible restriction into account and to evaluate the <span class="hlt">accelerated</span> method with samples from non</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1911420P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1911420P"><span>A Coupled Multiphysics Approach for Simulating Induced <span class="hlt">Seismicity</span>, Ground <span class="hlt">Acceleration</span> and Structural Damage</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Podgorney, Robert; Coleman, Justin; Wilkins, Amdrew; Huang, Hai; Veeraraghavan, Swetha; Xia, Yidong; Permann, Cody</p> <p>2017-04-01</p> <p>Numerical modeling has played an important role in understanding the behavior of coupled subsurface thermal-hydro-mechanical (THM) processes associated with a number of energy and environmental applications since as early as the 1970s. While the ability to rigorously describe all key tightly coupled controlling physics still remains a challenge, there have been significant advances in recent decades. These advances are related primarily to the exponential growth of computational power, the development of more accurate equations of state, improvements in the ability to represent heterogeneity and reservoir geometry, and more robust nonlinear solution schemes. The work described in this paper documents the development and linkage of several fully-coupled and fully-implicit modeling tools. These tools simulate: (1) the dynamics of fluid flow, heat transport, and quasi-static rock mechanics; (2) <span class="hlt">seismic</span> wave propagation from the sources of energy <span class="hlt">release</span> through heterogeneous material; and (3) the soil-structural damage resulting from ground <span class="hlt">acceleration</span>. These tools are developed in Idaho National Laboratory's parallel Multiphysics Object Oriented Simulation Environment, and are integrated together using a global implicit approach. The governing equations are presented, the numerical approach for simultaneously solving and coupling the three coupling physics tools is discussed, and the data input and output methodology is outlined. An example is presented to demonstrate the capabilities of the coupled multiphysics approach. The example involves simulating a system conceptually similar to the geothermal development in Basel Switzerland, and the resultant induced <span class="hlt">seismicity</span>, ground motion and structural damage is predicted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T54A..05S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T54A..05S"><span>Stress concentration on Intraplate <span class="hlt">Seismicity</span>: Numerical Modeling of Slab-<span class="hlt">released</span> Fluids in the New Madrid <span class="hlt">Seismic</span> Zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saxena, A.; Choi, E.; Powell, C. A.</p> <p>2017-12-01</p> <p>The mechanism behind the <span class="hlt">seismicity</span> of the New Madrid <span class="hlt">Seismic</span> Zone (NMSZ), the major intraplate earthquake source in the Central and Eastern US (CEUS), is still debated but new insights are being provided by recent tomographic studies involving USArray. A high-resolution tomography study by Nyamwandha et al. (2016) in the NMSZ indicates the presence of low (3 % - 5 %) upper mantle Vp and Vs anomalies in the depth range 100 to 250 km. The elevated anomaly magnitudes are difficult to explain by temperature alone. As the low-velocity anomalies beneath the northeast China are attributed to fluids <span class="hlt">released</span> from the stagnant Pacific slab, water <span class="hlt">released</span> from the stagnant Laramide Slab, presently located at transition zone depths beneath the CEUS might be contributing to the low velocity features in this region's upper mantle. Here, we investigate the potential impact of the slab-<span class="hlt">released</span> fluids on the stresses at seismogenic depths using numerical modeling. We convert the tomographic results into temperature field under various assumed values of spatially uniform water content. In more realistic cases, water content is added only when the converted temperature exceeds the melting temperature of olivine. Viscosities are then computed based on the temperature and water content and given to our geodynamic models created by Pylith, an open source software for crustal dynamics. The model results show that increasing water content weakens the upper mantle more than temperature alone and thus elevates the differential stress in the upper crust. These results can better explain the tomography results and <span class="hlt">seismicity</span> without invoking melting. We also invert the tomography results for volume fraction of orthopyroxene and temperature and compare the resultant stresses with those for pure olivine. To enhance the reproducibility, selected models in this study will be made available in the form of sharable and reproducible packages enabled by EarthCube Building block project, GeoTrust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/34944','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/34944"><span><span class="hlt">Seismic</span> Performance of Columns with Grouted Couplers in Idaho <span class="hlt">Accelerated</span> Bridge Construction Applications</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>2016-10-16</p> <p>n <span class="hlt">Accelerated</span> Bridge Construction (ABC) methods, one way to connect prefabricated columns is by using grouted steel bar couplers. As of October 2016, in the U.S., only Utah DOT allows the use of grouted couplers in plastic hinge locations in <span class="hlt">seismic</span> ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoJI.tmp..226E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoJI.tmp..226E"><span>Convergence <span class="hlt">acceleration</span> in scattering series and <span class="hlt">seismic</span> waveform inversion using nonlinear Shanks transformation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eftekhar, Roya; Hu, Hao; Zheng, Yingcai</p> <p>2018-06-01</p> <p>Iterative solution process is fundamental in <span class="hlt">seismic</span> inversions, such as in full-waveform inversions and some inverse scattering methods. However, the convergence could be slow or even divergent depending on the initial model used in the iteration. We propose to apply Shanks transformation (ST for short) to <span class="hlt">accelerate</span> the convergence of the iterative solution. ST is a local nonlinear transformation, which transforms a series locally into another series with an improved convergence property. ST works by separating the series into a smooth background trend called the secular term versus an oscillatory transient term. ST then <span class="hlt">accelerates</span> the convergence of the secular term. Since the transformation is local, we do not need to know all the terms in the original series which is very important in the numerical implementation. The ST performance was tested numerically for both the forward Born series and the inverse scattering series (ISS). The ST has been shown to <span class="hlt">accelerate</span> the convergence in several examples, including three examples of forward modeling using the Born series and two examples of velocity inversion based on a particular type of the ISS. We observe that ST is effective in <span class="hlt">accelerating</span> the convergence and it can also achieve convergence even for a weakly divergent scattering series. As such, it provides a useful technique to invert for a large-contrast medium perturbation in <span class="hlt">seismic</span> inversion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.V53C1416L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.V53C1416L"><span>Exponential <span class="hlt">Acceleration</span> of VT <span class="hlt">Seismicity</span> in the Years Prior to Major Eruptions of Basaltic Volcanoes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lengline, O.; Marsan, D.; Got, J.; Pinel, V.</p> <p>2007-12-01</p> <p>The evolution of the <span class="hlt">seismicity</span> at three basaltic volcanoes (Kilauea, Mauna-Loa and Piton de la Fournaise) is analysed during phases of magma accumulation. We show that the VT <span class="hlt">seismicity</span> during these time-periods is characterized by an exponential increase at long-time scale (years). Such an exponential <span class="hlt">acceleration</span> can be explained by a model of <span class="hlt">seismicity</span> forced by the replenishment of a magmatic reservoir. The increase in stress in the edifice caused by this replenishment is modeled. This stress history leads to a cumulative number of damage, ie VT earthquakes, following the same exponential increase as found for <span class="hlt">seismicity</span>. A long-term <span class="hlt">seismicity</span> precursor is thus detected at basaltic volcanoes. Although this precursory signal is not able to predict the onset times of futures eruptions (as no diverging point is present in the model), it may help mitigating volcanic hazards.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26705156','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26705156"><span>A reproducible <span class="hlt">accelerated</span> in vitro <span class="hlt">release</span> testing method for PLGA microspheres.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shen, Jie; Lee, Kyulim; Choi, Stephanie; Qu, Wen; Wang, Yan; Burgess, Diane J</p> <p>2016-02-10</p> <p>The objective of the present study was to develop a discriminatory and reproducible <span class="hlt">accelerated</span> in vitro <span class="hlt">release</span> method for long-acting PLGA microspheres with inner structure/porosity differences. Risperidone was chosen as a model drug. Qualitatively and quantitatively equivalent PLGA microspheres with different inner structure/porosity were obtained using different manufacturing processes. Physicochemical properties as well as degradation profiles of the prepared microspheres were investigated. Furthermore, in vitro <span class="hlt">release</span> testing of the prepared risperidone microspheres was performed using the most common in vitro <span class="hlt">release</span> methods (i.e., sample-and-separate and flow through) for this type of product. The obtained compositionally equivalent risperidone microspheres had similar drug loading but different inner structure/porosity. When microsphere particle size appeared similar, porous risperidone microspheres showed faster microsphere degradation and drug <span class="hlt">release</span> compared with less porous microspheres. Both in vitro <span class="hlt">release</span> methods investigated were able to differentiate risperidone microsphere formulations with differences in porosity under real-time (37 °C) and <span class="hlt">accelerated</span> (45 °C) testing conditions. Notably, only the <span class="hlt">accelerated</span> USP apparatus 4 method showed good reproducibility for highly porous risperidone microspheres. These results indicated that the <span class="hlt">accelerated</span> USP apparatus 4 method is an appropriate fast quality control tool for long-acting PLGA microspheres (even with porous structures). Copyright © 2015 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3246580','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3246580"><span><span class="hlt">Accelerated</span> in vitro <span class="hlt">release</span> testing of implantable PLGA microsphere/PVA hydrogel composite coatings</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shen, Jie; Burgess, Diane J.</p> <p>2011-01-01</p> <p>Dexamethasone loaded poly(lactic-co-glycolic acid) (PLGA) microsphere/PVA hydrogel composites have been investigated as an outer drug-eluting coating for implantable devices such as glucose sensors to counter negative tissue responses to implants. The objective of this study was to develop a discriminatory, <span class="hlt">accelerated</span> in vitro <span class="hlt">release</span> testing method for this drug-eluting coating using United States Pharmacopeia (USP) apparatus 4. Polymer degradation and drug <span class="hlt">release</span> kinetics were investigated under “real-time” and <span class="hlt">accelerated</span> conditions (i.e. extreme pH, hydro-alcoholic solutions and elevated temperatures). Compared to “real-time” conditions, the initial burst and lag phases were similar using hydro-alcoholic solutions and extreme pH conditions, while the secondary apparent zero-order <span class="hlt">release</span> phase was slightly <span class="hlt">accelerated</span>. Elevated temperatures resulted in a significant <span class="hlt">acceleration</span> of dexamethasone <span class="hlt">release</span>. The <span class="hlt">accelerated</span> <span class="hlt">release</span> data were able to predict “real-time” <span class="hlt">release</span> when applying the Arrhenius equation. Microsphere batches with faster and slower <span class="hlt">release</span> profiles were investigated under “real-time” and elevated temperature (60°C) conditions to determine the discriminatory ability of the method. The results demonstrated both the feasibility and the discriminatory ability of this USP apparatus 4 method for in vitro <span class="hlt">release</span> testing of drug loaded PLGA microsphere/PVA hydrogel composites. This method may be appropriate for similar drug/device combination products and drug delivery systems. PMID:22016033</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22016033','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22016033"><span><span class="hlt">Accelerated</span> in vitro <span class="hlt">release</span> testing of implantable PLGA microsphere/PVA hydrogel composite coatings.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shen, Jie; Burgess, Diane J</p> <p>2012-01-17</p> <p>Dexamethasone loaded poly(lactic-co-glycolic acid) (PLGA) microsphere/PVA hydrogel composites have been investigated as an outer drug-eluting coating for implantable devices such as glucose sensors to counter negative tissue responses to implants. The objective of this study was to develop a discriminatory, <span class="hlt">accelerated</span> in vitro <span class="hlt">release</span> testing method for this drug-eluting coating using United States Pharmacopeia (USP) apparatus 4. Polymer degradation and drug <span class="hlt">release</span> kinetics were investigated under "real-time" and <span class="hlt">accelerated</span> conditions (i.e. extreme pH, hydro-alcoholic solutions and elevated temperatures). Compared to "real-time" conditions, the initial burst and lag phases were similar using hydro-alcoholic solutions and extreme pH conditions, while the secondary apparent zero-order <span class="hlt">release</span> phase was slightly <span class="hlt">accelerated</span>. Elevated temperatures resulted in a significant <span class="hlt">acceleration</span> of dexamethasone <span class="hlt">release</span>. The <span class="hlt">accelerated</span> <span class="hlt">release</span> data were able to predict "real-time" <span class="hlt">release</span> when applying the Arrhenius equation. Microsphere batches with faster and slower <span class="hlt">release</span> profiles were investigated under "real-time" and elevated temperature (60°C) conditions to determine the discriminatory ability of the method. The results demonstrated both the feasibility and the discriminatory ability of this USP apparatus 4 method for in vitro <span class="hlt">release</span> testing of drug loaded PLGA microsphere/PVA hydrogel composites. This method may be appropriate for similar drug/device combination products and drug delivery systems. Copyright © 2011 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70029349','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70029349"><span>Evidence for a global <span class="hlt">seismic</span>-moment <span class="hlt">release</span> sequence</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bufe, C.G.; Perkins, D.M.</p> <p>2005-01-01</p> <p>Temporal clustering of the larger earthquakes (foreshock-mainshock-aftershock) followed by relative quiescence (stress shadow) are characteristic of <span class="hlt">seismic</span> cycles along plate boundaries. A global <span class="hlt">seismic</span>-moment <span class="hlt">release</span> history, based on a little more than 100 years of instrumental earthquake data in an extended version of the catalog of Pacheco and Sykes (1992), illustrates similar behavior for Earth as a whole. Although the largest earthquakes have occurred in the circum-Pacific region, an analysis of moment <span class="hlt">release</span> in the hemisphere antipodal to the Pacific plate shows a very similar pattern. Monte Carlo simulations confirm that the global temporal clustering of great shallow earthquakes during 1952-1964 at M ??? 9.0 is highly significant (4% random probability) as is the clustering of the events of M ??? 8.6 (0.2% random probability) during 1950-1965. We have extended the Pacheco and Sykes (1992) catalog from 1989 through 2001 using Harvard moment centroid data. Immediately after the 1950-1965 cluster, significant quiescence at and above M 8.4 begins and continues until 2001 (0.5% random probability). In alternative catalogs derived by correcting for possible random errors in magnitude estimates in the extended Pacheco-Sykes catalog, the clustering of M ??? 9 persists at a significant level. These observations indicate that, for great earthquakes, Earth behaves as a coherent seismotectonic system. A very-large-scale mechanism for global earthquake triggering and/or stress transfer is implied. There are several candidates, but so far only viscoelastic relaxation has been modeled on a global scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1210096K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1210096K"><span>Soft computing analysis of the possible correlation between temporal and energy <span class="hlt">release</span> patterns in <span class="hlt">seismic</span> activity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Konstantaras, Anthony; Katsifarakis, Emmanouil; Artzouxaltzis, Xristos; Makris, John; Vallianatos, Filippos; Varley, Martin</p> <p>2010-05-01</p> <p>This paper is a preliminary investigation of the possible correlation of temporal and energy <span class="hlt">release</span> patterns of <span class="hlt">seismic</span> activity involving the preparation processes of consecutive sizeable <span class="hlt">seismic</span> events [1,2]. The background idea is that during periods of low-level <span class="hlt">seismic</span> activity, stress processes in the crust accumulate energy at the seismogenic area whilst larger <span class="hlt">seismic</span> events act as a decongesting mechanism <span class="hlt">releasing</span> considerable energy [3,4]. A dynamic algorithm is being developed aiming to identify and cluster pre- and post- <span class="hlt">seismic</span> events to the main earthquake following on research carried out by Zubkov [5] and Dobrovolsky [6,7]. This clustering technique along with energy <span class="hlt">release</span> equations dependent on Richter's scale [8,9] allow for an estimate to be drawn regarding the amount of the energy being <span class="hlt">released</span> by the <span class="hlt">seismic</span> sequence. The above approach is being implemented as a monitoring tool to investigate the behaviour of the underlying energy management system by introducing this information to various neural [10,11] and soft computing models [1,12,13,14]. The incorporation of intelligent systems aims towards the detection and simulation of the possible relationship between energy <span class="hlt">release</span> patterns and time-intervals among consecutive sizeable earthquakes [1,15]. Anticipated successful training of the imported intelligent systems may result in a real-time, on-line processing methodology [1,16] capable to dynamically approximate the time-interval between the latest and the next forthcoming sizeable <span class="hlt">seismic</span> event by monitoring the energy <span class="hlt">release</span> process in a specific seismogenic area. Indexing terms: pattern recognition, long-term earthquake precursors, neural networks, soft computing, earthquake occurrence intervals References [1] Konstantaras A., Vallianatos F., Varley M.R. and Makris J. P.: ‘Soft computing modelling of <span class="hlt">seismicity</span> in the southern Hellenic arc', IEEE Geoscience and Remote Sensing Letters, vol. 5 (3), pp. 323-327, 2008 [2] Eneva M. and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992PApGe.139..293T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992PApGe.139..293T"><span>Time-lag of the earthquake energy <span class="hlt">release</span> between three <span class="hlt">seismic</span> regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsapanos, Theodoros M.; Liritzis, Ioannis</p> <p>1992-06-01</p> <p>Three complete data sets of strong earthquakes ( M≥5.5), which occurred in the <span class="hlt">seismic</span> regions of Chile, Mexico and Kamchatka during the time period 1899 1985, have been used to test the existence of a time-lag in the <span class="hlt">seismic</span> energy <span class="hlt">release</span> between these regions. These data sets were cross-correlated in order to determine whether any pair of the sets are correlated. For this purpose statistical tests, such as the T-test, the Fisher's transformation and probability distribution have been applied to determine the significance of the obtained correlation coefficients. The results show that the time-lag between Chile and Kamchatka is -2, which means that Kamchatka precedes Chile by 2 years, with a correlation coefficient significant at 99.80% level, a weak correlation between Kamchatka-Mexico and noncorrelation for Mexico-Chile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1811106M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1811106M"><span>Causality between expansion of <span class="hlt">seismic</span> cloud and maximum magnitude of induced <span class="hlt">seismicity</span> in geothermal field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mukuhira, Yusuke; Asanuma, Hiroshi; Ito, Takatoshi; Häring, Markus</p> <p>2016-04-01</p> <p>Occurrence of induced <span class="hlt">seismicity</span> with large magnitude is critical environmental issues associated with fluid injection for shale gas/oil extraction, waste water disposal, carbon capture and storage, and engineered geothermal systems (EGS). Studies for prediction of the hazardous <span class="hlt">seismicity</span> and risk assessment of induced <span class="hlt">seismicity</span> has been activated recently. Many of these studies are based on the seismological statistics and these models use the information of the occurrence time and event magnitude. We have originally developed physics based model named "possible <span class="hlt">seismic</span> moment model" to evaluate <span class="hlt">seismic</span> activity and assess <span class="hlt">seismic</span> moment which can be ready to <span class="hlt">release</span>. This model is totally based on microseismic information of occurrence time, hypocenter location and magnitude (<span class="hlt">seismic</span> moment). This model assumes existence of representative parameter having physical meaning that <span class="hlt">release-able</span> <span class="hlt">seismic</span> moment per rock volume (<span class="hlt">seismic</span> moment density) at given field. <span class="hlt">Seismic</span> moment density is to be estimated from microseismic distribution and their <span class="hlt">seismic</span> moment. In addition to this, stimulated rock volume is also inferred by progress of microseismic cloud at given time and this quantity can be interpreted as the rock volume which can <span class="hlt">release</span> <span class="hlt">seismic</span> energy due to weakening effect of normal stress by injected fluid. Product of these two parameters (equation (1)) provide possible <span class="hlt">seismic</span> moment which can be <span class="hlt">released</span> from current stimulated zone as a model output. Difference between output of this model and observed cumulative <span class="hlt">seismic</span> moment corresponds the <span class="hlt">seismic</span> moment which will be <span class="hlt">released</span> in future, based on current stimulation conditions. This value can be translated into possible maximum magnitude of induced <span class="hlt">seismicity</span> in future. As this way, possible <span class="hlt">seismic</span> moment can be used to have feedback to hydraulic stimulation operation in real time as an index which can be interpreted easily and intuitively. Possible <span class="hlt">seismic</span> moment is defined as equation (1), where D</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....5301N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....5301N"><span>Amplification of <span class="hlt">seismic</span> waves beneath active volcanoes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Navon, O.; Lensky, N. G.; Collier, L.; Neuberg, J.; Lyakhovsky, V.</p> <p>2003-04-01</p> <p>Long-period (LP) <span class="hlt">seismic</span> events are typical of many volcanoes and are attributed to energy leaking from waves traveling through the volcanic conduit or along the conduit - country-rock interface. The LP events are triggered locally, at the volcanic edifice, but the source of energy for the formation of tens of events per day is not clear. Energy may be supplied by volatile-<span class="hlt">release</span> from a supersaturated melt. If bubbles are present in equilibrium with the melt in the conduit, and the melt is suddenly decompressed, transfer of volatiles from the supersaturated melt into the bubbles transforms stored potential energy into expansion work. For example, small dome collapses may decompress the conduit by a few bars and lead to solubility decrease, exsolution of volatiles and, consequently, to work done by the expansion of the bubbles under pressure. This energy is <span class="hlt">released</span> over a timescale that is similar to that of LP events and may amplify the original weak <span class="hlt">seismic</span> signals associated with the collapse. Using the formulation of Lensky et al. (2002), following the decompression, when the transfer of volatiles into bubbles is fast enough, expansion <span class="hlt">accelerates</span> and the bulk viscosity of the bubbly magma is negative. New calculations show that under such conditions a sinusoidal P-wave is amplified. We note that <span class="hlt">seismic</span> waves created by tectonic earthquakes that are not associated with net decompression, do not lead to net <span class="hlt">release</span> of volatiles or to net expansion. In this case, the bulk viscosity is positive and waves traveling through the magma should attenuate. The proposed model explains how weak <span class="hlt">seismic</span> signals may be amplified as they travel through a conduit that contains supersaturated bubbly magma. It provides the general framework for amplifying volcanic <span class="hlt">seismicity</span> such as the signals associated with long-period events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PhDT.......171C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PhDT.......171C"><span>Distribution, origin and implications of <span class="hlt">seismic</span> stress <span class="hlt">release</span> in shallow and intermediate-depth subduction systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Po-Fei</p> <p></p> <p>A characterization of focal mechanisms is developed for shallow and intermediate-depth earthquakes in the context of the local geometry of subduction systems. Its application to the Ryukyu-Taiwan-Luzon system is used to refine the spatial distribution of characteristic groups of earthquakes in the framework of local tectonic processes, such as flipping of the polarity of subduction and the nascent processes of arc-continent collision. The Harvard catalogue of Centroid Moment Tensor solutions is expanded to include intermediate-depth earthquakes from the WWSSN-HGLP era (1962--1975). Seventy-six new solutions are obtained, with the resulting dataset estimated to be complete for M0 ≥ 1026 dyn-cm. While source mechanisms from our new dataset are generally similar to those previously compiled in the Harvard catalogue, <span class="hlt">seismic</span> moment <span class="hlt">release</span> rates are found to be significantly smaller for the WWSSN era. The intermediate-depth <span class="hlt">seismicity</span> of South America is compiled from the Harvard catalogue, using projection along local slab coordinates, to determine along-strike variations in the distribution of earthquakes and in the geometry of their stress <span class="hlt">release</span>. Slab geometry is investigated in relation to slab stresses and the presence or absence of arc volcanism. Steeper-dipping slabs are found to exhibit consistent down-dip extension, a higher rate of <span class="hlt">seismic</span> moment <span class="hlt">release</span> and surface volcanism. Visualization using slab coordinate projections is extended systematically to a global survey of the geometry of stress <span class="hlt">release</span> in intermediate-depth earthquakes. Various proposed models for all subduction zones are appraised, as contributors to stress regimes, based on global data compilations. Down-dip stresses, where prominent, are found to be consistent with the thermo-mechanical and petrological force models. Slab-normal conjugate stresses generally support the concept of earthquake reactivation of fossil faults. Patterns of lateral stresses support the predictions of the so</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_2 --> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006Tectp.423...35J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006Tectp.423...35J"><span>A Moore's cellular automaton model to get probabilistic <span class="hlt">seismic</span> hazard maps for different magnitude <span class="hlt">releases</span>: A case study for Greece</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiménez, A.; Posadas, A. M.</p> <p>2006-09-01</p> <p>Cellular automata are simple mathematical idealizations of natural systems and they supply useful models for many investigations in natural science. Examples include sandpile models, forest fire models, and slider block models used in seismology. In the present paper, they have been used for establishing temporal relations between the energy <span class="hlt">releases</span> of the <span class="hlt">seismic</span> events that occurred in neighboring parts of the crust. The catalogue is divided into time intervals, and the region is divided into cells which are declared active or inactive by means of a threshold energy <span class="hlt">release</span> criterion. Thus, a pattern of active and inactive cells which evolves over time is determined. A stochastic cellular automaton is constructed starting with these patterns, in order to simulate their spatio-temporal evolution, by supposing a Moore's neighborhood interaction between the cells. The best model is chosen by maximizing the mutual information between the past and the future states. Finally, a Probabilistic <span class="hlt">Seismic</span> Hazard Map is given for the different energy <span class="hlt">releases</span> considered. The method has been applied to the Greece catalogue from 1900 to 1999. The Probabilistic <span class="hlt">Seismic</span> Hazard Maps for energies corresponding to m = 4 and m = 5 are close to the real <span class="hlt">seismicity</span> after the data in that area, and they correspond to a background <span class="hlt">seismicity</span> in the whole area. This background <span class="hlt">seismicity</span> seems to cover the whole area in periods of around 25-50 years. The optimum cell size is in agreement with other studies; for m > 6 the optimum area increases according to the threshold of clear spatial resolution, and the active cells are not so clustered. The results are coherent with other hazard studies in the zone and with the <span class="hlt">seismicity</span> recorded after the data set, as well as provide an interaction model which points out the large scale nature of the earthquake occurrence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoJI.198.1159H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoJI.198.1159H"><span>A smoothed stochastic earthquake rate model considering <span class="hlt">seismicity</span> and fault moment <span class="hlt">release</span> for Europe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hiemer, S.; Woessner, J.; Basili, R.; Danciu, L.; Giardini, D.; Wiemer, S.</p> <p>2014-08-01</p> <p>We present a time-independent gridded earthquake rate forecast for the European region including Turkey. The spatial component of our model is based on kernel density estimation techniques, which we applied to both past earthquake locations and fault moment <span class="hlt">release</span> on mapped crustal faults and subduction zone interfaces with assigned slip rates. Our forecast relies on the assumption that the locations of past <span class="hlt">seismicity</span> is a good guide to future <span class="hlt">seismicity</span>, and that future large-magnitude events occur more likely in the vicinity of known faults. We show that the optimal weighted sum of the corresponding two spatial densities depends on the magnitude range considered. The kernel bandwidths and density weighting function are optimized using retrospective likelihood-based forecast experiments. We computed earthquake activity rates (a- and b-value) of the truncated Gutenberg-Richter distribution separately for crustal and subduction <span class="hlt">seismicity</span> based on a maximum likelihood approach that considers the spatial and temporal completeness history of the catalogue. The final annual rate of our forecast is purely driven by the maximum likelihood fit of activity rates to the catalogue data, whereas its spatial component incorporates contributions from both earthquake and fault moment-rate densities. Our model constitutes one branch of the earthquake source model logic tree of the 2013 European <span class="hlt">seismic</span> hazard model <span class="hlt">released</span> by the EU-FP7 project `<span class="hlt">Seismic</span> HAzard haRmonization in Europe' (SHARE) and contributes to the assessment of epistemic uncertainties in earthquake activity rates. We performed retrospective and pseudo-prospective likelihood consistency tests to underline the reliability of our model and SHARE's area source model (ASM) using the testing algorithms applied in the collaboratory for the study of earthquake predictability (CSEP). We comparatively tested our model's forecasting skill against the ASM and find a statistically significant better performance for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997JGR...10211677B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997JGR...10211677B"><span>A hierarchical stress <span class="hlt">release</span> model for synthetic <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bebbington, Mark</p> <p>1997-06-01</p> <p>We construct a stochastic dynamic model for synthetic <span class="hlt">seismicity</span> involving stochastic stress input, <span class="hlt">release</span>, and transfer in an environment of heterogeneous strength and interacting segments. The model is not fault-specific, having a number of adjustable parameters with physical interpretation, namely, stress relaxation, stress transfer, stress dissipation, segment structure, strength, and strength heterogeneity, which affect the <span class="hlt">seismicity</span> in various ways. Local parameters are chosen to be consistent with large historical events, other parameters to reproduce bulk <span class="hlt">seismicity</span> statistics for the fault as a whole. The one-dimensional fault is divided into a number of segments, each comprising a varying number of nodes. Stress input occurs at each node in a simple random process, representing the slow buildup due to tectonic plate movements. Events are initiated, subject to a stochastic hazard function, when the stress on a node exceeds the local strength. An event begins with the transfer of excess stress to neighboring nodes, which may in turn transfer their excess stress to the next neighbor. If the event grows to include the entire segment, then most of the stress on the segment is transferred to neighboring segments (or dissipated) in a characteristic event. These large events may themselves spread to other segments. We use the Middle America Trench to demonstrate that this model, using simple stochastic stress input and triggering mechanisms, can produce behavior consistent with the historical record over five units of magnitude. We also investigate the effects of perturbing various parameters in order to show how the model might be tailored to a specific fault structure. The strength of the model lies in this ability to reproduce the behavior of a general linear fault system through the choice of a relatively small number of parameters. It remains to develop a procedure for estimating the internal state of the model from the historical observations in order to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830014615','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830014615"><span>The energy <span class="hlt">release</span> in earthquakes, and subduction zone <span class="hlt">seismicity</span> and stress in slabs. Ph.D. Thesis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vassiliou, M. S.</p> <p>1983-01-01</p> <p>Energy <span class="hlt">release</span> in earthquakes is discussed. Dynamic energy from source time function, a simplified procedure for modeling deep focus events, static energy estimates, near source energy studies, and energy and magnitude are addressed. Subduction zone <span class="hlt">seismicity</span> and stress in slabs are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5039447','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5039447"><span>An <span class="hlt">Accelerated</span> <span class="hlt">Release</span> Study to Evaluate Long-Acting Contraceptive Levonorgestrel-Containing in Situ Forming Depot Systems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Janagam, Dileep R.; Wang, Lizhu; Ananthula, Suryatheja; Johnson, James R.; Lowe, Tao L.</p> <p>2016-01-01</p> <p>Biodegradable polymer-based injectable in situ forming depot (ISD) systems that solidify in the body to form a solid or semisolid reservoir are becoming increasingly attractive as an injectable dosage form for sustained (months to years) parenteral drug delivery. Evaluation of long-term drug <span class="hlt">release</span> from the ISD systems during the formulation development is laborious and costly. An <span class="hlt">accelerated</span> <span class="hlt">release</span> method that can effectively correlate the months to years of long-term <span class="hlt">release</span> in a short time such as days or weeks is economically needed. However, no such <span class="hlt">accelerated</span> ISD system <span class="hlt">release</span> method has been reported in the literature to date. The objective of the current study was to develop a short-term <span class="hlt">accelerated</span> in vitro <span class="hlt">release</span> method for contraceptive levonorgestrel (LNG)-containing ISD systems to screen formulations for more than 3-month contraception after a single subcutaneous injection. The LNG-containing ISD formulations were prepared by using biodegradable poly(lactide-co-glycolide) and polylactic acid polymer and solvent mixtures containing N-methyl-2-pyrrolidone and benzyl benzoate or triethyl citrate. Drug <span class="hlt">release</span> studies were performed under real-time (long-term) conditions (PBS, pH 7.4, 37 °C) and four <span class="hlt">accelerated</span> (short-term) conditions: (A) PBS, pH 7.4, 50 °C; (B) 25% ethanol in PBS, pH 7.4, 50 °C; (C) 25% ethanol in PBS, 2% Tween 20, pH 7.4, 50 °C; and (D) 25% ethanol in PBS, 2% Tween 20, pH 9, 50 °C. The LNG <span class="hlt">release</span> profile, including the <span class="hlt">release</span> mechanism under the <span class="hlt">accelerated</span> condition D within two weeks, correlated (r2 ≥ 0.98) well with that under real-time conditions at four months. PMID:27598191</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70022988','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70022988"><span>A <span class="hlt">seismic</span> hazard uncertainty analysis for the New Madrid <span class="hlt">seismic</span> zone</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cramer, C.H.</p> <p>2001-01-01</p> <p>A review of the scientific issues relevant to characterizing earthquake sources in the New Madrid <span class="hlt">seismic</span> zone has led to the development of a logic tree of possible alternative parameters. A variability analysis, using Monte Carlo sampling of this consensus logic tree, is presented and discussed. The analysis shows that for 2%-exceedence-in-50-year hazard, the best-estimate <span class="hlt">seismic</span> hazard map is similar to previously published <span class="hlt">seismic</span> hazard maps for the area. For peak ground <span class="hlt">acceleration</span> (PGA) and spectral <span class="hlt">acceleration</span> at 0.2 and 1.0 s (0.2 and 1.0 s Sa), the coefficient of variation (COV) representing the knowledge-based uncertainty in <span class="hlt">seismic</span> hazard can exceed 0.6 over the New Madrid <span class="hlt">seismic</span> zone and diminishes to about 0.1 away from areas of <span class="hlt">seismic</span> activity. Sensitivity analyses show that the largest contributor to PGA, 0.2 and 1.0 s Sa <span class="hlt">seismic</span> hazard variability is the uncertainty in the location of future 1811-1812 New Madrid sized earthquakes. This is followed by the variability due to the choice of ground motion attenuation relation, the magnitude for the 1811-1812 New Madrid earthquakes, and the recurrence interval for M>6.5 events. <span class="hlt">Seismic</span> hazard is not very sensitive to the variability in seismogenic width and length. Published by Elsevier Science B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840024800','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840024800"><span><span class="hlt">Seismic</span> Analysis Capability in NASTRAN</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Butler, T. G.; Strang, R. F.</p> <p>1984-01-01</p> <p><span class="hlt">Seismic</span> analysis is a technique which pertains to loading described in terms of boundary <span class="hlt">accelerations</span>. Earthquake shocks to buildings is the type of excitation which usually comes to mind when one hears the word <span class="hlt">seismic</span>, but this technique also applied to a broad class of <span class="hlt">acceleration</span> excitations which are applied at the base of a structure such as vibration shaker testing or shocks to machinery foundations. Four different solution paths are available in NASTRAN for <span class="hlt">seismic</span> analysis. They are: Direct <span class="hlt">Seismic</span> Frequency Response, Direct <span class="hlt">Seismic</span> Transient Response, Modal <span class="hlt">Seismic</span> Frequency Response, and Modal <span class="hlt">Seismic</span> Transient Response. This capability, at present, is invoked not as separate rigid formats, but as pre-packaged ALTER packets to existing RIGID Formats 8, 9, 11, and 12. These ALTER packets are included with the delivery of the NASTRAN program and are stored on the computer as a library of callable utilities. The user calls one of these utilities and merges it into the Executive Control Section of the data deck to perform any of the four options are invoked by setting parameter values in the bulk data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70034083','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70034083"><span>Toward a consistent model for strain accrual and <span class="hlt">release</span> for the New Madrid <span class="hlt">Seismic</span> Zone, central United States</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hough, S.E.; Page, M.</p> <p>2011-01-01</p> <p>At the heart of the conundrum of seismogenesis in the New Madrid <span class="hlt">Seismic</span> Zone is the apparently substantial discrepancy between low strain rate and high recent <span class="hlt">seismic</span> moment <span class="hlt">release</span>. In this study we revisit the magnitudes of the four principal 1811–1812 earthquakes using intensity values determined from individual assessments from four experts. Using these values and the grid search method of Bakun and Wentworth (1997), we estimate magnitudes around 7.0 for all four events, values that are significantly lower than previously published magnitude estimates based on macroseismic intensities. We further show that the strain rate predicted from postglacial rebound is sufficient to produce a sequence with the moment <span class="hlt">release</span> of one Mmax6.8 every 500 years, a rate that is much lower than previous estimates of late Holocene moment <span class="hlt">release</span>. However, Mw6.8 is at the low end of the uncertainty range inferred from analysis of intensities for the largest 1811–1812 event. We show that Mw6.8 is also a reasonable value for the largest main shock given a plausible rupture scenario. One can also construct a range of consistent models that permit a somewhat higher Mmax, with a longer average recurrence rate. It is thus possible to reconcile predicted strain and <span class="hlt">seismic</span> moment <span class="hlt">release</span> rates with alternative models: one in which 1811–1812 sequences occur every 500 years, with the largest events being Mmax∼6.8, or one in which sequences occur, on average, less frequently, with Mmax of ∼7.0. Both models predict that the late Holocene rate of activity will continue for the next few to 10 thousand years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4356028','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4356028"><span>Insights into <span class="hlt">accelerated</span> liposomal <span class="hlt">release</span> of topotecan in plasma monitored by a non-invasive fluorescence spectroscopic method</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fugit, Kyle D.; Jyoti, Amar; Upreti, Meenakshi; Anderson, Bradley D.</p> <p>2014-01-01</p> <p>A non-invasive fluorescence method was developed to monitor liposomal <span class="hlt">release</span> kinetics of the anticancer agent topotecan (TPT) in physiological fluids and subsequently used to explore the cause of <span class="hlt">accelerated</span> <span class="hlt">release</span> in plasma. Analyses of fluorescence excitation spectra confirmed that unencapsulated TPT exhibits a red shift in its spectrum as pH is increased. This property was used to monitor TPT <span class="hlt">release</span> from actively loaded liposomal formulations having a low intravesicular pH. Mathematical <span class="hlt">release</span> models were developed to extract reliable rate constants for TPT <span class="hlt">release</span> in aqueous solutions monitored by fluorescence and <span class="hlt">release</span> kinetics obtained by HPLC. Using the fluorescence method, <span class="hlt">accelerated</span> TPT <span class="hlt">release</span> was observed in plasma as previously reported in the literature. Simulations to estimate the intravesicular pH were conducted to demonstrate that <span class="hlt">accelerated</span> <span class="hlt">release</span> correlated with alterations in the low intravesicular pH. This was attributed to the presence of ammonia in plasma samples rather than proteins and other plasma components generally believed to alter <span class="hlt">release</span> kinetics in physiological samples. These findings shed light on the critical role that ammonia may play in contributing to the preclinical/clinical variability and performance seen with actively-loaded liposomal formulations of TPT and other weakly-basic anticancer agents. PMID:25456833</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15..921S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15..921S"><span>Forecasting volcanic unrest using <span class="hlt">seismicity</span>: The good, the bad and the time consuming</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salvage, Rebecca; Neuberg, Jurgen W.</p> <p>2013-04-01</p> <p>Volcanic eruptions are inherently unpredictable in nature, with scientists struggling to forecast the type and timing of events, in particular in real time scenarios. Current understanding suggests that the use of statistical patterns within precursory datasets of <span class="hlt">seismicity</span> prior to eruptive events could hold the potential to be used as real time forecasting tools. They allow us to determine times of clear deviation in data, which might be indicative of volcanic unrest. The identification of low frequency <span class="hlt">seismic</span> swarms and the <span class="hlt">acceleration</span> of this <span class="hlt">seismicity</span> prior to observed volcanic unrest may be key in developing forecasting tools. The development of these real time forecasting models which can be implemented at volcano observatories is of particular importance since the identification of early warning signals allows danger to the proximal population to be minimized. We concentrate on understanding the significance and development of these <span class="hlt">seismic</span> swarms as unrest develops at the volcano. In particular, analysis of <span class="hlt">accelerations</span> in event rate, amplitude and energy rates <span class="hlt">released</span> by <span class="hlt">seismicity</span> prior to eruption suggests that these are important indicators of developing unrest. Real time analysis of these parameters simultaneously allows possible improvements to forecasting models. Although more time and computationally intense, cross correlation techniques applied to continuous <span class="hlt">seismicity</span> prior to volcanic unrest scenarios allows all significant <span class="hlt">seismic</span> events to be analysed, rather than only those which can be detected by an automated identification system. This may allow a more accurate forecast since all precursory <span class="hlt">seismicity</span> can be taken into account. In addition, the classification of <span class="hlt">seismic</span> events based on spectral characteristics may allow us to isolate individual types of signals which are responsible for certain types of unrest. In this way, we may be able to better forecast the type of eruption that may ensue, or at least some of its prevailing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2012/1015/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2012/1015/"><span><span class="hlt">Seismic</span> hazard assessment for Guam and the Northern Mariana Islands</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Mueller, Charles S.; Haller, Kathleen M.; Luco, Nicholas; Petersen, Mark D.; Frankel, Arthur D.</p> <p>2012-01-01</p> <p>We present the results of a new probabilistic <span class="hlt">seismic</span> hazard assessment for Guam and the Northern Mariana Islands. The Mariana island arc has formed in response to northwestward subduction of the Pacific plate beneath the Philippine Sea plate, and this process controls <span class="hlt">seismic</span> activity in the region. Historical <span class="hlt">seismicity</span>, the Mariana megathrust, and two crustal faults on Guam were modeled as <span class="hlt">seismic</span> sources, and ground motions were estimated by using published relations for a firm-rock site condition. Maps of peak ground <span class="hlt">acceleration</span>, 0.2-second spectral <span class="hlt">acceleration</span> for 5 percent critical damping, and 1.0-second spectral <span class="hlt">acceleration</span> for 5 percent critical damping were computed for exceedance probabilities of 2 percent and 10 percent in 50 years. For 2 percent probability of exceedance in 50 years, probabilistic peak ground <span class="hlt">acceleration</span> is 0.94 gravitational <span class="hlt">acceleration</span> at Guam and 0.57 gravitational <span class="hlt">acceleration</span> at Saipan, 0.2-second spectral <span class="hlt">acceleration</span> is 2.86 gravitational <span class="hlt">acceleration</span> at Guam and 1.75 gravitational <span class="hlt">acceleration</span> at Saipan, and 1.0-second spectral <span class="hlt">acceleration</span> is 0.61 gravitational <span class="hlt">acceleration</span> at Guam and 0.37 gravitational <span class="hlt">acceleration</span> at Saipan. For 10 percent probability of exceedance in 50 years, probabilistic peak ground <span class="hlt">acceleration</span> is 0.49 gravitational <span class="hlt">acceleration</span> at Guam and 0.29 gravitational <span class="hlt">acceleration</span> at Saipan, 0.2-second spectral <span class="hlt">acceleration</span> is 1.43 gravitational <span class="hlt">acceleration</span> at Guam and 0.83 gravitational <span class="hlt">acceleration</span> at Saipan, and 1.0-second spectral <span class="hlt">acceleration</span> is 0.30 gravitational <span class="hlt">acceleration</span> at Guam and 0.18 gravitational <span class="hlt">acceleration</span> at Saipan. The dominant hazard source at the islands is upper Benioff-zone <span class="hlt">seismicity</span> (depth 40–160 kilometers). The large probabilistic ground motions reflect the strong concentrations of this activity below the arc, especially near Guam.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28404990','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28404990"><span>Aseismic transient during the 2010-2014 <span class="hlt">seismic</span> swarm: evidence for longer recurrence of M ≥ 6.5 earthquakes in the Pollino gap (Southern Italy)?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cheloni, Daniele; D'Agostino, Nicola; Selvaggi, Giulio; Avallone, Antonio; Fornaro, Gianfranco; Giuliani, Roberta; Reale, Diego; Sansosti, Eugenio; Tizzani, Pietro</p> <p>2017-04-12</p> <p>In actively deforming regions, crustal deformation is accommodated by earthquakes and through a variety of transient aseismic phenomena. Here, we study the 2010-2014 Pollino (Southern Italy) swarm sequence (main shock M W 5.1) located within the Pollino <span class="hlt">seismic</span> gap, by analysing the surface deformation derived from Global Positioning System and Synthetic Aperture Radar data. Inversions of geodetic time series show that a transient slip, with the same mechanism of the main shock, started about 3-4 months before the main shock and lasted almost one year, evolving through time with <span class="hlt">acceleration</span> phases that correlate with the rate of <span class="hlt">seismicity</span>. The moment <span class="hlt">released</span> by the transient slip is equivalent to M W 5.5, significantly larger than the <span class="hlt">seismic</span> moment <span class="hlt">release</span> revealing therefore that a significant fraction of the overall deformation is <span class="hlt">released</span> aseismically. Our findings suggest that crustal deformation in the Pollino gap is accommodated by infrequent "large" earthquakes (M W  ≥ 6.5) and by aseismic episodes <span class="hlt">releasing</span> a significant fraction of the accrued strain. Lower strain rates, relative to the adjacent Southern Apennines, and a mixed <span class="hlt">seismic</span>/aseismic strain <span class="hlt">release</span> are in favour of a longer recurrence for large magnitude earthquakes in the Pollino gap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.3721N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.3721N"><span>Evaluation <span class="hlt">Seismicity</span> west of block-lut for Deterministic <span class="hlt">Seismic</span> Hazard Assessment of Shahdad ,Iran</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ney, B.; Askari, M.</p> <p>2009-04-01</p> <p>Evaluation <span class="hlt">Seismicity</span> west of block-lut for Deterministic <span class="hlt">Seismic</span> Hazard Assessment of Shahdad ,Iran Behnoosh Neyestani , Mina Askari Students of Science and Research University,Iran. <span class="hlt">Seismic</span> Hazard Assessment has been done for Shahdad city in this study , and four maps (Kerman-Bam-Nakhil Ab-Allah Abad) has been prepared to indicate the Deterministic estimate of Peak Ground <span class="hlt">Acceleration</span> (PGA) in this area. Deterministic <span class="hlt">Seismic</span> Hazard Assessment has been preformed for a region in eastern Iran (Shahdad) based on the available geological, seismological and geophysical information and <span class="hlt">seismic</span> zoning map of region has been constructed. For this assessment first Seimotectonic map of study region in a radius of 100km is prepared using geological maps, distribution of historical and instrumental earthquake data and focal mechanism solutions it is used as the base map for delineation of potential <span class="hlt">seismic</span> sources. After that minimum distance, for every <span class="hlt">seismic</span> sources until site (Shahdad) and maximum magnitude for each source have been determined. In Shahdad ,according to results, peak ground <span class="hlt">acceleration</span> using the Yoshimitsu Fukushima &Teiji Tanaka'1990 attenuation relationship is estimated to be 0.58 g, that is related to the movement of nayband fault with distance 2.4km of the site and maximum magnitude Ms=7.5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18785078','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18785078"><span><span class="hlt">Accelerated</span> dissolution testing for controlled <span class="hlt">release</span> microspheres using the flow-through dissolution apparatus.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Collier, Jarrod W; Thakare, Mohan; Garner, Solomon T; Israel, Bridg'ette; Ahmed, Hisham; Granade, Saundra; Strong, Deborah L; Price, James C; Capomacchia, A C</p> <p>2009-01-01</p> <p>Theophylline controlled <span class="hlt">release</span> capsules (THEO-24 CR) were used as a model system to evaluate <span class="hlt">accelerated</span> dissolution tests for process and quality control and formulation development of controlled <span class="hlt">release</span> formulations. Dissolution test <span class="hlt">acceleration</span> was provided by increasing temperature, pH, flow rate, or adding surfactant. Electron microscope studies on the theophylline microspheres subsequent to each experiment showed that at pH values of 6.6 and 7.6 the microspheres remained intact, but at pH 8.6 they showed deterioration. As temperature was increased from 37-57 degrees C, no change in microsphere integrity was noted. Increased flow rate also showed no detrimental effect on integrity. The effect of increased temperature was determined to be the statistically significant variable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21148988-evaluation-horizontal-seismic-hazard-shahrekord-iran','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21148988-evaluation-horizontal-seismic-hazard-shahrekord-iran"><span>Evaluation of Horizontal <span class="hlt">Seismic</span> Hazard of Shahrekord, Iran</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Amiri, G. Ghodrati; Dehkordi, M. Raeisi; Amrei, S. A. Razavian</p> <p>2008-07-08</p> <p>This paper presents probabilistic horizontal <span class="hlt">seismic</span> hazard assessment of Shahrekord, Iran. It displays the probabilistic estimate of Peak Ground Horizontal <span class="hlt">Acceleration</span> (PGHA) for the return period of 75, 225, 475 and 2475 years. The output of the probabilistic <span class="hlt">seismic</span> hazard analysis is based on peak ground <span class="hlt">acceleration</span> (PGA), which is the most common criterion in designing of buildings. A catalogue of <span class="hlt">seismic</span> events that includes both historical and instrumental events was developed and covers the period from 840 to 2007. The <span class="hlt">seismic</span> sources that affect the hazard in Shahrekord were identified within the radius of 150 km and the recurrencemore » relationships of these sources were generated. Finally four maps have been prepared to indicate the earthquake hazard of Shahrekord in the form of iso-<span class="hlt">acceleration</span> contour lines for different hazard levels by using SEISRISK III software.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S42B..01V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S42B..01V"><span>Exploring the Differences Between the European (SHARE) and the Reference Italian <span class="hlt">Seismic</span> Hazard Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Visini, F.; Meletti, C.; D'Amico, V.; Rovida, A.; Stucchi, M.</p> <p>2014-12-01</p> <p>The recent <span class="hlt">release</span> of the probabilistic <span class="hlt">seismic</span> hazard assessment (PSHA) model for Europe by the SHARE project (Giardini et al., 2013, www.share-eu.org) arises questions about the comparison between its results for Italy and the official Italian <span class="hlt">seismic</span> hazard model (MPS04; Stucchi et al., 2011) adopted by the building code. The goal of such a comparison is identifying the main input elements that produce the differences between the two models. It is worthwhile to remark that each PSHA is realized with data and knowledge available at the time of the <span class="hlt">release</span>. Therefore, even if a new model provides estimates significantly different from the previous ones that does not mean that old models are wrong, but probably that the current knowledge is strongly changed and improved. Looking at the hazard maps with 10% probability of exceedance in 50 years (adopted as the standard input in the Italian building code), the SHARE model shows increased expected values with respect to the MPS04 model, up to 70% for PGA. However, looking in detail at all output parameters of both the models, we observe a different behaviour for other spectral <span class="hlt">accelerations</span>. In fact, for spectral periods greater than 0.3 s, the current reference PSHA for Italy proposes higher values than the SHARE model for many and large areas. This observation suggests that this behaviour could not be due to a different definition of <span class="hlt">seismic</span> sources and relevant <span class="hlt">seismicity</span> rates; it mainly seems the result of the adoption of recent ground-motion prediction equations (GMPEs) that estimate higher values for PGA and for <span class="hlt">accelerations</span> with periods lower than 0.3 s and lower values for higher periods with respect to old GMPEs. Another important set of tests consisted in analysing separately the PSHA results obtained by the three source models adopted in SHARE (i.e., area sources, fault sources with background, and a refined smoothed <span class="hlt">seismicity</span> model), whereas MPS04 only uses area sources. Results seem to confirm the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/10143151','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/10143151"><span>Annotated bibliography, <span class="hlt">seismicity</span> of and near the island of Hawaii and <span class="hlt">seismic</span> hazard analysis of the East Rift of Kilauea</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Klein, F.W.</p> <p>1994-03-28</p> <p>This bibliography is divided into the following four sections: <span class="hlt">Seismicity</span> of Hawaii and Kilauea Volcano; Occurrence, locations and <span class="hlt">accelerations</span> from large historical Hawaiian earthquakes; <span class="hlt">Seismic</span> hazards of Hawaii; and Methods of <span class="hlt">seismic</span> hazard analysis. It contains 62 references, most of which are accompanied by short abstracts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..153f2031J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..153f2031J"><span>Research on Influencing Factors and Generalized Power of Synthetic Artificial <span class="hlt">Seismic</span> Wave</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Yanpei</p> <p>2018-05-01</p> <p>Start your abstract here… In this paper, according to the trigonometric series method, the author adopts different envelope functions and the <span class="hlt">acceleration</span> design spectrum in <span class="hlt">Seismic</span> Code For Urban Bridge Design to simulate the <span class="hlt">seismic</span> <span class="hlt">acceleration</span> time history which meets the engineering accuracy requirements by modifying and iterating the initial wave. Spectral analysis is carried out to find out the the distribution law of the changing frequencies of the energy of <span class="hlt">seismic</span> time history and to determine the main factors that affect the <span class="hlt">acceleration</span> amplitude spectrum and energy spectrum density. The generalized power formula of <span class="hlt">seismic</span> time history is derived from the discrete energy integral formula and the author studied the changing characteristics of generalized power of the <span class="hlt">seismic</span> time history under different envelop functions. Examples are analyzed to illustrate that generalized power can measure the <span class="hlt">seismic</span> performance of bridges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2014/1091/pdf/ofr2014-1091.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2014/1091/pdf/ofr2014-1091.pdf"><span>Documentation for the 2014 update of the United States national <span class="hlt">seismic</span> hazard maps</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Petersen, Mark D.; Moschetti, Morgan P.; Powers, Peter M.; Mueller, Charles S.; Haller, Kathleen M.; Frankel, Arthur D.; Zeng, Yuehua; Rezaeian, Sanaz; Harmsen, Stephen C.; Boyd, Oliver S.; Field, Edward; Chen, Rui; Rukstales, Kenneth S.; Luco, Nico; Wheeler, Russell L.; Williams, Robert A.; Olsen, Anna H.</p> <p>2014-01-01</p> <p>The national <span class="hlt">seismic</span> hazard maps for the conterminous United States have been updated to account for new methods, models, and data that have been obtained since the 2008 maps were <span class="hlt">released</span> (Petersen and others, 2008). The input models are improved from those implemented in 2008 by using new ground motion models that have incorporated about twice as many earthquake strong ground shaking data and by incorporating many additional scientific studies that indicate broader ranges of earthquake source and ground motion models. These time-independent maps are shown for 2-percent and 10-percent probability of exceedance in 50 years for peak horizontal ground <span class="hlt">acceleration</span> as well as 5-hertz and 1-hertz spectral <span class="hlt">accelerations</span> with 5-percent damping on a uniform firm rock site condition (760 meters per second shear wave velocity in the upper 30 m, VS30). In this report, the 2014 updated maps are compared with the 2008 version of the maps and indicate changes of plus or minus 20 percent over wide areas, with larger changes locally, caused by the modifications to the <span class="hlt">seismic</span> source and ground motion inputs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8074M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8074M"><span>Increasing rock-avalanche frequency correlates with increasing <span class="hlt">seismic</span> moment <span class="hlt">release</span> in New Zealand's Southern Alps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McSaveney, Mauri; Cox, Simon; Hancox, Graham</p> <p>2015-04-01</p> <p>The occurrence rate of large, spontaneous rock avalanches in New Zealand's Southern Alps has increasing over the last 50 years. The rate has been about 20 events per decade for the last 10 years, whereas for the period 1976-1999, it was 4 per decade. Allen et al. 2011 and Allen and Huggel, 2013 link the increase to alpine permafrost decay due to anthropogenic global warming, similar to the increased occurrence rate in the European Alps which is attributed to this cause. We however suggest a different primary cause, linking the increase to tectonic strain, which has been shown to also affect valley-bottom hot springs in the region. The altitudes from which these landslides have fallen are coincident with the region's topographically protruding slopes which favour stress concentration and failure, and many, but not all, failures have been from already highly fractured rock masses, for which an explanation of the fracturing is called for. Also, the earliest documented spontaneous rock avalanche in the Southern Alps occurred in 1873 and fell from a similar altitude on the same face of the same mountain as the most recent event in 2014. Cox et al. (2014) shows that valley-bottom hot springs in the Southern Alps respond to distant strong earthquakes in a manner suggesting weak local ground deformation and increased bedrock permeability. We suggest that the surrounding slopes respond to the same stimuli. We find that the observed occurrence-rate increase has occurred simultaneously with a <span class="hlt">seismic-moment-release</span> increase in New Zealand, which follows the trend of global <span class="hlt">seismic</span> moment <span class="hlt">release</span>. It may also be associated with the accumulating slope deformations since about 1717 AD, when a great earthquake triggered much slope collapse in the region. In support of this link, Barff (1873) which reports the 1873 landslide from Aoraki/Mount Cook, also reports a seemingly associated but unexplained shift of hot springs in the area. The timing of both coincides with a distant</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27025293','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27025293"><span>Setting <span class="hlt">accelerated</span> dissolution test for PLGA microspheres containing peptide, investigation of critical parameters affecting drug <span class="hlt">release</span> rate and mechanism.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tomic, I; Vidis-Millward, A; Mueller-Zsigmondy, M; Cardot, J-M</p> <p>2016-05-30</p> <p>The objective of this study was development of <span class="hlt">accelerated</span> in vitro <span class="hlt">release</span> method for peptide loaded PLGA microspheres using flow-through apparatus and assessment of the effect of dissolution parameters (pH, temperature, medium composition) on drug <span class="hlt">release</span> rate and mechanism. <span class="hlt">Accelerated</span> <span class="hlt">release</span> conditions were set as pH 2 and 45°C, in phosphate buffer saline (PBS) 0.02M. When the pH was changed from 2 to 4, diffusion controlled phases (burst and lag) were not affected, while <span class="hlt">release</span> rate during erosion phase decreased two-fold due to slower ester bonds hydrolyses. Decreasing temperature from 45°C to 40°C, <span class="hlt">release</span> rate showed three-fold deceleration without significant change in <span class="hlt">release</span> mechanism. Effect of medium composition on drug <span class="hlt">release</span> was tested in PBS 0.01M (200 mOsm/kg) and PBS 0.01M with glucose (380 mOsm/kg). Buffer concentration significantly affected drug <span class="hlt">release</span> rate and mechanism due to the change in osmotic pressure, while ionic strength did not have any effect on peptide <span class="hlt">release</span>. Furthermore, dialysis sac and sample-and-separate techniques were used, in order to evaluate significance of dissolution technique choice on the <span class="hlt">release</span> process. After fitting obtained data to different mathematical models, flow-through method was confirmed as the most appropriate for <span class="hlt">accelerated</span> in vitro dissolution testing for a given formulation. Copyright © 2016 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26455313','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26455313"><span>A SERS protocol as a potential tool to access 6-mercaptopurine <span class="hlt">release</span> <span class="hlt">accelerated</span> by glutathione-S-transferase.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Ying; Sun, Jie; Yang, Qingran; Lu, Wenbo; Li, Yan; Dong, Jian; Qian, Weiping</p> <p>2015-11-21</p> <p>The developed method for monitoring GST, an important drug metabolic enzyme, could greatly facilitate researches on relative biological fields. In this work, we have developed a SERS technique to monitor the absorbance behaviour of 6-mercaptopurine (6-MP) and its glutathione-S-transferase (GST)-<span class="hlt">accelerated</span> glutathione (GSH)-triggered <span class="hlt">release</span> behaviour on the surface of gold nanoflowers (GNFs), using the GNFs as excellent SERS substrates. The SERS signal was used as an indicator of absorbance or <span class="hlt">release</span> of 6-MP on the gold surface. We found that GST can <span class="hlt">accelerate</span> GSH-triggered <span class="hlt">release</span> behaviour of 6-MP from the gold surface. We speculated that GST catalyzes nucleophilic GSH to competitively bind with the electrophilic substance 6-MP. Experimental results have proved that the presented SERS protocol can be utilized as an effective tool for accessing the <span class="hlt">release</span> of anticancer drugs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21149048-seismic-safety-simple-masonry-buildings','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21149048-seismic-safety-simple-masonry-buildings"><span><span class="hlt">Seismic</span> Safety Of Simple Masonry Buildings</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Guadagnuolo, Mariateresa; Faella, Giuseppe</p> <p>2008-07-08</p> <p>Several masonry buildings comply with the rules for simple buildings provided by <span class="hlt">seismic</span> codes. For these buildings explicit safety verifications are not compulsory if specific code rules are fulfilled. In fact it is assumed that their fulfilment ensures a suitable <span class="hlt">seismic</span> behaviour of buildings and thus adequate safety under earthquakes. Italian and European <span class="hlt">seismic</span> codes differ in the requirements for simple masonry buildings, mostly concerning the building typology, the building geometry and the <span class="hlt">acceleration</span> at site. Obviously, a wide percentage of buildings assumed simple by codes should satisfy the numerical safety verification, so that no confusion and uncertainty have tomore » be given rise to designers who must use the codes. This paper aims at evaluating the <span class="hlt">seismic</span> response of some simple unreinforced masonry buildings that comply with the provisions of the new Italian <span class="hlt">seismic</span> code. Two-story buildings, having different geometry, are analysed and results from nonlinear static analyses performed by varying the <span class="hlt">acceleration</span> at site are presented and discussed. Indications on the congruence between code rules and results of numerical analyses performed according to the code itself are supplied and, in this context, the obtained result can provide a contribution for improving the <span class="hlt">seismic</span> code requirements.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008spa..book.1535W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008spa..book.1535W"><span><span class="hlt">Seismic</span> Wave Propagation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Xianyun; Wu, Ru-Shan</p> <p></p> <p>A <span class="hlt">seismic</span> wave is a mechanical disturbance or energy packet that can propagate from point to point in the Earth. <span class="hlt">Seismic</span> waves can be generated by a sudden <span class="hlt">release</span> of energy such as an earthquake, volcanic eruption, or chemical explosion. There are several types of <span class="hlt">seismic</span> waves, often classified as body waves, which propagate through the volume of the Earth, and surface waves, which travel along the surface of the Earth. Compressional and shear waves are the two main types of body wave and Rayleigh and Love waves are the most common forms of surface wave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EEEV...16..263P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EEEV...16..263P"><span><span class="hlt">Seismic</span> passive earth resistance using modified pseudo-dynamic method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pain, Anindya; Choudhury, Deepankar; Bhattacharyya, S. K.</p> <p>2017-04-01</p> <p>In earthquake prone areas, understanding of the <span class="hlt">seismic</span> passive earth resistance is very important for the design of different geotechnical earth retaining structures. In this study, the limit equilibrium method is used for estimation of critical <span class="hlt">seismic</span> passive earth resistance for an inclined wall supporting horizontal cohesionless backfill. A composite failure surface is considered in the present analysis. <span class="hlt">Seismic</span> forces are computed assuming the backfill soil as a viscoelastic material overlying a rigid stratum and the rigid stratum is subjected to a harmonic shaking. The present method satisfies the boundary conditions. The amplification of <span class="hlt">acceleration</span> depends on the properties of the backfill soil and on the characteristics of the input motion. The <span class="hlt">acceleration</span> distribution along the depth of the backfill is found to be nonlinear in nature. The present study shows that the horizontal and vertical <span class="hlt">acceleration</span> distribution in the backfill soil is not always in-phase for the critical value of the <span class="hlt">seismic</span> passive earth pressure coefficient. The effect of different parameters on the <span class="hlt">seismic</span> passive earth pressure is studied in detail. A comparison of the present method with other theories is also presented, which shows the merits of the present study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.9588K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.9588K"><span>MyShake: Initial observations from a global smartphone <span class="hlt">seismic</span> network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kong, Qingkai; Allen, Richard M.; Schreier, Louis</p> <p>2016-09-01</p> <p>MyShake is a global smartphone <span class="hlt">seismic</span> network that harnesses the power of crowdsourcing. In the first 6 months since the <span class="hlt">release</span> of the MyShake app, there were almost 200,000 downloads. On a typical day about 8000 phones provide <span class="hlt">acceleration</span> waveform data to the MyShake archive. The on-phone app can detect and trigger on P waves and is capable of recording magnitude 2.5 and larger events. More than 200 <span class="hlt">seismic</span> events have been recorded so far, including events in Chile, Argentina, Mexico, Morocco, Nepal, New Zealand, Taiwan, Japan, and across North America. The largest number of waveforms from a single earthquake to date comes from the M5.2 Borrego Springs earthquake in Southern California, for which MyShake collected 103 useful three-component waveforms. The network continues to grow with new downloads from the Google Play store everyday and expands rapidly when public interest in earthquakes peaks such as during an earthquake sequence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSM.S51A..01M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSM.S51A..01M"><span>Applications of the <span class="hlt">seismic</span> hazard model of Italy: from a new building code to the L'Aquila trial against seismologists</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meletti, C.</p> <p>2013-05-01</p> <p>In 2003, a large national project fur updating the <span class="hlt">seismic</span> hazard map and the <span class="hlt">seismic</span> zoning in Italy started, according to the rules fixed by an Ordinance by Italian Prime Minister. New input elements for probabilistic <span class="hlt">seismic</span> hazard assessment were compiled: the earthquake catalogue, the seismogenic zonation, the catalogue completeness, a set of new attenuation relationships. The map of expected PGA on rock soil condition with 10% probability of exceedance is the new reference <span class="hlt">seismic</span> hazard map for Italy (http://zonesismiche.mi.ingv.it). In the following, further 9 probabilities of exceedance and the uniform hazard spectra up to 2 seconds together with the disaggregation of the PGA was also <span class="hlt">released</span>. A comprehensive <span class="hlt">seismic</span> hazard model that fully describes the <span class="hlt">seismic</span> hazard in Italy was then available, accessible by a webGis application (http://esse1-gis.mi.ingv.it/en.php). The detailed information make possible to change the approach for evaluating the proper <span class="hlt">seismic</span> action for designing: from a zone-dependent approach (in Italy there were 4 <span class="hlt">seismic</span> zones, each one with a single design spectrum) to a site-dependent approach: the design spectrum is now defined at each site of a grid of about 11000 points covering the whole national territory. The new building code becomes mandatory only after the 6 April 2009 L'Aquila earthquake, the first strong event in Italy after the <span class="hlt">release</span> of the <span class="hlt">seismic</span> hazard map. The large number of recordings and the values of the experienced <span class="hlt">accelerations</span> suggested the comparisons between the recorded spectra and spectra defined in the <span class="hlt">seismic</span> codes Even if such comparisons could be robust only after several consecutive 50-year periods of observation and in a probabilistic approach it is not a single observation that can validate or not the hazard estimate, some of the comparisons that can be undertaken between the observed ground motions and the hazard model used for the <span class="hlt">seismic</span> code have been performed and have shown that the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NHESD...3.7555A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NHESD...3.7555A"><span>An extended stochastic method for <span class="hlt">seismic</span> hazard estimation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abd el-aal, A. K.; El-Eraki, M. A.; Mostafa, S. I.</p> <p>2015-12-01</p> <p>In this contribution, we developed an extended stochastic technique for <span class="hlt">seismic</span> hazard assessment purposes. This technique depends on the hypothesis of stochastic technique of Boore (2003) "Simulation of ground motion using the stochastic method. Appl. Geophy. 160:635-676". The essential characteristics of extended stochastic technique are to obtain and simulate ground motion in order to minimize future earthquake consequences. The first step of this technique is defining the <span class="hlt">seismic</span> sources which mostly affect the study area. Then, the maximum expected magnitude is defined for each of these <span class="hlt">seismic</span> sources. It is followed by estimating the ground motion using an empirical attenuation relationship. Finally, the site amplification is implemented in calculating the peak ground <span class="hlt">acceleration</span> (PGA) at each site of interest. We tested and applied this developed technique at Cairo, Suez, Port Said, Ismailia, Zagazig and Damietta cities to predict the ground motion. Also, it is applied at Cairo, Zagazig and Damietta cities to estimate the maximum peak ground <span class="hlt">acceleration</span> at actual soil conditions. In addition, 0.5, 1, 5, 10 and 20 % damping median response spectra are estimated using the extended stochastic simulation technique. The calculated highest <span class="hlt">acceleration</span> values at bedrock conditions are found at Suez city with a value of 44 cm s-2. However, these <span class="hlt">acceleration</span> values decrease towards the north of the study area to reach 14.1 cm s-2 at Damietta city. This comes in agreement with the results of previous studies of <span class="hlt">seismic</span> hazards in northern Egypt and is found to be comparable. This work can be used for <span class="hlt">seismic</span> risk mitigation and earthquake engineering purposes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.2674R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.2674R"><span>The <span class="hlt">seismic</span> traffic footprint: Tracking trains, aircraft, and cars <span class="hlt">seismically</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Riahi, Nima; Gerstoft, Peter</p> <p>2015-04-01</p> <p>Although naturally occurring vibrations have proven useful to probe the subsurface, the vibrations caused by traffic have not been explored much. Such data, however, are less sensitive to weather and low visibility compared to some common out-of-road traffic sensing systems. We study traffic-generated <span class="hlt">seismic</span> noise measured by an array of 5200 geophones that covered a 7 × 10 km area in Long Beach (California, USA) with a receiver spacing of 100 m. This allows us to look into urban vibrations below the resolution of a typical city block. The spatiotemporal structure of the anthropogenic <span class="hlt">seismic</span> noise intensity reveals the Blue Line Metro train activity, departing and landing aircraft in Long Beach Airport and their <span class="hlt">acceleration</span>, and gives clues about traffic movement along the I-405 highway at night. As low-cost, stand-alone <span class="hlt">seismic</span> sensors are becoming more common, these findings indicate that <span class="hlt">seismic</span> data may be useful for traffic monitoring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29146240','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29146240"><span>Channelled tablets: An innovative approach to <span class="hlt">accelerating</span> drug <span class="hlt">release</span> from 3D printed tablets.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sadia, Muzna; Arafat, Basel; Ahmed, Waqar; Forbes, Robert T; Alhnan, Mohamed A</p> <p>2018-01-10</p> <p>Conventional immediate <span class="hlt">release</span> dosage forms involve compressing the powder with a disintegrating agent that enables rapid disintegration and dissolution upon oral ingestion. Among 3D printing technologies, the fused deposition modelling (FDM) 3D printing technique has a considerable potential for patient-specific dosage forms. However, the use of FDM 3D printing in tablet manufacturing requires a large portion of polymer, which slows down drug <span class="hlt">release</span> through erosion and diffusion mechanisms. In this study, we demonstrate for the first time the use of a novel design approach of caplets with perforated channels to <span class="hlt">accelerate</span> drug <span class="hlt">release</span> from 3D printed tablets. This strategy has been implemented using a caplet design with perforating channels of increasing width (0.2, 0.4, 0.6, 0.8 or 1.0mm) and variable length, and alignment (parallel or at right angle to tablet long axis). Hydrochlorothiazide (BCS class IV drug) was chosen as the model drug as enhanced dissolution rate is vital to guarantee oral bioavailability. The inclusion of channels exhibited an increase in the surface area/volume ratio, however, the <span class="hlt">release</span> pattern was also influenced by the width and the length of the channel. A channel width was ≥0.6mm deemed critical to meet the USP criteria of immediate <span class="hlt">release</span> products. Shorter multiple channels (8.6mm) were more efficient at <span class="hlt">accelerating</span> drug <span class="hlt">release</span> than longer channels (18.2mm) despite having comparable surface area/mass ratio. This behaviour may be linked to the reduced flow resistance within the channels and the faster fragmentation during dissolution of these tablets. In conclusion, the width and length of the channel should be carefully considered in addition to surface area/mass when optimizing drug <span class="hlt">release</span> from 3D printed designs. The incorporation of short channels can be adopted in the designs of dosage forms, implants or stents to enhance the <span class="hlt">release</span> rate of eluting drug from polymer-rich structures. Copyright © 2017 Elsevier B.V. All</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28498127','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28498127"><span><span class="hlt">Accelerated</span> anaerobic <span class="hlt">release</span> of K, Mg and P from surplus activated sludge for element recovery and struvite formation inhibition.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ito, A; Kawakami, H; Ishikawa, N; Ito, M; Oikawa, T; Sato, A; Umita, T</p> <p>2017-05-01</p> <p><span class="hlt">Accelerated</span> <span class="hlt">release</span> of potassium (K), magnesium (Mg) and phosphorus (P) from surplus activated sludge (SAS) was investigated to develop a new system for the recovery of the elements. Anaerobic cultivation of SAS during 24 h <span class="hlt">released</span> 78% of K and about 50% of Mg and P from SAS more effectively compared to aerobic cultivation (K: 40%, Mg: 15%, P: 15%). Furthermore, the addition of sodium acetate as an organic carbon source remarkably <span class="hlt">accelerated</span> the <span class="hlt">release</span> of K, Mg and P from SAS under anaerobic condition. However, no increase in the maximum <span class="hlt">release</span> efficiencies was observed. The elements <span class="hlt">released</span> from SAS could be transferred to separate liquid with the existing mechanical thickener and be recovered as MgKPO 4 by some additional process. Furthermore, the removal of the elements from SAS would inhibit the formation of struvite causing the blockage of sludge transport pipe after anaerobic digestion process of thickened sludge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1411009S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1411009S"><span>Using <span class="hlt">Seismic</span> Signals to Forecast Volcanic Processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salvage, R.; Neuberg, J. W.</p> <p>2012-04-01</p> <p>Understanding <span class="hlt">seismic</span> signals generated during volcanic unrest have the ability to allow scientists to more accurately predict and understand active volcanoes since they are intrinsically linked to rock failure at depth (Voight, 1988). In particular, low frequency long period signals (LP events) have been related to the movement of fluid and the brittle failure of magma at depth due to high strain rates (Hammer and Neuberg, 2009). This fundamentally relates to surface processes. However, there is currently no physical quantitative model for determining the likelihood of an eruption following precursory <span class="hlt">seismic</span> signals, or the timing or type of eruption that will ensue (Benson et al., 2010). Since the beginning of its current eruptive phase, <span class="hlt">accelerating</span> LP swarms (< 10 events per hour) have been a common feature at Soufriere Hills volcano, Montserrat prior to surface expressions such as dome collapse or eruptions (Miller et al., 1998). The dynamical behaviour of such swarms can be related to <span class="hlt">accelerated</span> magma ascent rates since the <span class="hlt">seismicity</span> is thought to be a consequence of magma deformation as it rises to the surface. In particular, <span class="hlt">acceleration</span> rates can be successfully used in collaboration with the inverse material failure law; a linear relationship against time (Voight, 1988); in the accurate prediction of volcanic eruption timings. Currently, this has only been investigated for retrospective events (Hammer and Neuberg, 2009). The identification of LP swarms on Montserrat and analysis of their dynamical characteristics allows a better understanding of the nature of the <span class="hlt">seismic</span> signals themselves, as well as their relationship to surface processes such as magma extrusion rates. <span class="hlt">Acceleration</span> and deceleration rates of <span class="hlt">seismic</span> swarms provide insights into the plumbing system of the volcano at depth. The application of the material failure law to multiple LP swarms of data allows a critical evaluation of the accuracy of the method which further refines current</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Geote..52..151H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Geote..52..151H"><span><span class="hlt">Seismic</span> Hazard Assessment at Esfaraen‒Bojnurd Railway, North‒East of Iran</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haerifard, S.; Jarahi, H.; Pourkermani, M.; Almasian, M.</p> <p>2018-01-01</p> <p>The objective of this study is to evaluate the <span class="hlt">seismic</span> hazard at the Esfarayen-Bojnurd railway using the probabilistic <span class="hlt">seismic</span> hazard assessment (PSHA) method. This method was carried out based on a recent data set to take into account the historic <span class="hlt">seismicity</span> and updated instrumental <span class="hlt">seismicity</span>. A homogenous earthquake catalogue was compiled and a proposed <span class="hlt">seismic</span> sources model was presented. Attenuation equations that recently recommended by experts and developed based upon earthquake data obtained from tectonic environments similar to those in and around the studied area were weighted and used for assessment of <span class="hlt">seismic</span> hazard in the frame of logic tree approach. Considering a grid of 1.2 × 1.2 km covering the study area, ground <span class="hlt">acceleration</span> for every node was calculated. Hazard maps at bedrock conditions were produced for peak ground <span class="hlt">acceleration</span>, in addition to return periods of 74, 475 and 2475 years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSeis..21..941K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSeis..21..941K"><span><span class="hlt">Seismic</span> hazard estimation of northern Iran using smoothed <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khoshnevis, Naeem; Taborda, Ricardo; Azizzadeh-Roodpish, Shima; Cramer, Chris H.</p> <p>2017-07-01</p> <p>This article presents a <span class="hlt">seismic</span> hazard assessment for northern Iran, where a smoothed <span class="hlt">seismicity</span> approach has been used in combination with an updated <span class="hlt">seismic</span> catalog and a ground motion prediction equation recently found to yield good fit with data. We evaluate the hazard over a geographical area including the <span class="hlt">seismic</span> zones of Azerbaijan, the Alborz Mountain Range, and Kopeh-Dagh, as well as parts of other neighboring <span class="hlt">seismic</span> zones that fall within our region of interest. In the chosen approach, <span class="hlt">seismic</span> events are not assigned to specific faults but assumed to be potential seismogenic sources distributed within regular grid cells. After performing the corresponding magnitude conversions, we decluster both historical and instrumental <span class="hlt">seismicity</span> catalogs to obtain earthquake rates based on the number of events within each cell, and smooth the results to account for the uncertainty in the spatial distribution of future earthquakes. <span class="hlt">Seismicity</span> parameters are computed for each <span class="hlt">seismic</span> zone separately, and for the entire region of interest as a single uniform seismotectonic region. In the analysis, we consider uncertainties in the ground motion prediction equation, the <span class="hlt">seismicity</span> parameters, and combine the resulting models using a logic tree. The results are presented in terms of expected peak ground <span class="hlt">acceleration</span> (PGA) maps and hazard curves at selected locations, considering exceedance probabilities of 2 and 10% in 50 years for rock site conditions. According to our results, the highest levels of hazard are observed west of the North Tabriz and east of the North Alborz faults, where expected PGA values are between about 0.5 and 1 g for 10 and 2% probability of exceedance in 50 years, respectively. We analyze our results in light of similar estimates available in the literature and offer our perspective on the differences observed. We find our results to be helpful in understanding <span class="hlt">seismic</span> hazard for northern Iran, but recognize that additional efforts are necessary to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003GeoRL..30.2177Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003GeoRL..30.2177Y"><span>Co-<span class="hlt">seismic</span> slip, post-<span class="hlt">seismic</span> slip, and largest aftershock associated with the 1994 Sanriku-haruka-oki, Japan, earthquake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yagi, Yuji; Kikuchi, Masayuki; Nishimura, Takuya</p> <p>2003-11-01</p> <p>We analyzed continuous GPS data to investigate the spatio-temporal distribution of co-<span class="hlt">seismic</span> slip, post-<span class="hlt">seismic</span> slip, and largest aftershock associated with the 1994 Sanriku-haruka-oki, Japan, earthquake (Mw = 7.7). To get better resolution for co-<span class="hlt">seismic</span> and post-<span class="hlt">seismic</span> slip distribution, we imposed a weak constraint as a priori information of the co-<span class="hlt">seismic</span> slip determined by <span class="hlt">seismic</span> wave analyses. We found that the post-<span class="hlt">seismic</span> slip during 100 days following the main-shock amount to as much moment <span class="hlt">release</span> as the main-shock, and that the sites of co-<span class="hlt">seismic</span> slip and post-<span class="hlt">seismic</span> slip are partitioning on a plate boundary region in complimentary fashion. The major post-<span class="hlt">seismic</span> slip was triggered by the mainshock in western side of the co-<span class="hlt">seismic</span> slip, and the extent of the post-<span class="hlt">seismic</span> slip is almost unchanged with time. It rapidly developed a shear stress concentration ahead of the slip area, and triggered the largest aftershock.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70047526','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70047526"><span>Rapid <span class="hlt">acceleration</span> leads to rapid weakening in earthquake-like laboratory experiments</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Chang, Jefferson C.; Lockner, David A.; Reches, Z.</p> <p>2012-01-01</p> <p>After nucleation, a large earthquake propagates as an expanding rupture front along a fault. This front activates countless fault patches that slip by consuming energy stored in Earth’s crust. We simulated the slip of a fault patch by rapidly loading an experimental fault with energy stored in a spinning flywheel. The spontaneous evolution of strength, <span class="hlt">acceleration</span>, and velocity indicates that our experiments are proxies of fault-patch behavior during earthquakes of moment magnitude (Mw) = 4 to 8. We show that <span class="hlt">seismically</span> determined earthquake parameters (e.g., displacement, velocity, magnitude, or fracture energy) can be used to estimate the intensity of the energy <span class="hlt">release</span> during an earthquake. Our experiments further indicate that high <span class="hlt">acceleration</span> imposed by the earthquake’s rupture front quickens dynamic weakening by intense wear of the fault zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2001/ofr-01-437/ofr-01-437.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2001/ofr-01-437/ofr-01-437.pdf"><span><span class="hlt">Seismic</span> design parameters - A user guide</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Leyendecker, E.V.; Frankel, A.D.; Rukstales, K.S.</p> <p>2001-01-01</p> <p>The 1997 NEHRP Recommended Provisions for <span class="hlt">Seismic</span> Regulations for New Buildings (1997 NEHRP Provisions) introduced <span class="hlt">seismic</span> design procedure that is based on the explicit use of spectral response <span class="hlt">acceleration</span> rather than the traditional peak ground <span class="hlt">acceleration</span> and/or peak ground velocity or zone factors. The spectral response <span class="hlt">accelerations</span> are obtained from spectral response <span class="hlt">acceleration</span> maps accompanying the report. Maps are available for the United States and a number of U.S. territories. Since 1997 additional codes and standards have also adopted <span class="hlt">seismic</span> design approaches based on the same procedure used in the NEHRP Provisions and the accompanying maps. The design documents using the 1997 NEHRP Provisions procedure may be divided into three categories -(1) Design of New Construction, (2) Design and Evaluation of Existing Construction, and (3) Design of Residential Construction. A CD-ROM has been prepared for use in conjunction with the design documents in each of these three categories. The spectral <span class="hlt">accelerations</span> obtained using the software on the CD are the same as those that would be obtained by using the maps accompanying the design documents. The software has been prepared to operate on a personal computer using a Windows (Microsoft Corporation) operating environment and a point and click type of interface. The user can obtain the spectral <span class="hlt">acceleration</span> values that would be obtained by use of the maps accompanying the design documents, include site factors appropriate for the Site Class provided by the user, calculate a response spectrum that includes the site factor, and plot a response spectrum. Sites may be located by providing the latitude-longitude or zip code for all areas covered by the maps. All of the maps used in the various documents are also included on the CDROM</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRE..123..163P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRE..123..163P"><span>Expected <span class="hlt">Seismicity</span> and the <span class="hlt">Seismic</span> Noise Environment of Europa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panning, Mark P.; Stähler, Simon C.; Huang, Hsin-Hua; Vance, Steven D.; Kedar, Sharon; Tsai, Victor C.; Pike, William T.; Lorenz, Ralph D.</p> <p>2018-01-01</p> <p><span class="hlt">Seismic</span> data will be a vital geophysical constraint on internal structure of Europa if we land instruments on the surface. Quantifying expected <span class="hlt">seismic</span> activity on Europa both in terms of large, recognizable signals and ambient background noise is important for understanding dynamics of the moon, as well as interpretation of potential future data. <span class="hlt">Seismic</span> energy sources will likely include cracking in the ice shell and turbulent motion in the oceans. We define a range of models of <span class="hlt">seismic</span> activity in Europa's ice shell by assuming each model follows a Gutenberg-Richter relationship with varying parameters. A range of cumulative <span class="hlt">seismic</span> moment <span class="hlt">release</span> between 1016 and 1018 Nm/yr is defined by scaling tidal dissipation energy to tectonic events on the Earth's moon. Random catalogs are generated and used to create synthetic continuous noise records through numerical wave propagation in thermodynamically self-consistent models of the interior structure of Europa. Spectral characteristics of the noise are calculated by determining probabilistic power spectral densities of the synthetic records. While the range of <span class="hlt">seismicity</span> models predicts noise levels that vary by 80 dB, we show that most noise estimates are below the self-noise floor of high-frequency geophones but may be recorded by more sensitive instruments. The largest expected signals exceed background noise by ˜50 dB. Noise records may allow for constraints on interior structure through autocorrelation. Models of <span class="hlt">seismic</span> noise generated by pressure variations at the base of the ice shell due to turbulent motions in the subsurface ocean may also generate observable <span class="hlt">seismic</span> noise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24713470','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24713470"><span>Thyrotropin-<span class="hlt">releasing</span> hormone and its analogs <span class="hlt">accelerate</span> wound healing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nie, Chunlei; Yang, Daping; Liu, Nan; Dong, Deli; Xu, Jin; Zhang, Jiewu</p> <p>2014-06-15</p> <p>Thyrotropin-<span class="hlt">releasing</span> hormone (TRH) is a classical hormone that controls thyroid hormone production in the anterior pituitary gland. However, recent evidence suggested that TRH is expressed in nonhypothalamic tissues such as epidermal keratinocytes and dermal fibroblasts, but its function is not clear. This study aimed to investigate the effects of TRH and its analogs on wound healing and explore the underlying mechanisms. A stented excisional wound model was established, and the wound healing among vehicle control, TRH, and TRH analog taltirelin treatment groups was evaluated by macroscopic and histologic analyses. Primary fibroblasts were isolated from rat dermis and treated with vehicle control, TRH or taltirelin, cell migration, and proliferation were examined by scratch migration assay, MTT, and 5-ethynyl-2'- deoxyuridine (EdU) assay. The expression of α-Smooth muscle actin in fibroblasts was detected by Western blot and immunocytochemical analysis. TRH or taltirelin-treated wounds exhibited <span class="hlt">accelerated</span> wound healing with enhanced granulation tissue formation and increased re-epithelialization and tissue formation. Furthermore, TRH or taltirelin promoted the migration and proliferation of fibroblasts and induced the expression of α-Smooth muscle actin in fibroblasts. TRH is important in upregulating the phenotypes of dermal fibroblasts and plays a role in <span class="hlt">accelerating</span> wound healing. Copyright © 2014 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUSM.S52A..02P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSM.S52A..02P"><span><span class="hlt">Seismic</span> sequences in the Sombrero <span class="hlt">Seismic</span> Zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pulliam, J.; Huerfano, V. A.; ten Brink, U.; von Hillebrandt, C.</p> <p>2007-05-01</p> <p>The northeastern Caribbean, in the vicinity of Puerto Rico and the Virgin Islands, has a long and well-documented history of devastating earthquakes and tsunamis, including major events in 1670, 1787, 1867, 1916, 1918, and 1943. Recently, <span class="hlt">seismicity</span> has been concentrated to the north and west of the British Virgin Islands, in the region referred to as the Sombrero <span class="hlt">Seismic</span> Zone by the Puerto Rico <span class="hlt">Seismic</span> Network (PRSN). In the combined <span class="hlt">seismicity</span> catalog maintained by the PRSN, several hundred small to moderate magnitude events can be found in this region prior to 2006. However, beginning in 2006 and continuing to the present, the rate of <span class="hlt">seismicity</span> in the Sombrero suddenly increased, and a new locus of activity developed to the east of the previous location. Accurate estimates of <span class="hlt">seismic</span> hazard, and the tsunamigenic potential of <span class="hlt">seismic</span> events, depend on an accurate and comprehensive understanding of how strain is being accommodated in this corner region. Are faults locked and accumulating strain for <span class="hlt">release</span> in a major event? Or is strain being <span class="hlt">released</span> via slip over a diffuse system of faults? A careful analysis of <span class="hlt">seismicity</span> patterns in the Sombrero region has the potential to both identify faults and modes of failure, provided the aggregation scheme is tuned to properly identify related events. To this end, we experimented with a scheme to identify <span class="hlt">seismic</span> sequences based on physical and temporal proximity, under the assumptions that (a) events occur on related fault systems as stress is refocused by immediately previous events and (b) such 'stress waves' die out with time, so that two events that occur on the same system within a relatively short time window can be said to have a similar 'trigger' in ways that two nearby events that occurred years apart cannot. Patterns that emerge from the identification, temporal sequence, and refined locations of such sequences of events carry information about stress accommodation that is obscured by large clouds of</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..106a2003S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..106a2003S"><span>Intelligent <span class="hlt">seismic</span> risk mitigation system on structure building</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suryanita, R.; Maizir, H.; Yuniorto, E.; Jingga, H.</p> <p>2018-01-01</p> <p>Indonesia located on the Pacific Ring of Fire, is one of the highest-risk <span class="hlt">seismic</span> zone in the world. The strong ground motion might cause catastrophic collapse of the building which leads to casualties and property damages. Therefore, it is imperative to properly design the structural response of building against <span class="hlt">seismic</span> hazard. <span class="hlt">Seismic</span>-resistant building design process requires structural analysis to be performed to obtain the necessary building responses. However, the structural analysis could be very difficult and time consuming. This study aims to predict the structural response includes displacement, velocity, and <span class="hlt">acceleration</span> of multi-storey building with the fixed floor plan using Artificial Neural Network (ANN) method based on the 2010 Indonesian <span class="hlt">seismic</span> hazard map. By varying the building height, soil condition, and <span class="hlt">seismic</span> location in 47 cities in Indonesia, 6345 data sets were obtained and fed into the ANN model for the learning process. The trained ANN can predict the displacement, velocity, and <span class="hlt">acceleration</span> responses with up to 96% of predicted rate. The trained ANN architecture and weight factors were later used to build a simple tool in Visual Basic program which possesses the features for prediction of structural response as mentioned previously.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.1132A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.1132A"><span>New <span class="hlt">seismic</span> sources parameterization in El Salvador. Implications to <span class="hlt">seismic</span> hazard.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alonso-Henar, Jorge; Staller, Alejandra; Jesús Martínez-Díaz, José; Benito, Belén; Álvarez-Gómez, José Antonio; Canora, Carolina</p> <p>2014-05-01</p> <p>El Salvador is located at the pacific active margin of Central America, here, the subduction of the Cocos Plate under the Caribbean Plate at a rate of ~80 mm/yr is the main <span class="hlt">seismic</span> source. Although the <span class="hlt">seismic</span> sources located in the Central American Volcanic Arc have been responsible for some of the most damaging earthquakes in El Salvador. The El Salvador Fault Zone is the main geological structure in El Salvador and accommodates 14 mm/yr of horizontal displacement between the Caribbean Plate and the forearc sliver. The ESFZ is a right lateral strike-slip fault zone c. 150 km long and 20 km wide .This shear band distributes the deformation among strike-slip faults trending N90º-100ºE and secondary normal faults trending N120º- N170º. The ESFZ is relieved westward by the Jalpatagua Fault and becomes less clear eastward disappearing at Golfo de Fonseca. Five sections have been proposed for the whole fault zone. These fault sections are (from west to east): ESFZ Western Section, San Vicente Section, Lempa Section, Berlin Section and San Miguel Section. Paleoseismic studies carried out in the Berlin and San Vicente Segments reveal an important amount of quaternary deformation and paleoearthquakes up to Mw 7.6. In this study we present 45 capable <span class="hlt">seismic</span> sources in El Salvador and their preliminary slip-rate from geological and GPS data. The GPS data detailled results are presented by Staller et al., 2014 in a complimentary communication. The calculated preliminary slip-rates range from 0.5 to 8 mm/yr for individualized faults within the ESFZ. We calculated maximum magnitudes from the mapped lengths and paleoseismic observations.We propose different earthquakes scenario including the potential combined rupture of different fault sections of the ESFZ, resulting in maximum earthquake magnitudes of Mw 7.6. We used deterministic models to calculate <span class="hlt">acceleration</span> distribution related with maximum earthquakes of the different proposed scenario. The spatial distribution of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.S21E..10L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.S21E..10L"><span>Irregularities in Early <span class="hlt">Seismic</span> Rupture Propagation for Large Events in a Crustal Earthquake Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lapusta, N.; Rice, J. R.; Rice, J. R.</p> <p>2001-12-01</p> <p> behavior at depth. Small events appear in our model at that transition as we decrease the characteristic slip distance for evolution of frictional strength (but not if that distance is unrealistically large). Such clustering of small events at transitions from seismogenic to creeping behavior seems to occur on real faults as well, as we show in examples. To compute moment <span class="hlt">acceleration</span> that can be compared with data, we translate the results of our 2-D fault model to a 3-D model with essentially radial symmetry on the fault plane. We will discuss limitations of that interpretation; in particular, it may overestimate the effect of partial arrest of rupture in creeping regions. Our present work cannot resolve whether there are any differences in the early phases of <span class="hlt">seismic</span> moment <span class="hlt">release</span>, i.e. in the <span class="hlt">seismic</span> nucleation phase, that would make the beginning of larger events look different from smaller ones that are about to arrest. We have shown that the aseismic nucleation phase and the earliest phases of dynamic breakout are virtually identical for small and large events in our simulations. If early moment <span class="hlt">release</span> is mostly affected by stress heterogeneities left by previous small events and by creep processes, as our present study suggests, then any such differences would have to be related to as yet unidentified properties of the pre-stress field that might determine the ultimate event size. See http://esag.harvard.edu/lapusta/Lapusta_Rice_Jun01.pdf, Lapusta and Rice, submitted to JGR, 2001.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009Tectp.476...85C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009Tectp.476...85C"><span>A decade of passive <span class="hlt">seismic</span> monitoring experiments with local networks in four Italian regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chiaraluce, L.; Valoroso, L.; Anselmi, M.; Bagh, S.; Chiarabba, C.</p> <p>2009-10-01</p> <p>We report on four <span class="hlt">seismic</span> monitoring experiments that in the past ten years we carried out with dense local networks in <span class="hlt">seismically</span> active Italian areas where for at least a year, tens of three component <span class="hlt">seismic</span> stations were set up to record microseismicity. The areas observed are Alpago-Cansiglio, located in the Venetian Alps, Città di Castello in the Northern Apennines, Marsica in the Central Apennines and Val d'Agri located in the Southern Apennines. We produced homogeneous catalogues regarding earthquake locations and local magnitudes to investigate <span class="hlt">seismicity</span> patterns during an inter-<span class="hlt">seismic</span> period. The four regions are characterised by different kinematics, strain rates and historical/recent <span class="hlt">seismicity</span>. We investigate earthquake distribution in space, time and size obtaining reference <span class="hlt">seismic</span> rates and parameters of the Gutenberg and Richter law. We declustered the catalogues to look for coherent signs in the background <span class="hlt">seismic</span> activity. Despite a difference in the catalogues magnitudes of completeness due both to the diverse detection threshold of the local networks and different <span class="hlt">seismic</span> <span class="hlt">release</span>, we detect and observe two common main behaviours: a) The Alpago-Cansiglio and Marsica regions are characterised by a relatively lower rate of <span class="hlt">seismic</span> <span class="hlt">release</span> associated to the episodic occurrence of <span class="hlt">seismic</span> sequences with the largest event being 3 < ML < 4. In these areas the <span class="hlt">seismicity</span> is not localised around the main faults. b) The Città di Castello and Val d'Agri regions have a relatively high rate of <span class="hlt">seismicity</span> <span class="hlt">release</span> almost continuously with time, and the increase in earthquake production is not clearly related to <span class="hlt">seismic</span> sequences. In these areas the <span class="hlt">seismicity</span> nucleates around defined fault systems and is usually lower than ML < 3. We suggest that the presence of over-pressured fluids in the Città di Castello and Val d'Agri uppermost crustal volume may favour and mould the higher rate of microseismic <span class="hlt">release</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSM.S51A..04E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSM.S51A..04E"><span>Updated Colombian <span class="hlt">Seismic</span> Hazard Map</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eraso, J.; Arcila, M.; Romero, J.; Dimate, C.; Bermúdez, M. L.; Alvarado, C.</p> <p>2013-05-01</p> <p>The Colombian <span class="hlt">seismic</span> hazard map used by the National Building Code (NSR-98) in effect until 2009 was developed in 1996. Since then, the National Seismological Network of Colombia has improved in both coverage and technology providing fifteen years of additional <span class="hlt">seismic</span> records. These improvements have allowed a better understanding of the regional geology and tectonics which in addition to the <span class="hlt">seismic</span> activity in Colombia with destructive effects has motivated the interest and the need to develop a new <span class="hlt">seismic</span> hazard assessment in this country. Taking advantage of new instrumental information sources such as new broad band stations of the National Seismological Network, new historical <span class="hlt">seismicity</span> data, standardized global databases availability, and in general, of advances in models and techniques, a new Colombian <span class="hlt">seismic</span> hazard map was developed. A PSHA model was applied. The use of the PSHA model is because it incorporates the effects of all <span class="hlt">seismic</span> sources that may affect a particular site solving the uncertainties caused by the parameters and assumptions defined in this kind of studies. First, the <span class="hlt">seismic</span> sources geometry and a complete and homogeneous <span class="hlt">seismic</span> catalog were defined; the parameters of <span class="hlt">seismic</span> rate of each one of the <span class="hlt">seismic</span> sources occurrence were calculated establishing a national seismotectonic model. Several of attenuation-distance relationships were selected depending on the type of <span class="hlt">seismicity</span> considered. The <span class="hlt">seismic</span> hazard was estimated using the CRISIS2007 software created by the Engineering Institute of the Universidad Nacional Autónoma de México -UNAM (National Autonomous University of Mexico). A uniformly spaced grid each 0.1° was used to calculate the peak ground <span class="hlt">acceleration</span> (PGA) and response spectral values at 0.1, 0.2, 0.3, 0.5, 0.75, 1, 1.5, 2, 2.5 and 3.0 seconds with return periods of 75, 225, 475, 975 and 2475 years. For each site, a uniform hazard spectrum and exceedance rate curves were calculated. With the results, it is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988PApGe.128..625W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988PApGe.128..625W"><span>Subduction zone <span class="hlt">seismicity</span> and the thermo-mechanical evolution of downgoing lithosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wortel, M. J. R.; Vlaar, N. J.</p> <p>1988-09-01</p> <p>In this paper we discuss characteristic features of subduction zone <span class="hlt">seismicity</span> at depths between about 100 km and 700 km, with emphasis on the role of temperature and rheology in controlling the deformation of, and the <span class="hlt">seismic</span> energy <span class="hlt">release</span> in downgoing lithosphere. This is done in two steps. After a brief review of earlier developments, we first show that the depth distribution of hypocentres at depths between 100 km and 700 km in subducted lithosphere can be explained by a model in which <span class="hlt">seismic</span> activity is confined to those parts of the slab which have temperatures below a depth-dependent critical value T cr. Second, the variation of <span class="hlt">seismic</span> energy <span class="hlt">release</span> (frequency of events, magnitude) with depth is addressed by inferring a rheological evolution from the slab's thermal evolution and by combining this with models for the system of forces acting on the subducting lithosphere. It is found that considerable stress concentration occurs in a reheating slab in the depth range of 400 to 650 700 km: the slab weakens, but the stress level strongly increases. On the basis of this stress concentration a model is formulated for earthquake generation within subducting slabs. The model predicts a maximum depth of <span class="hlt">seismic</span> activity in the depth range of 635 to 760 km and, for deep earthquake zones, a relative maximum in <span class="hlt">seismic</span> energy <span class="hlt">release</span> near the maximum depth of earthquakes. From our modelling it follows that, whereas such a maximum is indeed likely to develop in deep earthquake zones, zones with a maximum depth around 300 km (such as the Aleutians) are expected to exhibit a smooth decay in <span class="hlt">seismic</span> energy <span class="hlt">release</span> with depth. This is in excellent agreement with observational data. In conclusion, the incoroporation of both depth-dependent forces and depth-dependent rheology provides new insight into the generation of intermediate and deep earthquakes and into the variation of <span class="hlt">seismic</span> activity with depth. Our results imply that no barrier to slab penetration at a depth of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EP%26S...62..939O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EP%26S...62..939O"><span><span class="hlt">Accelerating</span> large-scale simulation of <span class="hlt">seismic</span> wave propagation by multi-GPUs and three-dimensional domain decomposition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Okamoto, Taro; Takenaka, Hiroshi; Nakamura, Takeshi; Aoki, Takayuki</p> <p>2010-12-01</p> <p>We adopted the GPU (graphics processing unit) to <span class="hlt">accelerate</span> the large-scale finite-difference simulation of <span class="hlt">seismic</span> wave propagation. The simulation can benefit from the high-memory bandwidth of GPU because it is a "memory intensive" problem. In a single-GPU case we achieved a performance of about 56 GFlops, which was about 45-fold faster than that achieved by a single core of the host central processing unit (CPU). We confirmed that the optimized use of fast shared memory and registers were essential for performance. In the multi-GPU case with three-dimensional domain decomposition, the non-contiguous memory alignment in the ghost zones was found to impose quite long time in data transfer between GPU and the host node. This problem was solved by using contiguous memory buffers for ghost zones. We achieved a performance of about 2.2 TFlops by using 120 GPUs and 330 GB of total memory: nearly (or more than) 2200 cores of host CPUs would be required to achieve the same performance. The weak scaling was nearly proportional to the number of GPUs. We therefore conclude that GPU computing for large-scale simulation of <span class="hlt">seismic</span> wave propagation is a promising approach as a faster simulation is possible with reduced computational resources compared to CPUs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JVGR..261..153B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JVGR..261..153B"><span>Analysis of the <span class="hlt">seismic</span> activity associated with the 2010 eruption of Merapi Volcano, Java</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Budi-Santoso, Agus; Lesage, Philippe; Dwiyono, Sapari; Sumarti, Sri; Subandriyo; Surono; Jousset, Philippe; Metaxian, Jean-Philippe</p> <p>2013-07-01</p> <p>The 2010 eruption of Merapi is the first large explosive eruption of the volcano that has been instrumentally observed. The main characteristics of the <span class="hlt">seismic</span> activity during the pre-eruptive period and the crisis are presented and interpreted in this paper. The first <span class="hlt">seismic</span> precursors were a series of four shallow swarms during the period between 12 and 4 months before the eruption. These swarms are interpreted as the result of perturbations of the hydrothermal system by increasing heat flow. Shorter-term and more continuous precursory <span class="hlt">seismic</span> activity started about 6 weeks before the initial explosion on 26 October 2010. During this period, the rate of <span class="hlt">seismicity</span> increased almost constantly yielding a cumulative <span class="hlt">seismic</span> energy <span class="hlt">release</span> for volcano-tectonic (VT) and multiphase events (MP) of 7.5 × 1010 J. This value is 3 times the maximum energy <span class="hlt">release</span> preceding previous effusive eruptions of Merapi. The high level reached and the <span class="hlt">accelerated</span> behavior of both the deformation of the summit and the <span class="hlt">seismic</span> activity are distinct features of the 2010 eruption. The hypocenters of VT events in 2010 occur in two clusters at of 2.5 to 5 km and less than 1.5 km depths below the summit. An aseismic zone was detected at 1.5-2.5 km depth, consistent with studies of previous eruptions, and indicating that this is a robust feature of Merapi's subsurface structure. Our analysis suggests that the aseismic zone is a poorly consolidated layer of altered material within the volcano. Deep VT events occurred mainly before 17 October 2010; subsequent to that time shallow activity strongly increased. The deep <span class="hlt">seismic</span> activity is interpreted as associated with the enlargement of a narrow conduit by an unusually large volume of rapidly ascending magma. The shallow <span class="hlt">seismicity</span> is interpreted as recording the final magma ascent and the rupture of a summit-dome plug, which triggered the eruption on 26 October 2010. Hindsight forecasting of the occurrence time of the eruption is performed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Sci...359.1251H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Sci...359.1251H"><span>Oklahoma's induced <span class="hlt">seismicity</span> strongly linked to wastewater injection depth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hincks, Thea; Aspinall, Willy; Cooke, Roger; Gernon, Thomas</p> <p>2018-03-01</p> <p>The sharp rise in Oklahoma <span class="hlt">seismicity</span> since 2009 is due to wastewater injection. The role of injection depth is an open, complex issue, yet critical for hazard assessment and regulation. We developed an advanced Bayesian network to model joint conditional dependencies between spatial, operational, and <span class="hlt">seismicity</span> parameters. We found that injection depth relative to crystalline basement most strongly correlates with <span class="hlt">seismic</span> moment <span class="hlt">release</span>. The joint effects of depth and volume are critical, as injection rate becomes more influential near the basement interface. Restricting injection depths to 200 to 500 meters above basement could reduce annual <span class="hlt">seismic</span> moment <span class="hlt">release</span> by a factor of 1.4 to 2.8. Our approach enables identification of subregions where targeted regulation may mitigate effects of induced earthquakes, aiding operators and regulators in wastewater disposal regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70191533','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70191533"><span>Micro-<span class="hlt">seismicity</span> within the Coso Geothermal field, California, from 1996-2012</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kaven, Joern; Hickman, Stephen H.; Weber, Lisa C.</p> <p>2017-01-01</p> <p>We extend our previous catalog of <span class="hlt">seismicity</span> within the Coso Geothermal field by adding over two and a half years of additional data to prior results. In total, we locate over 16 years of <span class="hlt">seismicity</span> spanning from April 1996 to May of 2012 using a refined velocity model, apply it to all events and utilize differential travel times in relocations to improve the accuracy of event locations. The improved locations elucidate major structural features within the reservoir that we interpret to be faults that contribute to heat and fluid flow within the reservoir. Much of the relocated <span class="hlt">seismicity</span> remains diffuse between these major structural features, suggesting that a large volume of accessible and distributed fracture porosity is maintained within the geothermal reservoir through ongoing brittle failure. We further track changes in b value and <span class="hlt">seismic</span> moment <span class="hlt">release</span> within the reservoir as a whole through time. We find that b values decrease significantly during 2009 and 2010, coincident with the occurrence of a greater number of moderate magnitude earthquakes (3.0 ≤ ML < 4.5). Analysis of spatial variations in <span class="hlt">seismic</span> moment <span class="hlt">release</span> between years reveals that localized <span class="hlt">seismicity</span> tends to spread from regions of high moment <span class="hlt">release</span> into regions with previously low moment <span class="hlt">release</span>, akin to aftershock sequences. These results indicate that the Coso reservoir is comprised of a network of fractures at a variety of spatial scales that evolves dynamically over time, with progressive changes in characteristics of microseismicity and inferred fractures and faults that are only evident from a long period of <span class="hlt">seismic</span> monitoring analyzed using self-consistent methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17..441N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17..441N"><span>Development of <span class="hlt">seismic</span> tomography software for hybrid supercomputers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nikitin, Alexandr; Serdyukov, Alexandr; Duchkov, Anton</p> <p>2015-04-01</p> <p><span class="hlt">Seismic</span> tomography is a technique used for computing velocity model of geologic structure from first arrival travel times of <span class="hlt">seismic</span> waves. The technique is used in processing of regional and global <span class="hlt">seismic</span> data, in <span class="hlt">seismic</span> exploration for prospecting and exploration of mineral and hydrocarbon deposits, and in <span class="hlt">seismic</span> engineering for monitoring the condition of engineering structures and the surrounding host medium. As a consequence of development of <span class="hlt">seismic</span> monitoring systems and increasing volume of <span class="hlt">seismic</span> data, there is a growing need for new, more effective computational algorithms for use in <span class="hlt">seismic</span> tomography applications with improved performance, accuracy and resolution. To achieve this goal, it is necessary to use modern high performance computing systems, such as supercomputers with hybrid architecture that use not only CPUs, but also <span class="hlt">accelerators</span> and co-processors for computation. The goal of this research is the development of parallel <span class="hlt">seismic</span> tomography algorithms and software package for such systems, to be used in processing of large volumes of <span class="hlt">seismic</span> data (hundreds of gigabytes and more). These algorithms and software package will be optimized for the most common computing devices used in modern hybrid supercomputers, such as Intel Xeon CPUs, NVIDIA Tesla <span class="hlt">accelerators</span> and Intel Xeon Phi co-processors. In this work, the following general scheme of <span class="hlt">seismic</span> tomography is utilized. Using the eikonal equation solver, arrival times of <span class="hlt">seismic</span> waves are computed based on assumed velocity model of geologic structure being analyzed. In order to solve the linearized inverse problem, tomographic matrix is computed that connects model adjustments with travel time residuals, and the resulting system of linear equations is regularized and solved to adjust the model. The effectiveness of parallel implementations of existing algorithms on target architectures is considered. During the first stage of this work, algorithms were developed for execution on</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PApGe.174.2381Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PApGe.174.2381Y"><span>An Ensemble Approach for Improved Short-to-Intermediate-Term <span class="hlt">Seismic</span> Potential Evaluation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Huaizhong; Zhu, Qingyong; Zhou, Faren; Tian, Lei; Zhang, Yongxian</p> <p>2017-06-01</p> <p>Pattern informatics (PI), load/unload response ratio (LURR), state vector (SV), and <span class="hlt">accelerating</span> moment <span class="hlt">release</span> (AMR) are four previously unrelated subjects, which are sensitive, in varying ways, to the earthquake's source. Previous studies have indicated that the spatial extent of the stress perturbation caused by an earthquake scales with the moment of the event, allowing us to combine these methods for <span class="hlt">seismic</span> hazard evaluation. The long-range earthquake forecasting method PI is applied to search for the <span class="hlt">seismic</span> hotspots and identify the areas where large earthquake could be expected. And the LURR and SV methods are adopted to assess short-to-intermediate-term <span class="hlt">seismic</span> potential in each of the critical regions derived from the PI hotspots, while the AMR method is used to provide us with asymptotic estimates of time and magnitude of the potential earthquakes. This new approach, by combining the LURR, SV and AMR methods with the choice of identified area of PI hotspots, is devised to augment current techniques for <span class="hlt">seismic</span> hazard estimation. Using the approach, we tested the strong earthquakes occurred in Yunnan-Sichuan region, China between January 1, 2013 and December 31, 2014. We found that most of the large earthquakes, especially the earthquakes with magnitude greater than 6.0 occurred in the <span class="hlt">seismic</span> hazard regions predicted. Similar results have been obtained in the prediction of annual earthquake tendency in Chinese mainland in 2014 and 2015. The studies evidenced that the ensemble approach could be a useful tool to detect short-to-intermediate-term precursory information of future large earthquakes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.4679F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.4679F"><span>Spatial Temporal Analysis Of Mine-induced <span class="hlt">Seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fedotova, I. V.; Yunga, S. L.</p> <p></p> <p>The results of analysis of influence mine-induced <span class="hlt">seismicity</span> on state of stress of a rock mass are represented. The spatial-temporal analysis of influence of mass explosions on rock massif deformation is carried out in the territory of a mine field Yukspor of a wing of the Joined Kirovsk mine JSC "Apatite". Estimation of influence of mass explosions on a massif were determined based firstly on the parameters of natural <span class="hlt">seismicic</span> regime, and secondly taking into consideration change of <span class="hlt">seismic</span> energy <span class="hlt">release</span>. After long series of explosions variations in average number of <span class="hlt">seismic</span> events was fixed. Is proved, that with increase of a volume of rocks, involved in a deforma- tion the <span class="hlt">released</span> energy of <span class="hlt">seismic</span> events, and characteristic intervals of time of their preparation are also varied. At the same time, the mechanism of destruction changes also: from destruction's, of a type shift - separation before destruction's, in a quasi- solid heterogeneous massif (in oxidized zones and zones of actuated faults). Analysis of a database <span class="hlt">seismicity</span> of a massif from 1993 to 1999 years has confirmed, that the response of a massif on explosions is connected to stress-deformations state a mas- sif and parameters of a mining working. The analysis of spatial-temporal distribution of hypocenters of <span class="hlt">seismic</span> events has allowed to allocate migration of fissile regions of destruction after mass explosions. The researches are executed at support of the Russian foundation for basic research, - projects 00-05-64758, 01-05-65340.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S43B2793Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S43B2793Z"><span>A combined method to calculate co-<span class="hlt">seismic</span> displacements through strong motion <span class="hlt">acceleration</span> baseline correction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhan, W.; Sun, Y.</p> <p>2015-12-01</p> <p>High frequency strong motion data, especially near field <span class="hlt">acceleration</span> data, have been recorded widely through different observation station systems among the world. Due to tilting and a lot other reasons, recordings from these seismometers usually have baseline drift problems when big earthquake happens. It is hard to obtain a reasonable and precision co-<span class="hlt">seismic</span> displacement through simply double integration. Here presents a combined method using wavelet transform and several simple liner procedures. Owning to the lack of dense high rate GNSS data in most of region of the world, we did not contain GNSS data in this method first but consider it as an evaluating mark of our results. This semi-automatic method unpacks a raw signal into two portions, a summation of high ranks and a low ranks summation using a cubic B-spline wavelet decomposition procedure. Independent liner treatments are processed against these two summations, which are then composed together to recover useable and reasonable result. We use data of 2008 Wenchuan earthquake and choose stations with a near GPS recording to validate this method. Nearly all of them have compatible co-<span class="hlt">seismic</span> displacements when compared with GPS stations or field survey. Since seismometer stations and GNSS stations from observation systems in China are sometimes quite far from each other, we also test this method with some other earthquakes (1999 Chi-Chi earthquake and 2011 Tohoku earthquake). And for 2011 Tohoku earthquake, we will introduce GPS recordings to this combined method since the existence of a dense GNSS systems in Japan.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhDT........33Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT........33Y"><span>Probabilistic <span class="hlt">seismic</span> hazard assessment for the effect of vertical ground motions on <span class="hlt">seismic</span> response of highway bridges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yilmaz, Zeynep</p> <p></p> <p>Typically, the vertical component of the ground motion is not considered explicitly in <span class="hlt">seismic</span> design of bridges, but in some cases the vertical component can have a significant effect on the structural response. The key question of when the vertical component should be incorporated in design is answered by the probabilistic <span class="hlt">seismic</span> hazard assessment study incorporating the probabilistic <span class="hlt">seismic</span> demand models and ground motion models. Nonlinear simulation models with varying configurations of an existing bridge in California were considered in the analytical study. The simulation models were subjected to the set of selected ground motions in two stages: at first, only horizontal components of the motion were applied; while in the second stage the structures were subjected to both horizontal and vertical components applied simultaneously and the ground motions that produced the largest adverse effects on the bridge system were identified. Moment demand in the mid-span and at the support of the longitudinal girder and the axial force demand in the column are found to be significantly affected by the vertical excitations. These response parameters can be modeled using simple ground motion parameters such as horizontal spectral <span class="hlt">acceleration</span> and vertical spectral <span class="hlt">acceleration</span> within 5% to 30% error margin depending on the type of the parameter and the period of the structure. For a complete hazard assessment, both of these ground motion parameters explaining the structural behavior should also be modeled. For the horizontal spectral <span class="hlt">acceleration</span>, Abrahamson and Silva (2008) model was used within many available standard model. A new NGA vertical ground motion model consistent with the horizontal model was constructed. These models are combined in a vector probabilistic <span class="hlt">seismic</span> hazard analyses. Series of hazard curves developed and presented for different locations in Bay Area for soil site conditions to provide a roadmap for the prediction of these features for future</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T43D3049B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T43D3049B"><span>Source Characterization and <span class="hlt">Seismic</span> Hazard Considerations for Hydraulic Fracture Induced <span class="hlt">Seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bosman, K.; Viegas, G. F.; Baig, A. M.; Urbancic, T.</p> <p>2015-12-01</p> <p>Large microseismic events (M>0) have been shown to be generated during hydraulic fracture treatments relatively frequently. These events are a concern both from public safety and engineering viewpoints. Recent microseismic monitoring projects in the Horn River Basin have utilized both downhole and surface sensors to record events associated with hydraulic fracturing. The resulting hybrid monitoring system has produced a large dataset with two distinct groups of events: large events recorded by the surface network (0<M<3), and small events recorded only by the downhole sensors (-4<M<0). Large events tend to occur well below the reservoir on pre-existing structures; small events are concentrated at reservoir depth. Differences in behavior have been observed between these two datasets, leading to conclusions of different underlying processes responsible for the recorded activity. Both datasets show very low <span class="hlt">seismic</span> efficiency, implying slip weakening and possibly the presence of fluids in the source region. Reservoir events have shear-tensile source mechanisms ranging between tensile opening and tensile closing, and fracture orientations dominated by the rock fabric which are not always optimally oriented to the regional stress field. The observed source characteristics are expected for events driven by increased pore pressure and reduced friction due to lubrication. On average, deep events show higher stress drop, apparent stress, and rupture velocity than reservoir events. This reflects higher confining stresses with depth, and possibly the <span class="hlt">release</span> of stored energy in the existing zone of weakness. Deep events are dominated by shear failures, but source characteristics are smaller than for naturally occurring tectonic earthquakes of similar magnitude. Most importantly from a <span class="hlt">seismic</span> hazard perspective, large earthquakes associated with hydrofracing have lower stress drops than tectonic earthquakes, and thus produce smaller peak ground <span class="hlt">acceleration</span> and less damage on</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23878524','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23878524"><span>Estimation of recurrence interval of large earthquakes on the central Longmen Shan fault zone based on <span class="hlt">seismic</span> moment accumulation/<span class="hlt">release</span> model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ren, Junjie; Zhang, Shimin</p> <p>2013-01-01</p> <p>Recurrence interval of large earthquake on an active fault zone is an important parameter in assessing <span class="hlt">seismic</span> hazard. The 2008 Wenchuan earthquake (Mw 7.9) occurred on the central Longmen Shan fault zone and ruptured the Yingxiu-Beichuan fault (YBF) and the Guanxian-Jiangyou fault (GJF). However, there is a considerable discrepancy among recurrence intervals of large earthquake in preseismic and postseismic estimates based on slip rate and paleoseismologic results. Post-<span class="hlt">seismic</span> trenches showed that the central Longmen Shan fault zone probably undertakes an event similar to the 2008 quake, suggesting a characteristic earthquake model. In this paper, we use the published seismogenic model of the 2008 earthquake based on Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data and construct a characteristic <span class="hlt">seismic</span> moment accumulation/<span class="hlt">release</span> model to estimate recurrence interval of large earthquakes on the central Longmen Shan fault zone. Our results show that the seismogenic zone accommodates a moment rate of (2.7 ± 0.3) × 10¹⁷ N m/yr, and a recurrence interval of 3900 ± 400 yrs is necessary for accumulation of strain energy equivalent to the 2008 earthquake. This study provides a preferred interval estimation of large earthquakes for <span class="hlt">seismic</span> hazard analysis in the Longmen Shan region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3710655','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3710655"><span>Estimation of Recurrence Interval of Large Earthquakes on the Central Longmen Shan Fault Zone Based on <span class="hlt">Seismic</span> Moment Accumulation/<span class="hlt">Release</span> Model</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Shimin</p> <p>2013-01-01</p> <p>Recurrence interval of large earthquake on an active fault zone is an important parameter in assessing <span class="hlt">seismic</span> hazard. The 2008 Wenchuan earthquake (Mw 7.9) occurred on the central Longmen Shan fault zone and ruptured the Yingxiu-Beichuan fault (YBF) and the Guanxian-Jiangyou fault (GJF). However, there is a considerable discrepancy among recurrence intervals of large earthquake in preseismic and postseismic estimates based on slip rate and paleoseismologic results. Post-<span class="hlt">seismic</span> trenches showed that the central Longmen Shan fault zone probably undertakes an event similar to the 2008 quake, suggesting a characteristic earthquake model. In this paper, we use the published seismogenic model of the 2008 earthquake based on Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data and construct a characteristic <span class="hlt">seismic</span> moment accumulation/<span class="hlt">release</span> model to estimate recurrence interval of large earthquakes on the central Longmen Shan fault zone. Our results show that the seismogenic zone accommodates a moment rate of (2.7 ± 0.3) × 1017 N m/yr, and a recurrence interval of 3900 ± 400 yrs is necessary for accumulation of strain energy equivalent to the 2008 earthquake. This study provides a preferred interval estimation of large earthquakes for <span class="hlt">seismic</span> hazard analysis in the Longmen Shan region. PMID:23878524</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70034189','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70034189"><span>New <span class="hlt">seismic</span> hazard maps for Puerto Rico and the U.S. Virgin Islands</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Mueller, C.; Frankel, A.; Petersen, M.; Leyendecker, E.</p> <p>2010-01-01</p> <p>The probabilistic methodology developed by the U.S. Geological Survey is applied to a new <span class="hlt">seismic</span> hazard assessment for Puerto Rico and the U.S. Virgin Islands. Modeled <span class="hlt">seismic</span> sources include gridded historical <span class="hlt">seismicity</span>, subduction-interface and strike-slip faults with known slip rates, and two broad zones of crustal extension with <span class="hlt">seismicity</span> rates constrained by GPS geodesy. We use attenuation relations from western North American and worldwide data, as well as a Caribbean-specific relation. Results are presented as maps of peak ground <span class="hlt">acceleration</span> and 0.2- and 1.0-second spectral response <span class="hlt">acceleration</span> for 2% and 10% probabilities of exceedance in 50 years (return periods of about 2,500 and 500 years, respectively). This paper describes the hazard model and maps that were balloted by the Building <span class="hlt">Seismic</span> Safety Council and recommended for the 2003 NEHRP Provisions and the 2006 International Building Code. ?? 2010, Earthquake Engineering Research Institute.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.G42A..02J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.G42A..02J"><span>Interseismic Coupling, Co- and Post-<span class="hlt">seismic</span> Slip: a Stochastic View on the Northern Chilean Subduction Zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jolivet, R.; Duputel, Z.; Simons, M.; Jiang, J.; Riel, B. V.; Moore, A. W.; Owen, S. E.</p> <p>2017-12-01</p> <p>Mapping subsurface fault slip during the different phases of the <span class="hlt">seismic</span> cycle provides a probe of the mechanical properties and the state of stress along these faults. We focus on the northern Chile megathrust where first order estimates of interseismic fault locking suggests little to no overlap between regions slipping <span class="hlt">seismically</span> versus those that are dominantly aseismic. However, published distributions of slip, be they during <span class="hlt">seismic</span> or aseismic phases, rely on unphysical regularization of the inverse problem, thereby cluttering attempts to quantify the degree of overlap between <span class="hlt">seismic</span> and aseismic slip. Considering all the implications of aseismic slip on our understanding of the nucleation, propagation and arrest of <span class="hlt">seismic</span> ruptures, it is of utmost importance to quantify our confidence in the current description of fault coupling. Here, we take advantage of 20 years of InSAR observations and more than a decade of GPS measurements to derive probabilistic maps of inter-<span class="hlt">seismic</span> coupling, as well as co-<span class="hlt">seismic</span> and post-<span class="hlt">seismic</span> slip along the northern Chile subduction megathrust. A wide InSAR velocity map is derived using a novel multi-pixel time series analysis method accounting for orbital errors, atmospheric noise and ground deformation. We use AlTar, a massively parallel Monte Carlo Markov Chain algorithm exploiting the <span class="hlt">acceleration</span> capabilities of Graphic Processing Units, to derive the probability density functions (PDF) of slip. In northern Chile, we find high probabilities for a complete <span class="hlt">release</span> of the elastic strain accumulated since the 1877 earthquake by the 2014, Iquique earthquake and for the presence of a large, independent, locked asperity left untapped by recent events, north of the Mejillones peninsula. We evaluate the probability of overlap between the co-, inter- and post-<span class="hlt">seismic</span> slip and consider the potential occurrence of slow, aseismic slip events along this portion of the subduction zone.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70187494','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70187494"><span>Using strain rates to forecast <span class="hlt">seismic</span> hazards</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Evans, Eileen</p> <p>2017-01-01</p> <p>One essential component in forecasting <span class="hlt">seismic</span> hazards is observing the gradual accumulation of tectonic strain accumulation along faults before this strain is suddenly <span class="hlt">released</span> as earthquakes. Typically, <span class="hlt">seismic</span> hazard models are based on geologic estimates of slip rates along faults and historical records of <span class="hlt">seismic</span> activity, neither of which records actively accumulating strain. But this strain can be estimated by geodesy: the precise measurement of tiny position changes of Earth’s surface, obtained from GPS, interferometric synthetic aperture radar (InSAR), or a variety of other instruments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997APS..PAC..7P68T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997APS..PAC..7P68T"><span>Ground Motion Studies for Large Future <span class="hlt">Accelerator</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takeda, Shigeru; Oide, Katsunobu</p> <p>1997-05-01</p> <p>The future large <span class="hlt">accelerator</span>, such as TeV linear collider, should have extremely small emittance to perform the required luminosity. Precise alignment of machine components is essential to prevent emittance dilution. The ground motion spoils alignment of <span class="hlt">accelerator</span> elements and results in emittance growth. The ground motion in the frequency range of <span class="hlt">seismic</span> vibration is mostly coherent in the related <span class="hlt">accelerator</span>. But the incoherent diffusive or Brownian like motion becomes dominant at frequency region less than <span class="hlt">seismic</span> vibration [1, 2, 3]. Slow ground motion with respect to the machine performance is discussed including the method of tunnel construction. Our experimental results and recent excavated results clarify that application of TBMs is better excavating method than NATM (Drill + Blast) for <span class="hlt">accelerator</span> tunnel to prevent emittance dilution. ([1] V. Shiltsev, Proc. of IWAA95 Tsukuba, 1995. [2] Shigeru Takeda et al., Proc. of EPAC96, 1996. [3] A. Sery, Proc. of LINAC96, 1996.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E..40A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E..40A"><span><span class="hlt">Seismic</span> hazard assessment of Syria using <span class="hlt">seismicity</span>, DEM, slope, active tectonic and GIS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahmad, Raed; Adris, Ahmad; Singh, Ramesh</p> <p>2016-07-01</p> <p>In the present work, we discuss the use of an integrated remote sensing and Geographical Information System (GIS) techniques for evaluation of <span class="hlt">seismic</span> hazard areas in Syria. The present study is the first time effort to create <span class="hlt">seismic</span> hazard map with the help of GIS. In the proposed approach, we have used Aster satellite data, digital elevation data (30 m resolution), earthquake data, and active tectonic maps. Many important factors for evaluation of <span class="hlt">seismic</span> hazard were identified and corresponding thematic data layers (past earthquake epicenters, active faults, digital elevation model, and slope) were generated. A numerical rating scheme has been developed for spatial data analysis using GIS to identify ranking of parameters to be included in the evaluation of <span class="hlt">seismic</span> hazard. The resulting earthquake potential map delineates the area into different relative susceptibility classes: high, moderate, low and very low. The potential earthquake map was validated by correlating the obtained different classes with the local probability that produced using conventional analysis of observed earthquakes. Using earthquake data of Syria and the peak ground <span class="hlt">acceleration</span> (PGA) data is introduced to the model to develop final <span class="hlt">seismic</span> hazard map based on Gutenberg-Richter (a and b values) parameters and using the concepts of local probability and recurrence time. The application of the proposed technique in Syrian region indicates that this method provides good estimate of <span class="hlt">seismic</span> hazard map compared to those developed from traditional techniques (Deterministic (DSHA) and probabilistic <span class="hlt">seismic</span> hazard (PSHA). For the first time we have used numerous parameters using remote sensing and GIS in preparation of <span class="hlt">seismic</span> hazard map which is found to be very realistic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSeis..22..539A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSeis..22..539A"><span>Probabilistic <span class="hlt">seismic</span> hazard assessment of southern part of Ghana</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahulu, Sylvanus T.; Danuor, Sylvester Kojo; Asiedu, Daniel K.</p> <p>2018-05-01</p> <p>This paper presents a <span class="hlt">seismic</span> hazard map for the southern part of Ghana prepared using the probabilistic approach, and <span class="hlt">seismic</span> hazard assessment results for six cities. The <span class="hlt">seismic</span> hazard map was prepared for 10% probability of exceedance for peak ground <span class="hlt">acceleration</span> in 50 years. The input parameters used for the computations of hazard were obtained using data from a catalogue that was compiled and homogenised to moment magnitude (Mw). The catalogue covered a period of over a century (1615-2009). The hazard assessment is based on the Poisson model for earthquake occurrence, and hence, dependent events were identified and removed from the catalogue. The following attenuation relations were adopted and used in this study—Allen (for south and eastern Australia), Silva et al. (for Central and eastern North America), Campbell and Bozorgnia (for worldwide active-shallow-crust regions) and Chiou and Youngs (for worldwide active-shallow-crust regions). Logic-tree formalism was used to account for possible uncertainties associated with the attenuation relationships. OpenQuake software package was used for the hazard calculation. The highest level of <span class="hlt">seismic</span> hazard is found in the Accra and Tema <span class="hlt">seismic</span> zones, with estimated peak ground <span class="hlt">acceleration</span> close to 0.2 g. The level of the <span class="hlt">seismic</span> hazard in the southern part of Ghana diminishes with distance away from the Accra/Tema region to a value of 0.05 g at a distance of about 140 km.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1186748','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1186748"><span>NSR&D Program Fiscal Year (FY) 2015 Call for Proposals Mitigation of <span class="hlt">Seismic</span> Risk at Nuclear Facilities using <span class="hlt">Seismic</span> Isolation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Coleman, Justin</p> <p>2015-02-01</p> <p><span class="hlt">Seismic</span> isolation (SI) has the potential to drastically reduce <span class="hlt">seismic</span> response of structures, systems, or components (SSCs) and therefore the risk associated with large <span class="hlt">seismic</span> events (large <span class="hlt">seismic</span> event could be defined as the design basis earthquake (DBE) and/or the beyond design basis earthquake (BDBE) depending on the site location). This would correspond to a potential increase in nuclear safety by minimizing the structural response and thus minimizing the risk of material <span class="hlt">release</span> during large <span class="hlt">seismic</span> events that have uncertainty associated with their magnitude and frequency. The national consensus standard America Society of Civil Engineers (ASCE) Standard 4, <span class="hlt">Seismic</span> Analysismore » of Safety Related Nuclear Structures recently incorporated language and commentary for <span class="hlt">seismically</span> isolating a large light water reactor or similar large nuclear structure. Some potential benefits of SI are: 1) substantially decoupling the SSC from the earthquake hazard thus decreasing risk of material <span class="hlt">release</span> during large earthquakes, 2) cost savings for the facility and/or equipment, and 3) applicability to both nuclear (current and next generation) and high hazard non-nuclear facilities. Issue: To date no one has evaluated how the benefit of <span class="hlt">seismic</span> risk reduction reduces cost to construct a nuclear facility. Objective: Use <span class="hlt">seismic</span> probabilistic risk assessment (SPRA) to evaluate the reduction in <span class="hlt">seismic</span> risk and estimate potential cost savings of <span class="hlt">seismic</span> isolation of a generic nuclear facility. This project would leverage ongoing Idaho National Laboratory (INL) activities that are developing advanced (SPRA) methods using Nonlinear Soil-Structure Interaction (NLSSI) analysis. Technical Approach: The proposed study is intended to obtain an estimate on the reduction in <span class="hlt">seismic</span> risk and construction cost that might be achieved by <span class="hlt">seismically</span> isolating a nuclear facility. The nuclear facility is a representative pressurized water reactor building nuclear power plant (NPP</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMNG34B..01M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMNG34B..01M"><span><span class="hlt">Acceleration</span> to failure in geophysical signals prior to laboratory rock failure and volcanic eruptions (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Main, I. G.; Bell, A. F.; Greenhough, J.; Heap, M. J.; Meredith, P. G.</p> <p>2010-12-01</p> <p>The nucleation processes that ultimately lead to earthquakes, volcanic eruptions, rock bursts in mines, and landslides from cliff slopes are likely to be controlled at some scale by brittle failure of the Earth’s crust. In laboratory brittle deformation experiments geophysical signals commonly exhibit an <span class="hlt">accelerating</span> trend prior to dynamic failure. Similar signals have been observed prior to volcanic eruptions, including volcano-tectonic earthquake event and moment <span class="hlt">release</span> rates. Despite a large amount of effort in the search, no such statistically robust systematic trend is found prior to natural earthquakes. Here we describe the results of a suite of laboratory tests on Mount Etna Basalt and other rocks to examine the nature of the non-linear scaling from laboratory to field conditions, notably using laboratory ‘creep’ tests to reduce the boundary strain rate to conditions more similar to those in the field. <span class="hlt">Seismic</span> event rate, <span class="hlt">seismic</span> moment <span class="hlt">release</span> rate and rate of porosity change show a classic ‘bathtub’ graph that can be derived from a simple damage model based on separate transient and <span class="hlt">accelerating</span> sub-critical crack growth mechanisms, resulting from separate processes of negative and positive feedback in the population dynamics. The signals exhibit clear precursors based on formal statistical model tests using maximum likelihood techniques with Poisson errors. After correcting for the finite loading time of the signal, the results show a transient creep rate that decays as a classic Omori law for earthquake aftershocks, and remarkably with an exponent near unity, as commonly observed for natural earthquake sequences. The <span class="hlt">accelerating</span> trend follows an inverse power law when fitted in retrospect, i.e. with prior knowledge of the failure time. In contrast the strain measured on the sample boundary shows a less obvious but still <span class="hlt">accelerating</span> signal that is often absent altogether in natural strain data prior to volcanic eruptions. To test the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.1078P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.1078P"><span>Effective <span class="hlt">seismic</span> <span class="hlt">acceleration</span> measurements for low-cost Structural Health Monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pentaris, Fragkiskos; Makris, John P.</p> <p>2015-04-01</p> <p>There is increasing demand on cost effective Structural Health Monitoring systems for buildings as well as important and/or critical constructions. The front end for all these systems is the accelerometer. We present a comparative study of two low cost MEMS accelaration sensors against a very sensitive, high dynamic range strong motion accelerometer of force balance type but much more expensive. A real experiment was realized by deploying the three sesnors in a reinforced concrete building of the premises of TEI of Crete at Chania Crete, an earthquake prone region. The analysis of the collected accelararion data from many <span class="hlt">seismic</span> events indicates that all sensors are able to efficiently reveal the <span class="hlt">seismic</span> response of the construction in terms of PSD. Furthermore, it is shown that coherence diagrams between excitation and response of the building under study, depict structural characteristics but also the <span class="hlt">seismic</span> energy distribution. This work is supported by the Archimedes III Program of the Ministry of Education of Greece, through the Operational Program "Educational and Lifelong Learning", in the framework of the project entitled "Interdisciplinary Multi-Scale Research of Earthquake Physics and Seismotectonics at the front of the Hellenic Arc (IMPACT-ARC)" and is co-financed by the European Union (European Social Fund) and Greek national funds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUSM.U54B..06P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSM.U54B..06P"><span><span class="hlt">Seismic</span> and Geodetic Monitoring of the Nicoya, Costa Rica, <span class="hlt">Seismic</span> Gap</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Protti, M.; Gonzalez, V.; Schwartz, S.; Dixon, T.; Kato, T.; Kaneda, Y.; Simila, G.; Sampson, D.</p> <p>2007-05-01</p> <p>The Nicoya segment of the Middle America Trench has been recognized as a mature <span class="hlt">seismic</span> gap with potential to generate a large earthquake in the near future (it ruptured with large earthquakes in 1853, 1900 and 1950). Low level of background <span class="hlt">seismicity</span> and fast crustal deformation of the forearc are indicatives of strong coupling along the plate interface. Given its high <span class="hlt">seismic</span> potential, the available data and especially the fact that the Nicoya peninsula extends over large part of the rupture area, this gap was selected as one of the two sites for a MARGINS-SEIZE experiment. With the goal of documenting the evolution of loading and stress <span class="hlt">release</span> along this <span class="hlt">seismic</span> gap, an international effort involving several institutions from Costa Rica, the United States and Japan is being carried out for over a decade in the region. This effort involves the installation of temporary and permanent <span class="hlt">seismic</span> and geodetic networks. The <span class="hlt">seismic</span> network includes short period, broad band and strong motion instruments. The <span class="hlt">seismic</span> monitoring has provided valuable information on the geometry and characteristics of the plate interface. The geodetic network includes temporary and permanent GPS stations as well as surface and borehole tiltmeters. The geodetic networks have helped quantify the extend and degree of coupling. A continuously recording, three- station GPS network on the Nicoya Peninsula, Costa Rica, recorded what we believe is the first slow slip event observed along the plate interface of the Costa Rica subduction zone. We will present results from these monitoring networks. Collaborative international efforts are focused on expanding these <span class="hlt">seismic</span> and geodetic networks to provide improved resolution of future creep events, to enhanced understanding of the mechanical behavior of the Nicoya subduction segment of the Middle American Trench and possibly capture the next large earthquake and its potential precursor deformation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSM.S43B..18G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSM.S43B..18G"><span>Probabilistic <span class="hlt">seismic</span> hazard zonation for the Cuban building code update</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garcia, J.; Llanes-Buron, C.</p> <p>2013-05-01</p> <p>A probabilistic <span class="hlt">seismic</span> hazard assessment has been performed in response to a revision and update of the Cuban building code (NC-46-99) for earthquake-resistant building construction. The hazard assessment have been done according to the standard probabilistic approach (Cornell, 1968) and importing the procedures adopted by other nations dealing with the problem of revising and updating theirs national building codes. Problems of earthquake catalogue treatment, attenuation of peak and spectral ground <span class="hlt">acceleration</span>, as well as <span class="hlt">seismic</span> source definition have been rigorously analyzed and a logic-tree approach was used to represent the inevitable uncertainties encountered through the whole <span class="hlt">seismic</span> hazard estimation process. The <span class="hlt">seismic</span> zonation proposed here, is formed by a map where it is reflected the behaviour of the spectral <span class="hlt">acceleration</span> values for short (0.2 seconds) and large (1.0 seconds) periods on rock conditions with a 1642 -year return period, which being considered as maximum credible earthquake (ASCE 07-05). In addition, other three design levels are proposed (severe earthquake: with a 808 -year return period, ordinary earthquake: with a 475 -year return period and minimum earthquake: with a 225 -year return period). The <span class="hlt">seismic</span> zonation proposed here fulfils the international standards (IBC-ICC) as well as the world tendencies in this thematic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JSeis..20..233H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JSeis..20..233H"><span>Re-evaluation and updating of the <span class="hlt">seismic</span> hazard of Lebanon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huijer, Carla; Harajli, Mohamed; Sadek, Salah</p> <p>2016-01-01</p> <p>This paper presents the results of a study undertaken to evaluate the implications of the newly mapped offshore Mount Lebanon Thrust (MLT) fault system on the <span class="hlt">seismic</span> hazard of Lebanon and the current <span class="hlt">seismic</span> zoning and design parameters used by the local engineering community. This re-evaluation is critical, given that the MLT is located at close proximity to the major cities and economic centers of the country. The updated <span class="hlt">seismic</span> hazard was assessed using probabilistic methods of analysis. The potential sources of <span class="hlt">seismic</span> activities that affect Lebanon were integrated along with any/all newly established characteristics within an updated database which includes the newly mapped fault system. The earthquake recurrence relationships of these sources were developed from instrumental seismology data, historical records, and earlier studies undertaken to evaluate the <span class="hlt">seismic</span> hazard of neighboring countries. Maps of peak ground <span class="hlt">acceleration</span> contours, based on 10 % probability of exceedance in 50 years (as per Uniform Building Code (UBC) 1997), as well as 0.2 and 1 s peak spectral <span class="hlt">acceleration</span> contours, based on 2 % probability of exceedance in 50 years (as per International Building Code (IBC) 2012), were also developed. Finally, spectral charts for the main coastal cities of Beirut, Tripoli, Jounieh, Byblos, Saida, and Tyre are provided for use by designers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPA21C0353B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPA21C0353B"><span>Rescaled Range analysis of Induced <span class="hlt">Seismicity</span>: rapid classification of clusters in <span class="hlt">seismic</span> crisis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bejar-Pizarro, M.; Perez Lopez, R.; Benito-Parejo, M.; Guardiola-Albert, C.; Herraiz, M.</p> <p>2017-12-01</p> <p>Different underground fluid operations, mainly gas storing, fracking and water pumping, can trigger Induced <span class="hlt">Seismicity</span> (IS). This <span class="hlt">seismicity</span> is normally featured by small-sized earthquakes (M<2.5), although particular cases reach magnitude as great as 5. It has been up for debate whether earthquakes greater than 5 can be triggered by IS or this level of magnitude only corresponds to tectonic earthquakes caused by stress change. Whatever the case, the characterization of IS for <span class="hlt">seismic</span> clusters and <span class="hlt">seismic</span> series recorded close but not into the gas storage, is still under discussion. Time-series of earthquakes obey non-linear patterns where the Hurst exponent describes the persistency or anti-persistency of the sequence. Natural <span class="hlt">seismic</span> sequences have an H-exponent close to 0.7, which combined with the b-value time evolution during the time clusters, give us valuable information about the stationarity of the phenomena. Tectonic earthquakes consist in a main shock with a decay of time-occurrence of <span class="hlt">seismic</span> shocks obeying the Omori's empirical law. On the contrary, IS does not exhibit a main shock and the time occurrence depends on the injection operations instead of on the tectonic energy <span class="hlt">released</span>. In this context, the H-exponent can give information about the origin of the sequence. In 2013, a <span class="hlt">seismic</span> crisis was declared from the Castor underground gas storing located off-shore in the Mediterranean Sea, close to the Northeastern Spanish cost. The greatest induced earthquake was 3.7. However, a 4.2 earthquake, probably of tectonic origin, occurred few days after the operations stopped. In this work, we have compared the H-exponent and the b-value time evolution according to the timeline of gas injection. Moreover, we have divided the <span class="hlt">seismic</span> sequence into two groups: (1) Induced <span class="hlt">Seismicity</span> and (2) Triggered <span class="hlt">Seismicity</span>. The rescaled range analysis allows the differentiation between natural and induced <span class="hlt">seismicity</span> and gives information about the persistency and long</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Tectp.728..130B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Tectp.728..130B"><span><span class="hlt">Seismic</span> b-values and its correlation with <span class="hlt">seismic</span> moment and Bouguer gravity anomaly over Indo-Burma ranges of northeast India: Tectonic implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bora, Dipok K.; Borah, Kajaljyoti; Mahanta, Rinku; Borgohain, Jayanta Madhab</p> <p>2018-03-01</p> <p>b-value is one of the most significant <span class="hlt">seismic</span> parameters for describing the <span class="hlt">seismicity</span> of a given region at a definite time window. In this study, high-resolution map of the Gutenberg-Richter b-value, <span class="hlt">seismic</span> moment-<span class="hlt">release</span>, Bouguer gravity anomaly and fault-plane solutions containing faulting styles are analyzed in the Indo-Burma ranges of northeast India using the unified and homogeneous part of the <span class="hlt">seismicity</span> record in the region (January 1964-December 2016). The study region is subdivided into few square grids of geographical window size 1° × 1° and b-values are calculated in each square grid. Our goal is to explore the spatial correlations and anomalous patterns between the b-value and parameters like <span class="hlt">seismic</span> moment <span class="hlt">release</span>, Bouguer gravity anomaly and faulting styles that can help us to better understand the seismotectonics and the state of present-day crustal stress within the Indo-Burma region. Most of the areas show an inverse correlation between b-value and <span class="hlt">seismic</span> moment <span class="hlt">release</span> as well as convergence rates. While estimating the b-value as a function of depth, a sudden increase of b-value at a depth of 50-60 km was found out and the receiver function modeling confirms that this depth corresponds to the crust-mantle transition beneath the study region. The region is also associated with negative Bouguer gravity anomalies and an inverse relation is found between Gravity anomaly and b-value. Comparing b-values with different faulting styles, reveal that the areas containing low b-values show thrust mechanism, while the areas associated with intermediate b-values show strike-slip mechanism. Those areas, where the events show thrust mechanism but containing a strike-slip component has the highest b-value.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16...16J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16...16J"><span><span class="hlt">Seismic</span> Hazard analysis of Adjaria Region in Georgia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jorjiashvili, Nato; Elashvili, Mikheil</p> <p>2014-05-01</p> <p>The most commonly used approach to determining <span class="hlt">seismic</span>-design loads for engineering projects is probabilistic <span class="hlt">seismic</span>-hazard analysis (PSHA). The primary output from a PSHA is a hazard curve showing the variation of a selected ground-motion parameter, such as peak ground <span class="hlt">acceleration</span> (PGA) or spectral <span class="hlt">acceleration</span> (SA), against the annual frequency of exceedance (or its reciprocal, return period). The design value is the ground-motion level that corresponds to a preselected design return period. For many engineering projects, such as standard buildings and typical bridges, the <span class="hlt">seismic</span> loading is taken from the appropriate <span class="hlt">seismic</span>-design code, the basis of which is usually a PSHA. For more important engineering projects— where the consequences of failure are more serious, such as dams and chemical plants—it is more usual to obtain the <span class="hlt">seismic</span>-design loads from a site-specific PSHA, in general, using much longer return periods than those governing code based design. Calculation of Probabilistic <span class="hlt">Seismic</span> Hazard was performed using Software CRISIS2007 by Ordaz, M., Aguilar, A., and Arboleda, J., Instituto de Ingeniería, UNAM, Mexico. CRISIS implements a classical probabilistic <span class="hlt">seismic</span> hazard methodology where <span class="hlt">seismic</span> sources can be modelled as points, lines and areas. In the case of area sources, the software offers an integration procedure that takes advantage of a triangulation algorithm used for <span class="hlt">seismic</span> source discretization. This solution improves calculation efficiency while maintaining a reliable description of source geometry and <span class="hlt">seismicity</span>. Additionally, supplementary filters (e.g. fix a sitesource distance that excludes from calculation sources at great distance) allow the program to balance precision and efficiency during hazard calculation. Earthquake temporal occurrence is assumed to follow a Poisson process, and the code facilitates two types of MFDs: a truncated exponential Gutenberg-Richter [1944] magnitude distribution and a characteristic magnitude</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH21A0156T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH21A0156T"><span>Probabilistic <span class="hlt">Seismic</span> Hazard Analysis for Georgia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsereteli, N. S.; Varazanashvili, O.; Sharia, T.; Arabidze, V.; Tibaldi, A.; Bonali, F. L. L.; Russo, E.; Pasquaré Mariotto, F.</p> <p>2017-12-01</p> <p>Nowadays, <span class="hlt">seismic</span> hazard studies are developed in terms of the calculation of Peak Ground <span class="hlt">Acceleration</span> (PGA), Spectral <span class="hlt">Acceleration</span> (SA), Peak Ground Velocity (PGV) and other recorded parameters. In the frame of EMME project PSH were calculated for Georgia using GMPE based on selection criteria. In the frame of Project N 216758 (supported by Shota Rustaveli National Science Foundation (SRNF)) PSH maps were estimated using hybrid- empirical ground motion prediction equation developed for Georgia. Due to the paucity of <span class="hlt">seismically</span> recorded information, in this work we focused our research on a more robust dataset related to macroseismic data,and attempted to calculate the probabilistic <span class="hlt">seismic</span> hazard directly in terms of macroseismicintensity. For this reason, we started calculating new intensity prediction equations (IPEs)for Georgia taking into account different sets, belonging to the same new database, as well as distances from the <span class="hlt">seismic</span> source.With respect to the <span class="hlt">seismic</span> source, in order to improve the quality of the results, we have also hypothesized the size of faults from empirical relations, and calculated new IPEs also by considering Joyner-Boore and rupture distances in addition to epicentral and hypocentral distances. Finally, site conditions have been included as variables for IPEs calculation Regarding the database, we used a brand new revised set of macroseismic data and instrumental records for the significant earthquakes that struck Georgia between 1900 and 2002.Particularly, a large amount of research and documents related to macroseismic effects of individual earthquakes, stored in the archives of the Institute of Geophysics, were used as sources for the new macroseismic data. The latter are reported in the Medvedev-Sponheuer-Karnikmacroseismic scale (MSK64). For each earthquake the magnitude, the focal depth and the epicenter location are also reported. An online version of the database, with therelated metadata,has been produced for the 69</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUSM.S21A..05G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUSM.S21A..05G"><span>Influence of Spatial Variation in Ground Motion Peak <span class="hlt">Acceleration</span> on Local Site Effects Estimation at Bucovina <span class="hlt">Seismic</span> Array (BURAR) Romania</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghica, D. V.; Radulian, M.; Popa, M.; Grecu, B.</p> <p>2006-05-01</p> <p>Basically, array processing techniques require a high signal coherency across the <span class="hlt">seismic</span> site; therefore the local crustal velocities below the station, signal amplitude differences between array elements and local noise conditions, resulting in local site effects will affect calculation of phase arrival times, propagation velocities and ground motion amplitudes. In general, array techniques assume a homogenous structure for all sites, and a simple relief correction is taking in account for the data analysis. To increase the results accuracy, individual element corrections must be applied, based on the biases factors systematically observed. This study aims at identifying the anomalous amplitude variations recorded at the Bucovina <span class="hlt">Seismic</span> Array (BURAR) and at explaining their influence on site effects estimation. Maximum amplitudes for the teleseismic and regional phases in four narrow frequency bands (0.25-0.5Hz; 0.5-1Hz; 1-2Hz; 1.5-3Hz) are measured. Spatial distribution of ground motion peak <span class="hlt">acceleration</span> in BURAR site, for each band, is plotted; a different behavior was observed at frequencies below 2Hz. The most important aspect observed is the largest amplitude exhibited by BUR07 across the whole array at high frequencies (an amplification factor of about two). This can be explained by the different geology at BUR07 site (mica schist outcrops), comparing with the rest of elements (green schist outcrops). At the lowest frequencies (0.25-0.5Hz), BUR09 peak amplitudes dominate the other sites. Considering BUR07 as reference site, peak <span class="hlt">acceleration</span> ratios were investigated. The largest scattering of these ratios appears at the highest frequencies (1.5-3Hz), when the weight of over unit values is about 90 %. No azimuth and distance dependence was found for these effects, suggesting the absence of the dipping layer structures. Although an increase of the ratio values is noticed for epicentral distance between 8000 and 10000 km, for frequencies over 1 Hz. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1712654R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1712654R"><span>The Pollino <span class="hlt">Seismic</span> Sequence: Activated Graben Structures in a <span class="hlt">Seismic</span> Gap</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rößler, Dirk; Passarelli, Luigi; Govoni, Aladino; Bindi, Dino; Cesca, Simone; Hainzl, Sebatian; Maccaferri, Francesco; Rivalta, Eleonora; Woith, Heiko; Dahm, Torsten</p> <p>2015-04-01</p> <p> mapped for the area. Consistent with mapped faults, the <span class="hlt">seismicity</span> interested both eastwards and westwards dipping normal faults that define the geometry of <span class="hlt">seismically</span> active graben-like structures. At least one cluster shows an additional spatio-temporal migration with spreading hypocentres similar to other swarm areas with fluid-triggering mechanisms. The static Coulomb stress change transferred by the largest shock onto the swarm area and on the CF cannot explain the observed high <span class="hlt">seismicity</span> rate. We study the evolution of the frequency-size distribution of the events and the <span class="hlt">seismicity</span> rate changes. We find that the majority of the earthquakes cannot be justified as aftershocks (directly related to the tectonics or to earthquake-earthquake interaction) and are best explained by an additional forcing active over the entire sequence. Our findings are consistent with the action of fluids (e.g. pore-pressure diffusion) triggering <span class="hlt">seismicity</span> on pre-loaded faults. Additional aseismic <span class="hlt">release</span> of tectonic strain by transient, slow slip is also consistent with our analysis. Analysis of deformation time series may clarify this point in future studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.S13B1989M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.S13B1989M"><span>Characterizing and comparing <span class="hlt">seismicity</span> at Cascade Range (USA) volcanoes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moran, S. C.; Thelen, W. A.</p> <p>2010-12-01</p> <p>The Cascade Range includes 13 volcanic systems across Washington, Oregon, and northern California that are considered to have the potential to erupt at any time, including two that have erupted in the last 100 years (Mount St. Helens (MSH) and Lassen Peak). We investigated how <span class="hlt">seismicity</span> compares among these volcanoes, and whether the character of <span class="hlt">seismicity</span> (rate, type, style of occurrence over time, etc.) is related to eruptive activity at the surface. <span class="hlt">Seismicity</span> at Cascade volcanoes has been monitored by <span class="hlt">seismic</span> networks of variable apertures, station densities, and lengths of operation, which makes a direct comparison of <span class="hlt">seismicity</span> among volcanoes somewhat problematic. Here we present results of two non-network-dependent approaches to making such <span class="hlt">seismicity</span> comparisons. In the first, we used network geometry and a grid-search method to compute the minimum magnitude required for a network to locate an earthquake (“theoretical location threshold”, defined as an event recorded on at least 4 stations with gap of <135o) for each volcano out to 7 km. We then selected earthquakes with magnitudes greater than the highest theoretical location threshold determined for any Cascade volcano. To account for improving network densities with time, we used M 2.1 (location threshold for the Three Sisters 1980s-90s network) for 1987-1999 and M 1.6 (threshold for the Crater Lake 2000s network) for 2000-2010. In order to include only background <span class="hlt">seismicity</span>, we excluded earthquakes occurring at any volcano during the 2004-2008 MSH eruption. We found that Mount Hood, Lassen Peak, and MSH had the three highest <span class="hlt">seismicity</span> rates over that period, with Mount Hood, Medicine Lake volcano, and MSH having the three highest cumulative <span class="hlt">seismic</span> energy <span class="hlt">releases</span>. The Medicine Lake energy <span class="hlt">release</span> is dominated by a single swarm in September 1988; if that swarm is removed, then Lassen would have the third-highest cumulative <span class="hlt">seismic</span> energy <span class="hlt">release</span>. For the second comparison, we determined the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1981EOSTr..62R..33R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981EOSTr..62R..33R"><span>Antarctica: As <span class="hlt">seismic</span> as other plates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Richman, Barbara T.</p> <p></p> <p>Antarctica shakes, rattles, and rolls just as much as other slow-moving plates. Emile Okal, a Yale University seismologist, told colleagues at the AGU Fall Meeting that although the Antarctic plate is not moving across the earth as fast as other continents, it has a <span class="hlt">seismicity</span> similar to other plates. His findings refute the claim that a ring of spreading ridges that surrounds the plate leaves Antarctica stress free.The small number of reports of plate <span class="hlt">seismicity</span>, Okal explained, has been used to argue that the ridges that surround the plate are unable to transmit tectonic stresses and would make the Antarctic plate motionless and free of <span class="hlt">seismic</span> stress. However, when Okal added up the total <span class="hlt">seismic</span> energy <span class="hlt">released</span> during the last 55 years, he found it similar to that of the African plate, which is comparable in size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70030869','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70030869"><span>First USGS urban <span class="hlt">seismic</span> hazard maps predict the effects of soils</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cramer, C.H.; Gomberg, J.S.; Schweig, E.S.; Waldron, B.A.; Tucker, K.</p> <p>2006-01-01</p> <p>Probabilistic and scenario urban <span class="hlt">seismic</span> hazard maps have been produced for Memphis, Shelby County, Tennessee covering a six-quadrangle area of the city. The nine probabilistic maps are for peak ground <span class="hlt">acceleration</span> and 0.2 s and 1.0 s spectral <span class="hlt">acceleration</span> and for 10%, 5%, and 2% probability of being exceeded in 50 years. Six scenario maps for these three ground motions have also been generated for both an M7.7 and M6.2 on the southwest arm of the New Madrid <span class="hlt">seismic</span> zone ending at Marked Tree, Arkansas. All maps include the effect of local geology. Relative to the national <span class="hlt">seismic</span> hazard maps, the effect of the thick sediments beneath Memphis is to decrease 0.2 s probabilistic ground motions by 0-30% and increase 1.0 s probabilistic ground motions by ???100%. Probabilistic peak ground <span class="hlt">accelerations</span> remain at levels similar to the national maps, although the ground motion gradient across Shelby County is reduced and ground motions are more uniform within the county. The M7.7 scenario maps show ground motions similar to the 5%-in-50-year probabilistic maps. As an effect of local geology, both M7.7 and M6.2 scenario maps show a more uniform <span class="hlt">seismic</span> ground-motion hazard across Shelby County than scenario maps with constant site conditions (i.e., NEHRP B/C boundary).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.S41A1319C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.S41A1319C"><span>Observed Melt Season <span class="hlt">Seismicity</span> of Taylor Glacier, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carmichael, J. D.; Pettit, E. C.; Creager, K. C.</p> <p>2006-12-01</p> <p>Sufficient evidence exists to suggest that interaction of crevasses and meltwater <span class="hlt">accelerates</span> ice cliff disintegration of tidewater glaciers. It is not clear what role meltwater plays in calving characteristics from dry- based polar glaciers. We have obtained <span class="hlt">seismic</span> data from a six-sensor <span class="hlt">seismic</span> array deployed in October of 2004 near the terminus cliffs of Taylor Glacier, West Antarctica, to analyze near-cliff <span class="hlt">seismicity</span> throughout a melt season. Discharge data from the adjacent Lawson stream suggests that dramatic increases in meltwater volume temporally correlate with changes in <span class="hlt">seismic</span> character near ice cliffs. We calculated source-locations for ice-quake during hours of melting and re-freezing and found most large energy events to be located near the ice cliffs. The associated spectra and waveform characteristics are indicative of literature descriptions of crevassing events.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PApGe.173.2653D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PApGe.173.2653D"><span>Probabilistic <span class="hlt">Seismic</span> Hazard Assessment for Northeast India Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Das, Ranjit; Sharma, M. L.; Wason, H. R.</p> <p>2016-08-01</p> <p>Northeast India bounded by latitudes 20°-30°N and longitudes 87°-98°E is one of the most <span class="hlt">seismically</span> active areas in the world. This region has experienced several moderate-to-large-sized earthquakes, including the 12 June, 1897 Shillong earthquake ( M w 8.1) and the 15 August, 1950 Assam earthquake ( M w 8.7) which caused loss of human lives and significant damages to buildings highlighting the importance of <span class="hlt">seismic</span> hazard assessment for the region. Probabilistic <span class="hlt">seismic</span> hazard assessment of the region has been carried out using a unified moment magnitude catalog prepared by an improved General Orthogonal Regression methodology (Geophys J Int, 190:1091-1096, 2012; Probabilistic <span class="hlt">seismic</span> hazard assessment of Northeast India region, Ph.D. Thesis, Department of Earthquake Engineering, IIT Roorkee, Roorkee, 2013) with events compiled from various databases (ISC, NEIC,GCMT, IMD) and other available catalogs. The study area has been subdivided into nine seismogenic source zones to account for local variation in tectonics and <span class="hlt">seismicity</span> characteristics. The <span class="hlt">seismicity</span> parameters are estimated for each of these source zones, which are input variables into <span class="hlt">seismic</span> hazard estimation of a region. The <span class="hlt">seismic</span> hazard analysis of the study region has been performed by dividing the area into grids of size 0.1° × 0.1°. Peak ground <span class="hlt">acceleration</span> (PGA) and spectral <span class="hlt">acceleration</span> ( S a) values (for periods of 0.2 and 1 s) have been evaluated at bedrock level corresponding to probability of exceedance (PE) of 50, 20, 10, 2 and 0.5 % in 50 years. These exceedance values correspond to return periods of 100, 225, 475, 2475, and 10,000 years, respectively. The <span class="hlt">seismic</span> hazard maps have been prepared at the bedrock level, and it is observed that the <span class="hlt">seismic</span> hazard estimates show a significant local variation in contrast to the uniform hazard value suggested by the Indian standard <span class="hlt">seismic</span> code [Indian standard, criteria for earthquake-resistant design of structures, fifth edition, Part</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JESS..127...16P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JESS..127...16P"><span>Probabilistic <span class="hlt">seismic</span> hazard at the archaeological site of Gol Gumbaz in Vijayapura, south India</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Patil, Shivakumar G.; Menon, Arun; Dodagoudar, G. R.</p> <p>2018-03-01</p> <p>Probabilistic <span class="hlt">seismic</span> hazard analysis (PSHA) is carried out for the archaeological site of Vijayapura in south India in order to obtain hazard consistent <span class="hlt">seismic</span> input ground-motions for <span class="hlt">seismic</span> risk assessment and design of <span class="hlt">seismic</span> protection measures for monuments, where warranted. For this purpose the standard Cornell-McGuire approach, based on seismogenic zones with uniformly distributed <span class="hlt">seismicity</span> is employed. The main features of this study are the usage of an updated and unified <span class="hlt">seismic</span> catalogue based on moment magnitude, new seismogenic source models and recent ground motion prediction equations (GMPEs) in logic tree framework. <span class="hlt">Seismic</span> hazard at the site is evaluated for level and rock site condition with 10% and 2% probabilities of exceedance in 50 years, and the corresponding peak ground <span class="hlt">accelerations</span> (PGAs) are 0.074 and 0.142 g, respectively. In addition, the uniform hazard spectra (UHS) of the site are compared to the Indian code-defined spectrum. Comparisons are also made with results from National Disaster Management Authority (NDMA 2010), in terms of PGA and pseudo spectral <span class="hlt">accelerations</span> (PSAs) at T = 0.2, 0.5, 1.0 and 1.25 s for 475- and 2475-yr return periods. Results of the present study are in good agreement with the PGA calculated from isoseismal map of the Killari earthquake, {M}w = 6.4 (1993). Disaggregation of PSHA results for the PGA and spectral <span class="hlt">acceleration</span> ({S}a) at 0.5 s, displays the controlling scenario earthquake for the study region as low to moderate magnitude with the source being at a short distance from the study site. Deterministic <span class="hlt">seismic</span> hazard (DSHA) is also carried out by taking into account three scenario earthquakes. The UHS corresponding to 475-yr return period (RP) is used to define the target spectrum and accordingly, the spectrum-compatible natural accelerograms are selected from the suite of recorded accelerograms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615672D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615672D"><span>Spatial correlation analysis of <span class="hlt">seismic</span> noise for STAR X-ray infrastructure design</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>D'Alessandro, Antonino; Agostino, Raffaele; Festa, Lorenzo; Gervasi, Anna; Guerra, Ignazio; Palmer, Dennis T.; Serafini, Luca</p> <p>2014-05-01</p> <p>. For this reason, we performed some measurements of <span class="hlt">seismic</span> noise in order to characterize the environmental noise in the site in which the X-ray <span class="hlt">accelerator</span> arise. For the characterization of the site, we carried out several passive <span class="hlt">seismic</span> monitoring experiments at different times of the day and in different weather conditions. We recorded microtremor using an array of broadband 3C <span class="hlt">seismic</span> sensors arranged along the linear <span class="hlt">accelerator</span>. For each measurement point, we determined the displacement, velocity and <span class="hlt">acceleration</span> spectrogram and power spectral density of both horizontal and vertical components. We determined also the microtremor horizontal to vertical spectral ratio as function of azimuth to individuate the main ground vibration direction and detect the existence of site or building resonance frequencies. We applied a rotation matrix to transform the North-South and East-West signal components in transversal and radial components, respect to the direction of the linear <span class="hlt">accelerator</span>. Subsequently, for each couple of <span class="hlt">seismic</span> stations we determined the coherence function to analyze the <span class="hlt">seismic</span> noise spatial correlation. These analyses have allowed us to exhaustively characterize the <span class="hlt">seismic</span> noise of the study area, from the point of view of the power and space-time variability, both in frequency and wavelength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29142726','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29142726"><span>Signal transduction and amplification through enzyme-triggered ligand <span class="hlt">release</span> and <span class="hlt">accelerated</span> catalysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Goggins, Sean; Marsh, Barrie J; Lubben, Anneke T; Frost, Christopher G</p> <p>2015-08-01</p> <p>Signal transduction and signal amplification are both important mechanisms used within biological signalling pathways. Inspired by this process, we have developed a signal amplification methodology that utilises the selectivity and high activity of enzymes in combination with the robustness and generality of an organometallic catalyst, achieving a hybrid biological and synthetic catalyst cascade. A proligand enzyme substrate was designed to selectively self-immolate in the presence of the enzyme to <span class="hlt">release</span> a ligand that can bind to a metal pre-catalyst and <span class="hlt">accelerate</span> the rate of a transfer hydrogenation reaction. Enzyme-triggered catalytic signal amplification was then applied to a range of catalyst substrates demonstrating that signal amplification and signal transduction can both be achieved through this methodology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..44.6771L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44.6771L"><span>Time lag between deformation and <span class="hlt">seismicity</span> along monogenetic volcanic unrest periods: The case of El Hierro Island (Canary Islands)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lamolda, Héctor; Felpeto, Alicia; Bethencourt, Abelardo</p> <p>2017-07-01</p> <p>Between 2011 and 2014 there were at least seven episodes of magmatic intrusion in El Hierro Island, but only the first one led to a submarine eruption in 2011-2012. In order to study the relationship between GPS deformation and <span class="hlt">seismicity</span> during these episodes, we compare the temporal evolution of the deformation with the cumulative <span class="hlt">seismic</span> energy <span class="hlt">released</span>. In some of the episodes both deformation and <span class="hlt">seismicity</span> evolve in a very similar way, but in others a time lag appears between them, in which the deformation precedes the <span class="hlt">seismicity</span>. Furthermore, a linear correlation between decimal logarithm of intruded magma volume and decimal logarithm of total <span class="hlt">seismic</span> energy <span class="hlt">released</span> along the different episodes has been observed. Therefore, if a future magmatic intrusion in El Hierro Island follows this behavior with a proper time lag, we could have an a priori estimate on the order of magnitude the <span class="hlt">seismic</span> energy <span class="hlt">released</span> would reach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/2008/3018/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/2008/3018/"><span>2008 United States National <span class="hlt">Seismic</span> Hazard Maps</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Petersen, M.D.; ,</p> <p>2008-01-01</p> <p>The U.S. Geological Survey recently updated the National <span class="hlt">Seismic</span> Hazard Maps by incorporating new <span class="hlt">seismic</span>, geologic, and geodetic information on earthquake rates and associated ground shaking. The 2008 versions supersede those <span class="hlt">released</span> in 1996 and 2002. These maps are the basis for <span class="hlt">seismic</span> design provisions of building codes, insurance rate structures, earthquake loss studies, retrofit priorities, and land-use planning. Their use in design of buildings, bridges, highways, and critical infrastructure allows structures to better withstand earthquake shaking, saving lives and reducing disruption to critical activities following a damaging event. The maps also help engineers avoid costs from over-design for unlikely levels of ground motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNS42A..07O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNS42A..07O"><span>Development of Towed Marine <span class="hlt">Seismic</span> Vibrator as an Alternative <span class="hlt">Seismic</span> Source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ozasa, H.; Mikada, H.; Murakami, F.; Jamali Hondori, E.; Takekawa, J.; Asakawa, E.; Sato, F.</p> <p>2015-12-01</p> <p>The principal issue with respect to marine impulsive sources to acquire <span class="hlt">seismic</span> data is if the emission of acoustic energy inflicts harm on marine mammals or not, since the volume of the source signal being <span class="hlt">released</span> into the marine environment could be so large compared to the sound range of the mammals. We propose a marine <span class="hlt">seismic</span> vibrator as an alternative to the impulsive sources to mitigate a risk of the impact to the marine environment while satisfying the necessary conditions of <span class="hlt">seismic</span> surveys. These conditions include the repeatability and the controllability of source signals both in amplitude and phase for high-quality measurements. We, therefore, designed a towed marine <span class="hlt">seismic</span> vibrator (MSV) as a new type marine vibratory <span class="hlt">seismic</span> source that employed the hydraulic servo system for the controllability condition in phase and in amplitude that assures the repeatability as well. After fabricating a downsized MSV that requires the power of 30 kVA at a depth of about 250 m in water, several sea trials were conducted to test the source characteristics of the downsized MSV in terms of amplitude, frequency, horizontal and vertical directivities of the generated field. The maximum sound level satisfied the designed specification in the frequencies ranging from 3 to 300 Hz almost omnidirectionally. After checking the source characteristics, we then conducted a trial <span class="hlt">seismic</span> survey, using both the downsized MSV and an airgun of 480 cubic-inches for comparison, with a streamer cable of 2,000m long right above a cabled earthquake observatory in the Japan Sea. The result showed that the penetration of <span class="hlt">seismic</span> signals generated by the downsized MSV was comparable to that by the airgun, although there was a slight difference in the signal-to-noise ratio. The MSV could become a versatile source that will not harm living marine mammals as an alternative to the existing impulsive <span class="hlt">seismic</span> sources such as airgun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2014/1047/pdf/ofr2014-1047.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2014/1047/pdf/ofr2014-1047.pdf"><span>A brief test of the Hewlett-Packard MEMS <span class="hlt">seismic</span> accelerometer</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Homeijer, Brian D.; Milligan, Donald J.; Hutt, Charles R.</p> <p>2014-01-01</p> <p>Testing was performed on a prototype of Hewlett-Packard (HP) Micro-Electro-Mechanical Systems (MEMS) <span class="hlt">seismic</span> accelerometer at the U.S. Geological Survey’s Albuquerque Seismological Laboratory. This prototype was built using discrete electronic components. The self-noise level was measured during low <span class="hlt">seismic</span> background conditions and found to be 9.8 ng/√Hz at periods below 0.2 s (frequencies above 5 Hz). The six-second microseism noise was also discernible. The HP MEMS accelerometer was compared to a Geotech Model GS-13 reference seismometer during <span class="hlt">seismic</span> noise and signal levels well above the self-noise of the accelerometer. Matching power spectral densities (corrected for accelerometer and seismometer responses to represent true ground motion) indicated that the HP MEMS accelerometer has a flat (constant) response to <span class="hlt">acceleration</span> from 0.0125 Hz to at least 62.5 Hz. Tilt calibrations of the HP MEMS accelerometer verified that the flat response to <span class="hlt">acceleration</span> extends to 0 Hz. Future development of the HP MEMS accelerometer includes replacing the discreet electronic boards with a low power application-specific integrated circuit (ASIC) and increasing the dynamic range of the sensor to detect strong motion signals above one gravitational <span class="hlt">acceleration</span>, while maintaining the self-noise observed during these tests.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70026567','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70026567"><span><span class="hlt">Seismic</span> hazard maps of Mexico, the Caribbean, and Central and South America</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Tanner, J.G.; Shedlock, K.M.</p> <p>2004-01-01</p> <p>The growth of megacities in <span class="hlt">seismically</span> active regions around the world often includes the construction of <span class="hlt">seismically</span> unsafe buildings and infrastructures due to an insufficient knowledge of existing <span class="hlt">seismic</span> hazard and/or economic constraints. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of <span class="hlt">seismic</span> hazard. We have produced a suite of <span class="hlt">seismic</span> hazard estimates for Mexico, the Caribbean, and Central and South America. One of the preliminary maps in this suite served as the basis for the Caribbean and Central and South America portion of the Global <span class="hlt">Seismic</span> Hazard Map (GSHM) published in 1999, which depicted peak ground <span class="hlt">acceleration</span> (pga) with a 10% chance of exceedance in 50 years for rock sites. Herein we present maps depicting pga and 0.2 and 1.0 s spectral <span class="hlt">accelerations</span> (SA) with 50%, 10%, and 2% chances of exceedance in 50 years for rock sites. The <span class="hlt">seismicity</span> catalog used in the generation of these maps adds 3 more years of data to those used to calculate the GSH Map. Different attenuation functions (consistent with those used to calculate the U.S. and Canadian maps) were used as well. These nine maps are designed to assist in global risk mitigation by providing a general <span class="hlt">seismic</span> hazard framework and serving as a resource for any national or regional agency to help focus further detailed studies required for regional/local needs. The largest <span class="hlt">seismic</span> hazard values in Mexico, the Caribbean, and Central and South America generally occur in areas that have been, or are likely to be, the sites of the largest plate boundary earthquakes. High hazard values occur in areas where shallow-to-intermediate <span class="hlt">seismicity</span> occurs frequently. ?? 2004 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70178111','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70178111"><span>Observations of <span class="hlt">seismicity</span> and ground motion in the northeast U.S. Atlantic margin from ocean bottom seismometer data</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Flores, Claudia; ten Brink, Uri S.; McGuire, Jeffrey J.; Collins, John A.</p> <p>2017-01-01</p> <p>Earthquake data from two short-period ocean-bottom seismometer (OBS) networks deployed for over a year on the continental slope off New York and southern New England were used to evaluate <span class="hlt">seismicity</span> and ground motions along the continental margin. Our OBS networks located only one earthquake of Mc∼1.5 near the shelf edge during six months of recording, suggesting that <span class="hlt">seismic</span> activity (MLg>3.0) of the margin as far as 150–200 km offshore is probably successfully monitored by land stations without the need for OBS deployments. The spectral <span class="hlt">acceleration</span> from two local earthquakes recorded by the OBS was found to be generally similar to the <span class="hlt">acceleration</span> from these earthquakes recorded at several <span class="hlt">seismic</span> stations on land and to hybrid empirical <span class="hlt">acceleration</span> relationships for eastern North America. Therefore, the <span class="hlt">seismic</span> attenuation used for eastern North America can be extended in this region at least to the continental slope. However, additional offshore studies are needed to verify these preliminary conclusions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....5459C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....5459C"><span>Ischia Island: Historical <span class="hlt">Seismicity</span> and Dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carlino, S.; Cubellis, E.; Iannuzzi, R.; Luongo, G.; Obrizzo, F.</p> <p>2003-04-01</p> <p>The <span class="hlt">seismic</span> energy <span class="hlt">release</span> in volcanic areas is a complex process and the island of Ischia provides a significant scenario of historical <span class="hlt">seismicity</span>. This is characterized by the occurence of earthquakes with low energy and high intensity. Information on the <span class="hlt">seismicity</span> of the island spans about eight centuries, starting from 1228. With regard to effects, the most recent earthquake of 1883 is extensively documented both in the literature and unpublished sources. The earthquake caused 2333 deaths and the destruction of the historical and environmental heritage of some areas of the island. The most severe damage occurred in Casamicciola. This event, which was the first great catastrophe after the unification of Italy in the 1860s (Imax = XI degree MCS), represents an important date in the prevention of natural disasters, in that it was after this earthquake that the first <span class="hlt">Seismic</span> Safety Act in Italy was passed by which lower risk zones were identified for new settlements. Thanks to such detailed analysis, reliable modelling of the <span class="hlt">seismic</span> source was also obtained. The historical data onwards makes it possible to identify the area of the epicenter of all known earthquakes as the northern slope of Monte Epomeo, while analysis of the effects of earthquakes and the geological structures allows us to evaluate the stress fields that generate the earthquakes. In a volcanic area, interpretation of the mechanisms of <span class="hlt">release</span> and propagation of <span class="hlt">seismic</span> energy is made even more complex as the stress field that acts at a regional level is compounded by that generated from migration of magmatic masses towards the surface, as well as the rheologic properties of the rocks dependent on the high geothermic gradient. Such structural and dynamic conditions make the island of Ischia a <span class="hlt">seismic</span> area of considerable interest. It would appear necessary to evaluate the expected damage caused by a new event linked to the renewal of dynamics of the island, where high population density and the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27109362','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27109362"><span><span class="hlt">Accelerated</span> nucleation of the 2014 Iquique, Chile Mw 8.2 Earthquake.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kato, Aitaro; Fukuda, Jun'ichi; Kumazawa, Takao; Nakagawa, Shigeki</p> <p>2016-04-25</p> <p>The earthquake nucleation process has been vigorously investigated based on geophysical observations, laboratory experiments, and theoretical studies; however, a general consensus has yet to be achieved. Here, we studied nucleation process for the 2014 Iquique, Chile Mw 8.2 megathrust earthquake located within the current North Chile <span class="hlt">seismic</span> gap, by analyzing a long-term earthquake catalog constructed from a cross-correlation detector using continuous <span class="hlt">seismic</span> data. <span class="hlt">Accelerations</span> in <span class="hlt">seismicity</span>, the amount of aseismic slip inferred from repeating earthquakes, and the background <span class="hlt">seismicity</span>, accompanied by an increasing frequency of earthquake migrations, started around 270 days before the mainshock at locations up-dip of the largest coseismic slip patch. These signals indicate that repetitive sequences of fast and slow slip took place on the plate interface at a transition zone between fully locked and creeping portions. We interpret that these different sliding modes interacted with each other and promoted <span class="hlt">accelerated</span> unlocking of the plate interface during the nucleation phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...624792K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...624792K"><span><span class="hlt">Accelerated</span> nucleation of the 2014 Iquique, Chile Mw 8.2 Earthquake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kato, Aitaro; Fukuda, Jun'Ichi; Kumazawa, Takao; Nakagawa, Shigeki</p> <p>2016-04-01</p> <p>The earthquake nucleation process has been vigorously investigated based on geophysical observations, laboratory experiments, and theoretical studies; however, a general consensus has yet to be achieved. Here, we studied nucleation process for the 2014 Iquique, Chile Mw 8.2 megathrust earthquake located within the current North Chile <span class="hlt">seismic</span> gap, by analyzing a long-term earthquake catalog constructed from a cross-correlation detector using continuous <span class="hlt">seismic</span> data. <span class="hlt">Accelerations</span> in <span class="hlt">seismicity</span>, the amount of aseismic slip inferred from repeating earthquakes, and the background <span class="hlt">seismicity</span>, accompanied by an increasing frequency of earthquake migrations, started around 270 days before the mainshock at locations up-dip of the largest coseismic slip patch. These signals indicate that repetitive sequences of fast and slow slip took place on the plate interface at a transition zone between fully locked and creeping portions. We interpret that these different sliding modes interacted with each other and promoted <span class="hlt">accelerated</span> unlocking of the plate interface during the nucleation phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4842989','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4842989"><span><span class="hlt">Accelerated</span> nucleation of the 2014 Iquique, Chile Mw 8.2 Earthquake</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kato, Aitaro; Fukuda, Jun’ichi; Kumazawa, Takao; Nakagawa, Shigeki</p> <p>2016-01-01</p> <p>The earthquake nucleation process has been vigorously investigated based on geophysical observations, laboratory experiments, and theoretical studies; however, a general consensus has yet to be achieved. Here, we studied nucleation process for the 2014 Iquique, Chile Mw 8.2 megathrust earthquake located within the current North Chile <span class="hlt">seismic</span> gap, by analyzing a long-term earthquake catalog constructed from a cross-correlation detector using continuous <span class="hlt">seismic</span> data. <span class="hlt">Accelerations</span> in <span class="hlt">seismicity</span>, the amount of aseismic slip inferred from repeating earthquakes, and the background <span class="hlt">seismicity</span>, accompanied by an increasing frequency of earthquake migrations, started around 270 days before the mainshock at locations up-dip of the largest coseismic slip patch. These signals indicate that repetitive sequences of fast and slow slip took place on the plate interface at a transition zone between fully locked and creeping portions. We interpret that these different sliding modes interacted with each other and promoted <span class="hlt">accelerated</span> unlocking of the plate interface during the nucleation phase. PMID:27109362</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DPS....4922005P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DPS....4922005P"><span><span class="hlt">Seismic</span> signal and noise on Europa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panning, Mark; Stähler, Simon; Bills, Bruce; Castillo Castellanos, Jorge; Huang, Hsin-Hua; Husker, Allen; Kedar, Sharon; Lorenz, Ralph; Pike, William T.; Schmerr, Nicholas; Tsai, Victor; Vance, Steven</p> <p>2017-10-01</p> <p>Seismology is one of our best tools for detailing interior structure of planetary bodies, and a seismometer is included in the baseline and threshold mission design for the upcoming Europa Lander mission. Guiding mission design and planning for adequate science return, though, requires modeling of both the anticipated signal and noise. Assuming ice <span class="hlt">seismicity</span> on Europa behaves according to statistical properties observed in Earth catalogs and scaling cumulative <span class="hlt">seismic</span> moment <span class="hlt">release</span> to the moon, we can simulate long <span class="hlt">seismic</span> records and estimate background noise and peak signal amplitudes (Panning et al., 2017). This suggests a sensitive instrument comparable to many broadband terrestrial instruments or the SP instrument from the InSight mission to Mars will be able to record signals, while high frequency geophones are likely inadequate. We extend this analysis to also begin incorporation of spatial and temporal variation due to the tidal cycle, which can help inform landing site selection. We also begin exploration of how chaotic terrane at the bottom of the ice shell and inter-ice heterogeneities (i.e. internal melt structures) may affect anticipated <span class="hlt">seismic</span> observations using 2D numerical <span class="hlt">seismic</span> simulations.M. P. Panning, S. C. Stähler, H.-H. Huang, S. D. Vance, S. Kedar, V. C. Tsai, W. T. Pike, R. D. Lorenz, “Expected <span class="hlt">seismicity</span> and the <span class="hlt">seismic</span> noise environment of Europa,” J. Geophys. Res., in revision, 2017.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/5868981','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/5868981"><span><span class="hlt">Seismic</span> risk analysis for the Babcock and Wilcox facility, Leechburg, Pennsylvania</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Not Available</p> <p>1977-10-21</p> <p>The results of a detailed <span class="hlt">seismic</span> risk analysis of the Babcock and Wilcox Plutonium Fuel Fabrication facility at Leechburg, Pennsylvania are presented. This report focuses on earthquakes; the other natural hazards, being addressed in separate reports, are severe weather (strong winds and tornados) and floods. The calculational method used is based on Cornell's work (1968); it has been previously applied to safety evaluations of major projects. The historical <span class="hlt">seismic</span> record was established after a review of available literature, consultation with operators of local <span class="hlt">seismic</span> arrays and examination of appropriate <span class="hlt">seismic</span> data bases. Because of the aseismicity of the region aroundmore » the site, an analysis different from the conventional closest approach in a tectonic province was adapted. Earthquakes as far from the site as 1,000 km were included, as were the possibility of earthquakes at the site. In addition, various uncertainties in the input were explicitly considered in the analysis. The results of the risk analysis, which include a Bayesian estimate of the uncertainties, are presented, expressed as return period <span class="hlt">accelerations</span>. The best estimate curve indicates that the Babcock and Wilcox facility will experience 0.05 g every 220 years and 0.10 g every 1400 years. The bounding curves roughly represent the one standard deviation confidence limits about the best estimate, reflecting the uncertainty in certain of the input. Detailed examination of the results show that the <span class="hlt">accelerations</span> are very insensitive to the details of the source region geometries or the historical earthquake statistics in each region and that each of the source regions contributes almost equally to the cumulative risk at the site. If required for structural analysis, <span class="hlt">acceleration</span> response spectra for the site can be constructed by scaling the mean response spectrum for alluvium in WASH 1255 by these peak <span class="hlt">accelerations</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JGE.....6..288D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JGE.....6..288D"><span>Probabilistic <span class="hlt">seismic</span> hazard maps for Sinai Peninsula, Egypt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deif, A.; Abou Elenean, K.; El Hadidy, M.; Tealeb, A.; Mohamed, A.</p> <p>2009-09-01</p> <p>Sinai experienced the largest Egyptian earthquake with moment magnitude (Mw) 7.2 in 1995 in the Gulf of Aqaba, 350 km from Cairo. It is characterized by the presence of many tourist projects in addition to different natural resources. The aim of the current study is to present, for the first time, the probabilistic spectral hazard maps for Sinai. Revised earthquake catalogues for Sinai and its surroundings, from 112 BC to 2006 AD with magnitude equal or greater than 3.0, are used to calculate <span class="hlt">seismic</span> hazard in the region of interest between 27°N and 31.5°N and 32°E and 36°E. We declustered these catalogues to include only independent events. The catalogues were tested for the completeness of different magnitude ranges. 28 <span class="hlt">seismic</span> source zones are used to define the <span class="hlt">seismicity</span>. The recurrence rates and the maximum earthquakes across these zones were also determined from these modified catalogues. Strong ground motion relations for rock are used to produce 5% damped spectral <span class="hlt">acceleration</span> values for four different periods (0.2, 0.5, 1.0 and 2.0 s) to define the uniform response spectra at each site (grid of 0.2° × 0.2° all over the area). Maps showing spectral <span class="hlt">acceleration</span> values at 0.2, 0.5, 1.0 and 2.0 s periods as well as peak ground <span class="hlt">acceleration</span> (PGA) for the return period of 475 years (equivalent to 90% probability on non-exceedence in 50 years) are presented. In addition, Uniform Hazard Spectra (UHS) at 25 different periods for the four main cities (Hurghda, Sharm El-Sheikh, Nuweibaa and Suez) are graphed. The highest hazard is found in the Gulf of Aqaba with maximum spectral <span class="hlt">accelerations</span> 356 cm s-2 at a period of 0.22 s for a return period of 475 years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T21A0538W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T21A0538W"><span>Fault Mechanics and Post-<span class="hlt">seismic</span> Deformation at Bam, SE Iran</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wimpenny, S. E.; Copley, A.</p> <p>2017-12-01</p> <p>The extent to which aseismic deformation relaxes co-<span class="hlt">seismic</span> stress changes on a fault zone is fundamental to assessing the future <span class="hlt">seismic</span> hazard following any earthquake, and in understanding the mechanical behaviour of faults. We used models of stress-driven afterslip and visco-elastic relaxation, in conjunction with a dense time series of post-<span class="hlt">seismic</span> InSAR measurements, to show that there has been minimal <span class="hlt">release</span> of co-<span class="hlt">seismic</span> stress changes through post-<span class="hlt">seismic</span> deformation following the 2003 Mw 6.6 Bam earthquake. Our modelling indicates that the faults at Bam may remain predominantly locked, and that the co- plus inter-<span class="hlt">seismically</span> accumulated elastic strain stored down-dip of the 2003 rupture patch may be <span class="hlt">released</span> in a future Mw 6 earthquake. Modelling also suggests parts of the fault that experienced post-<span class="hlt">seismic</span> creep between 2003-2009 overlapped with areas that also slipped co-<span class="hlt">seismically</span>. Our observations and models also provide an opportunity to probe how aseismic fault slip leads to the growth of topography at Bam. We find that, for our modelled afterslip distribution to be consistent with forming the sharp step in the local topography at Bam over repeated earthquake cycles, and also to be consistent with the geodetic observations, requires either (1) far-field tectonic loading equivalent to a 2-10 MPa deviatoric stress acting across the fault system, which suggests it supports stresses 60-100 times less than classical views of static fault strength, or (2) that the fault surface has some form of mechanical anisotropy, potentially related to corrugations on the fault plane, that controls the sense of slip.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.6788S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.6788S"><span><span class="hlt">Seismic</span> hazard assessment of the cultural heritage sites: A case study in Cappadocia (Turkey)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seyrek, Evren; Orhan, Ahmet; Dinçer, İsmail</p> <p>2014-05-01</p> <p>Turkey is one of the most <span class="hlt">seismically</span> active regions in the world. Major earthquakes with the potential of threatening life and property occur frequently here. In the last decade, over 50,000 residents lost their lives, commonly as a result of building failures in <span class="hlt">seismic</span> events. The Cappadocia region is one of the most important touristic sites in Turkey. At the same time, the region has been included to the Word Heritage List by UNESCO at 1985 due to its natural, historical and cultural values. The region is undesirably affected by several environmental conditions, which are subjected in many previous studies. But, there are limited studies about the <span class="hlt">seismic</span> evaluation of the region. Some of the important historical and cultural heritage sites are: Goreme Open Air Museum, Uchisar Castle, Ortahisar Castle, Derinkuyu Underground City and Ihlara Valley. According to <span class="hlt">seismic</span> hazard zonation map published by the Ministry of Reconstruction and Settlement these heritage sites fall in Zone III, Zone IV and Zone V. This map show peak ground <span class="hlt">acceleration</span> or 10 percent probability of exceedance in 50 years for bedrock. In this connection, <span class="hlt">seismic</span> hazard assessment of these heritage sites has to be evaluated. In this study, <span class="hlt">seismic</span> hazard calculations are performed both deterministic and probabilistic approaches with local site conditions. A catalog of historical and instrumental earthquakes is prepared and used in this study. The <span class="hlt">seismic</span> sources have been identified for <span class="hlt">seismic</span> hazard assessment based on geological, seismological and geophysical information. Peak Ground <span class="hlt">Acceleration</span> (PGA) at bed rock level is calculated for different <span class="hlt">seismic</span> sources using available attenuation relationship formula applicable to Turkey. The result of the present study reveals that the <span class="hlt">seismic</span> hazard at these sites is closely matching with the <span class="hlt">Seismic</span> Zonation map published by the Ministry of Reconstruction and Settlement. Keywords: <span class="hlt">Seismic</span> Hazard Assessment, Probabilistic Approach</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EEEV...15..369H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EEEV...15..369H"><span>Numerical simulation on the <span class="hlt">seismic</span> absorption effect of the cushion in rigid-pile composite foundation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Han, Xiaolei; Li, Yaokun; Ji, Jing; Ying, Junhao; Li, Weichen; Dai, Baicheng</p> <p>2016-06-01</p> <p>In order to quantitatively study the <span class="hlt">seismic</span> absorption effect of the cushion on a superstructure, a numerical simulation and parametric study are carried out on the overall FEA model of a rigid-pile composite foundation in ABAQUS. A simulation of a shaking table test on a rigid mass block is first completed with ABAQUS and EERA, and the effectiveness of the Drucker-Prager constitutive model and the finite-infinite element coupling method is proved. Dynamic time-history analysis of the overall model under frequent and rare earthquakes is carried out using <span class="hlt">seismic</span> waves from the El Centro, Kobe, and Bonds earthquakes. The different responses of rigid-pile composite foundations and pile-raft foundations are discussed. Furthermore, the influence of thickness and modulus of cushion, and ground <span class="hlt">acceleration</span> on the <span class="hlt">seismic</span> absorption effect of the cushion are analyzed. The results show that: 1) the <span class="hlt">seismic</span> absorption effect of a cushion is good under rare earthquakes, with an absorption ratio of about 0.85; and 2) the <span class="hlt">seismic</span> absorption effect is strongly affected by cushion thickness and ground <span class="hlt">acceleration</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.V54B..04M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.V54B..04M"><span>A Fracture-Mechanical Model of Crack Growth and Interaction: Application to Pre-eruptive <span class="hlt">Seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matthews, C.; Sammonds, P.; Kilburn, C.</p> <p>2007-12-01</p> <p>A greater understanding of the physical processes occurring within a volcano is a key aspect in the success of eruption forecasting. By considering the role of fracture growth, interaction and coalescence in the formation of dykes and conduits as well as the source mechanism for observed <span class="hlt">seismicity</span> we can create a more general, more applicable model for precursory <span class="hlt">seismicity</span>. The frequency of volcano-tectonic earthquakes, created by fracturing of volcanic rock, often shows a short-term increase prior to eruption. Using fracture mechanics, the model presented here aims to determine the conditions necessary for the <span class="hlt">acceleration</span> in fracture events which produces the observed pre-eruptive <span class="hlt">seismicity</span>. By focusing on the cause of <span class="hlt">seismic</span> events rather than simply the <span class="hlt">acceleration</span> patterns observed, the model also highlights the distinction between an <span class="hlt">accelerating</span> <span class="hlt">seismic</span> sequence ending with an eruption and a short-term increase which returns to background levels with no activity occurring, an event also observed in the field and an important capability if false alarms are to be avoided. This 1-D model explores the effects of a surrounding stress field and the distribution of multi-scale cracks on the interaction and coalescence of these cracks to form an open pathway for magma ascent. Similarly to <span class="hlt">seismic</span> observations in the field, and acoustic emissions data from the laboratory, exponential and hyperbolic <span class="hlt">accelerations</span> in fracturing events are recorded. Crack distribution and inter-crack distance appears to be a significant controlling factor on the evolution of the fracture network, dominating over the effects of a remote stress field. The generality of the model and its basis on fundamental fracture mechanics results makes it applicable to studies of fracture networks in numerous situations. For example looking at the differences between high temperature fracture processes and purely brittle failure the model can be similarly applied to fracture dynamics in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2012/1087/OF12-1087.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2012/1087/OF12-1087.pdf"><span><span class="hlt">Seismic</span> hazard of American Samoa and neighboring South Pacific Islands--methods, data, parameters, and results</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Petersen, Mark D.; Harmsen, Stephen C.; Rukstales, Kenneth S.; Mueller, Charles S.; McNamara, Daniel E.; Luco, Nicolas; Walling, Melanie</p> <p>2012-01-01</p> <p>American Samoa and the neighboring islands of the South Pacific lie near active tectonic-plate boundaries that host many large earthquakes which can result in strong earthquake shaking and tsunamis. To mitigate earthquake risks from future ground shaking, the Federal Emergency Management Agency requested that the U.S. Geological Survey prepare <span class="hlt">seismic</span> hazard maps that can be applied in building-design criteria. This Open-File Report describes the data, methods, and parameters used to calculate the <span class="hlt">seismic</span> shaking hazard as well as the output hazard maps, curves, and deaggregation (disaggregation) information needed for building design. Spectral <span class="hlt">acceleration</span> hazard for 1 Hertz having a 2-percent probability of exceedance on a firm rock site condition (Vs30=760 meters per second) is 0.12 <span class="hlt">acceleration</span> of gravity (1 second, 1 Hertz) and 0.32 <span class="hlt">acceleration</span> of gravity (0.2 seconds, 5 Hertz) on American Samoa, 0.72 <span class="hlt">acceleration</span> of gravity (1 Hertz) and 2.54 <span class="hlt">acceleration</span> of gravity (5 Hertz) on Tonga, 0.15 <span class="hlt">acceleration</span> of gravity (1 Hertz) and 0.55 <span class="hlt">acceleration</span> of gravity (5 Hertz) on Fiji, and 0.89 <span class="hlt">acceleration</span> of gravity (1 Hertz) and 2.77 <span class="hlt">acceleration</span> of gravity (5 Hertz) on the Vanuatu Islands.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S13C0676L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S13C0676L"><span>Amplification Factors for Spectral <span class="hlt">Acceleration</span> Using Borehole <span class="hlt">Seismic</span> Array in Taiwan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lai, T. S.; Yih-Min, W.; Chao, W. A.; Chang, C. H.</p> <p>2017-12-01</p> <p>In order to reduce the noise from surface to get the high-quality <span class="hlt">seismic</span> recordings, there are 54 borehole <span class="hlt">seismic</span> arrays have been installed in Taiwan deployed by Central Weather Bureau (CWB) until the end of 2016. Each array includes two force balance accelerometers, one at the surface and other inside the borehole, as well as one broadband seismometer inside the borehole. The downhole instruments are placed at a depth between 120 and 400 m. The background noise level are lower at the borehole stations, but the amplitudes recorded by borehole stations are smaller than surface stations for the same earthquake due to the different geology conditions. Therefore, the earthquake magnitude estimated by borehole station is smaller than surface station. So far, CWB only use the surface stations in the magnitude determination due to this situation. In this study, we investigate the site effects between surface and downhole for borehole <span class="hlt">seismic</span> arrays. Using the spectral ratio derived by the two-station spectral method as the transfer function, simulated the waveform recorded by borehole stations to the surface stations. In the future, through the transfer function, the borehole stations will be included in the estimation of earthquake magnitude and the results of amplification factors can provide the information of near-surface site effects for the ground motion simulation applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CG....113....1Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CG....113....1Z"><span>Forecasting of future earthquakes in the northeast region of India considering energy <span class="hlt">released</span> concept</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zarola, Amit; Sil, Arjun</p> <p>2018-04-01</p> <p>This study presents the forecasting of time and magnitude size of the next earthquake in the northeast India, using four probability distribution models (Gamma, Lognormal, Weibull and Log-logistic) considering updated earthquake catalog of magnitude Mw ≥ 6.0 that occurred from year 1737-2015 in the study area. On the basis of past <span class="hlt">seismicity</span> of the region, two types of conditional probabilities have been estimated using their best fit model and respective model parameters. The first conditional probability is the probability of <span class="hlt">seismic</span> energy (e × 1020 ergs), which is expected to <span class="hlt">release</span> in the future earthquake, exceeding a certain level of <span class="hlt">seismic</span> energy (E × 1020 ergs). And the second conditional probability is the probability of <span class="hlt">seismic</span> energy (a × 1020 ergs/year), which is expected to <span class="hlt">release</span> per year, exceeding a certain level of <span class="hlt">seismic</span> energy per year (A × 1020 ergs/year). The logarithm likelihood functions (ln L) were also estimated for all four probability distribution models. A higher value of ln L suggests a better model and a lower value shows a worse model. The time of the future earthquake is forecasted by dividing the total <span class="hlt">seismic</span> energy expected to <span class="hlt">release</span> in the future earthquake with the total <span class="hlt">seismic</span> energy expected to <span class="hlt">release</span> per year. The epicentre of recently occurred 4 January 2016 Manipur earthquake (M 6.7), 13 April 2016 Myanmar earthquake (M 6.9) and the 24 August 2016 Myanmar earthquake (M 6.8) are located in zone Z.12, zone Z.16 and zone Z.15, respectively and that are the identified <span class="hlt">seismic</span> source zones in the study area which show that the proposed techniques and models yield good forecasting accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JESS..121.1351K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JESS..121.1351K"><span>Deterministic <span class="hlt">seismic</span> hazard macrozonation of India</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolathayar, Sreevalsa; Sitharam, T. G.; Vipin, K. S.</p> <p>2012-10-01</p> <p>Earthquakes are known to have occurred in Indian subcontinent from ancient times. This paper presents the results of <span class="hlt">seismic</span> hazard analysis of India (6°-38°N and 68°-98°E) based on the deterministic approach using latest <span class="hlt">seismicity</span> data (up to 2010). The hazard analysis was done using two different source models (linear sources and point sources) and 12 well recognized attenuation relations considering varied tectonic provinces in the region. The earthquake data obtained from different sources were homogenized and declustered and a total of 27,146 earthquakes of moment magnitude 4 and above were listed in the study area. The sesismotectonic map of the study area was prepared by considering the faults, lineaments and the shear zones which are associated with earthquakes of magnitude 4 and above. A new program was developed in MATLAB for smoothing of the point sources. For assessing the <span class="hlt">seismic</span> hazard, the study area was divided into small grids of size 0.1° × 0.1° (approximately 10 × 10 km), and the hazard parameters were calculated at the center of each of these grid cells by considering all the <span class="hlt">seismic</span> sources within a radius of 300 to 400 km. Rock level peak horizontal <span class="hlt">acceleration</span> (PHA) and spectral <span class="hlt">accelerations</span> for periods 0.1 and 1 s have been calculated for all the grid points with a deterministic approach using a code written in MATLAB. Epistemic uncertainty in hazard definition has been tackled within a logic-tree framework considering two types of sources and three attenuation models for each grid point. The hazard evaluation without logic tree approach also has been done for comparison of the results. The contour maps showing the spatial variation of hazard values are presented in the paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70029601','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70029601"><span><span class="hlt">Seismic</span> hazard in the South Carolina coastal plain: 2002 update of the USGS national <span class="hlt">seismic</span> hazard maps</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cramer, C.H.; Mays, T.W.; ,</p> <p>2005-01-01</p> <p>The damaging 1886 moment magnitude ???7 Charleston, South Carolina earthquake is indicative of the moderately likely earthquake activity along this portion of the Atlantic Coast. A recurrence of such an earthquake today would have serious consequences for the nation. The national <span class="hlt">seismic</span> hazard maps produced by the U.S. Geological Survey (USGS) provide a picture of the levels of <span class="hlt">seismic</span> hazard across the nation based on the best and most current scientific information. The USGS national maps were updated in 2002 and will become part of the International Codes in 2006. In the past decade, improvements have occurred in the scientific understanding of the nature and character of earthquake activity and expected ground motions in the central and eastern U.S. The paper summarizes the new knowledge of expected earthquake locations, magnitudes, recurrence, and ground-motion decay with distance. New estimates of peak ground <span class="hlt">acceleration</span> and 0.2 s and 1.0 s spectral <span class="hlt">acceleration</span> are compared with those displayed in the 1996 national maps. The 2002 maps show increased <span class="hlt">seismic</span> hazard in much of the coastal plain of South Carolina, but a decrease in long period (1 s and greater) hazard by up to 20% at distances of over 50 km from the Charleston earthquake zone. Although the national maps do not account for the effects of local or regional sediments, deep coastal-plain sediments can significally alter expected ground shaking, particularly at long period motions where it can be 100% higher than the national maps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.S11A0276C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.S11A0276C"><span>Diffraction of <span class="hlt">seismic</span> waves from 3-D canyons and alluvial basins modeled using the Fast Multipole-<span class="hlt">accelerated</span> BEM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chaillat, S.; Bonnet, M.; Semblat, J.</p> <p>2007-12-01</p> <p><span class="hlt">Seismic</span> wave propagation and amplification in complex media is a major issue in the field of seismology. To compute <span class="hlt">seismic</span> wave propagation in complex geological structures such as in alluvial basins, various numerical methods have been proposed. The main advantage of the Boundary Element Method (BEM) is that only the domain boundaries (and possibly interfaces) are discretized, leading to a reduction of the number of degrees of freedom. The main drawback of the standard BEM is that the governing matrix is full and non- symmetric, which gives rise to high computational and memory costs. In other areas where the BEM is used (electromagnetism, acoustics), considerable speedup of solution time and decrease of memory requirements have been achieved through the development, over the last decade, of the Fast Multipole Method (FMM). The goal of the FMM is to speed up the matrix-vector product computation needed at each iteration of the GMRES iterative solver. Moreover, the governing matrix is never explicitly formed, which leads to a storage requirement well below the memory necessary for holding the complete matrix. The FMM-<span class="hlt">accelerated</span> BEM therefore achieves substantial savings in both CPU time and memory. In this work, the FMM is extended to the 3-D frequency-domain elastodynamics and applied to the computation of <span class="hlt">seismic</span> wave propagation in 3-D. The efficiency of the present FMM-BEM is demonstrated on seismology- oriented examples. First, the diffraction of a plane wave or a point source by a 3-D canyon is studied. The influence of the size of the meshed part of the free surface is studied, and computations are performed for non- dimensional frequencies higher than those considered in other studies (thanks to the use of the FM-BEM), with which comparisons are made whenever possible. The method is also applied to analyze the diffraction of a plane wave or a point source by a 3-D alluvial basin. A parametrical study is performed on the effect of the shape of the basin</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.geoscienceworld.org/ssa/bssa/article/108/2/781/525972/seismic-hazard-risk-and-design-for-south','USGSPUBS'); return false;" href="https://pubs.geoscienceworld.org/ssa/bssa/article/108/2/781/525972/seismic-hazard-risk-and-design-for-south"><span><span class="hlt">Seismic</span> hazard, risk, and design for South America</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Petersen, Mark D.; Harmsen, Stephen; Jaiswal, Kishor; Rukstales, Kenneth S.; Luco, Nicolas; Haller, Kathleen; Mueller, Charles; Shumway, Allison</p> <p>2018-01-01</p> <p>We calculate <span class="hlt">seismic</span> hazard, risk, and design criteria across South America using the latest data, models, and methods to support public officials, scientists, and engineers in earthquake risk mitigation efforts. Updated continental scale <span class="hlt">seismic</span> hazard models are based on a new <span class="hlt">seismicity</span> catalog, <span class="hlt">seismicity</span> rate models, evaluation of earthquake sizes, fault geometry and rate parameters, and ground‐motion models. Resulting probabilistic <span class="hlt">seismic</span> hazard maps show peak ground <span class="hlt">acceleration</span>, modified Mercalli intensity, and spectral <span class="hlt">accelerations</span> at 0.2 and 1 s periods for 2%, 10%, and 50% probabilities of exceedance in 50 yrs. Ground shaking soil amplification at each site is calculated by considering uniform soil that is applied in modern building codes or by applying site‐specific factors based on VS30">VS30 shear‐wave velocities determined through a simple topographic proxy technique. We use these hazard models in conjunction with the Prompt Assessment of Global Earthquakes for Response (PAGER) model to calculate economic and casualty risk. Risk is computed by incorporating the new hazard values amplified by soil, PAGER fragility/vulnerability equations, and LandScan 2012 estimates of population exposure. We also calculate building design values using the guidelines established in the building code provisions. Resulting hazard and associated risk is high along the northern and western coasts of South America, reaching damaging levels of ground shaking in Chile, western Argentina, western Bolivia, Peru, Ecuador, Colombia, Venezuela, and in localized areas distributed across the rest of the continent where historical earthquakes have occurred. Constructing buildings and other structures to account for strong shaking in these regions of high hazard and risk should mitigate losses and reduce casualties from effects of future earthquake strong ground shaking. National models should be developed by scientists and engineers in each country using the best</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://nsmp.wr.usgs.gov/ekalkan/PDFs/A48_Kalkan_et_al.pdf','USGSPUBS'); return false;" href="http://nsmp.wr.usgs.gov/ekalkan/PDFs/A48_Kalkan_et_al.pdf"><span><span class="hlt">Seismic</span> hazard in the Istanbul metropolitan area: A preliminary re-evaluation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kalkan, E.; Gulkan, Polat; Ozturk, N.Y.; Celebi, M.</p> <p>2008-01-01</p> <p>In 1999, two destructive earthquakes (M7.4 Kocaeli and M7.2 Duzce) occurred in the north west of Turkey and resulted in major stress-drops on the western segment of the North Anatolian Fault system where it continues under the Marmara Sea. These undersea fault segments were recently explored using bathymetric and reflection surveys. These recent findings helped to reshape the seismotectonic environment of the Marmara basin, which is a perplexing tectonic domain. Based on collected new information, <span class="hlt">seismic</span> hazard of the Marmara region, particularly Istanbul Metropolitan Area and its vicinity, were re-examined using a probabilistic approach. Two <span class="hlt">seismic</span> source and alternate recurrence models combined with various indigenous and foreign attenuation relationships were adapted within a logic tree formulation to quantify and project the regional exposure on a set of hazard maps. The hazard maps show the peak horizontal ground <span class="hlt">acceleration</span> and spectral <span class="hlt">acceleration</span> at 1.0 s. These <span class="hlt">acceleration</span> levels were computed for 2 and 10 % probabilities of transcendence in 50 years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AREPS..43..233A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AREPS..43..233A"><span>From Geodetic Imaging of <span class="hlt">Seismic</span> and Aseismic Fault Slip to Dynamic Modeling of the <span class="hlt">Seismic</span> Cycle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Avouac, Jean-Philippe</p> <p>2015-05-01</p> <p>Understanding the partitioning of <span class="hlt">seismic</span> and aseismic fault slip is central to seismotectonics as it ultimately determines the <span class="hlt">seismic</span> potential of faults. Thanks to advances in tectonic geodesy, it is now possible to develop kinematic models of the spatiotemporal evolution of slip over the <span class="hlt">seismic</span> cycle and to determine the budget of <span class="hlt">seismic</span> and aseismic slip. Studies of subduction zones and continental faults have shown that aseismic creep is common and sometimes prevalent within the seismogenic depth range. Interseismic coupling is generally observed to be spatially heterogeneous, defining locked patches of stress accumulation, to be <span class="hlt">released</span> in future earthquakes or aseismic transients, surrounded by creeping areas. Clay-rich tectonites, high temperature, and elevated pore-fluid pressure seem to be key factors promoting aseismic creep. The generally logarithmic time evolution of afterslip is a distinctive feature of creeping faults that suggests a logarithmic dependency of fault friction on slip rate, as observed in laboratory friction experiments. Most faults can be considered to be paved with interlaced patches where the friction law is either rate-strengthening, inhibiting <span class="hlt">seismic</span> rupture propagation, or rate-weakening, allowing for earthquake nucleation. The rate-weakening patches act as asperities on which stress builds up in the interseismic period; they might rupture collectively in a variety of ways. The pattern of interseismic coupling can help constrain the return period of the maximum- magnitude earthquake based on the requirement that <span class="hlt">seismic</span> and aseismic slip sum to match long-term slip. Dynamic models of the <span class="hlt">seismic</span> cycle based on this conceptual model can be tuned to reproduce geodetic and seismological observations. The promise and pitfalls of using such models to assess <span class="hlt">seismic</span> hazard are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......406A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......406A"><span>Probabilistic <span class="hlt">seismic</span> vulnerability and risk assessment of stone masonry structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abo El Ezz, Ahmad</p> <p></p> <p>Earthquakes represent major natural hazards that regularly impact the built environment in <span class="hlt">seismic</span> prone areas worldwide and cause considerable social and economic losses. The high losses incurred following the past destructive earthquakes promoted the need for assessment of the <span class="hlt">seismic</span> vulnerability and risk of the existing buildings. Many historic buildings in the old urban centers in Eastern Canada such as Old Quebec City are built of stone masonry and represent un-measurable architectural and cultural heritage. These buildings were built to resist gravity loads only and generally offer poor resistance to lateral <span class="hlt">seismic</span> loads. <span class="hlt">Seismic</span> vulnerability assessment of stone masonry buildings is therefore the first necessary step in developing <span class="hlt">seismic</span> retrofitting and pre-disaster mitigation plans. The objective of this study is to develop a set of probability-based analytical tools for efficient <span class="hlt">seismic</span> vulnerability and uncertainty analysis of stone masonry buildings. A simplified probabilistic analytical methodology for vulnerability modelling of stone masonry building with systematic treatment of uncertainties throughout the modelling process is developed in the first part of this study. Building capacity curves are developed using a simplified mechanical model. A displacement based procedure is used to develop damage state fragility functions in terms of spectral displacement response based on drift thresholds of stone masonry walls. A simplified probabilistic <span class="hlt">seismic</span> demand analysis is proposed to capture the combined uncertainty in capacity and demand on fragility functions. In the second part, a robust analytical procedure for the development of <span class="hlt">seismic</span> hazard compatible fragility and vulnerability functions is proposed. The results are given by sets of <span class="hlt">seismic</span> hazard compatible vulnerability functions in terms of structure-independent intensity measure (e.g. spectral <span class="hlt">acceleration</span>) that can be used for <span class="hlt">seismic</span> risk analysis. The procedure is very efficient for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S11C0590P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S11C0590P"><span>Strong Motion Network of Medellín and Aburrá Valley: technical advances, <span class="hlt">seismicity</span> records and micro-earthquake monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Posada, G.; Trujillo, J. C., Sr.; Hoyos, C.; Monsalve, G.</p> <p>2017-12-01</p> <p>The tectonics setting of Colombia is determined by the interaction of Nazca, Caribbean and South American plates, together with the Panama-Choco block collision, which makes a <span class="hlt">seismically</span> active region. Regional <span class="hlt">seismic</span> monitoring is carried out by the National Seismological Network of Colombia and the Accelerometer National Network of Colombia. Both networks calculate locations, magnitudes, depths and <span class="hlt">accelerations</span>, and other <span class="hlt">seismic</span> parameters. The Medellín - Aburra Valley is located in the Northern segment of the Central Cordillera of Colombia, and according to the Colombian technical <span class="hlt">seismic</span> norm (NSR-10), is a region of intermediate hazard, because of the proximity to <span class="hlt">seismic</span> sources of the Valley. <span class="hlt">Seismic</span> monitoring in the Aburra Valley began in 1996 with an accelerometer network which consisted of 38 instruments. Currently, the network consists of 26 stations and is run by the Early Warning System of Medellin and Aburra Valley (SIATA). The technical advances have allowed the real-time communication since a year ago, currently with 10 stations; post-earthquake data is processed through operationally near-real-time, obtaining quick results in terms of location, <span class="hlt">acceleration</span>, spectrum response and Fourier analysis; this information is displayed at the SIATA web site. The strong motion database is composed by 280 earthquakes; this information is the basis for the estimation of <span class="hlt">seismic</span> hazards and risk for the region. A basic statistical analysis of the main information was carried out, including the total recorded events per station, natural frequency, maximum <span class="hlt">accelerations</span>, depths and magnitudes, which allowed us to identify the main <span class="hlt">seismic</span> sources, and some <span class="hlt">seismic</span> site parameters. With the idea of a more complete <span class="hlt">seismic</span> monitoring and in order to identify <span class="hlt">seismic</span> sources beneath the Valley, we are in the process of installing 10 low-cost shake seismometers for micro-earthquake monitoring. There is no historical record of earthquakes with a magnitude</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036844','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036844"><span>Reassessment of probabilistic <span class="hlt">seismic</span> hazard in the Marmara region</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kalkan, Erol; Gulkan, Polat; Yilmaz, Nazan; Çelebi, Mehmet</p> <p>2009-01-01</p> <p>In 1999, the eastern coastline of the Marmara region (Turkey) witnessed increased <span class="hlt">seismic</span> activity on the North Anatolian fault (NAF) system with two damaging earthquakes (M 7.4 Kocaeli and M 7.2 D??zce) that occurred almost three months apart. These events have reduced stress on the western segment of the NAF where it continues under the Marmara Sea. The undersea fault segments have been recently explored using bathymetric and reflection surveys. These recent findings helped scientists to understand the seismotectonic environment of the Marmara basin, which has remained a perplexing tectonic domain. On the basis of collected new data, <span class="hlt">seismic</span> hazard of the Marmara region is reassessed using a probabilistic approach. Two different earthquake source models: (1) the smoothed-gridded <span class="hlt">seismicity</span> model and (2) fault model and alternate magnitude-frequency relations, Gutenberg-Richter and characteristic, were used with local and imported ground-motion-prediction equations. Regional exposure is computed and quantified on a set of hazard maps that provide peak horizontal ground <span class="hlt">acceleration</span> (PGA) and spectral <span class="hlt">acceleration</span> at 0.2 and 1.0 sec on uniform firm-rock site condition (760 m=sec average shear wave velocity in the upper 30 m). These <span class="hlt">acceleration</span> levels were computed for ground motions having 2% and 10% probabilities of exceedance in 50 yr, corresponding to return periods of about 2475 and 475 yr, respectively. The maximum PGA computed (at rock site) is 1.5g along the fault segments of the NAF zone extending into the Marmara Sea. The new maps generally show 10% to 15% increase for PGA, 0.2 and 1.0 sec spectral <span class="hlt">acceleration</span> values across much of Marmara compared to previous regional hazard maps. Hazard curves and smooth design spectra for three site conditions: rock, soil, and soft-soil are provided for the Istanbul metropolitan area as possible tools in future risk estimates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.V54B..06N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.V54B..06N"><span>From Magma Fracture to a <span class="hlt">Seismic</span> Magma Flow Meter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neuberg, J. W.</p> <p>2007-12-01</p> <p><span class="hlt">Seismic</span> swarms of low-frequency events occur during periods of enhanced volcanic activity and have been related to the flow of magma at depth. Often they precede a dome collapse on volcanoes like Soufriere Hills, Montserrat, or Mt St Helens. This contribution is based on the conceptual model of magma rupture as a trigger mechanism. Several source mechanisms and radiation patterns at the focus of a single event are discussed. We investigate the <span class="hlt">accelerating</span> event rate and <span class="hlt">seismic</span> amplitudes during one swarm, as well as over a time period of several swarms. The <span class="hlt">seismic</span> slip vector will be linked to magma flow parameters resulting in estimates of magma flux for a variety of flow models such as plug flow, parabolic- or friction controlled flow. In this way we try to relate conceptual models to quantitative estimations which could lead to estimations of magma flux at depth from <span class="hlt">seismic</span> low-frequency signals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSeis.tmp...20B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSeis.tmp...20B"><span><span class="hlt">Seismic</span> hazard assessment in the megacity of Blida (Algeria) and its surrounding regions using parametric-historic procedure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bellalem, Fouzi; Talbi, Abdelhak; Djellit, Hamou; Ymmel, Hayet; Mobarki, Mourad</p> <p>2018-03-01</p> <p>The region of Blida is characterized by a relatively high <span class="hlt">seismic</span> activity, pointed especially during the past two centuries. Indeed, it experienced a significant number of destructive earthquakes such as the earthquakes of March 2, 1825 and January 2, 1867, with intensity of X and IX, respectively. This study aims to investigate potential <span class="hlt">seismic</span> hazard in Blida city and its surrounding regions. For this purpose, a typical <span class="hlt">seismic</span> catalog was compiled using historical macroseismic events that occurred over a period of a few hundred years, and the recent instrumental <span class="hlt">seismicity</span> dating back to 1900. The parametric-historic procedure introduced by Kijko and Graham (1998, 1999) was applied to assess <span class="hlt">seismic</span> hazard in the study region. It is adapted to deal with incomplete catalogs and does not use any subjective delineation of active <span class="hlt">seismic</span> zones. Because of the lack of recorded strong motion data, three ground prediction models have been considered, as they seem the most adapted to the <span class="hlt">seismicity</span> of the study region. Results are presented as peak ground <span class="hlt">acceleration</span> (PGA) <span class="hlt">seismic</span> hazard maps, showing expected peak <span class="hlt">accelerations</span> with 10% probability of exceedance in 50-year period. As the most significant result, hot spot regions with high PGA values are mapped. For example, a PGA of 0.44 g has been found in a small geographical area centered on Blida city.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSeis.tmp....7M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSeis.tmp....7M"><span>Multi scenario <span class="hlt">seismic</span> hazard assessment for Egypt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mostafa, Shaimaa Ismail; Abd el-aal, Abd el-aziz Khairy; El-Eraki, Mohamed Ahmed</p> <p>2018-01-01</p> <p>Egypt is located in the northeastern corner of Africa within a sensitive seismotectonic location. Earthquakes are concentrated along the active tectonic boundaries of African, Eurasian, and Arabian plates. The study area is characterized by northward increasing sediment thickness leading to more damage to structures in the north due to multiple reflections of <span class="hlt">seismic</span> waves. Unfortunately, man-made constructions in Egypt were not designed to resist earthquake ground motions. So, it is important to evaluate the <span class="hlt">seismic</span> hazard to reduce social and economic losses and preserve lives. The probabilistic <span class="hlt">seismic</span> hazard assessment is used to evaluate the hazard using alternative seismotectonic models within a logic tree framework. Alternate seismotectonic models, magnitude-frequency relations, and various indigenous attenuation relationships were amended within a logic tree formulation to compute and develop the regional exposure on a set of hazard maps. Hazard contour maps are constructed for peak ground <span class="hlt">acceleration</span> as well as 0.1-, 0.2-, 0.5-, 1-, and 2-s spectral periods for 100 and 475 years return periods for ground motion on rock. The results illustrate that Egypt is characterized by very low to high <span class="hlt">seismic</span> activity grading from the west to the eastern part of the country. The uniform hazard spectra are estimated at some important cities distributed allover Egypt. The deaggregation of <span class="hlt">seismic</span> hazard is estimated at some cities to identify the scenario events that contribute to a selected <span class="hlt">seismic</span> hazard level. The results of this study can be used in <span class="hlt">seismic</span> microzonation, risk mitigation, and earthquake engineering purposes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSeis..22..669M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSeis..22..669M"><span>Multi scenario <span class="hlt">seismic</span> hazard assessment for Egypt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mostafa, Shaimaa Ismail; Abd el-aal, Abd el-aziz Khairy; El-Eraki, Mohamed Ahmed</p> <p>2018-05-01</p> <p>Egypt is located in the northeastern corner of Africa within a sensitive seismotectonic location. Earthquakes are concentrated along the active tectonic boundaries of African, Eurasian, and Arabian plates. The study area is characterized by northward increasing sediment thickness leading to more damage to structures in the north due to multiple reflections of <span class="hlt">seismic</span> waves. Unfortunately, man-made constructions in Egypt were not designed to resist earthquake ground motions. So, it is important to evaluate the <span class="hlt">seismic</span> hazard to reduce social and economic losses and preserve lives. The probabilistic <span class="hlt">seismic</span> hazard assessment is used to evaluate the hazard using alternative seismotectonic models within a logic tree framework. Alternate seismotectonic models, magnitude-frequency relations, and various indigenous attenuation relationships were amended within a logic tree formulation to compute and develop the regional exposure on a set of hazard maps. Hazard contour maps are constructed for peak ground <span class="hlt">acceleration</span> as well as 0.1-, 0.2-, 0.5-, 1-, and 2-s spectral periods for 100 and 475 years return periods for ground motion on rock. The results illustrate that Egypt is characterized by very low to high <span class="hlt">seismic</span> activity grading from the west to the eastern part of the country. The uniform hazard spectra are estimated at some important cities distributed allover Egypt. The deaggregation of <span class="hlt">seismic</span> hazard is estimated at some cities to identify the scenario events that contribute to a selected <span class="hlt">seismic</span> hazard level. The results of this study can be used in <span class="hlt">seismic</span> microzonation, risk mitigation, and earthquake engineering purposes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29703964','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29703964"><span>Opto-mechanical lab-on-fibre <span class="hlt">seismic</span> sensors detected the Norcia earthquake.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pisco, Marco; Bruno, Francesco Antonio; Galluzzo, Danilo; Nardone, Lucia; Gruca, Grzegorz; Rijnveld, Niek; Bianco, Francesca; Cutolo, Antonello; Cusano, Andrea</p> <p>2018-04-27</p> <p>We have designed and developed lab-on-fibre <span class="hlt">seismic</span> sensors containing a micro-opto-mechanical cavity on the fibre tip. The mechanical cavity is designed as a double cantilever suspended on the fibre end facet and connected to a proof mass to tune its response. Ground <span class="hlt">acceleration</span> leads to displacement of the cavity length, which in turn can be remotely detected using an interferometric interrogation technique. After the sensors characterization, an experimental validation was conducted at the Italian National Institute of Geophysics and Volcanology (INGV), which is responsible for <span class="hlt">seismic</span> surveillance over the Italian country. The fabricated sensors have been continuously used for long periods to demonstrate their effectiveness as <span class="hlt">seismic</span> accelerometer sensors. During the tests, fibre optic <span class="hlt">seismic</span> accelerometers clearly detected the <span class="hlt">seismic</span> sequence that culminated in the severe Mw6.5 Norcia earthquake that struck central Italy on October 30, 2016. The <span class="hlt">seismic</span> data provided by the optical sensors were analysed by specialists at the INGV. The wave traces were compared with state-of-the-art traditional sensors typically incorporated into the INGV <span class="hlt">seismic</span> networks. The comparison verifies the high fidelity of the optical sensors in <span class="hlt">seismic</span> wave detection, indicating their suitability for a novel class of <span class="hlt">seismic</span> sensors to be employed in practical scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EEEV....9..157S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EEEV....9..157S"><span>Performance-based methodology for assessing <span class="hlt">seismic</span> vulnerability and capacity of buildings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shibin, Lin; Lili, Xie; Maosheng, Gong; Ming, Li</p> <p>2010-06-01</p> <p>This paper presents a performance-based methodology for the assessment of <span class="hlt">seismic</span> vulnerability and capacity of buildings. The vulnerability assessment methodology is based on the HAZUS methodology and the improved capacitydemand-diagram method. The spectral displacement ( S d ) of performance points on a capacity curve is used to estimate the damage level of a building. The relationship between S d and peak ground <span class="hlt">acceleration</span> (PGA) is established, and then a new vulnerability function is expressed in terms of PGA. Furthermore, the expected value of the <span class="hlt">seismic</span> capacity index (SCev) is provided to estimate the <span class="hlt">seismic</span> capacity of buildings based on the probability distribution of damage levels and the corresponding <span class="hlt">seismic</span> capacity index. The results indicate that the proposed vulnerability methodology is able to assess <span class="hlt">seismic</span> damage of a large number of building stock directly and quickly following an earthquake. The SCev provides an effective index to measure the <span class="hlt">seismic</span> capacity of buildings and illustrate the relationship between the <span class="hlt">seismic</span> capacity of buildings and <span class="hlt">seismic</span> action. The estimated result is compared with damage surveys of the cities of Dujiangyan and Jiangyou in the M8.0 Wenchuan earthquake, revealing that the methodology is acceptable for <span class="hlt">seismic</span> risk assessment and decision making. The primary reasons for discrepancies between the estimated results and the damage surveys are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..128a2089L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..128a2089L"><span>Study on the application of ambient vibration tests to evaluate the effectiveness of <span class="hlt">seismic</span> retrofitting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, Li; Takaaki, Ohkubo; Guang-hui, Li</p> <p>2018-03-01</p> <p>In recent years, earthquakes have occurred frequently, and the <span class="hlt">seismic</span> performance of existing school buildings has become particularly important. The main method for improving the <span class="hlt">seismic</span> resistance of existing buildings is reinforcement. However, there are few effective methods to evaluate the effect of reinforcement. Ambient vibration measurement experiments were conducted before and after <span class="hlt">seismic</span> retrofitting using wireless measurement system and the changes of vibration characteristics were compared. The changes of <span class="hlt">acceleration</span> response spectrum, natural periods and vibration modes indicate that the wireless vibration measurement system can be effectively applied to evaluate the effect of <span class="hlt">seismic</span> retrofitting. The method can evaluate the effect of <span class="hlt">seismic</span> retrofitting qualitatively, it is difficult to evaluate the effect of <span class="hlt">seismic</span> retrofitting quantitatively at this stage.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EEEV...17..311K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EEEV...17..311K"><span>Behavior of braced excavation in sand under a <span class="hlt">seismic</span> condition: experimental and numerical studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Konai, Sanku; Sengupta, Aniruddha; Deb, Kousik</p> <p>2018-04-01</p> <p>The behavior of braced excavation in dry sand under a <span class="hlt">seismic</span> condition is investigated in this paper. A series of shake table tests on a reduced scale model of a retaining wall with one level of bracing were conducted to study the effect of different design parameters such as excavation depth, <span class="hlt">acceleration</span> amplitude and wall stiffness. Numerical analyses using FLAC 2D were also performed considering one level of bracing. The strut forces, lateral displacements and bending moments in the wall at the end of earthquake motion were compared with experimental results. The study showed that in a post-<span class="hlt">seismic</span> condition, when other factors were constant, lateral displacement, bending moment, strut forces and maximum ground surface displacement increased with excavation depth and the amplitude of base <span class="hlt">acceleration</span>. The study also showed that as wall stiffness decreased, the lateral displacement of the wall and ground surface displacement increased, but the bending moment of the wall and strut forces decreased. The net earth pressure behind the walls was influenced by excavation depth and the peak <span class="hlt">acceleration</span> amplitude, but did not change significantly with wall stiffness. Strut force was the least affected parameter when compared with others under a <span class="hlt">seismic</span> condition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70162571','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70162571"><span>Historical <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dengler, L.</p> <p>1992-01-01</p> <p>The North Coast region of California in the vicinity of Cape Mendocino is one of the state's most <span class="hlt">seismically</span> active areas, accounting for 25 percent of <span class="hlt">seismic</span> energy <span class="hlt">release</span> in California during the last 50 years. the region is located in a geologically dynamic are surrounding the Mendocino triple junction where three of the Earth's tectonic plates join together ( see preceding article by Sam Clarke). In the historic past the North Coast has been affected by earthquakes occurring on the San Andreas fault system to the south, the Mendocino fault to the southwest, and intraplate earthquakes within both the Gorda and North American plates. More than sixty of these earthquakes have caused damage since the mid-1800's. Recent studies indicate that California's North Coast is also at risk with respect to very large earthquakes (magnitude >8) originating along the Cascadia subduction zone. Although the subduction zone has not generated great earthquakes in historic time, paleoseismic evidence suggests that such earthquakes have been generated by the subduction zone in the recent prehistoric past. </p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T42A..03B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T42A..03B"><span><span class="hlt">Seismic</span> Supercycles of Normal Faults in Central Italy over Various Time Scales Revealed by 36Cl Cosmogenic Dating</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benedetti, L. C.; Tesson, J.; Perouse, E.; Puliti, I.; Fleury, J.; Rizza, M.; Billant, J.; Pace, B.</p> <p>2017-12-01</p> <p>The use of 36Cl cosmogenic nuclide as a paleoseismological tool for normal faults in the Mediterranean has revolutionized our understanding of their <span class="hlt">seismic</span> cycle (Gran Mitchell et al. 2001, Benedetti et al. 2002). Here we synthetized results obtained on 13 faults in Central Italy. Those records cover a period of 8 to 45 ka. The mean recurrence time of retrieved <span class="hlt">seismic</span> events is 5.5 ±6 ka, with a mean slip per event of 2.5 ± 1.8 m and a mean slip-rate from 0.1 to 2.4 mm/yr. Most retrieved events correspond to single events according to scaling relationships. This is also supported by the 2 m-high co-<span class="hlt">seismic</span> slip observed on the Mt Vettore fault after the October 30, 2016 M6.5 earthquake in Central Italy (EMERGEO working group). Our results suggest that all faults have experienced one or several periods of slip <span class="hlt">acceleration</span> with bursts of <span class="hlt">seismic</span> activity, associated with very high slip-rate of 1.7-9 mm/yr, corresponding to 2-20 times their long-term slip-rate. The duration of those bursts is variable from a fault to another (from < 2 kyr to 4-10 kyr). Those periods of <span class="hlt">acceleration</span> are generally separated by longer periods of quiescence with no or very few events. Those alternating periods correspond to a long-term variation of the strain level with all faults oscillating between strain maximum and minimum, the length of strain loading and <span class="hlt">release</span> being significantly different from one fault to another, those supercycles occurring over periods of 8 to 45 ka. We found relationships between the mean slip-rate, the mean slip per event and the mean recurrence time. This might suggest that the <span class="hlt">seismic</span> activity of those faults could be controlled by their intrinsic properties (e.g. long-term slip-rate, fault-length, state of structural maturity). Our results also show events clustering with several faults rupturing in less than 500 yrs on adjacent or distant faults within the studied area. The Norcia-Amatrice <span class="hlt">seismic</span> sequence, ≈ 50 km north of our study area, also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29559404','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29559404"><span>Tablet fragmentation without a disintegrant: A novel design approach for <span class="hlt">accelerating</span> disintegration and drug <span class="hlt">release</span> from 3D printed cellulosic tablets.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Arafat, Basel; Wojsz, Magdalena; Isreb, Abdullah; Forbes, Robert T; Isreb, Mohammad; Ahmed, Waqar; Arafat, Tawfiq; Alhnan, Mohamed A</p> <p>2018-06-15</p> <p>Fused deposition modelling (FDM) 3D printing has shown the most immediate potential for on-demand dose personalisation to suit particular patient's needs. However, FDM 3D printing often involves employing a relatively large molecular weight thermoplastic polymer and results in extended <span class="hlt">release</span> pattern. It is therefore essential to fast-track drug <span class="hlt">release</span> from the 3D printed objects. This work employed an innovative design approach of tablets with unique built-in gaps (Gaplets) with the aim of <span class="hlt">accelerating</span> drug <span class="hlt">release</span>. The novel tablet design is composed of 9 repeating units (blocks) connected with 3 bridges to allow the generation of 8 gaps. The impact of size of the block, the number of bridges and the spacing between different blocks was investigated. Increasing the inter-block space reduced mechanical resistance of the unit, however, tablets continued to meet pharmacopeial standards for friability. Upon introduction into gastric medium, the 1 mm spaces gaplet broke into mini-structures within 4 min and met the USP criteria of immediate <span class="hlt">release</span> products (86.7% drug <span class="hlt">release</span> at 30 min). Real-time ultraviolet (UV) imaging indicated that the cellulosic matrix expanded due to swelling of hydroxypropyl cellulose (HPC) upon introduction to the dissolution medium. This was followed by a steady erosion of the polymeric matrix at a rate of 8 μm/min. The design approach was more efficient than a comparison conventional formulation approach of adding disintegrants to <span class="hlt">accelerate</span> tablet disintegration and drug <span class="hlt">release</span>. This work provides a novel example where computer-aided design was instrumental at modifying the performance of solid dosage forms. Such an example may serve as the foundation for a new generation of dosage forms with complicated geometric structures to achieve functionality that is usually achieved by a sophisticated formulation approach. Copyright © 2018 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70022856','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70022856"><span>USGS National <span class="hlt">Seismic</span> Hazard Maps</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Frankel, A.D.; Mueller, C.S.; Barnhard, T.P.; Leyendecker, E.V.; Wesson, R.L.; Harmsen, S.C.; Klein, F.W.; Perkins, D.M.; Dickman, N.C.; Hanson, S.L.; Hopper, M.G.</p> <p>2000-01-01</p> <p>The U.S. Geological Survey (USGS) recently completed new probabilistic <span class="hlt">seismic</span> hazard maps for the United States, including Alaska and Hawaii. These hazard maps form the basis of the probabilistic component of the design maps used in the 1997 edition of the NEHRP Recommended Provisions for <span class="hlt">Seismic</span> Regulations for New Buildings and Other Structures, prepared by the Building <span class="hlt">Seismic</span> Safety Council arid published by FEMA. The hazard maps depict peak horizontal ground <span class="hlt">acceleration</span> and spectral response at 0.2, 0.3, and 1.0 sec periods, with 10%, 5%, and 2% probabilities of exceedance in 50 years, corresponding to return times of about 500, 1000, and 2500 years, respectively. In this paper we outline the methodology used to construct the hazard maps. There are three basic components to the maps. First, we use spatially smoothed historic <span class="hlt">seismicity</span> as one portion of the hazard calculation. In this model, we apply the general observation that moderate and large earthquakes tend to occur near areas of previous small or moderate events, with some notable exceptions. Second, we consider large background source zones based on broad geologic criteria to quantify hazard in areas with little or no historic <span class="hlt">seismicity</span>, but with the potential for generating large events. Third, we include the hazard from specific fault sources. We use about 450 faults in the western United States (WUS) and derive recurrence times from either geologic slip rates or the dating of pre-historic earthquakes from trenching of faults or other paleoseismic methods. Recurrence estimates for large earthquakes in New Madrid and Charleston, South Carolina, were taken from recent paleoliquefaction studies. We used logic trees to incorporate different <span class="hlt">seismicity</span> models, fault recurrence models, Cascadia great earthquake scenarios, and ground-motion attenuation relations. We present disaggregation plots showing the contribution to hazard at four cities from potential earthquakes with various magnitudes and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800025279','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800025279"><span>An enhancement of NASTRAN for the <span class="hlt">seismic</span> analysis of structures. [nuclear power plants</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burroughs, J. W.</p> <p>1980-01-01</p> <p>New modules, bulk data cards and DMAP sequence were added to NASTRAN to aid in the <span class="hlt">seismic</span> analysis of nuclear power plant structures. These allow input consisting of <span class="hlt">acceleration</span> time histories and result in the generation of <span class="hlt">acceleration</span> floor response spectra. The resulting system contains numerous user convenience features, as well as being reasonably efficient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812243B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812243B"><span>Exploring uncertainties in probabilistic <span class="hlt">seismic</span> hazard estimates for Quito</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beauval, Celine; Yepes, Hugo; Audin, Laurence; Alvarado, Alexandra; Nocquet, Jean-Mathieu</p> <p>2016-04-01</p> <p>In the present study, probabilistic <span class="hlt">seismic</span> hazard estimates at 475 years return period for Quito, capital city of Ecuador, show that the crustal host zone is the only source zone that determines the city's hazard levels for such return period. Therefore, the emphasis is put on identifying the uncertainties characterizing the host zone, i.e. uncertainties in the recurrence of earthquakes expected in the zone and uncertainties on the ground motions that these earthquakes may produce. As the number of local strong-ground motions is still scant, ground-motion prediction equations are imported from other regions. Exploring recurrence models for the host zone based on different observations and assumptions, and including three GMPE candidates (Akkar and Bommer 2010, Zhao et al. 2006, Boore and Atkinson 2008), we obtain a significant variability on the estimated <span class="hlt">acceleration</span> at 475 years (site coordinates: -78.51 in longitude and -0.2 in latitude, VS30 760 m/s): 1) Considering historical earthquake catalogs, and relying on frequency-magnitude distributions where rates for magnitudes 6-7 are extrapolated from statistics of magnitudes 4.5-6.0 mostly in the 20th century, the <span class="hlt">acceleration</span> at the PGA varies between 0.28g and 0.55g with a mean value around 0.4g. The results show that both the uncertainties in the GMPE choice and in the <span class="hlt">seismicity</span> model are responsible for this variability. 2) Considering slip rates inferred form geodetic measurements across the Quito fault system, and assuming that most of the deformation occurs <span class="hlt">seismically</span> (conservative hypothesis), leads to a much greater range of <span class="hlt">accelerations</span>, 0.43 to 0.73g for the PGA (with a mean of 0.55g). 3) Considering slip rates inferred from geodetic measurements, and assuming that 50% only of the deformation is <span class="hlt">released</span> in earthquakes (partially locked fault, model based on 15 years of GPS data), leads to a range of <span class="hlt">accelerations</span> 0.32g to 0.58g for the PGA, with a mean of 0.42g. These <span class="hlt">accelerations</span> are in agreement</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..143a2048N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..143a2048N"><span>Performance of Single Friction Pendulum bearing for isolated buildings subjected to <span class="hlt">seismic</span> actions in Vietnam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nguyen, N. V.; Nguyen, C. H.; Hoang, H. P.; Huong, K. T.</p> <p>2018-04-01</p> <p>Using structural control technology in earthquake resistant design of buildings in Vietnam is very limited. In this paper, a performance evaluation of using Single Friction Pendulum (SFP) bearing for <span class="hlt">seismically</span> isolated buildings with earthquake conditions in Vietnam is presented. A two-dimensional (2-D) model of the 5-storey building subjected to earthquakes is analyzed in time domain. Accordingly, the model is analyzed for 2 cases: with and without SFP bearing. The ground <span class="hlt">acceleration</span> data is selected and scaled to suit the design <span class="hlt">acceleration</span> in Hanoi followed by the Standard TCVN 9386:2012. It is shown that the <span class="hlt">seismically</span> isolated buildings gets the performance objectives while achieving an 91% reduction in the base shear, a significant decrease in the inter-story drift and absolute <span class="hlt">acceleration</span> of each story.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20800043-seismic-hazard-assessment-baku-city-absheron-peninsula-azerbaijan','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20800043-seismic-hazard-assessment-baku-city-absheron-peninsula-azerbaijan"><span><span class="hlt">Seismic</span> Hazard Assessment for the Baku City and Absheron Peninsula, Azerbaijan</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Babayev, Gulam R.</p> <p>2006-03-23</p> <p>This paper deals with the <span class="hlt">seismic</span> hazard assessment for Baku and the Absheron peninsula. The assessment is based on the information on the features of earthquake ground motion excitation, <span class="hlt">seismic</span> wave propagation (attenuation), and site effect. I analyze active faults, <span class="hlt">seismicity</span>, soil and rock properties, geological cross-sections, the borehole data of measured shear-wave velocity, lithology, amplification factor of each geological unit, geomorphology, topography, and basic rock and surface ground motions. To estimate peak ground <span class="hlt">acceleration</span> (PGA) at the surface, PGA at the basic rock is multiplied by the amplification parameter of each surface layers. Quaternary soft deposits, representing a highmore » risk due to increasing PGA values at surface, are studied in detail. For a near-zone target earthquake PGA values are compared to intensity at MSK-64 scale for the Absheron peninsula. The amplification factor for the Baku city is assessed and provides estimations for a level of a <span class="hlt">seismic</span> motion and <span class="hlt">seismic</span> intensity of the studied area.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3282S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3282S"><span><span class="hlt">Seismic</span> imaging of post-glacial sediments - test study before Spitsbergen expedition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Szalas, Joanna; Grzyb, Jaroslaw; Majdanski, Mariusz</p> <p>2017-04-01</p> <p>This work presents results of the analysis of reflection <span class="hlt">seismic</span> data acquired from testing area in central Poland. For this experiment we used total number of 147 vertical component <span class="hlt">seismic</span> stations (DATA-CUBE and Reftek "Texan") with <span class="hlt">accelerated</span> weight drop (PEG-40). The profile was 350 metres long. It is a part of pilot study for future research project on Spitsbergen. The purpose of the study is to recognise the characteristics of <span class="hlt">seismic</span> response of post-glacial sediments in order to design the most adequate survey acquisition parameters and processing sequence for data from Spitsbergen. Multiple tests and comparisons have been performed to obtain the best possible quality of <span class="hlt">seismic</span> image. In this research we examine the influence of receiver interval size, front mute application and surface wave attenuation attempts. Although <span class="hlt">seismic</span> imaging is the main technique we are planning to support this analysis with additional data from traveltime tomography, MASW and other a priori information.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4746M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4746M"><span>Uncertainties in evaluation of hazard and <span class="hlt">seismic</span> risk</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marmureanu, Gheorghe; Marmureanu, Alexandru; Ortanza Cioflan, Carmen; Manea, Elena-Florinela</p> <p>2015-04-01</p> <p>Two methods are commonly used for <span class="hlt">seismic</span> hazard assessment: probabilistic (PSHA) and deterministic(DSHA) <span class="hlt">seismic</span> hazard analysis.Selection of a ground motion for engineering design requires a clear understanding of <span class="hlt">seismic</span> hazard and risk among stakeholders, seismologists and engineers. What is wrong with traditional PSHA or DSHA ? PSHA common used in engineering is using four assumptions developed by Cornell in 1968:(1)-Constant-in-time average occurrence rate of earthquakes; (2)-Single point source; (3).Variability of ground motion at a site is independent;(4)-Poisson(or "memory - less") behavior of earthquake occurrences. It is a probabilistic method and "when the causality dies, its place is taken by probability, prestigious term meant to define the inability of us to predict the course of nature"(Nils Bohr). DSHA method was used for the original design of Fukushima Daichii, but Japanese authorities moved to probabilistic assessment methods and the probability of exceeding of the design basis <span class="hlt">acceleration</span> was expected to be 10-4-10-6 . It was exceeded and it was a violation of the principles of deterministic hazard analysis (ignoring historical events)(Klügel,J,U, EGU,2014, ISSO). PSHA was developed from mathematical statistics and is not based on earthquake science(invalid physical models- point source and Poisson distribution; invalid mathematics; misinterpretation of annual probability of exceeding or return period etc.) and become a pure numerical "creation" (Wang, PAGEOPH.168(2011),11-25). An uncertainty which is a key component for <span class="hlt">seismic</span> hazard assessment including both PSHA and DSHA is the ground motion attenuation relationship or the so-called ground motion prediction equation (GMPE) which describes a relationship between a ground motion parameter (i.e., PGA,MMI etc.), earthquake magnitude M, source to site distance R, and an uncertainty. So far, no one is taking into consideration strong nonlinear behavior of soils during of strong earthquakes. But</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S51A2291K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S51A2291K"><span>Building a Smartphone <span class="hlt">Seismic</span> Network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kong, Q.; Allen, R. M.</p> <p>2013-12-01</p> <p>We are exploring to build a new type of <span class="hlt">seismic</span> network by using the smartphones. The accelerometers in smartphones can be used to record earthquakes, the GPS unit can give an accurate location, and the built-in communication unit makes the communication easier for this network. In the future, these smartphones may work as a supplement network to the current traditional network for scientific research and real-time applications. In order to build this network, we developed an application for android phones and server to record the <span class="hlt">acceleration</span> in real time. These records can be sent back to a server in real time, and analyzed at the server. We evaluated the performance of the smartphone as a <span class="hlt">seismic</span> recording instrument by comparing them with high quality accelerometer while located on controlled shake tables for a variety of tests, and also the noise floor test. Based on the daily human activity data recorded by the volunteers and the shake table tests data, we also developed algorithm for the smartphones to detect earthquakes from daily human activities. These all form the basis of setting up a new prototype smartphone <span class="hlt">seismic</span> network in the near future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..MAR.F9002H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..MAR.F9002H"><span>Induced <span class="hlt">Seismicity</span> Potential of Energy Technologies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hitzman, Murray</p> <p>2013-03-01</p> <p>Earthquakes attributable to human activities-``induced <span class="hlt">seismic</span> events''-have received heightened public attention in the United States over the past several years. Upon request from the U.S. Congress and the Department of Energy, the National Research Council was asked to assemble a committee of experts to examine the scale, scope, and consequences of <span class="hlt">seismicity</span> induced during fluid injection and withdrawal associated with geothermal energy development, oil and gas development, and carbon capture and storage (CCS). The committee's report, publicly <span class="hlt">released</span> in June 2012, indicates that induced <span class="hlt">seismicity</span> associated with fluid injection or withdrawal is caused in most cases by change in pore fluid pressure and/or change in stress in the subsurface in the presence of faults with specific properties and orientations and a critical state of stress in the rocks. The factor that appears to have the most direct consequence in regard to induced <span class="hlt">seismicity</span> is the net fluid balance (total balance of fluid introduced into or removed from the subsurface). Energy technology projects that are designed to maintain a balance between the amount of fluid being injected and withdrawn, such as most oil and gas development projects, appear to produce fewer <span class="hlt">seismic</span> events than projects that do not maintain fluid balance. Major findings from the study include: (1) as presently implemented, the process of hydraulic fracturing for shale gas recovery does not pose a high risk for inducing felt <span class="hlt">seismic</span> events; (2) injection for disposal of waste water derived from energy technologies does pose some risk for induced <span class="hlt">seismicity</span>, but very few events have been documented over the past several decades relative to the large number of disposal wells in operation; and (3) CCS, due to the large net volumes of injected fluids suggested for future large-scale carbon storage projects, may have potential for inducing larger <span class="hlt">seismic</span> events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24994652','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24994652"><span>Earthquake dynamics. Mapping pressurized volcanic fluids from induced crustal <span class="hlt">seismic</span> velocity drops.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brenguier, F; Campillo, M; Takeda, T; Aoki, Y; Shapiro, N M; Briand, X; Emoto, K; Miyake, H</p> <p>2014-07-04</p> <p>Volcanic eruptions are caused by the <span class="hlt">release</span> of pressure that has accumulated due to hot volcanic fluids at depth. Here, we show that the extent of the regions affected by pressurized fluids can be imaged through the measurement of their response to transient stress perturbations. We used records of <span class="hlt">seismic</span> noise from the Japanese Hi-net <span class="hlt">seismic</span> network to measure the crustal <span class="hlt">seismic</span> velocity changes below volcanic regions caused by the 2011 moment magnitude (M(w)) 9.0 Tohoku-Oki earthquake. We interpret coseismic crustal <span class="hlt">seismic</span> velocity reductions as related to the mechanical weakening of the pressurized crust by the dynamic stress associated with the <span class="hlt">seismic</span> waves. We suggest, therefore, that mapping <span class="hlt">seismic</span> velocity susceptibility to dynamic stress perturbations can be used for the imaging and characterization of volcanic systems. Copyright © 2014, American Association for the Advancement of Science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70015987','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70015987"><span><span class="hlt">Acceleration</span> spectra for subduction zone earthquakes</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Boatwright, J.; Choy, G.L.</p> <p>1989-01-01</p> <p>We estimate the source spectra of shallow earthquakes from digital recordings of teleseismic P wave groups, that is, P+pP+sP, by making frequency dependent corrections for the attenuation and for the interference of the free surface. The correction for the interference of the free surface assumes that the earthquake radiates energy from a range of depths. We apply this spectral analysis to a set of 12 subduction zone earthquakes which range in size from Ms = 6.2 to 8.1, obtaining corrected P wave <span class="hlt">acceleration</span> spectra on the frequency band from 0.01 to 2.0 Hz. <span class="hlt">Seismic</span> moment estimates from surface waves and normal modes are used to extend these P wave spectra to the frequency band from 0.001 to 0.01 Hz. The <span class="hlt">acceleration</span> spectra of large subduction zone earthquakes, that is, earthquakes whose <span class="hlt">seismic</span> moments are greater than 1027 dyn cm, exhibit intermediate slopes where u(w)???w5/4 for frequencies from 0.005 to 0.05 Hz. For these earthquakes, spectral shape appears to be a discontinuous function of <span class="hlt">seismic</span> moment. Using reasonable assumptions for the phase characteristics, we transform the spectral shape observed for large earthquakes into the time domain to fit Ekstrom's (1987) moment rate functions for the Ms=8.1 Michoacan earthquake of September 19, 1985, and the Ms=7.6 Michoacan aftershock of September 21, 1985. -from Authors</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S41B0744L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S41B0744L"><span>Microzonation of <span class="hlt">Seismic</span> Hazard Potential in Taipei, Taiwan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, K. S.; Lin, Y. P.</p> <p>2017-12-01</p> <p>The island of Taiwan lies at the boundary between the Philippine Sea plate and the Eurasia plate. Accordingly, the majority of <span class="hlt">seismic</span> energy <span class="hlt">release</span> near Taiwan originates from the two subduction zones. It is therefore not surprising that Taiwan has repeatedly been struck by large earthquakes such as 1986 Hualien earthquake, 1999 Chi Chi and 2002 Hualien earthquake. Microzonation of <span class="hlt">seismic</span> hazard potential becomes necessary in Taipei City for the Central Geological Survey announced the Sanchiao active fault as Category II. In this study, a catalog of more than 2000 shallow earthquakes occurred from 1900 to 2015 with Mw magnitudes ranging from 5.0 to 8.2, and 11 disastrous earthquakes occurred from 1683-1899, as well as Sanchiao active fault in the vicinity are used to estimate the <span class="hlt">seismic</span> hazard potential in Taipei City for <span class="hlt">seismic</span> microzonation. Furthermore, the probabilities of <span class="hlt">seismic</span> intensity exceeding CWB intensity 5, 6, 7 and MMI VI, VII, VIII in 10, 30, and 50-year periods in the above areas are also analyzed for the <span class="hlt">seismic</span> microzonation. Finally, by comparing with the <span class="hlt">seismic</span> zoning map of Taiwan in current building code that was revised after 921 earthquakes, Results of this study will show which areas with higher earthquake hazard potential in Taipei City. They provide a valuable database for the <span class="hlt">seismic</span> design of critical facilities. It will help mitigate Taipei City earthquake disaster loss in the future, as well as provide critical information for emergency response plans.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/pp/0544e/pp544e_text.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/pp/0544e/pp544e_text.pdf"><span><span class="hlt">Seismic</span> seiches from the March 1964 Alaska earthquake: Chapter E in The Alaska earthquake, March 27, 1964: effects on hydrologic regimen</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McGarr, Arthur; Vorhis, Robert C.</p> <p>1968-01-01</p> <p><span class="hlt">Seismic</span> seiches caused by the Alaska earthquake of March 27, 1964, were recorded at more than 850 surface-water gaging stations in North America and at 4 in Australia. In the United States, including Alaska and Hawaii, 763 of 6,435 gages registered seiches. Nearly all the <span class="hlt">seismic</span> seiches were recorded at teleseismic distance. This is the first time such far-distant effects have been reported from surface-water bodies in North America. The densest occurrence of seiches was in States bordering the Gulf of Mexico. The seiches were recorded on bodies of water having a wide range in depth, width, and rate of flow. In a region containing many bodies of water, seiche distribution is more dependent on geologic and <span class="hlt">seismic</span> factors than on hydro-dynamic ones. The concept that seiches are caused by the horizontal <span class="hlt">acceleration</span> of water by <span class="hlt">seismic</span> surface waves has been extended in this paper to show that the distribution of seiches is related to the amplitude distribution of short-period <span class="hlt">seismic</span> surface waves. These waves have their greatest horizontal <span class="hlt">acceleration</span> when their periods range from 5 to 15 seconds. Similarly, the water bodies on which seiches were recorded have low-order modes whose periods of oscillation also range from 5 to 15 seconds. Several factors seem to control the distribution of seiches. The most important is variations of thickness of low-rigidity sediments. This factor caused the abundance of seiches in the Gulf Coast area and along the edge of sedimentary overlaps. Major tectonic features such as thrust faults, basins, arches, and domes seem to control <span class="hlt">seismic</span> waves and thus affect the distribution of seiches. Lateral refraction of <span class="hlt">seismic</span> surface waves due to variations in local phase-velocity values was responsible for increase in seiche density in certain areas. For example, the Rocky Mountains provided a wave guide along which seiches were more numerous than in areas to either side. In North America, neither direction nor distance from the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10684570','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10684570"><span>Corticotropin-<span class="hlt">releasing</span> factor <span class="hlt">accelerates</span> metamorphosis in Bufo arenarum: effect on pituitary ACTH and TSH cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miranda, L A; Affanni, J M; Paz, D A</p> <p>2000-04-01</p> <p>The actions of several neuropeptides as hypothalamic mediators in the regulation of Bufo arenarum metamorphosis were investigated. Prometamorphic larvae were injected with 1.5 microg thyrotropin-<span class="hlt">releasing</span> hormone (TRH), 2 microg ovine corticotropin-<span class="hlt">releasing</span> factor (oCRF), 2 microg mammalian gonadotropin-<span class="hlt">releasing</span> hormone (mGnRH), 2 microg human growth hormone-<span class="hlt">releasing</span> hormone (hGHRH), or Holtfreter solution (control group). Larvae received two injections with the same dose: one at the beginning of the experiment and the other 7 days later. Several morphologic parameters (total length, tail length, wet weight, hind limb length, and metamorphic stages) were measured as indicators of growth and metamorphic development. These measurements were taken in 20 larvae per treatment or control group at the beginning of the experiment, at day 7 and at day 14 when the experiment ended. We observed that only the administration of exogenous CRF stimulated resorption of the tail and <span class="hlt">accelerated</span> the rate of metamorphosis. In the pituitary of CRF-treated larvae we observed that thyrotropin (TSH) and adrenocorticotropic hormone (ACTH) producing cells showed a weaker immunoreactivity, a decrease in cell number and a reduction of volume density when compared with normal larvae. In conclusion, the results obtained indicate a possible role for CRF in Bufo arenarum metamorphosis. CRF may regulate interrenal and thyroid activity by acting directly upon TSH and ACTH cells. On the other hand, TRH, GnRH and GHRH were inactive in stimulating growth or metamorphosis of Bufo arenarum. J. Exp. Zool. 286:473-480, 2000. Copyright 2000 Wiley-Liss, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8789R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8789R"><span>Scenario based <span class="hlt">seismic</span> hazard assessment and its application to the <span class="hlt">seismic</span> verification of relevant buildings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Romanelli, Fabio; Vaccari, Franco; Altin, Giorgio; Panza, Giuliano</p> <p>2016-04-01</p> <p>The procedure we developed, and applied to a few relevant cases, leads to the <span class="hlt">seismic</span> verification of a building by: a) use of a scenario based neodeterministic approach (NDSHA) for the calculation of the <span class="hlt">seismic</span> input, and b) control of the numerical modeling of an existing building, using free vibration measurements of the real structure. The key point of this approach is the strict collaboration, from the <span class="hlt">seismic</span> input definition to the monitoring of the response of the building in the calculation phase, of the seismologist and the civil engineer. The vibrometry study allows the engineer to adjust the computational model in the direction suggested by the experimental result of a physical measurement. Once the model has been calibrated by vibrometric analysis, one can select in the design spectrum the proper range of periods of interest for the structure. Then, the realistic values of spectral <span class="hlt">acceleration</span>, which include the appropriate amplification obtained through the modeling of a "scenario" input to be applied to the final model, can be selected. Generally, but not necessarily, the "scenario" spectra lead to higher <span class="hlt">accelerations</span> than those deduced by taking the spectra from the national codes (i.e. NTC 2008, for Italy). The task of the verifier engineer is to act so that the solution of the verification is conservative and realistic. We show some examples of the application of the procedure to some relevant (e.g. schools) buildings of the Trieste Province. The adoption of the scenario input has given in most of the cases an increase of critical elements that have to be taken into account in the design of reinforcements. However, the higher cost associated with the increase of elements to reinforce is reasonable, especially considering the important reduction of the risk level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23B..02M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23B..02M"><span>The New Italian <span class="hlt">Seismic</span> Hazard Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marzocchi, W.; Meletti, C.; Albarello, D.; D'Amico, V.; Luzi, L.; Martinelli, F.; Pace, B.; Pignone, M.; Rovida, A.; Visini, F.</p> <p>2017-12-01</p> <p>In 2015 the <span class="hlt">Seismic</span> Hazard Center (Centro Pericolosità Sismica - CPS) of the National Institute of Geophysics and Volcanology was commissioned of coordinating the national scientific community with the aim to elaborate a new reference <span class="hlt">seismic</span> hazard model, mainly finalized to the update of <span class="hlt">seismic</span> code. The CPS designed a roadmap for <span class="hlt">releasing</span> within three years a significantly renewed PSHA model, with regard both to the updated input elements and to the strategies to be followed. The main requirements of the model were discussed in meetings with the experts on earthquake engineering that then will participate to the revision of the building code. The activities were organized in 6 tasks: program coordination, input data, <span class="hlt">seismicity</span> models, ground motion predictive equations (GMPEs), computation and rendering, testing. The input data task has been selecting the most updated information about <span class="hlt">seismicity</span> (historical and instrumental), seismogenic faults, and deformation (both from <span class="hlt">seismicity</span> and geodetic data). The <span class="hlt">seismicity</span> models have been elaborating in terms of classic source areas, fault sources and gridded <span class="hlt">seismicity</span> based on different approaches. The GMPEs task has selected the most recent models accounting for their tectonic suitability and forecasting performance. The testing phase has been planned to design statistical procedures to test with the available data the whole <span class="hlt">seismic</span> hazard models, and single components such as the <span class="hlt">seismicity</span> models and the GMPEs. In this talk we show some preliminary results, summarize the overall strategy for building the new Italian PSHA model, and discuss in detail important novelties that we put forward. Specifically, we adopt a new formal probabilistic framework to interpret the outcomes of the model and to test it meaningfully; this requires a proper definition and characterization of both aleatory variability and epistemic uncertainty that we accomplish through an ensemble modeling strategy. We use a weighting scheme</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2015/1070/pdf/ofr2015-1070.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2015/1070/pdf/ofr2015-1070.pdf"><span>Incorporating induced <span class="hlt">seismicity</span> in the 2014 United States National <span class="hlt">Seismic</span> Hazard Model: results of the 2014 workshop and sensitivity studies</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Petersen, Mark D.; Mueller, Charles S.; Moschetti, Morgan P.; Hoover, Susan M.; Rubinstein, Justin L.; Llenos, Andrea L.; Michael, Andrew J.; Ellsworth, William L.; McGarr, Arthur F.; Holland, Austin A.; Anderson, John G.</p> <p>2015-01-01</p> <p>The U.S. Geological Survey National <span class="hlt">Seismic</span> Hazard Model for the conterminous United States was updated in 2014 to account for new methods, input models, and data necessary for assessing the <span class="hlt">seismic</span> ground shaking hazard from natural (tectonic) earthquakes. The U.S. Geological Survey National <span class="hlt">Seismic</span> Hazard Model project uses probabilistic <span class="hlt">seismic</span> hazard analysis to quantify the rate of exceedance for earthquake ground shaking (ground motion). For the 2014 National <span class="hlt">Seismic</span> Hazard Model assessment, the <span class="hlt">seismic</span> hazard from potentially induced earthquakes was intentionally not considered because we had not determined how to properly treat these earthquakes for the <span class="hlt">seismic</span> hazard analysis. The phrases “potentially induced” and “induced” are used interchangeably in this report, however it is acknowledged that this classification is based on circumstantial evidence and scientific judgment. For the 2014 National <span class="hlt">Seismic</span> Hazard Model update, the potentially induced earthquakes were removed from the NSHM’s earthquake catalog, and the documentation states that we would consider alternative models for including induced <span class="hlt">seismicity</span> in a future version of the National <span class="hlt">Seismic</span> Hazard Model. As part of the process of incorporating induced <span class="hlt">seismicity</span> into the <span class="hlt">seismic</span> hazard model, we evaluate the sensitivity of the <span class="hlt">seismic</span> hazard from induced <span class="hlt">seismicity</span> to five parts of the hazard model: (1) the earthquake catalog, (2) earthquake rates, (3) earthquake locations, (4) earthquake Mmax (maximum magnitude), and (5) earthquake ground motions. We describe alternative input models for each of the five parts that represent differences in scientific opinions on induced <span class="hlt">seismicity</span> characteristics. In this report, however, we do not weight these input models to come up with a preferred final model. Instead, we present a sensitivity study showing uniform <span class="hlt">seismic</span> hazard maps obtained by applying the alternative input models for induced <span class="hlt">seismicity</span>. The final model will be <span class="hlt">released</span> after</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812914K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812914K"><span>Probabilistic <span class="hlt">seismic</span> hazard study based on active fault and finite element geodynamic models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kastelic, Vanja; Carafa, Michele M. C.; Visini, Francesco</p> <p>2016-04-01</p> <p>We present a probabilistic <span class="hlt">seismic</span> hazard analysis (PSHA) that is exclusively based on active faults and geodynamic finite element input models whereas <span class="hlt">seismic</span> catalogues were used only in a posterior comparison. We applied the developed model in the External Dinarides, a slow deforming thrust-and-fold belt at the contact between Adria and Eurasia.. is the Our method consists of establishing s two earthquake rupture forecast models: (i) a geological active fault input (GEO) model and, (ii) a finite element (FEM) model. The GEO model is based on active fault database that provides information on fault location and its geometric and kinematic parameters together with estimations on its slip rate. By default in this model all deformation is set to be <span class="hlt">released</span> along the active faults. The FEM model is based on a numerical geodynamic model developed for the region of study. In this model the deformation is, besides along the active faults, <span class="hlt">released</span> also in the volumetric continuum elements. From both models we calculated their corresponding activity rates, its earthquake rates and their final expected peak ground <span class="hlt">accelerations</span>. We investigated both the source model and the earthquake model uncertainties by varying the main active fault and earthquake rate calculation parameters through constructing corresponding branches of the <span class="hlt">seismic</span> hazard logic tree. Hazard maps and UHS curves have been produced for horizontal ground motion on bedrock conditions VS 30 ≥ 800 m/s), thereby not considering local site amplification effects. The hazard was computed over a 0.2° spaced grid considering 648 branches of the logic tree and the mean value of 10% probability of exceedance in 50 years hazard level, while the 5th and 95th percentiles were also computed to investigate the model limits. We conducted a sensitivity analysis to control which of the input parameters influence the final hazard results in which measure. The results of such comparison evidence the deformation model and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26046355','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26046355"><span><span class="hlt">Release</span> of Phosphorylated HSP27 (HSPB1) from Platelets Is Accompanied with the <span class="hlt">Acceleration</span> of Aggregation in Diabetic Patients.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tokuda, Haruhiko; Kuroyanagi, Gen; Tsujimoto, Masanori; Enomoto, Yukiko; Matsushima-Nishiwaki, Rie; Onuma, Takashi; Kojima, Akiko; Doi, Tomoaki; Tanabe, Kumiko; Akamatsu, Shigeru; Iida, Hiroki; Ogura, Shinji; Otsuka, Takanobu; Iwama, Toru; Tanikawa, Takahisa; Ishikawa, Kei; Kojima, Kumi; Kozawa, Osamu</p> <p>2015-01-01</p> <p>We investigated the relationship between HSP27 phosphorylation and collagen-stimulated activation of platelets in patients with diabetes mellitus (DM). Platelet-rich plasma was prepared from blood of type 2 DM patients. The platelet aggregation was analyzed in size of aggregates by an aggregometer using a laser scattering method. The protein phosphorylation was analyzed by Western blotting. Phosphorylated-HSP27 and PDGF-AB <span class="hlt">released</span> from platelets were measured by ELISA. The phosphorylated-HSP27 levels at Ser-78 and Ser-82 induced by collagen were directly proportional to the platelet aggregation. Total HSP27 levels in platelets were decreased concomitantly with the phosphorylation. The <span class="hlt">released</span> HSP27 levels were significantly correlated with the phosphorylated levels of HSP27 in the platelets stimulated by 0.3 μg/ml collagen. The low dose collagen-stimulated <span class="hlt">release</span> of HSP27 was detected but relatively small in healthy donors. The <span class="hlt">released</span> levels of PDGF-AB were in parallel with the levels of <span class="hlt">released</span> HSP27. Area under the curve (AUC) of small aggregation (9-25 μm) induced by 0.3 μg/ml collagen was inversely proportional to the levels of <span class="hlt">released</span> HSP27. AUC of large aggregation (50-70 μm) was directly proportional to the levels of <span class="hlt">released</span> HSP27. Exogenous recombinant phosphorylated- HSP27 hardly affected the aggregation or the <span class="hlt">released</span> levels of PDGF-AB induced by collagen. These results strongly suggest that HSP27 is <span class="hlt">released</span> from human platelets accompanied with its phosphorylation induced by collagen, which is correlated with the <span class="hlt">acceleration</span> of platelet aggregation in type 2 DM patients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70021549','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70021549"><span><span class="hlt">Seismic</span> hazard map of the western hemisphere</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Shedlock, K.M.; Tanner, J.G.</p> <p>1999-01-01</p> <p>Vulnerability to natural disasters increases with urbanization and development of associated support systems (reservoirs, power plants, etc.). Catastrophic earthquakes account for 60% of worldwide casualties associated with natural disasters. Economic damage from earthquakes is increasing, even in technologically advanced countries with some level of <span class="hlt">seismic</span> zonation, as shown by the 1989 Loma Prieta, CA ($6 billion), 1994 Northridge, CA ($ 25 billion), and 1995 Kobe, Japan (> $ 100 billion) earthquakes. The growth of megacities in <span class="hlt">seismically</span> active regions around the world often includes the construction of <span class="hlt">seismically</span> unsafe buildings and infrastructures, due to an insufficient knowledge of existing <span class="hlt">seismic</span> hazard. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of <span class="hlt">seismic</span> hazard. National, state, and local governments, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require <span class="hlt">seismic</span> hazard estimates for land use planning, improved building design and construction (including adoption of building construction codes), emergency response preparedness plans, economic forecasts, housing and employment decisions, and many more types of risk mitigation. The <span class="hlt">seismic</span> hazard map of the Americas is the concatenation of various national and regional maps, involving a suite of approaches. The combined maps and documentation provide a useful global <span class="hlt">seismic</span> hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This <span class="hlt">seismic</span> hazard map depicts Peak Ground <span class="hlt">Acceleration</span> (PGA) with a 10% chance of exceedance in 50 years for the western hemisphere. PGA, a short-period ground motion parameter that is proportional to force, is the most commonly mapped ground motion parameter because current building codes that include <span class="hlt">seismic</span> provisions specify the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.2629G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.2629G"><span>Constraints on Long-Term <span class="hlt">Seismic</span> Hazard From Vulnerable Stalagmites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gribovszki, Katalin; Bokelmann, Götz; Mónus, Péter; Kovács, Károly; Konecny, Pavel; Lednicka, Marketa; Bednárik, Martin; Brimich, Ladislav</p> <p>2015-04-01</p> <p>Earthquakes hit urban centers in Europe infrequently, but occasionally with disastrous effects. This raises the important issue for society, how to react to the natural hazard: potential damages are huge, but infrastructure costs for addressing these hazards are huge as well. Furthermore, <span class="hlt">seismic</span> hazard is only one of the many hazards facing society. Societal means need to be distributed in a reasonable manner - to assure that all of these hazards (natural as well as societal) are addressed appropriately. Obtaining an unbiased view of <span class="hlt">seismic</span> hazard (and risk) is very important therefore. In principle, the best way to test PSHA models is to compare with observations that are entirely independent of the procedure used to produce the PSHA models. Arguably, the most valuable information in this context should be information on long-term hazard, namely maximum intensities (or magnitudes) occuring over time intervals that are at least as long as a <span class="hlt">seismic</span> cycle - if that exists. Such information would be very valuable, even if it concerned only a single site, namely that of a particularly sensitive infrastructure. Such a request may seem hopeless - but it is not. Long-term information can in principle be gained from intact stalagmites in natural caves. These have survived all earthquakes that have occurred, over thousands of years - depending on the age of the stalagmite. Their "survival" requires that the horizontal ground <span class="hlt">acceleration</span> has never exceeded a certain critical value within that period. We are focusing here on case studies in Austria, which has moderate <span class="hlt">seismicity</span>, but a well-documented history of major earthquake-induced damage, e.g., Villach in 1348 and 1690, Vienna in 1590, Leoben in 1794, and Innsbruck in 1551, 1572, and 1589. <span class="hlt">Seismic</span> intensities have reached levels up to 10. It is clearly important to know which "worst-case" damages to expect. We have identified sets of particularly sensitive stalagmites in the general vicinity of two major cities in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED030265.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED030265.pdf"><span><span class="hlt">Seismic</span> Risk Studies in the United States.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Algermissen, S.T.</p> <p></p> <p>A new <span class="hlt">seismic</span> risk map of the United States is presented, along with strain <span class="hlt">release</span> and maximum Modified Mercalli intesity maps of the country. Frequency of occurrence of damaging earthquakes was not considered in zone ratings, but included frequency studies may aid interpretation. Discussion of methods is included with review of calculations. (MH)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S31A2696S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S31A2696S"><span>IMS <span class="hlt">Seismic</span> and Infrasound Stations Instrumental Challenges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Starovoit, Y. O.; Dricker, I. G.; Marty, J.</p> <p>2016-12-01</p> <p>The IMS <span class="hlt">seismic</span> network is a set of monitoring facilities including 50 primary stations and 120 auxiliary stations. Besides the difference in the mode of data transmission to the IDC, technical specifications for seismographic equipment to be installed at both types of stations are essentially the same. The IMS infrasound network comprises 60 facilities with the requirement of continuous data transmission to IDC. The objective of this presentation is to report instrumental challenges associated with both <span class="hlt">seismic</span> and infrasound technologies. In context of specifications for IMS <span class="hlt">seismic</span> stations it was stressed that verification seismology is concerned with searching of reliable methods of signal detections at high frequencies. In the meantime MS/mb screening criteria between earthquakes and explosions relies on reliable detection of surface waves. The IMS <span class="hlt">seismic</span> requirements for instrumental noise and operational range of data logger are defined as certain dB level below minimum background within the required frequency band from 0.02 to 16Hz. The type of sensors response is requested to be flat either in velocity or <span class="hlt">acceleration</span>. The compliance with IMS specifications may thus introduce a challenging task when low-noise conditions have been recorded at the site. It means that as a station noise PSD approaches the NLNM it requires a high sensitive sensor to be connected to a quiet digitizer which may cause a quick system clip and waste of the available dynamic range. The experience has shown that hybrid frequency response of <span class="hlt">seismic</span> sensors where combination of flat to velocity and flat to <span class="hlt">acceleration</span> portions of the sensor frequency response may provide an optimal solution for utilization of the dynamic range and low digitizer noise floor. Vast efforts are also being undertaken and results achieved in the infrasound technology to standardize and optimize the response of the Wind-Noise Reduction System within the IMS infrasound passband from 0.02-4Hz and to deploy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.2615N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.2615N"><span>GIS-based <span class="hlt">seismic</span> shaking slope vulnerability map of Sicily (Central Mediterranean)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nigro, Fabrizio; Arisco, Giuseppe; Perricone, Marcella; Renda, Pietro; Favara, Rocco</p> <p>2010-05-01</p> <p> permanent displacement potentially induced by an <span class="hlt">seismic</span> scenario. Such methodologies found on the consideration that the conditions of <span class="hlt">seismic</span> stability and the post-<span class="hlt">seismic</span> functionality of engineering structures are tightly related to the entity of the permanent deformations that an earthquake can induce. Regarding the existing simplified procedures among slope stability models, Newmark's model is often used to derive indications about slope instabilities due to earthquakes. In this way, we have evaluated the <span class="hlt">seismically</span>-induced landslides hazard in Sicily (Central Mediterranean) using the Newmark-like model. In order to determine the map distribution of the <span class="hlt">seismic</span> ground-<span class="hlt">acceleration</span> from an earthquake scenario, the attenuation-law of Sabetta & Pugliese has been used, analyzing some <span class="hlt">seismic</span> recordings occurred in Italy. Also, by evaluating permanent displacements, the correlation of Ambraseys & Menu has been assumed. The <span class="hlt">seismic</span> shaking slope vulnerability map of Sicily has been carried out using GIS application, also considering max <span class="hlt">seismic</span> ground-<span class="hlt">acceleration</span> peak distribution (in terms of exceedance probability for fixed time), slope acclivity, cohesion/angle of internal friction of outcropping rocks, allowing the zoning of the unstable slopes under <span class="hlt">seismic</span> forces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1244699-seismic-risk-management-solution-nuclear-power-plants','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1244699-seismic-risk-management-solution-nuclear-power-plants"><span><span class="hlt">Seismic</span> risk management solution for nuclear power plants</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Coleman, Justin; Sabharwall, Piyush</p> <p>2014-12-01</p> <p>Nuclear power plants should safely operate during normal operations and maintain core-cooling capabilities during off-normal events, including external hazards (such as flooding and earthquakes). Management of external hazards to expectable levels of risk is critical to maintaining nuclear facility and nuclear power plant safety. <span class="hlt">Seismic</span> risk is determined by convolving the <span class="hlt">seismic</span> hazard with <span class="hlt">seismic</span> fragilities (capacity of systems, structures, and components). <span class="hlt">Seismic</span> isolation (SI) is one protective measure showing promise to minimize <span class="hlt">seismic</span> risk. Current SI designs (used in commercial industry) reduce horizontal earthquake loads and protect critical infrastructure from the potentially destructive effects of large earthquakes. The benefitmore » of SI application in the nuclear industry is being recognized and SI systems have been proposed in American Society of Civil Engineer Standard 4, ASCE-4, to be <span class="hlt">released</span> in the winter of 2014, for light water reactors facilities using commercially available technology. The intent of ASCE-4 is to provide criteria for <span class="hlt">seismic</span> analysis of safety related nuclear structures such that the responses to design basis <span class="hlt">seismic</span> events, computed in accordance with this standard, will have a small likelihood of being exceeded. The U.S. nuclear industry has not implemented SI to date; a <span class="hlt">seismic</span> isolation gap analysis meeting was convened on August 19, 2014, to determine progress on implementing SI in the U.S. nuclear industry. The meeting focused on the systems and components that could benefit from SI. As a result, this article highlights the gaps identified at this meeting.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S53C4520F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S53C4520F"><span>Imaging of early <span class="hlt">acceleration</span> phase of the 2013-2014 Boso slow slip event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fukuda, J.; Kato, A.; Obara, K.; Miura, S.; Kato, T.</p> <p>2014-12-01</p> <p>Based on GPS and <span class="hlt">seismic</span> data, we examine the spatiotemporal evolution of a slow slip event (SSE) and associated <span class="hlt">seismic</span> activity that occurred off the Boso peninsula, central Japan, from December 2013 to January 2014. We use GPS data from 71 stations of the GEONET and 6 stations operated by Earthquake Research Institute of the University of Tokyo and Tohoku University around the Boso peninsula. We apply a modified version of the Network Inversion Filter to the GPS time series at the 77 stations to estimate the spatiotemporal evolution of daily cumulative slip and slip rate on the subducting Philippine Sea plate. In addition, we create an improved earthquake catalog by applying a matched filter technique to continuous seismograms and examine the spatiotemporal relations between slow slip and <span class="hlt">seismicity</span>. We find that the SSE started in early December 2013. The spatiotemporal evolution of slow slip and <span class="hlt">seismicity</span> is divided into two distinct phases, an earlier slow phase from early to 30 December 2013 (Phase I) and a subsequent faster phase from 30 December 2013 to 9 January 2014 (Phase II). During Phase I, slip <span class="hlt">accelerated</span> slowly up to a maximum rate of 1.6 m/yr with potentially accelerating along-strike propagation at speeds on the order of 1 km/day or less and no accompanying <span class="hlt">seismicity</span>. On the other hand, during Phase II, slip <span class="hlt">accelerated</span> rapidly up to a maximum rate of 4.5 m/yr and then rapidly decelerated. The slip front propagated along strike at a constant speed of ~10 km/day. During the Phase II, slow slip was accompanied by <span class="hlt">seismic</span> swarm activity that was highly correlated in space and time with slip rate, suggesting that the swarm activity was triggered by stress loading due to slow slip. Early slow <span class="hlt">acceleration</span> of slip has not been identified in the past Boso SSEs in 1996, 2002, 2007, and 2011. It is not clear at this point whether the past Boso SSEs started with slow <span class="hlt">acceleration</span> similarly to the 2013-2014 SSE. The transition from the slow to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAfES.113..114E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAfES.113..114E"><span>Evaluation of <span class="hlt">seismic</span> hazard at the northwestern part of Egypt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ezzelarab, M.; Shokry, M. M. F.; Mohamed, A. M. E.; Helal, A. M. A.; Mohamed, Abuoelela A.; El-Hadidy, M. S.</p> <p>2016-01-01</p> <p>The objective of this study is to evaluate the <span class="hlt">seismic</span> hazard at the northwestern Egypt using the probabilistic <span class="hlt">seismic</span> hazard assessment approach. The Probabilistic approach was carried out based on a recent data set to take into account the historic <span class="hlt">seismicity</span> and updated instrumental <span class="hlt">seismicity</span>. A homogenous earthquake catalogue was compiled and a proposed <span class="hlt">seismic</span> sources model was presented. The doubly-truncated exponential model was adopted for calculations of the recurrence parameters. Ground-motion prediction equations that recently recommended by experts and developed based upon earthquake data obtained from tectonic environments similar to those in and around the studied area were weighted and used for assessment of <span class="hlt">seismic</span> hazard in the frame of logic tree approach. Considering a grid of 0.2° × 0.2° covering the study area, <span class="hlt">seismic</span> hazard curves for every node were calculated. Hazard maps at bedrock conditions were produced for peak ground <span class="hlt">acceleration</span>, in addition to six spectral periods (0.1, 0.2, 0.3, 1.0, 2.0 and 3.0 s) for return periods of 72, 475 and 2475 years. The unified hazard spectra of two selected rock sites at Alexandria and Mersa Matruh Cities were provided. Finally, the hazard curves were de-aggregated to determine the sources that contribute most of hazard level of 10% probability of exceedance in 50 years for the mentioned selected sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.7594G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.7594G"><span>Constraints on Long-Term <span class="hlt">Seismic</span> Hazard From Vulnerable Stalagmites from Vacska cave, Pilis Mountains of Hungary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gribovszki, Katalin; Bokelmann, Götz; Kovács, Károly; Mónus, Péter; Konecny, Pavel; Lednicka, Marketa; Novák, Attila</p> <p>2017-04-01</p> <p>Damaging earthquakes in central Europe are infrequent, but do occur. This raises the important issue for society of how to react to this hazard: potential damages are enormous, and infrastructure costs for addressing these hazards are huge as well. Obtaining an unbiased expert knowledge of the <span class="hlt">seismic</span> hazard (and risk) is therefore very important. <span class="hlt">Seismic</span> activity in the Pannonian Basin is moderate. In territories with low or moderate <span class="hlt">seismic</span> activity the recurrence time of large earthquakes can be as long as 10,000 years. Therefore, we cannot draw well-grounded inferences in the field of <span class="hlt">seismic</span> hazard assessment exclusively from the <span class="hlt">seismic</span> data of 1,000- to 2,000-years observational period, that we have in our earthquake catalogues. Long-term information can be gained from intact and vulnerable stalagmites (IVSTM) in natural karstic caves. These fragile formations survived all earthquakes that have occurred, over thousands of years - depending on the age of them. Their "survival" requires that the horizontal ground <span class="hlt">acceleration</span> has never exceeded a certain critical value within that time period. Here we present such a stalagmite-based case study from the Pilis Mountains of Hungary. Evidence of historic events and of differential uplifting (incision of Danube at the River Bend and in Buda and Gerecse Hills) exists in the vicinity of investigated cave site. These observations imply that a better understanding of possible co-<span class="hlt">seismic</span> ground motions in the nearby densely populated areas of Budapest is needed. A specially shaped (high, slim and more or less cylindrical form), intact and vulnerable stalagmites in the Vacska cave, Pilis Mountains were examined. The method of our investigation includes in-situ examination of the IVSTM and mechanical laboratory measurements of broken stalagmite samples. The used approach can yield significant new constraints on the <span class="hlt">seismic</span> hazard of the investigated area, since tectonic structures close to Vacska cave could not have</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JSeis..18..357A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JSeis..18..357A"><span>Considering potential <span class="hlt">seismic</span> sources in earthquake hazard assessment for Northern Iran</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abdollahzadeh, Gholamreza; Sazjini, Mohammad; Shahaky, Mohsen; Tajrishi, Fatemeh Zahedi; Khanmohammadi, Leila</p> <p>2014-07-01</p> <p>Located on the Alpine-Himalayan earthquake belt, Iran is one of the <span class="hlt">seismically</span> active regions of the world. Northern Iran, south of Caspian Basin, a hazardous subduction zone, is a densely populated and developing area of the country. Historical and instrumental documented <span class="hlt">seismicity</span> indicates the occurrence of severe earthquakes leading to many deaths and large losses in the region. With growth of seismological and tectonic data, updated <span class="hlt">seismic</span> hazard assessment is a worthwhile issue in emergency management programs and long-term developing plans in urban and rural areas of this region. In the present study, being armed with up-to-date information required for <span class="hlt">seismic</span> hazard assessment including geological data and active tectonic setting for thorough investigation of the active and potential seismogenic sources, and historical and instrumental events for compiling the earthquake catalogue, probabilistic <span class="hlt">seismic</span> hazard assessment is carried out for the region using three recent ground motion prediction equations. The logic tree method is utilized to capture epistemic uncertainty of the <span class="hlt">seismic</span> hazard assessment in delineation of the <span class="hlt">seismic</span> sources and selection of attenuation relations. The results are compared to a recent practice in code-prescribed <span class="hlt">seismic</span> hazard of the region and are discussed in detail to explore their variation in each branch of logic tree approach. Also, <span class="hlt">seismic</span> hazard maps of peak ground <span class="hlt">acceleration</span> in rock site for 475- and 2,475-year return periods are provided for the region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4457785','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4457785"><span><span class="hlt">Release</span> of Phosphorylated HSP27 (HSPB1) from Platelets Is Accompanied with the <span class="hlt">Acceleration</span> of Aggregation in Diabetic Patients</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tokuda, Haruhiko; Kuroyanagi, Gen; Tsujimoto, Masanori; Enomoto, Yukiko; Matsushima-Nishiwaki, Rie; Onuma, Takashi; Kojima, Akiko; Doi, Tomoaki; Tanabe, Kumiko; Akamatsu, Shigeru; Iida, Hiroki; Ogura, Shinji; Otsuka, Takanobu; Iwama, Toru; Tanikawa, Takahisa; Ishikawa, Kei; Kojima, Kumi; Kozawa, Osamu</p> <p>2015-01-01</p> <p>We investigated the relationship between HSP27 phosphorylation and collagen-stimulated activation of platelets in patients with diabetes mellitus (DM). Platelet-rich plasma was prepared from blood of type 2 DM patients. The platelet aggregation was analyzed in size of aggregates by an aggregometer using a laser scattering method. The protein phosphorylation was analyzed by Western blotting. Phosphorylated-HSP27 and PDGF-AB <span class="hlt">released</span> from platelets were measured by ELISA. The phosphorylated-HSP27 levels at Ser-78 and Ser-82 induced by collagen were directly proportional to the platelet aggregation. Total HSP27 levels in platelets were decreased concomitantly with the phosphorylation. The <span class="hlt">released</span> HSP27 levels were significantly correlated with the phosphorylated levels of HSP27 in the platelets stimulated by 0.3 μg/ml collagen. The low dose collagen-stimulated <span class="hlt">release</span> of HSP27 was detected but relatively small in healthy donors. The <span class="hlt">released</span> levels of PDGF-AB were in parallel with the levels of <span class="hlt">released</span> HSP27. Area under the curve (AUC) of small aggregation (9-25 μm) induced by 0.3 μg/ml collagen was inversely proportional to the levels of <span class="hlt">released</span> HSP27. AUC of large aggregation (50-70 μm) was directly proportional to the levels of <span class="hlt">released</span> HSP27. Exogenous recombinant phosphorylated- HSP27 hardly affected the aggregation or the <span class="hlt">released</span> levels of PDGF-AB induced by collagen. These results strongly suggest that HSP27 is <span class="hlt">released</span> from human platelets accompanied with its phosphorylation induced by collagen, which is correlated with the <span class="hlt">acceleration</span> of platelet aggregation in type 2 DM patients. PMID:26046355</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/10192651','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/10192651"><span>Site-wide <span class="hlt">seismic</span> risk model for Savannah River Site nuclear facilities</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Eide, S.A.; Shay, R.S.; Durant, W.S.</p> <p>1993-09-01</p> <p>The 200,000 acre Savannah River Site (SRS) has nearly 30 nuclear facilities spread throughout the site. The safety of each facility has been established in facility-specific safety analysis reports (SARs). Each SAR contains an analysis of risk from <span class="hlt">seismic</span> events to both on-site workers and the off-site population. Both radiological and chemical <span class="hlt">releases</span> are considered, and air and water pathways are modeled. Risks to the general public are generally characterized by evaluating exposure to the maximally exposed individual located at the SRS boundary and to the off-site population located within 50 miles. Although the SARs are appropriate methods for studyingmore » individual facility risks, there is a class of accident initiators that can simultaneously affect several of all of the facilities, Examples include <span class="hlt">seismic</span> events, strong winds or tornados, floods, and loss of off-site electrical power. Overall risk to the off-site population from such initiators is not covered by the individual SARs. In such cases multiple facility radionuclide or chemical <span class="hlt">releases</span> could occur, and off-site exposure would be greater than that indicated in a single facility SAR. As a step towards an overall site-wide risk model that adequately addresses multiple facility <span class="hlt">releases</span>, a site-wide <span class="hlt">seismic</span> model for determining off-site risk has been developed for nuclear facilities at the SRS. Risk from <span class="hlt">seismic</span> events up to the design basis earthquake (DBE) of 0.2 g (frequency of 2.0E-4/yr) is covered by the model. Present plans include expanding the scope of the model to include other types of initiators that can simultaneously affect multiple facilities.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPA....8d5307W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPA....8d5307W"><span><span class="hlt">Seismic</span> isolation of small modular reactors using metamaterials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Witarto, Witarto; Wang, S. J.; Yang, C. Y.; Nie, Xin; Mo, Y. L.; Chang, K. C.; Tang, Yu; Kassawara, Robert</p> <p>2018-04-01</p> <p>Adaptation of metamaterials at micro- to nanometer scales to metastructures at much larger scales offers a new alternative for <span class="hlt">seismic</span> isolation systems. These new isolation systems, known as periodic foundations, function both as a structural foundation to support gravitational weight of the superstructure and also as a <span class="hlt">seismic</span> isolator to isolate the superstructure from incoming <span class="hlt">seismic</span> waves. Here we describe the application of periodic foundations for the <span class="hlt">seismic</span> protection of nuclear power plants, in particular small modular reactors (SMR). For this purpose, a large-scale shake table test on a one-dimensional (1D) periodic foundation supporting an SMR building model was conducted. The 1D periodic foundation was designed and fabricated using reinforced concrete and synthetic rubber (polyurethane) materials. The 1D periodic foundation structural system was tested under various input waves, which include white noise, stepped sine and <span class="hlt">seismic</span> waves in the horizontal and vertical directions as well as in the torsional mode. The shake table test results show that the 1D periodic foundation can reduce the <span class="hlt">acceleration</span> response (transmissibility) of the SMR building up to 90%. In addition, the periodic foundation-isolated structure also exhibited smaller displacement than the non-isolated SMR building. This study indicates that the challenge faced in developing metastructures can be overcome and the periodic foundations can be applied to isolating vibration response of engineering structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EaSci..26..351L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EaSci..26..351L"><span>Continuous estimates on the earthquake early warning magnitude by use of the near-field <span class="hlt">acceleration</span> records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Jun; Jin, Xing; Wei, Yongxiang; Zhang, Hongcai</p> <p>2013-10-01</p> <p>In this article, the <span class="hlt">seismic</span> records of Japan's Kik-net are selected to measure the <span class="hlt">acceleration</span>, displacement, and effective peak <span class="hlt">acceleration</span> of each <span class="hlt">seismic</span> record within a certain time after P wave, then a continuous estimation is given on earthquake early warning magnitude through statistical analysis method, and Wenchuan earthquake record is utilized to check the method. The results show that the reliability of earthquake early warning magnitude continuously increases with the increase of the <span class="hlt">seismic</span> information, the biggest residual happens if the <span class="hlt">acceleration</span> is adopted to fit earthquake magnitude, which may be caused by rich high-frequency components and large dispersion of peak value in <span class="hlt">acceleration</span> record, the influence caused by the high-frequency components can be effectively reduced if the effective peak <span class="hlt">acceleration</span> and peak displacement is adopted, it is estimated that the dispersion of earthquake magnitude obviously reduces, but it is easy for peak displacement to be affected by long-period drifting. In various components, the residual enlargement phenomenon at vertical direction is almost unobvious, thus it is recommended in this article that the effective peak <span class="hlt">acceleration</span> at vertical direction is preferred to estimate earthquake early warning magnitude. Through adopting Wenchuan strong earthquake record to check the method mentioned in this article, it is found that this method can be used to quickly, stably, and accurately estimate the early warning magnitude of this earthquake, which shows that this method is completely applicable for earthquake early warning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JGeo...35..173M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JGeo...35..173M"><span>Fractal analysis of earthquake swarms of Vogtland/NW-Bohemia intraplate <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mittag, Reinhard J.</p> <p>2003-03-01</p> <p>The special type of intraplate microseismicity with swarm-like occurrence of earthquakes within the Vogtland/NW-Bohemian Region is analysed to reveal the nature and the origin of the seismogenic regime. The long-term data set of continuous <span class="hlt">seismic</span> monitoring since 1962, including more than 26000 events within a range of about 5 units of local magnitude, provides an unique database for statistical investigations. Most earthquakes occur in narrow hypocentral volumes (clusters) within the lower part of the upper crust, but also single event occurrence outside of spatial clusters is observed. Temporal distribution of events is concentrated in clusters (swarms), which last some days until few month in dependence of intensity. Since 1962 three strong swarms occurred (1962, 1985/86, 2000), including two <span class="hlt">seismic</span> cycles. Spatial clusters are distributed along a fault system of regional extension (Leipzig-Regensburger Störung), which is supposed to act as the joint tectonic fracture zone for the whole seismogenic region. <span class="hlt">Seismicity</span> is analysed by fractal analysis, suggesting a unifractal behaviour of <span class="hlt">seismicity</span> and uniform character of seismotectonic regime for the whole region. A tendency of decreasing fractal dimension values is observed for temporal distribution of earthquakes, indicating an increasing degree of temporal clustering from swarm to swarm. Following the idea of earthquake triggering by magma intrusions and related fluid and gas <span class="hlt">release</span> into the tectonically pre-stressed parts of the crust, a steady increased intensity of intrusion and/or fluid and gas <span class="hlt">release</span> might account for that observation. Additionally, <span class="hlt">seismic</span> parameters for Vogtland/NW-Bohemia intraplate <span class="hlt">seismicity</span> are compared with an adequate data set of mining-induced <span class="hlt">seismicity</span> in a nearby mine of Lubin/Poland and with synthetic data sets to evaluate parameter estimation. Due to different seismogenic regime of tectonic and induced <span class="hlt">seismicity</span>, significant differences between b-values and temporal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70045534','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70045534"><span>Calving <span class="hlt">seismicity</span> from iceberg-sea surface interactions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bartholomaus, T.C.; Larsen, C.F.; O'Neel, S.; West, M.E.</p> <p>2012-01-01</p> <p>Iceberg calving is known to <span class="hlt">release</span> substantial <span class="hlt">seismic</span> energy, but little is known about the specific mechanisms that produce calving icequakes. At Yahtse Glacier, a tidewater glacier on the Gulf of Alaska, we draw upon a local network of seismometers and focus on 80 hours of concurrent, direct observation of the terminus to show that calving is the dominant source of <span class="hlt">seismicity</span>. To elucidate seismogenic mechanisms, we synchronized video and seismograms to reveal that the majority of <span class="hlt">seismic</span> energy is produced during iceberg interactions with the sea surface. Icequake peak amplitudes coincide with the emergence of high velocity jets of water and ice from the fjord after the complete submergence of falling icebergs below sea level. These icequakes have dominant frequencies between 1 and 3 Hz. Detachment of an iceberg from the terminus produces comparatively weak <span class="hlt">seismic</span> waves at frequencies between 5 and 20 Hz. Our observations allow us to suggest that the most powerful sources of calving icequakes at Yahtse Glacier include iceberg-sea surface impact, deceleration under the influence of drag and buoyancy, and cavitation. Numerical simulations of seismogenesis during iceberg-sea surface interactions support our observational evidence. Our new understanding of iceberg-sea surface interactions allows us to reattribute the sources of calving <span class="hlt">seismicity</span> identified in earlier studies and offer guidance for the future use of seismology in monitoring iceberg calving.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017559','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017559"><span>The temporal distribution of <span class="hlt">seismic</span> radiation during deep earthquake rupture</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Houston, H.; Vidale, J.E.</p> <p>1994-01-01</p> <p>The time history of energy <span class="hlt">release</span> during earthquakes illuminates the process of failure, which remains enigmatic for events deeper than about 100 kilometers. Stacks of teleseismic records from regional arrays for 122 intermediate (depths of 100 to 350 kilometers) and deep (depths of 350 to 700 kilometers) earthquakes show that the temporal pattern of short-period <span class="hlt">seismic</span> radiation has a systematic variation with depth. On average, for intermediate depth events more radiation is <span class="hlt">released</span> toward the beginning of the rupture than near the end, whereas for deep events radiation is <span class="hlt">released</span> symmetrically over the duration of the event, with an abrupt beginning and end of rupture. These findings suggest a variation in the style of rupture related to decreasing fault heterogeneity with depth.The time history of energy <span class="hlt">release</span> during earthquakes illuminates the process of failure, which remains enigmatic for events deeper than about 100 kilometers. Stacks of teleseismic records from regional arrays for 122 intermediate (depths of 100 to 350 kilometers) and deep (depths of 350 to 700 kilometers) earthquakes show that the temporal pattern of short-period <span class="hlt">seismic</span> radiation has a systematic variation with depth. On average, for intermediate depth events more radiation is <span class="hlt">released</span> toward the beginning of the rupture than near the end, whereas for deep events radiation is <span class="hlt">released</span> symmetrically over the duration of the event, with an abrupt beginning and end of rupture. These findings suggest a variation in the style of rupture related to decreasing fault heterogeneity with depth.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH21A0158P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH21A0158P"><span>Tectonic styles of future earthquakes in Italy as input data for <span class="hlt">seismic</span> hazard</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pondrelli, S.; Meletti, C.; Rovida, A.; Visini, F.; D'Amico, V.; Pace, B.</p> <p>2017-12-01</p> <p>In a recent elaboration of a new seismogenic zonation and hazard model for Italy, we tried to understand how many indications we have on the tectonic style of future earthquake/rupture. Using all available or recomputed <span class="hlt">seismic</span> moment tensors for relevant <span class="hlt">seismic</span> events (Mw starting from 4.5) of the last 100 yrs, first arrival focal mechanisms for less recent earthquakes and also geological data on past activated faults, we collected a database gathering a thousands of data all over the Italian peninsula and regions around it. After several summations of <span class="hlt">seismic</span> moment tensors, over regular grids of different dimensions and different thicknesses of the seismogenic layer, we applied the same procedure to each of the 50 area sources that were designed in the seismogenic zonation. The results for several <span class="hlt">seismic</span> zones are very stable, e.g. along the southern Apennines we expect future earthquakes to be mostly extensional, although in the outer part of the chain strike-slip events are possible. In the Northern part of the Apennines we also expect different, opposite tectonic styles for different hypocentral depths. In several zones, characterized by a low <span class="hlt">seismic</span> moment <span class="hlt">release</span>, defined for the study region using 1000 yrs of catalog, the next possible tectonic style of future earthquakes is less clear. It is worth to note that for some zones the possible greatest earthquake could be not represented in the available observations. We also add to our analysis the computation of the <span class="hlt">seismic</span> <span class="hlt">release</span> rate, computed using a distributed completeness, identified for single great events of the historical <span class="hlt">seismic</span> catalog for Italy. All these information layers, overlapped and compared, may be used to characterize each new seismogenic zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/10149812','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/10149812"><span>Evaluation of <span class="hlt">seismic</span> spatial interaction effects through an impact testing program</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Thomas, B.D.; Driesen, G.E.</p> <p></p> <p>The consequences of non-<span class="hlt">seismically</span> qualified objects falling and striking essential, <span class="hlt">seismically</span> qualified objects is an analytically difficult problem to assess. Analytical solutions to impact problems are conservative and only available for simple situations. In a nuclear facility, the numerous ``sources`` and ``targets`` requiring evaluation often have complex geometric configurations, which makes calculations and computer modeling difficult. Few industry or regulatory rules are available for this specialized assessment. A drop test program was recently conducted to ``calibrate`` the judgment of <span class="hlt">seismic</span> qualification engineers who perform interaction evaluations and to further develop <span class="hlt">seismic</span> interaction criteria. Impact tests on varying combinations of sourcesmore » and targets were performed by dropping the sources from various heights onto targets that were connected to instruments. This paper summarizes the scope, test configurations, and some results of the drop test program. Force and <span class="hlt">acceleration</span> time history data and general observations are presented on the ruggedness of various targets when subjected to impacts from different types of sources.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/6583157','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/6583157"><span>Evaluation of <span class="hlt">seismic</span> spatial interaction effects through an impact testing program</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Thomas, B.D.; Driesen, G.E.</p> <p></p> <p>The consequences of non-<span class="hlt">seismically</span> qualified objects falling and striking essential, <span class="hlt">seismically</span> qualified objects is an analytically difficult problem to assess. Analytical solutions to impact problems are conservative and only available for simple situations. In a nuclear facility, the numerous sources'' and targets'' requiring evaluation often have complex geometric configurations, which makes calculations and computer modeling difficult. Few industry or regulatory rules are available for this specialized assessment. A drop test program was recently conducted to calibrate'' the judgment of <span class="hlt">seismic</span> qualification engineers who perform interaction evaluations and to further develop <span class="hlt">seismic</span> interaction criteria. Impact tests on varying combinations of sourcesmore » and targets were performed by dropping the sources from various heights onto targets that were connected to instruments. This paper summarizes the scope, test configurations, and some results of the drop test program. Force and <span class="hlt">acceleration</span> time history data and general observations are presented on the ruggedness of various targets when subjected to impacts from different types of sources.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031302','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031302"><span><span class="hlt">Seismic</span> precursory patterns before a cliff collapse and critical point phenomena</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Amitrano, D.; Grasso, J.-R.; Senfaute, G.</p> <p>2005-01-01</p> <p>We analyse the statistical pattern of <span class="hlt">seismicity</span> before a 1-2 103 m3 chalk cliff collapse on the Normandie ocean shore, Western France. We show that a power law <span class="hlt">acceleration</span> of <span class="hlt">seismicity</span> rate and energy in both 40 Hz-1.5 kHz and 2 Hz-10kHz frequency range, is defined on 3 orders of magnitude, within 2 hours from the collapse time. Simultaneously, the average size of the <span class="hlt">seismic</span> events increases toward the time to failure. These in situ results are derived from the only station located within one rupture length distance from the rock fall rupture plane. They mimic the "critical point" like behavior recovered from physical and numerical experiments before brittle failures and tertiary creep failures. Our analysis of this first <span class="hlt">seismic</span> monitoring data of a cliff collapse suggests that the thermodynamic phase transition models for failure may apply for cliff collapse. Copyright 2005 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29949806','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29949806"><span><span class="hlt">Accelerated</span> Episodic LH <span class="hlt">Release</span> Accompanies Blunted Progesterone Regulation in PCOS-like Female Rhesus Monkeys (Macaca mulatta) Exposed to Testosterone During Early-to-Mid Gestation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abbott, David H; Vepraskas, Sarah H; Horton, Teresa H; Terasawa, Ei; Levine, Jon E</p> <p>2018-06-15</p> <p>Ovarian theca cell hyperandrogenism in women with PCOS is compounded by androgen receptor-mediated impairment of estradiol and progesterone negative feedback regulation of episodic LH <span class="hlt">release</span>. The resultant LH hypersecretion, likely the product of <span class="hlt">accelerated</span> episodic <span class="hlt">release</span> of GnRH from the median eminence of the hypothalamus, hyperstimulates ovarian theca cell steroidogenesis, enabling testosterone (T) and androstenedione excess. Prenatally androgenized female monkeys (PA) exposed to fetal male levels of T during early-to-mid gestation, when adult, demonstrate PCOS-like traits, including high T and LH levels. This study tests the hypothesis that progesterone resistance-associated <span class="hlt">acceleration</span> in episodic LH <span class="hlt">release</span> contributes to PA monkey LH excess. 4 PA and 3 regularly cycling, healthy control adult female rhesus monkeys of comparable age and body mass index underwent (1) a 10 h, frequent intravenous sampling assessment for LH episodic <span class="hlt">release</span>, immediately followed by (2) IV infusion of exogenous GnRH to quantify continuing pituitary LH responsiveness, and subsequently (3) an SC injection of a progesterone receptor antagonist, mifepristone, to examine LH responses to blockade of progesterone-mediated action. Compared to controls, the relatively hyperandrogenic PA females exhibited ~100% increase (p = 0.037) in LH pulse frequency, positive correlation of LH pulse amplitude (p = 0.017) with androstenedione, ~100% greater increase (p = 0.034) in acute (0--10 min) LH responses to exogenous GnRH, and an absence (p = 0.008) of modest LH elevation following acute progesterone receptor blockade suggestive of diminished progesterone negative feedback. Such dysregulation of LH <span class="hlt">release</span> in PCOS-like monkeys implicates impaired feedback control of episodic <span class="hlt">release</span> of hypothalamic GnRH reminiscent of PCOS neuroendocrinopathy. 2018 S. Karger AG, Basel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012Tectp.530...80V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012Tectp.530...80V"><span>Global pattern of earthquakes and <span class="hlt">seismic</span> energy distributions: Insights for the mechanisms of plate tectonics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Varga, P.; Krumm, F.; Riguzzi, F.; Doglioni, C.; Süle, B.; Wang, K.; Panza, G. F.</p> <p>2012-03-01</p> <p>In this paper, we analyse the distributions of number of events (N) and <span class="hlt">seismic</span> energy (E) on the Earth's surface and along its radius as obtained from the global declustered catalogue of large independent events (M ≥ 7.0), dissipating about 95% of the Earth's elastic budget. The latitude distribution of the <span class="hlt">seismic</span> event density is almost symmetric with respect to the equator and the <span class="hlt">seismic</span> energy flux distribution is bimodal; both have their medians near the equator so that they are equally distributed in the two hemispheres. This symmetry with respect to the equator suggests that the Earth's rotational dynamics contributes to modulate the long-term tectonic processes. The distributions of number and energy of earthquakes versus depth are not uniform as well: 76% of the total earthquakes dissipates about 60% of the total energy in the first ~ 50 km; only 6% of events dissipates about 20% of the total amount of energy in a narrow depth interval, at the lower boundary of the upper mantle (550-680 km). Therefore, only the remaining 20% of energy is <span class="hlt">released</span> along most of the depth extent of subduction zones (50-550 km). Since the energetic <span class="hlt">release</span> along slabs is a minor fraction of the total <span class="hlt">seismic</span> budget, the role of the slab pull appears as ancillary, if any, in driving plate tectonics. Moreover the concentration of <span class="hlt">seismic</span> <span class="hlt">release</span> in the not yet subducted lithosphere suggests that the force moving the plates acts on the uppermost lithosphere and contemporaneously all over the Earth's outer shell, again supporting a rotational/tidal modulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNS31A1939B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNS31A1939B"><span>Instrument Correction and Dynamic Site Profile Validation at the Central United States <span class="hlt">Seismic</span> Observatory, New Madrid <span class="hlt">Seismic</span> Zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brengman, C.; Woolery, E. W.; Wang, Z.; Carpenter, S.</p> <p>2016-12-01</p> <p>The Central United States <span class="hlt">Seismic</span> Observatory (CUSSO) is a vertical <span class="hlt">seismic</span> array located in southwestern Kentucky within the New Madrid <span class="hlt">seismic</span> zone. It is intended to describe the effects of local geology, including thick sediment overburden, on <span class="hlt">seismic</span>-wave propagation, particularly strong-motion. The three-borehole array at CUSSO is composed of <span class="hlt">seismic</span> sensors placed on the surface, and in the bedrock at various depths within the 585 m thick sediment overburden. The array's deep borehole provided a unique opportunity in the northern Mississippi embayment for the direct geological description and geophysical measurement of the complete late Cretaceous-Quaternary sediment column. A seven layer, intra-sediment velocity model is interpreted from the complex, inhomogeneous stratigraphy. The S- and P-wave sediment velocities range between 160 and 875 m/s and between 1000 and 2300 m/s, respectively, with bedrock velocities of 1452 and 3775 m/s, respectively. Cross-correlation and direct comparisons were used to filter out the instrument response and determine the instrument orientation, making CUSSO data ready for analysis, and making CUSSO a viable calibration site for other free-field sensors in the area. The corrected bedrock motions were numerically propagated through the CUSSO soil profile (transfer function) and compared, in terms of both peak <span class="hlt">acceleration</span> and amplitude spectra, to the recorded surface observations. Initial observations reveal a complex spectral mix of amplification and de-amplification across the array, indicating the site effect in this deep sediment setting is not simply generated by the shallowest layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S13C0679K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S13C0679K"><span>Comparison of <span class="hlt">Seismic</span> Sources and Frequencies in West Texas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaip, G.; Harder, S. H.; Karplus, M. S.</p> <p>2017-12-01</p> <p>During October 2017 the <span class="hlt">Seismic</span> Source Facility (SSF) located at the University of Texas at El Paso (UTEP) Department of Geological Sciences collected <span class="hlt">seismic</span> data at SSF test facility located near Fabens, TX. The project objective was to compare source amplitudes and frequencies of various <span class="hlt">seismic</span> sources available through the SSF. Selecting the appropriate <span class="hlt">seismic</span> source is important to reach geological objectives. We compare <span class="hlt">seismic</span> sources between explosive sources (pentolite and shotgun) and mechanical sources (<span class="hlt">accelerated</span> weight drop and hammer on plate), focusing on amplitude and frequency. All sources were tested in same geologic environment. Although this is not an ideal geologic formation for source coupling, it does allow an "apples to apples" comparison. Twenty Reftek RT125A <span class="hlt">seismic</span> recorders with 4.5 Hz geophones were laid out in a line with 3m station separation. Mechanical sources were tested first to minimize changes in the subsurface related to explosive sources Explosive sources, while yielding higher amplitudes, have lower frequency content. The explosions exhibit a higher signal-to-noise ratio, allowing us to recognize <span class="hlt">seismic</span> energy deeper and farther from the source. Mechanical sources yield higher frequencies allowing better resolution at shallower depths, but have a lower signal-to-noise ratio and lower amplitudes, even with source stacking. We analyze the details of the shot spectra from the different types of sources. A combination of source types can improve data resolution and amplitude, thereby improving imaging potential. However, cost, logistics, and complexities also have a large influence on source selection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7516R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7516R"><span>Probabilistic <span class="hlt">Seismic</span> Hazard Assessment of the Chiapas State (SE Mexico)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rodríguez-Lomelí, Anabel Georgina; García-Mayordomo, Julián</p> <p>2015-04-01</p> <p>The Chiapas State, in southeastern Mexico, is a very active <span class="hlt">seismic</span> region due to the interaction of three tectonic plates: Northamerica, Cocos and Caribe. We present a probabilistic <span class="hlt">seismic</span> hazard assessment (PSHA) specifically performed to evaluate <span class="hlt">seismic</span> hazard in the Chiapas state. The PSHA was based on a composited <span class="hlt">seismic</span> catalogue homogenized to Mw and was used a logic tree procedure for the consideration of different seismogenic source models and ground motion prediction equations (GMPEs). The results were obtained in terms of peak ground <span class="hlt">acceleration</span> as well as spectral <span class="hlt">accelerations</span>. The earthquake catalogue was compiled from the International Seismological Center and the Servicio Sismológico Nacional de México sources. Two different seismogenic source zones (SSZ) models were devised based on a revision of the tectonics of the region and the available geomorphological and geological maps. The SSZ were finally defined by the analysis of geophysical data, resulting two main different SSZ models. The Gutenberg-Richter parameters for each SSZ were calculated from the declustered and homogenized catalogue, while the maximum expected earthquake was assessed from both the catalogue and geological criteria. Several worldwide and regional GMPEs for subduction and crustal zones were revised. For each SSZ model we considered four possible combinations of GMPEs. Finally, hazard was calculated in terms of PGA and SA for 500-, 1000-, and 2500-years return periods for each branch of the logic tree using the CRISIS2007 software. The final hazard maps represent the mean values obtained from the two seismogenic and four attenuation models considered in the logic tree. For the three return periods analyzed, the maps locate the most hazardous areas in the Chiapas Central Pacific Zone, the Pacific Coastal Plain and in the Motagua and Polochic Fault Zone; intermediate hazard values in the Chiapas Batholith Zone and in the Strike-Slip Faults Province. The hazard decreases</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8048R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8048R"><span>First approximations in avalanche model validations using <span class="hlt">seismic</span> information</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roig Lafon, Pere; Suriñach, Emma; Bartelt, Perry; Pérez-Guillén, Cristina; Tapia, Mar; Sovilla, Betty</p> <p>2017-04-01</p> <p>Avalanche dynamics modelling is an essential tool for snow hazard management. Scenario based numerical modelling provides quantitative arguments for decision-making. The software tool RAMMS (WSL Institute for Snow and Avalanche Research SLF) is one such tool, often used by government authorities and geotechnical offices. As avalanche models improve, the quality of the numerical results will depend increasingly on user experience on the specification of input (e.g. <span class="hlt">release</span> and entrainment volumes, secondary <span class="hlt">releases</span>, snow temperature and quality). New model developments must continue to be validated using real phenomena data, for improving performance and reliability. The avalanches group form University of Barcelona (RISKNAT - UB), has studied the <span class="hlt">seismic</span> signals generated from avalanches since 1994. Presently, the group manages the <span class="hlt">seismic</span> installation at SLF's Vallée de la Sionne experimental site (VDLS). At VDLS the recorded <span class="hlt">seismic</span> signals can be correlated to other avalanche measurement techniques, including both advanced remote sensing methods (radars, videogrammetry) and obstacle based sensors (pressure, capacitance, optical sender-reflector barriers). This comparison between different measurement techniques allows the group to address the question if <span class="hlt">seismic</span> analysis can be used alone, on more additional avalanche tracks, to gain insight and validate numerical avalanche dynamics models in different terrain conditions. In this study, we aim to add the <span class="hlt">seismic</span> data as an external record of the phenomena, able to validate RAMMS models. The <span class="hlt">seismic</span> sensors are considerable easy and cheaper to install than other physical measuring tools, and are able to record data from the phenomena in every atmospheric conditions (e.g. bad weather, low light, freezing make photography, and other kind of sensors not usable). With <span class="hlt">seismic</span> signals, we record the temporal evolution of the inner and denser parts of the avalanche. We are able to recognize the approximate position</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GMD.....9.1567G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GMD.....9.1567G"><span>SiSeRHMap v1.0: a simulator for mapped <span class="hlt">seismic</span> response using a hybrid model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grelle, Gerardo; Bonito, Laura; Lampasi, Alessandro; Revellino, Paola; Guerriero, Luigi; Sappa, Giuseppe; Guadagno, Francesco Maria</p> <p>2016-04-01</p> <p>The SiSeRHMap (simulator for mapped <span class="hlt">seismic</span> response using a hybrid model) is a computerized methodology capable of elaborating prediction maps of <span class="hlt">seismic</span> response in terms of <span class="hlt">acceleration</span> spectra. It was realized on the basis of a hybrid model which combines different approaches and models in a new and non-conventional way. These approaches and models are organized in a code architecture composed of five interdependent modules. A GIS (geographic information system) cubic model (GCM), which is a layered computational structure based on the concept of lithodynamic units and zones, aims at reproducing a parameterized layered subsoil model. A meta-modelling process confers a hybrid nature to the methodology. In this process, the one-dimensional (1-D) linear equivalent analysis produces <span class="hlt">acceleration</span> response spectra for a specified number of site profiles using one or more input motions. The shear wave velocity-thickness profiles, defined as trainers, are randomly selected in each zone. Subsequently, a numerical adaptive simulation model (Emul-spectra) is optimized on the above trainer <span class="hlt">acceleration</span> response spectra by means of a dedicated evolutionary algorithm (EA) and the Levenberg-Marquardt algorithm (LMA) as the final optimizer. In the final step, the GCM maps executor module produces a serial map set of a stratigraphic <span class="hlt">seismic</span> response at different periods, grid solving the calibrated Emul-spectra model. In addition, the spectra topographic amplification is also computed by means of a 3-D validated numerical prediction model. This model is built to match the results of the numerical simulations related to isolate reliefs using GIS morphometric data. In this way, different sets of <span class="hlt">seismic</span> response maps are developed on which maps of design <span class="hlt">acceleration</span> response spectra are also defined by means of an enveloping technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoJI.tmp..176M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoJI.tmp..176M"><span>The modest <span class="hlt">seismicity</span> of the northern Red Sea rift</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mitchell, Neil C.; Stewart, Ian C. F.</p> <p>2018-05-01</p> <p>Inferring tectonic movements from earthquakes (`seismotectonics') relies on earthquakes faithfully recording tectonic motions. In the northern half of the Red Sea, however, events of magnitude 5.0 and above are almost entirely absent from global catalogues, even though GPS and other plate motion data suggest that the basin is actively rifting at ˜10 mm yr-1. <span class="hlt">Seismic</span> moments computed here from event magnitudes contributed to the International Seismology Centre (ISC) suggest that the moment <span class="hlt">release</span> rate is more than an order of magnitude smaller than for the southern Red Sea and for the Southwest Indian Ridge (SWIR), which is spreading at a comparable rate to the central Red Sea and is more remote from recording stations. A smaller moment <span class="hlt">release</span> rate in the northern Red Sea might be anticipated from its smaller spreading rate, but <span class="hlt">seismic</span> coupling coefficients, which account for spreading rate variations, are also one order of magnitude smaller than for the other two areas. We explore potential explanations for this apparently reduced <span class="hlt">seismicity</span>. The northern Red Sea is almost continuously covered with thick evaporites and overlying Plio-Pleistocene sediments. These deposits may have reduced the thickness of the seismogenic layer, for example, by elevating lithosphere temperatures by a thermal blanketing effect or by leading to excess pore fluid pressures that reduce effective stress. The presence of subdued <span class="hlt">seismicity</span> here implies that tectonic movements can in places be poorly recorded by earthquake data and requires that alternative data be sought when investigating the active tectonics of sedimented rifts in particular.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S22B..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S22B..05L"><span>Aseismic and <span class="hlt">seismic</span> slip induced by fluid injection from poroelastic and rate-state friction modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Y.; Deng, K.; Harrington, R. M.; Clerc, F.</p> <p>2016-12-01</p> <p>Solid matrix stress change and pore pressure diffusion caused by fluid injection has been postulated as key factors for inducing earthquakes and aseismic slip on pre-existing faults. In this study, we have developed a numerical model that simulates aseismic and <span class="hlt">seismic</span> slip in a rate-and-state friction framework with poroelastic stress perturbations from multi-stage hydraulic fracturing scenarios. We apply the physics-based model to the 2013-2015 earthquake sequences near Fox Creek, Alberta, Canada, where three magnitude 4.5 earthquakes were potentially induced by nearby hydraulic fracturing activity. In particular, we use the relocated December 2013 <span class="hlt">seismicity</span> sequence to approximate the fault orientation, and find the <span class="hlt">seismicity</span> migration spatiotemporally correlate with the positive Coulomb stress changes calculated from the poroelastic model. When the poroelastic stress changes are introduced to the rate-state friction model, we find that slip on the fault evolves from aseismic to <span class="hlt">seismic</span> in a manner similar to the onset of <span class="hlt">seismicity</span>. For a 15-stage hydraulic fracturing that lasted for 10 days, modeled fault slip rate starts to <span class="hlt">accelerate</span> after 3 days of fracking, and rapidly develops into a <span class="hlt">seismic</span> event, which also temporally coincides with the onset of induced <span class="hlt">seismicity</span>. The poroelastic stress perturbation and consequently fault slip rate continue to evolve and remain high for several weeks after hydraulic fracturing has stopped, which may explain the continued <span class="hlt">seismicity</span> after shut-in. In a comparison numerical experiment, fault slip rate quickly decreases to the interseismic level when stress perturbations are instantaneously returned to zero at shut-in. Furthermore, when stress perturbations are removed just a few hours after the fault slip rate starts to <span class="hlt">accelerate</span> (that is, hydraulic fracturing is shut down prematurely), only aseismic slip is observed in the model. Our preliminary results thus suggest the design of fracturing duration and flow</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70044007','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70044007"><span>What can we learn from the Wells, NV earthquake sequence about <span class="hlt">seismic</span> hazard in the intermountain west?</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Petersen, M.D.; Pankow, K.L.; Biasi, G.P.; Meremonte, M.</p> <p>2008-01-01</p> <p>The February 21, 2008 Wells, NV earthquake (M 6) was felt throughout eastern Nevada, southern Idaho, and western Utah. The town of Wells sustained significant damage to unreinforced masonry buildings. The earthquake occurred in a region of low <span class="hlt">seismic</span> hazard with little <span class="hlt">seismicity</span>, low geodetic strain rates, and few mapped faults. The peak horizontal ground <span class="hlt">acceleration</span> predicted by the USGS National <span class="hlt">Seismic</span> Hazard Maps is about 0.2 g at 2% probability of exceedance in 50 years, with the contributions coming mostly from the Ruby Mountain fault and background <span class="hlt">seismicity</span> (M5-7.0). The hazard model predicts that the probability of occurrence of an M>6 event within 50 km of Wells is about 15% in 100 years. Although the earthquake was inside the USArray Transportable Array network, the nearest on-scale recordings of ground motions from the mainshock were too distant to estimate <span class="hlt">accelerations</span> in town. The University of Nevada Reno, the University of Utah, and the U.S. Geological Survey deployed portable instruments to capture the ground motions from aftershocks of this rare normal-faulting event. Shaking from a M 4.7 aftershock recorded on portable instruments at distances less than 10 km exceeded 0.3 g, and sustained <span class="hlt">accelerations</span> above 0.1 g lasted for about 5 seconds. For a magnitude 5 earthquake at 10 km distance the NGA equations predict median peak ground <span class="hlt">accelerations</span> about 0.1 g. Ground motions from normal faulting earthquakes are poorly represented in the ground motion prediction equations. We compare portable and Transportable Array ground-motion recordings with prediction equations. Advanced National <span class="hlt">Seismic</span> System stations in Utah recorded ground motions 250 km from the mainshock of about 2% g. The maximum ground motion recorded in Salt Lake City was in the center of the basin. We analyze the spatial variability of ground motions (rock vs. soil) and the influence of the Salt Lake Basin in modifying the ground motions. We then compare this data with the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAfES.134..257A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAfES.134..257A"><span>Probabilistic <span class="hlt">seismic</span> hazard analysis (PSHA) for Ethiopia and the neighboring region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ayele, Atalay</p> <p>2017-10-01</p> <p><span class="hlt">Seismic</span> hazard calculation is carried out for the Horn of Africa region (0°-20° N and 30°-50°E) based on the probabilistic <span class="hlt">seismic</span> hazard analysis (PSHA) method. The earthquakes catalogue data obtained from different sources were compiled, homogenized to Mw magnitude scale and declustered to remove the dependent events as required by Poisson earthquake source model. The seismotectonic map of the study area that avails from recent studies is used for area sources zonation. For assessing the <span class="hlt">seismic</span> hazard, the study area was divided into small grids of size 0.5° × 0.5°, and the hazard parameters were calculated at the center of each of these grid cells by considering contributions from all <span class="hlt">seismic</span> sources. Peak Ground <span class="hlt">Acceleration</span> (PGA) corresponding to 10% and 2% probability of exceedance in 50 years were calculated for all the grid points using generic rock site with Vs = 760 m/s. Obtained values vary from 0.0 to 0.18 g and 0.0-0.35 g for 475 and 2475 return periods, respectively. The corresponding contour maps showing the spatial variation of PGA values for the two return periods are presented here. Uniform hazard response spectrum (UHRS) for 10% and 2% probability of exceedance in 50 years and hazard curves for PGA and 0.2 s spectral <span class="hlt">acceleration</span> (Sa) all at rock site are developed for the city of Addis Ababa. The hazard map of this study corresponding to the 475 return periods has already been used to update and produce the 3rd generation building code of Ethiopia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987MarGR...9...67H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987MarGR...9...67H"><span>A permanent <span class="hlt">seismic</span> station beneath the Ocean Bottom</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harris, David; Cessaro, Robert K.; Duennebier, Fred K.; Byrne, David A.</p> <p>1987-03-01</p> <p>The Hawaii Institute of Geophysics began development of the Ocean Subbottom Seisometer (OSS) system in 1978, and OSS systems were installed in four locations between 1979 and 1982. The OSS system is a permanent, deep ocean borehole <span class="hlt">seismic</span> recording system composed of a borehole sensor package (tool), an electromechanical cable, recorder package, and recovery system. Installed near the bottom of a borehole (drilled by the D/V Glomar Challenger), the tool contains three orthogonal, 4.5-Hz geophones, two orthogonal tilt meters; and a temperature sensor. Signals from these sensors are multiplexed, digitized (with a floating point technique), and telemetered through approximately 10 km of electromechanical cable to a recorder package located near the ocean bottom. Electrical power for the tool is supplied from the recorder package. The digital <span class="hlt">seismic</span> signals are demultiplexed, converted back to analog form, processed through an automatic gain control (AGC) circuit, and recorded along with a time code on magnetic tape cassettes in the recorder package. Data may be recorded continuously for up to two months in the self-contained recorder package. Data may also be recorded in real time (digital formal) during the installation and subsequent recorder package servicing. The recorder package is connected to a submerged recovery buoy by a length of bouyant polypropylene rope. The anchor on the recovery buoy is <span class="hlt">released</span> by activating either of the acoustical command <span class="hlt">releases</span>. The polypropylene rope may also be seized with a grappling hook to effect recovery. The recorder package may be repeatedly serviced as long as the tool remains functional A wide range of data has been recovered from the OSS system. Recovered analog records include signals from natural <span class="hlt">seismic</span> sources such as earthquakes (teleseismic and local), man-made <span class="hlt">seismic</span> sources such as refraction <span class="hlt">seismic</span> shooting (explosives and air cannons), and nuclear tests. Lengthy continuous recording has permitted analysis</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EEEV....9..459K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EEEV....9..459K"><span>A neural network based methodology to predict site-specific spectral <span class="hlt">acceleration</span> values</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kamatchi, P.; Rajasankar, J.; Ramana, G. V.; Nagpal, A. K.</p> <p>2010-12-01</p> <p>A general neural network based methodology that has the potential to replace the computationally-intensive site-specific <span class="hlt">seismic</span> analysis of structures is proposed in this paper. The basic framework of the methodology consists of a feed forward back propagation neural network algorithm with one hidden layer to represent the <span class="hlt">seismic</span> potential of a region and soil amplification effects. The methodology is implemented and verified with parameters corresponding to Delhi city in India. For this purpose, strong ground motions are generated at bedrock level for a chosen site in Delhi due to earthquakes considered to originate from the central <span class="hlt">seismic</span> gap of the Himalayan belt using necessary geological as well as geotechnical data. Surface level ground motions and corresponding site-specific response spectra are obtained by using a one-dimensional equivalent linear wave propagation model. Spectral <span class="hlt">acceleration</span> values are considered as a target parameter to verify the performance of the methodology. Numerical studies carried out to validate the proposed methodology show that the errors in predicted spectral <span class="hlt">acceleration</span> values are within acceptable limits for design purposes. The methodology is general in the sense that it can be applied to other <span class="hlt">seismically</span> vulnerable regions and also can be updated by including more parameters depending on the state-of-the-art in the subject.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PEPI..261...24X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PEPI..261...24X"><span>Fast 3D elastic micro-<span class="hlt">seismic</span> source location using new GPU features</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xue, Qingfeng; Wang, Yibo; Chang, Xu</p> <p>2016-12-01</p> <p>In this paper, we describe new GPU features and their applications in passive <span class="hlt">seismic</span> - micro-<span class="hlt">seismic</span> location. Locating micro-<span class="hlt">seismic</span> events is quite important in <span class="hlt">seismic</span> exploration, especially when searching for unconventional oil and gas resources. Different from the traditional ray-based methods, the wave equation method, such as the method we use in our paper, has a remarkable advantage in adapting to low signal-to-noise ratio conditions and does not need a person to select the data. However, because it has a conspicuous deficiency due to its computation cost, these methods are not widely used in industrial fields. To make the method useful, we implement imaging-like wave equation micro-<span class="hlt">seismic</span> location in a 3D elastic media and use GPU to <span class="hlt">accelerate</span> our algorithm. We also introduce some new GPU features into the implementation to solve the data transfer and GPU utilization problems. Numerical and field data experiments show that our method can achieve a more than 30% performance improvement in GPU implementation just by using these new features.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..245c2021K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..245c2021K"><span>Bridges Dynamic Parameters Identification Based On Experimental and Numerical Method Comparison in Regard with Traffic <span class="hlt">Seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krkošková, Katarína; Papán, Daniel; Papánová, Zuzana</p> <p>2017-10-01</p> <p>The technical <span class="hlt">seismicity</span> negatively affects the environment, buildings and structures. Technical <span class="hlt">seismicity</span> means <span class="hlt">seismic</span> shakes caused by force impulse, random process and unnatural origin. The vibration influence on buildings is evaluated in the Eurocode 8 in Slovak Republic, however, the Slovak Technical Standard STN 73 0036 includes solution of the technical <span class="hlt">seismicity</span>. This standard also classes bridges into the group of structures that are significant in light of the technical <span class="hlt">seismicity</span> - the group “U”. Using the case studies analysis by FEM simulation and comparison is necessary because of brief norm evaluation of this issue. In this article, determinate dynamic parameters by experimental measuring and numerical method on two real bridges are compared. First bridge, (D201 - 00) is Scaffold Bridge on the road I/11 leading to the city of Čadca and is situated in the city of Žilina. It is eleven - span concrete road bridge. The railway is the obstacle, which this bridge spans. Second bridge (M5973 Brodno) is situated in the part of Žilina City on the road of I/11. It is concrete three - span road bridge built as box girder. The computing part includes 3D computational models of the bridges. First bridge (D201 - 00) was modelled in the software of IDA Nexis as the slab - wall model. The model outputs are natural frequencies and natural vibration modes. Second bridge (M5973 Brodno) was modelled in the software of VisualFEA. The technical <span class="hlt">seismicity</span> corresponds with the force impulse, which was put into this model. The model outputs are vibration displacements, velocities and <span class="hlt">accelerations</span>. The aim of the experiments was measuring of the vibration <span class="hlt">acceleration</span> time record of bridges, and there was need to systematic placement of accelerometers. The vibration <span class="hlt">acceleration</span> time record is important during the under - bridge train crossing, about the first bridge (D201 - 00) and the vibration <span class="hlt">acceleration</span> time domain is important during deducing the force</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S51D..05M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S51D..05M"><span>Effects of Strike-Slip Fault Segmentation on Earthquake Energy and <span class="hlt">Seismic</span> Hazard</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Madden, E. H.; Cooke, M. L.; Savage, H. M.; McBeck, J.</p> <p>2014-12-01</p> <p>Many major strike-slip faults are segmented along strike, including those along plate boundaries in California and Turkey. Failure of distinct fault segments at depth may be the source of multiple pulses of <span class="hlt">seismic</span> radiation observed for single earthquakes. However, how and when segmentation affects fault behavior and energy <span class="hlt">release</span> is the basis of many outstanding questions related to the physics of faulting and <span class="hlt">seismic</span> hazard. These include the probability for a single earthquake to rupture multiple fault segments and the effects of segmentation on earthquake magnitude, radiated <span class="hlt">seismic</span> energy, and ground motions. Using numerical models, we quantify components of the earthquake energy budget, including the tectonic work acting externally on the system, the energy of internal rock strain, the energy required to overcome fault strength and initiate slip, the energy required to overcome frictional resistance during slip, and the radiated <span class="hlt">seismic</span> energy. We compare the energy budgets of systems of two en echelon fault segments with various spacing that include both <span class="hlt">releasing</span> and restraining steps. First, we allow the fault segments to fail simultaneously and capture the effects of segmentation geometry on the earthquake energy budget and on the efficiency with which applied displacement is accommodated. Assuming that higher efficiency correlates with higher probability for a single, larger earthquake, this approach has utility for assessing the <span class="hlt">seismic</span> hazard of segmented faults. Second, we nucleate slip along a weak portion of one fault segment and let the quasi-static rupture propagate across the system. Allowing fractures to form near faults in these models shows that damage develops within <span class="hlt">releasing</span> steps and promotes slip along the second fault, while damage develops outside of restraining steps and can prohibit slip along the second fault. Work is consumed in both the propagation of and frictional slip along these new fractures, impacting the energy available</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018IJEaS.tmp...41K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018IJEaS.tmp...41K"><span>Long-term <span class="hlt">seismic</span> observations along Myanmar-Sunda subduction margin: insights for 2004 M w > 9.0 earthquake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khan, Prosanta Kumar; Banerjee, Jayashree; Shamim, Sk; Mohanty, Manoranjan</p> <p>2018-03-01</p> <p>The present study investigates the temporal variation of few <span class="hlt">seismic</span> parameters between the Myanmar (Zone I), Andaman-Nicobar-Northwest Sumatra (Zone II), Southeast Sumatra-West Indonesia (Zone III) and East Indonesia (Zone IV) converging boundaries in reference to the generation of 26 December 2004 M w > 9.0 off-Sumatra mega-earthquake event. The four segments are distinguished based on tectonics parameters, distinct geological locations, great earthquake occurrences, and the Wadati-Benioff zone characteristics. Two important <span class="hlt">seismic</span> parameters such as <span class="hlt">seismic</span> energy and b values are computed over a time-window of 6-month period during the entire 1976-2013 period for these segments. The b values show a constant decrease in Zones II, III, and IV, whereas the Zone I does not show any such pattern prior to the 2004 mega-event. The <span class="hlt">release</span> of <span class="hlt">seismic</span> energy was also gradually decreasing in Zones II and III till the 2004 event, and little similar pattern was also noted in Zone IV. This distinct observation might be indicating that the stress accumulation was dominant near the Sumatra-Java area located towards southeast of Zone II and northwest of Zone III. The <span class="hlt">released</span> strain energy during the 2004 event was subsequently migrated towards north, rupturing 1300 km of the boundary between the Northwest Sumatra and the North Andaman. The occurrence of 2004 mega-event was apparently concealed behind the long-term <span class="hlt">seismic</span> quiescence existing near the Sumatra and Nicobar margin. A systematic study of the patterns of <span class="hlt">seismic</span> energy <span class="hlt">release</span> and b values, and the long-term observation of collective behaviour of the margin tectonics might have had given clues to the possibility of the 2004 mega-event.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS51B2057F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS51B2057F"><span>Methane Hydrate Concentrations at GC955 and WR313 Drilling Sites in the Gulf of Mexico Determined from <span class="hlt">Seismic</span> Prestack Waveform Inversion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fortin, W.; Goldberg, D.; Küçük, H. M.</p> <p>2016-12-01</p> <p>Gas hydrates are naturally occurring compounds, which, at a molecular scale, are lattice structures of ice embedded with various gas molecules in the lattice voids. Volumetric estimates of associated hydrocarbons vary greatly due to the difficulty in remotely estimating hydrate concentrations in marine sediments but embedded hydrocarbon stores are thought to represent a significant portion of global deposits. The unstable nature of methane hydrates has been linked to submarine landslides and the subsequent <span class="hlt">release</span> of large quantities of methane can <span class="hlt">accelerate</span> global climate change. Understanding the details of gas hydrate systems is important for potential economic production and assessing natural hazards risks. <span class="hlt">Seismic</span> reflection techniques are uniquely capable of detecting gas hydrates. Often, hydrate layers appear as bottom simulating reflectors (BSRs); however, BSRs are not present everywhere gas hydrates are known to occur. Using recently reprocessed prestack time migrated data and prestack waveform inversion (PWI) techniques, we produce velocity models at high vertical and horizontal resolution in order to investigate the presence of gas hydrates in the Gulf of Mexico. Coupling our PWI results with known velocity-property relationships and data from nearby well controls, we determine the viability of recently collected high-resolution <span class="hlt">seismic</span> data and outline small-scale heterogeneities at GC955 and WR313. We outline where PWI techniques are capable of identifying gas hydrates in <span class="hlt">seismic</span> reflection data where BSRs are not present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1371515','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1371515"><span>Application of Nonlinear <span class="hlt">Seismic</span> Soil-Structure Interaction Analysis for Identification of <span class="hlt">Seismic</span> Margins at Nuclear Power Plants</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Varma, Amit H.; Seo, Jungil; Coleman, Justin Leigh</p> <p>2015-11-01</p> <p><span class="hlt">Seismic</span> probabilistic risk assessment (SPRA) methods and approaches at nuclear power plants (NPP) were first developed in the 1970s and aspects of them have matured over time as they were applied and incrementally improved. SPRA provides information on risk and risk insights and allows for some accounting for uncertainty and variability. As a result, SPRA is now used as an important basis for risk-informed decision making for both new and operating NPPs in the US and in an increasing number of countries globally. SPRAs are intended to provide best estimates of the various combinations of structural and equipment failures thatmore » can lead to a <span class="hlt">seismic</span> induced core damage event. However, in some instances the current SPRA approach contains large uncertainties, and potentially masks other important events (for instance, it was not the <span class="hlt">seismic</span> motions that caused the Fukushima core melt events, but the tsunami ingress into the facility). INL has an advanced SPRA research and development (R&D) activity that will identify areas in the calculation process that contain significant uncertainties. One current area of focus is the use of nonlinear soil-structure interaction (NLSSI) analysis methods to accurately capture: 1) nonlinear soil behavior and 2) gapping and sliding between the NPP and soil. The goal of this study is to compare numerical NLSSI analysis results with recorded earthquake ground motions at Fukushima Daichii (Great Tohuku Earthquake) and evaluate the sources of nonlinearity contributing to the observed reduction in peak <span class="hlt">acceleration</span>. Comparisons are made using recorded data in the free-field (soil column with no structural influence) and recorded data on the NPP basemat (in-structure response). Results presented in this study should identify areas of focus for future R&D activities with the goal of minimizing uncertainty in SPRA calculations. This is not a validation activity since there are too many sources of uncertainty that a numerical analysis</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sim/3077/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sim/3077/"><span>Maps Showing <span class="hlt">Seismic</span> Landslide Hazards in Anchorage, Alaska</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Jibson, Randall W.; Michael, John A.</p> <p>2009-01-01</p> <p>The devastating landslides that accompanied the great 1964 Alaska earthquake showed that <span class="hlt">seismically</span> triggered landslides are one of the greatest geologic hazards in Anchorage. Maps quantifying <span class="hlt">seismic</span> landslide hazards are therefore important for planning, zoning, and emergency-response preparation. The accompanying maps portray <span class="hlt">seismic</span> landslide hazards for the following conditions: (1) deep, translational landslides, which occur only during great subduction-zone earthquakes that have return periods of =~300-900 yr; (2) shallow landslides for a peak ground <span class="hlt">acceleration</span> (PGA) of 0.69 g, which has a return period of 2,475 yr, or a 2 percent probability of exceedance in 50 yr; and (3) shallow landslides for a PGA of 0.43 g, which has a return period of 475 yr, or a 10 percent probability of exceedance in 50 yr. Deep, translational landslide hazard zones were delineated based on previous studies of such landslides, with some modifications based on field observations of locations of deep landslides. Shallow-landslide hazards were delineated using a Newmark-type displacement analysis for the two probabilistic ground motions modeled.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70058880','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70058880"><span>Maps showing <span class="hlt">seismic</span> landslide hazards in Anchorage, Alaska</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Jibson, Randall W.</p> <p>2014-01-01</p> <p>The devastating landslides that accompanied the great 1964 Alaska earthquake showed that <span class="hlt">seismically</span> triggered landslides are one of the greatest geologic hazards in Anchorage. Maps quantifying <span class="hlt">seismic</span> landslide hazards are therefore important for planning, zoning, and emergency-response preparation. The accompanying maps portray <span class="hlt">seismic</span> landslide hazards for the following conditions: (1) deep, translational landslides, which occur only during great subduction-zone earthquakes that have return periods of =300-900 yr; (2) shallow landslides for a peak ground <span class="hlt">acceleration</span> (PGA) of 0.69 g, which has a return period of 2,475 yr, or a 2 percent probability of exceedance in 50 yr; and (3) shallow landslides for a PGA of 0.43 g, which has a return period of 475 yr, or a 10 percent probability of exceedance in 50 yr. Deep, translational landslide hazards were delineated based on previous studies of such landslides, with some modifications based on field observations of locations of deep landslides. Shallow-landslide hazards were delineated using a Newmark-type displacement analysis for the two probabilistic ground motions modeled.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10464E..1GW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10464E..1GW"><span>Field test investigation of high sensitivity fiber optic <span class="hlt">seismic</span> geophone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Meng; Min, Li; Zhang, Xiaolei; Zhang, Faxiang; Sun, Zhihui; Li, Shujuan; Wang, Chang; Zhao, Zhong; Hao, Guanghu</p> <p>2017-10-01</p> <p><span class="hlt">Seismic</span> reflection, whose measured signal is the artificial <span class="hlt">seismic</span> waves ,is the most effective method and widely used in the geophysical prospecting. And this method can be used for exploration of oil, gas and coal. When a <span class="hlt">seismic</span> wave travelling through the Earth encounters an interface between two materials with different acoustic impedances, some of the wave energy will reflect off the interface and some will refract through the interface. At its most basic, the <span class="hlt">seismic</span> reflection technique consists of generating <span class="hlt">seismic</span> waves and measuring the time taken for the waves to travel from the source, reflect off an interface and be detected by an array of geophones at the surface. Compared to traditional geophones such as electric, magnetic, mechanical and gas geophone, optical fiber geophones have many advantages. Optical fiber geophones can achieve sensing and signal transmission simultaneously. With the development of fiber grating sensor technology, fiber bragg grating (FBG) is being applied in <span class="hlt">seismic</span> exploration and draws more and more attention to its advantage of anti-electromagnetic interference, high sensitivity and insensitivity to meteorological conditions. In this paper, we designed a high sensitivity geophone and tested its sensitivity, based on the theory of FBG sensing. The frequency response range is from 10 Hz to 100 Hz and the <span class="hlt">acceleration</span> of the fiber optic <span class="hlt">seismic</span> geophone is over 1000pm/g. sixteen-element fiber optic <span class="hlt">seismic</span> geophone array system is presented and the field test is performed in Shengli oilfield of China. The field test shows that: (1) the fiber optic <span class="hlt">seismic</span> geophone has a higher sensitivity than the traditional geophone between 1-100 Hz;(2) The low frequency reflection wave continuity of fiber Bragg grating geophone is better.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17..920B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17..920B"><span>High Voltage <span class="hlt">Seismic</span> Generator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bogacz, Adrian; Pala, Damian; Knafel, Marcin</p> <p>2015-04-01</p> <p>This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage <span class="hlt">seismic</span> wave generator. Constructed device uses a high-energy electrical discharge to generate <span class="hlt">seismic</span> wave in ground. This type of device can be applied in several different methods of <span class="hlt">seismic</span> measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then <span class="hlt">released</span> in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate <span class="hlt">seismic</span> waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated <span class="hlt">seismic</span> signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T13E..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T13E..03M"><span><span class="hlt">Seismic</span> and Aseismic Slip on the Cascadia Megathrust</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Michel, S. G. R. M.; Gualandi, A.; Avouac, J. P.</p> <p>2017-12-01</p> <p>Our understanding of the dynamics governing aseismic and <span class="hlt">seismic</span> slip hinges on our ability to image the time evolution of fault slip during and in between earthquakes and transients. Such kinematic descriptions are also pivotal to assess <span class="hlt">seismic</span> hazard as, on the long term, elastic strain accumulating around a fault should be balanced by elastic strain <span class="hlt">released</span> by <span class="hlt">seismic</span> slip and aseismic transients. In this presentation, we will discuss how such kinematic descriptions can be obtained from the analysis and modelling of geodetic time series. We will use inversion methods based on Independent Component Analysis (ICA) decomposition of the time series to extract and model the aseismic slip (afterslip and slow slip events). We will show that this approach is very effective to identify, and filter out, non-tectonic sources of geodetic strain such as the strain due to surface loads, which can be estimated using gravimetric measurements from GRACE, and thermal strain. We will discuss in particular the application to the Cascadia subduction zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S53B2410D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S53B2410D"><span><span class="hlt">Seismic</span> Hazard Maps for the Maltese Archipelago: Preliminary Results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>D'Amico, S.; Panzera, F.; Galea, P. M.</p> <p>2013-12-01</p> <p>The Maltese islands form an archipelago of three major islands lying in the Sicily channel at about 140 km south of Sicily and 300 km north of Libya. So far very few investigations have been carried out on <span class="hlt">seismicity</span> around the Maltese islands and no maps of <span class="hlt">seismic</span> hazard for the archipelago are available. Assessing the <span class="hlt">seismic</span> hazard for the region is currently of prime interest for the near-future development of industrial and touristic facilities as well as for urban expansion. A culture of <span class="hlt">seismic</span> risk awareness has never really been developed in the country, and the public perception is that the islands are relatively safe, and that any earthquake phenomena are mild and infrequent. However, the Archipelago has been struck by several moderate/large events. Although recent constructions of a certain structural and strategic importance have been built according to high engineering standards, the same probably cannot be said for all residential buildings, many higher than 3 storeys, which have mushroomed rapidly in recent years. Such buildings are mostly of unreinforced masonry, with heavy concrete floor slabs, which are known to be highly vulnerable to even moderate ground shaking. We can surely state that in this context planning and design should be based on available national hazard maps. Unfortunately, these kinds of maps are not available for the Maltese islands. In this paper we attempt to compute a first and preliminary probabilistic <span class="hlt">seismic</span> hazard assessment of the Maltese islands in terms of Peak Ground <span class="hlt">Acceleration</span> (PGA) and Spectral <span class="hlt">Acceleration</span> (SA) at different periods. <span class="hlt">Seismic</span> hazard has been computed using the Esteva-Cornell (1968) approach which is the most widely utilized probabilistic method. It is a zone-dependent approach: seismotectonic and geological data are used coupled with earthquake catalogues to identify seismogenic zones within which earthquakes occur at certain rates. Therefore the earthquake catalogues can be reduced to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH21B1818T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH21B1818T"><span><span class="hlt">Seismic</span> Hazard Legislation in California: Challenges and Changes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Testa, S. M.</p> <p>2015-12-01</p> <p><span"><span class="hlt">Seismic</span> hazards in California are legislatively controlled by three specific Acts: the Field Act of 1933; the Alquist-Priolo Earthquake Fault Zoning Act (AP) of 1975; and the <span class="hlt">Seismic</span> Hazards Mapping Act (SHMA) of 1980. The Field Act recognized the need for earthquake resistant construction for California schools and banned unreinforced masonry buildings, and imposed structural design under <span class="hlt">seismic</span> conditions. The AP requires the California Geological Survey (CGS) to delineate "active fault zones" for general planning and mitigation by various state and local agencies. Under the AP, surface and near-surface faults are presumed active (about 11,000 years before present) unless proven otherwise; and can only be mitigated by avoidance (setback zones). The SHMA requires that earthquake-induced landslides, liquefaction zones, high ground <span class="hlt">accelerations</span>, tsunamis and seiches similarly be demarcated on CGS-issued maps. <span">Experience over the past ~45 years and related technological advances now show that more than ~95 percent of <span class="hlt">seismically</span> induced damage and loss of life stems from high ground <span class="hlt">accelerations</span>, from related ground deformation and from catastrophic structural failure, often far beyond State-mapped AP zones. The SHMA therefore enables the engineering community to mitigate natural hazards from a holistic standpoint that considers protection of public health, safety and welfare. In conformance with the SHMA, structural design and related planning and building codes focus on acceptable risk for natural hazards with a typical recurrence of ~100 yrs to a few thousand years. This contrasts with the current AP "total avoidance" for surface-fault rupture that may have occurred within the last 11,000 years. Accordingly, avoidance may be reasonable for well expressed surface faults in high-density urban areas or where relative fault activity is uncertain. However, in the interest of overall public, health and safety, and for consistency with the SHMA and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70013548','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70013548"><span>SOME APPLICATIONS OF <span class="hlt">SEISMIC</span> SOURCE MECHANISM STUDIES TO ASSESSING UNDERGROUND HAZARD.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McGarr, A.; ,</p> <p>1984-01-01</p> <p>Various measures of the <span class="hlt">seismic</span> source mechanism of mine tremors, such as magnitude, moment, stress drop, apparent stress, and <span class="hlt">seismic</span> efficiency, can be related directly to several aspects of the problem of determining the underground hazard arising from strong ground motion of large <span class="hlt">seismic</span> events. First, the relation between the sum of <span class="hlt">seismic</span> moments of tremors and the volume of stope closure caused by mining during a given period can be used in conjunction with magnitude-frequency statistics and an empirical relation between moment and magnitude to estimate the maximum possible sized tremor for a given mining situation. Second, it is shown that the 'energy <span class="hlt">release</span> rate,' a commonly-used parameter for predicting underground <span class="hlt">seismic</span> hazard, may be misleading in that the importance of overburden stress, or depth, is overstated. Third, results involving the relation between peak velocity and magnitude, magnitude-frequency statistics, and the maximum possible magnitude are applied to the problem of estimating the frequency at which design limits of certain underground support equipment are likely to be exceeded.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S53B0704B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S53B0704B"><span>Long <span class="hlt">seismic</span> activity in the Porto dos Gaúchos <span class="hlt">Seismic</span> Zone(PGSZ) - Amazon Craton Brazil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barros, L. V.; Bowen, B. M. D.; Schmidt, K.</p> <p>2017-12-01</p> <p>The largest earthquake ever observed in the stable continental interior of the South American plate occurred in Serra do Tombador (ST), Mato Grosso state - Brazil, on January 31, 1955 with magnitude 6.2 m b . Since then no other earthquake has been located near the 1955 epicenter. However, in Porto dos Gaúchos (PG), 100 km northeast of ST, a recurrent <span class="hlt">seismicity</span> has been observed since 1959. Both ST and PG are located in the Phanerozoic Parecis basin whose sediments overlies the crystalline basement of Amazon craton. Two magnitude 5 earthquakes occurred in PG, in 1998 and 2005 with intensities up to VI and V, respectively. These two main shocks were followed by aftershock sequences, studied by local <span class="hlt">seismic</span> networks, last up today, almost 30 years later, period in which it was detected more than seven thousand of <span class="hlt">seismic</span> events. Both sequences occurred in the same WSW-ENE oriented fault zone with right-lateral strike-slip mechanisms. The epicentral zone is near the northern border of Parecis basin, where there are buried grabens, generally trending WNW-ESE, such as the deep Mesoproterozoic Caiabis graben which lies partly beneath the Parecis basin. The seismogenic fault is located in a basement high, which is probably related with the same seismogenic feature responsible for the earthquakes in PGSZ. The 1955 earthquake, despite the uncertainty in its epicenter, does not seem to be directly related to any buried graben either. The <span class="hlt">seismicity</span> in the PGSZ, therefore, is not directly related to rifted crust.Not considering the possibility of miss location in the ST earthquake, its isolated occurrence - from the perspective of new studies on intraplate <span class="hlt">seismicity</span> - lead us to think that the PGSZ was activated by stresses <span class="hlt">released</span> by the earthquake of 1955 and that the seismogenic fault of ST would have closed a cycle of activity. This would explain its <span class="hlt">seismic</span> quiescence. However, other studies are necessary to prove this hypothesis, such as the measurement of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43C1874R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43C1874R"><span>Analysis and determination of susceptibility Risk from slope instability at Colima State Mexico due to the <span class="hlt">accelerators</span> factors of rain and <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramirez-Ruiz, J. J.</p> <p>2016-12-01</p> <p>Slope instability is presented each year in the mountain region of the Colima State, Mexico. It occurs due to the combination of different factors existing in this area as: Precipitation, topography contrast, type and mechanical properties of deposits that constitute the rocks and soils of the region and the erosion due to the elimination of vegetation deck to develop and grow urban areas. To these geological factors we can extend the tectonic activity of the Western part of Mexico that originate high <span class="hlt">seismicity</span> by the interaction of Cocos plate and North America plate forming the region of Graben de Colima, were is located our study area. Here we will present a Zonification and determination of the Susceptibility maps of slope instability due to the rain and <span class="hlt">seismicity</span> <span class="hlt">accelerators</span> factors. The North part of the State Colima is covered by deposits of the Volcan de Colima with an elevation of 3860 masl. It is the area of major precipitation yearly with more than 1200 mm in comparison to the average precipitation of about 900 mm of the State of Colima. Using a SIG system and the mapping of more than 30 sites we realize a zonification and analysis of the Risk using a methodology developed by CENAPRED. The susceptibility map developed in this area in combination with erosion factors permit us to determine an approximation of the Risk considering some limitations that will be present in this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20541389','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20541389"><span><span class="hlt">Seismic</span> analysis for translational failure of landfills with retaining walls.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Feng, Shi-Jin; Gao, Li-Ya</p> <p>2010-11-01</p> <p>In the <span class="hlt">seismic</span> impact zone, <span class="hlt">seismic</span> force can be a major triggering mechanism for translational failures of landfills. The scope of this paper is to develop a three-part wedge method for <span class="hlt">seismic</span> analysis of translational failures of landfills with retaining walls. The approximate solution of the factor of safety can be calculated. Unlike previous conventional limit equilibrium methods, the new method is capable of revealing the effects of both the solid waste shear strength and the retaining wall on the translational failures of landfills during earthquake. Parameter studies of the developed method show that the factor of safety decreases with the increase of the <span class="hlt">seismic</span> coefficient, while it increases quickly with the increase of the minimum friction angle beneath waste mass for various horizontal <span class="hlt">seismic</span> coefficients. Increasing the minimum friction angle beneath the waste mass appears to be more effective than any other parameters for increasing the factor of safety under the considered condition. Thus, selecting liner materials with higher friction angle will considerably reduce the potential for translational failures of landfills during earthquake. The factor of safety gradually increases with the increase of the height of retaining wall for various horizontal <span class="hlt">seismic</span> coefficients. A higher retaining wall is beneficial to the <span class="hlt">seismic</span> stability of the landfill. Simply ignoring the retaining wall will lead to serious underestimation of the factor of safety. Besides, the approximate solution of the yield <span class="hlt">acceleration</span> coefficient of the landfill is also presented based on the calculated method. Copyright © 2010 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3949308','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3949308"><span>Caffeine <span class="hlt">accelerates</span> recovery from general anesthesia</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Qiang; Fong, Robert; Mason, Peggy; Fox, Aaron P.</p> <p>2013-01-01</p> <p>General anesthetics inhibit neurotransmitter <span class="hlt">release</span> from both neurons and secretory cells. If inhibition of neurotransmitter <span class="hlt">release</span> is part of an anesthetic mechanism of action, then drugs that facilitate neurotransmitter <span class="hlt">release</span> may aid in reversing general anesthesia. Drugs that elevate intracellular cAMP levels are known to facilitate neurotransmitter <span class="hlt">release</span>. Three cAMP elevating drugs (forskolin, theophylline, and caffeine) were tested; all three drugs reversed the inhibition of neurotransmitter <span class="hlt">release</span> produced by isoflurane in PC12 cells in vitro. The drugs were tested in isoflurane-anesthetized rats. Animals were injected with either saline or saline containing drug. All three drugs dramatically <span class="hlt">accelerated</span> recovery from isoflurane anesthesia, but caffeine was most effective. None of the drugs, at the concentrations tested, had significant effects on breathing rates, O2 saturation, heart rate, or blood pressure in anesthetized animals. Caffeine alone was tested on propofol-anesthetized rats where it dramatically <span class="hlt">accelerated</span> recovery from anesthesia. The ability of caffeine to <span class="hlt">accelerate</span> recovery from anesthesia for different chemical classes of anesthetics, isoflurane and propofol, opens the possibility that it will do so for all commonly used general anesthetics, although additional studies will be required to determine whether this is in fact the case. Because anesthesia in rodents is thought to be similar to that in humans, these results suggest that caffeine might allow for rapid and uniform emergence from general anesthesia in human patients. PMID:24375022</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999GeoJI.137..535M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999GeoJI.137..535M"><span>Constraints on the frequency-magnitude relation and maximum magnitudes in the UK from observed <span class="hlt">seismicity</span> and glacio-isostatic recovery rates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Main, Ian; Irving, Duncan; Musson, Roger; Reading, Anya</p> <p>1999-05-01</p> <p>Earthquake populations have recently been shown to have many similarities with critical-point phenomena, with fractal scaling of source sizes (energy or <span class="hlt">seismic</span> moment) corresponding to the observed Gutenberg-Richter (G-R) frequency-magnitude law holding at low magnitudes. At high magnitudes, the form of the distribution depends on the <span class="hlt">seismic</span> moment <span class="hlt">release</span> rate Msolar and the maximum magnitude m_max . The G-R law requires a sharp truncation at an absolute maximum magnitude for finite Msolar. In contrast, the gamma distribution has an exponential tail which allows a soft or `credible' maximum to be determined by negligible contribution to the total <span class="hlt">seismic</span> moment <span class="hlt">release</span>. Here we apply both distributions to <span class="hlt">seismic</span> hazard in the mainland UK and its immediate continental shelf, constrained by a mixture of instrumental, historical and neotectonic data. Tectonic moment <span class="hlt">release</span> rates for the seismogenic part of the lithosphere are calculated from a flexural-plate model for glacio-isostatic recovery, constrained by vertical deformation rates from tide-gauge and geomorphological data. Earthquake focal mechanisms in the UK show near-vertical strike-slip faulting, with implied directions of maximum compressive stress approximately in the NNW-SSE direction, consistent with the tectonic model. Maximum magnitudes are found to be in the range 6.3-7.5 for the G-R law, or 7.0-8.2 m_L for the gamma distribution, which compare with a maximum observed in the time period of interest of 6.1 m_L . The upper bounds are conservative estimates, based on 100 per cent <span class="hlt">seismic</span> <span class="hlt">release</span> of the observed vertical neotectonic deformation. Glacio-isostatic recovery is predominantly an elastic rather than a <span class="hlt">seismic</span> process, so the true value of m_max is likely to be nearer the lower end of the quoted range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017P%26SS..144...89M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017P%26SS..144...89M"><span>Probing the internal structure of the asteriod Didymoon with a passive <span class="hlt">seismic</span> investigation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murdoch, N.; Hempel, S.; Pou, L.; Cadu, A.; Garcia, R. F.; Mimoun, D.; Margerin, L.; Karatekin, O.</p> <p>2017-09-01</p> <p>Understanding the internal structure of an asteroid has important implications for interpreting its evolutionary history, for understanding its continuing geological evolution, and also for asteroid deflection and in-situ space resource utilisation. Given the strong evidence that asteroids are <span class="hlt">seismically</span> active, an in-situ passive <span class="hlt">seismic</span> experiment could provide information about the asteroid surface and interior properties. Here, we discuss the natural <span class="hlt">seismic</span> activity that may be present on Didymoon, the secondary component of asteroid (65803) Didymos. Our analysis of the tidal stresses in Didymoon shows that tidal quakes are likely to occur if the secondary has an eccentric orbit. Failure occurs most easily at the asteroid poles and close to the surface for both homogeneous and layered internal structures. Simulations of <span class="hlt">seismic</span> wave propagation in Didymoon show that the <span class="hlt">seismic</span> moment of even small meteoroid impacts can generate clearly observable body and surface waves if the asteroid's internal structure is homogeneous. The presence of a regolith layer over a consolidated core can result in the <span class="hlt">seismic</span> energy becoming trapped in the regolith due to the strong impedance contrast at the regolith-core boundary. The inclusion of macro-porosity (voids) further complexifies the wavefield due to increased scattering. The most prominent <span class="hlt">seismic</span> waves are always found to be those traveling along the surface of the asteroid and those focusing in the antipodal point of the <span class="hlt">seismic</span> source. We find also that the waveforms and ground <span class="hlt">acceleration</span> spectra allow discrimination between the different internal structure models. Although the science return of a passive <span class="hlt">seismic</span> experiment would be enhanced by having multiple <span class="hlt">seismic</span> stations, one single <span class="hlt">seismic</span> station can already vastly improve our knowledge about the <span class="hlt">seismic</span> environment and sub-surface structure of an asteroid. We describe several <span class="hlt">seismic</span> measurement techniques that could be applied in order to study the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....11276P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....11276P"><span>Variations of <span class="hlt">seismic</span> parameters during different activity levels of the Soufriere Hills Volcano, Montserrat</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Powell, T.; Neuberg, J.</p> <p>2003-04-01</p> <p>The low-frequency <span class="hlt">seismic</span> events on Montserrat are linked to conduit resonance and the pressurisation of the volcanic system. Analysis of these events tell us more about the behaviour of the volcanic system and provide a monitoring and interpretation tool. We have written an Automated Event Classification Algorithm Program (AECAP), which finds and classifies <span class="hlt">seismic</span> events and calculates <span class="hlt">seismic</span> parameters such as energy, intermittency, peak frequency and event duration. Comparison of low-frequency energy with the tilt cycles in 1997 allows us to link pressurisation of the volcano with <span class="hlt">seismic</span> behaviour. An empirical relationship provides us with an estimate of pressurisation through <span class="hlt">released</span> <span class="hlt">seismic</span> energy. During 1997, the activity of the volcano varied considerably. We compare <span class="hlt">seismic</span> parameters from quiet periods to those from active periods and investigate how the relationships between these parameters change. These changes are then used to constrain models of magmatic processes during different stages of volcanic activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003GeoJI.152...94K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003GeoJI.152...94K"><span>Maximum earthquake magnitudes in the Aegean area constrained by tectonic moment <span class="hlt">release</span> rates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ch. Koravos, G.; Main, I. G.; Tsapanos, T. M.; Musson, R. M. W.</p> <p>2003-01-01</p> <p><span class="hlt">Seismic</span> moment <span class="hlt">release</span> is usually dominated by the largest but rarest events, making the estimation of <span class="hlt">seismic</span> hazard inherently uncertain. This uncertainty can be reduced by combining long-term tectonic deformation rates with short-term recurrence rates. Here we adopt this strategy to estimate recurrence rates and maximum magnitudes for tectonic zones in the Aegean area. We first form a merged catalogue for historical and instrumentally recorded earthquakes in the Aegean, based on a recently published catalogue for Greece and surrounding areas covering the time period 550BC-2000AD, at varying degrees of completeness. The historical data are recalibrated to allow for changes in damping in <span class="hlt">seismic</span> instruments around 1911. We divide the area up into zones that correspond to recent determinations of deformation rate from satellite data. In all zones we find that the Gutenberg-Richter (GR) law holds at low magnitudes. We use Akaike's information criterion to determine the best-fitting distribution at high magnitudes, and classify the resulting frequency-magnitude distributions of the zones as critical (GR law), subcritical (gamma density distribution) or supercritical (`characteristic' earthquake model) where appropriate. We determine the ratio η of <span class="hlt">seismic</span> to tectonic moment <span class="hlt">release</span> rate. Low values of η (<0.5) corresponding to relatively aseismic deformation, are associated with higher b values (>1.0). The <span class="hlt">seismic</span> and tectonic moment <span class="hlt">release</span> rates are then combined to constrain recurrence rates and maximum credible magnitudes (in the range 6.7-7.6 mW where the results are well constrained) based on extrapolating the short-term <span class="hlt">seismic</span> data. With current earthquake data, many of the tectonic zones show a characteristic distribution that leads to an elevated probability of magnitudes around 7, but a reduced probability of larger magnitudes above this value when compared with the GR trend. A modification of the generalized gamma distribution is suggested to account</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..44.3509M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44.3509M"><span>Bayesian identification of multiple <span class="hlt">seismic</span> change points and varying <span class="hlt">seismic</span> rates caused by induced <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Montoya-Noguera, Silvana; Wang, Yu</p> <p>2017-04-01</p> <p>The Central and Eastern United States (CEUS) has experienced an abnormal increase in <span class="hlt">seismic</span> activity, which is believed to be related to anthropogenic activities. The U.S. Geological Survey has acknowledged this situation and developed the CEUS 2016 1 year <span class="hlt">seismic</span> hazard model using the catalog of 2015 by assuming stationary <span class="hlt">seismicity</span> in that period. However, due to the nonstationary nature of induced <span class="hlt">seismicity</span>, it is essential to identify change points for accurate probabilistic <span class="hlt">seismic</span> hazard analysis (PSHA). We present a Bayesian procedure to identify the most probable change points in <span class="hlt">seismicity</span> and define their respective <span class="hlt">seismic</span> rates. It uses prior distributions in agreement with conventional PSHA and updates them with recent data to identify <span class="hlt">seismicity</span> changes. It can determine the change points in a regional scale and may incorporate different types of information in an objective manner. It is first successfully tested with simulated data, and then it is used to evaluate Oklahoma's regional <span class="hlt">seismicity</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24727141','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24727141"><span><span class="hlt">Accelerating</span> the dissolution of enteric coatings in the upper small intestine: evolution of a novel pH 5.6 bicarbonate buffer system to assess drug <span class="hlt">release</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Varum, Felipe J O; Merchant, Hamid A; Goyanes, Alvaro; Assi, Pardis; Zboranová, Veronika; Basit, Abdul W</p> <p>2014-07-01</p> <p>Despite rapid dissolution in compendial phosphate buffers, gastro resistant (enteric coated) products can take up to 2 h to disintegrate in the human small intestine, which clearly highlights the inadequacy of the in vitro test method to predict in vivo behaviour of these formulations. The aim of this study was to establish the utility of a novel pH 5.6 bicarbonate buffer, stabilized by an Auto pH™ System, as a better surrogate of the conditions of the proximal small intestine to investigate the dissolution behaviour of standard and <span class="hlt">accelerated</span> <span class="hlt">release</span> enteric double coating formulations. Prednisolone tablets were coated with 3 or 5 mg/cm(2) of partially neutralized EUDRAGIT(®) L 30 D-55, HP-55 or HPMC adjusted to pH 6 or 8. An outer layer of EUDRAGIT(®) L 30 D-55 was applied at 5mg/cm(2). For comparison purposes, a standard single layer of EUDRAGIT(®) L 30 D-55 was applied to the tablets. Dissolution was carried out using USP II apparatus in 0.1 M HCl for 2 h, followed by pH 5.6 bicarbonate buffer. EUDRAGIT(®) L 30 D-55 single-coated tablets showed a slow drug <span class="hlt">release</span> with a lag time of 75 min in buffer, whereas <span class="hlt">release</span> from the EUDRAGIT(®) L 30 D-55 double-coated tablets was <span class="hlt">accelerated</span>. These in vitro lag times closely match the in vivo disintegration times for these coated tablets reported previously. Drug <span class="hlt">release</span> was further <span class="hlt">accelerated</span> from modified double coatings, particularly in the case of coatings with a thinner inner layer of HP-55 or HPMC (pH 8 and KH2PO4). This study confirms that the pH 5.6 bicarbonate buffer system offers significant advantages during the development of dosage forms designed to <span class="hlt">release</span> the drug in the upper small intestine. Copyright © 2014. Published by Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70176638','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70176638"><span><span class="hlt">Seismic</span> velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for <span class="hlt">accelerated</span> porosity reduction?</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Shimeld, John; Li, Qingmou; Chian, Deping; Lebedeva-Ivanova, Nina; Jackson, Ruth; Mosher, David; Hutchinson, Deborah R.</p> <p>2016-01-01</p> <p> favourably with borehole data for Miocene turbidites in the eastern Gulf of Mexico. The station-specific results also indicate that Quaternary sediments coarsen towards the Beaufort-Mackenzie and Banks Island margins in a manner that is consistent with the variable history of Laurentide Ice Sheet advance documented for these margins. Lithological factors do not fully account for the elevated velocity–depth trends that are associated with the southwestern Canada Basin and the Alpha-Mendeleev magnetic domain. <span class="hlt">Accelerated</span> porosity reduction due to elevated palaeo-heat flow is inferred for these regions, which may be related to the underlying crustal types or possibly volcanic intrusion of the sedimentary succession. Beyond exploring the variation of an important physical property in the Arctic Ocean basin, this study provides comparative reference for global studies of <span class="hlt">seismic</span> velocity, burial history, sedimentary compaction, <span class="hlt">seismic</span> inversion and overpressure prediction, particularly in mudrock-dominated successions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoJI.204....1S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoJI.204....1S"><span><span class="hlt">Seismic</span> velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for <span class="hlt">accelerated</span> porosity reduction?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shimeld, John; Li, Qingmou; Chian, Deping; Lebedeva-Ivanova, Nina; Jackson, Ruth; Mosher, David; Hutchinson, Deborah</p> <p>2016-01-01</p> <p> borehole data for Miocene turbidites in the eastern Gulf of Mexico. The station-specific results also indicate that Quaternary sediments coarsen towards the Beaufort-Mackenzie and Banks Island margins in a manner that is consistent with the variable history of Laurentide Ice Sheet advance documented for these margins. Lithological factors do not fully account for the elevated velocity-depth trends that are associated with the southwestern Canada Basin and the Alpha-Mendeleev magnetic domain. <span class="hlt">Accelerated</span> porosity reduction due to elevated palaeo-heat flow is inferred for these regions, which may be related to the underlying crustal types or possibly volcanic intrusion of the sedimentary succession. Beyond exploring the variation of an important physical property in the Arctic Ocean basin, this study provides comparative reference for global studies of <span class="hlt">seismic</span> velocity, burial history, sedimentary compaction, <span class="hlt">seismic</span> inversion and overpressure prediction, particularly in mudrock-dominated successions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036809','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036809"><span><span class="hlt">Seismic</span> Hazard and Risk Assessments for Beijing-Tianjin-Tangshan, China, Area</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Xie, F.; Wang, Z.; Liu, J.</p> <p>2011-01-01</p> <p><span class="hlt">Seismic</span> hazard and risk in the Beijing-Tianjin-Tangshan, China, area were estimated from 500-year intensity observations. First, we digitized the intensity observations (maps) using ArcGIS with a cell size of 0.1 ?? 0.1??. Second, we performed a statistical analysis on the digitized intensity data, determined an average b value (0.39), and derived the intensity-frequency relationship (hazard curve) for each cell. Finally, based on a Poisson model for earthquake occurrence, we calculated <span class="hlt">seismic</span> risk in terms of a probability of I ??? 7, 8, or 9 in 50 years. We also calculated the corresponding 10 percent probability of exceedance of these intensities in 50 years. The advantages of assessing <span class="hlt">seismic</span> hazard and risk from intensity records are that (1) fewer assumptions (i. e., earthquake source and ground motion attenuation) are made, and (2) site-effect is included. Our study shows that the area has high <span class="hlt">seismic</span> hazard and risk. Our study also suggests that current design peak ground <span class="hlt">acceleration</span> or intensity for the area may not be adequate. ?? 2010 Birkh??user / Springer Basel AG.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T23A0606K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T23A0606K"><span>Linking Incoming Plate Faulting and Intermediate Depth <span class="hlt">Seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kwong, K. B.; van Zelst, I.; Tong, X.; Eimer, M. O.; Naif, S.; Hu, Y.; Zhan, Z.; Boneh, Y.; Schottenfels, E.; Miller, M. S.; Moresi, L. N.; Warren, J. M.; Wiens, D. A.</p> <p>2017-12-01</p> <p>Intermediate depth earthquakes, occurring between 70-350 km depth, are often attributed to dehydration reactions within the subducting plate. It is proposed that incoming plate normal faulting associated with plate bending at the trench may control the amount of hydration in the plate by producing large damage zones that create pathways for the infiltration of seawater deep into the subducting mantle. However, a relationship between incoming plate <span class="hlt">seismicity</span>, faulting, and intermediate depth <span class="hlt">seismicity</span> has not been established. We compiled a global dataset consisting of incoming plate earthquake moment tensor (CMT) solutions, focal depths, bend fault spacing and offset measurements, along with plate age and convergence rates. In addition, a global intermediate depth <span class="hlt">seismicity</span> dataset was compiled with parameters such as the maximum <span class="hlt">seismic</span> moment and <span class="hlt">seismicity</span> rate, as well as thicknesses of double <span class="hlt">seismic</span> zones. The maximum fault offset in the bending region has a strong correlation with the intermediate depth <span class="hlt">seismicity</span> rate, but a more modest correlation with other parameters such as convergence velocity and plate age. We estimated the expected rate of <span class="hlt">seismic</span> moment <span class="hlt">release</span> for the incoming plate faults using mapped fault scarps from bathymetry. We compare this with the cumulative moment from normal faulting earthquakes in the incoming plate from the global CMT catalog to determine whether outer rise fault movement has an aseismic component. Preliminary results from Tonga and the Middle America Trench suggest there may be an aseismic component to incoming plate bending faulting. The cumulative <span class="hlt">seismic</span> moment calculated for the outer rise faults will also be compared to the cumulative moment from intermediate depth earthquakes to assess whether these parameters are related. To support the observational part of this study, we developed a geodynamic numerical modeling study to systematically explore the influence of parameters such as plate age and convergence</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2007/1043/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2007/1043/"><span>Revision of Time-Independent Probabilistic <span class="hlt">Seismic</span> Hazard Maps for Alaska</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wesson, Robert L.; Boyd, Oliver S.; Mueller, Charles S.; Bufe, Charles G.; Frankel, Arthur D.; Petersen, Mark D.</p> <p>2007-01-01</p> <p>We present here time-independent probabilistic <span class="hlt">seismic</span> hazard maps of Alaska and the Aleutians for peak ground <span class="hlt">acceleration</span> (PGA) and 0.1, 0.2, 0.3, 0.5, 1.0 and 2.0 second spectral <span class="hlt">acceleration</span> at probability levels of 2 percent in 50 years (annual probability of 0.000404), 5 percent in 50 years (annual probability of 0.001026) and 10 percent in 50 years (annual probability of 0.0021). These maps represent a revision of existing maps based on newly obtained data and assumptions reflecting best current judgments about methodology and approach. These maps have been prepared following the procedures and assumptions made in the preparation of the 2002 National <span class="hlt">Seismic</span> Hazard Maps for the lower 48 States. A significant improvement relative to the 2002 methodology is the ability to include variable slip rate along a fault where appropriate. These maps incorporate new data, the responses to comments received at workshops held in Fairbanks and Anchorage, Alaska, in May, 2005, and comments received after draft maps were posted on the National <span class="hlt">Seismic</span> Hazard Mapping Web Site. These maps will be proposed for adoption in future revisions to the International Building Code. In this documentation we describe the maps and in particular explain and justify changes that have been made relative to the 1999 maps. We are also preparing a series of experimental maps of time-dependent hazard that will be described in future documents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S21B2732W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S21B2732W"><span>Effects of Bounded Fault on <span class="hlt">Seismic</span> Radiation and Rupture Propagation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weng, H.; Yang, H.</p> <p>2016-12-01</p> <p>It has been suggested that narrow rectangle fault may emit stopping phases that can largely affect <span class="hlt">seismic</span> radiation and thus rupture propagation, e.g., generation of short-duration pulse-like ruptures. Here we investigate the effects of narrow along-dip rectangle fault (analogously to 2015 Nepal earthquake with 200 km * 40 km) on <span class="hlt">seismic</span> radiation and rupture propagation through numerical modeling in the framework of the linear slip-weakening friction law. First, we found the critical slip-weakening distance Dc may largely affect the <span class="hlt">seismic</span> radiation and other source parameters, such as rupture speed, final slip and stress drop. Fixing all other uniform parameters, decreasing Dc could decrease the duration time of slip rate and increase the peak slip rate, thus increase the <span class="hlt">seismic</span> radiation energy spectrum of slip <span class="hlt">acceleration</span>. In addition, smaller Dc could lead to larger rupture speed (close to S wave velocity), but smaller stress drop and final slip. The results show that Dc may control the efficiency of far-field radiation. Furthermore, the duration time of slip rate at locations close to boundaries is 1.5 - 4 s less than that in the center of the fault. Such boundary effect is especially remarkable for smaller Dc due to the smaller average duration time of slip rate, which could increase the high-frequency radiation energy and impede low-frequency component near the boundaries from the analysis of energy spectrum of slip <span class="hlt">acceleration</span>. These results show high frequency energy tends to be radiated near the fault boundaries as long as Dc is small enough. In addition, ruptures are fragile and easy to self-arrest if the width of the seismogenic zone is very narrow. In other words, the sizes of nucleation zone need to be larger to initiate runaway ruptures. Our results show the critical sizes of nucleation zones increase as the widths of seismogenic zones decrease.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7561Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7561Z"><span>Field Installation and Real-Time Data Processing of the New Integrated SeismoGeodetic System with Real-Time <span class="hlt">Acceleration</span> and Displacement Measurements for Earthquake Characterization Based on High-Rate <span class="hlt">Seismic</span> and GPS Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zimakov, Leonid; Jackson, Michael; Passmore, Paul; Raczka, Jared; Alvarez, Marcos; Barrientos, Sergio</p> <p>2015-04-01</p> <p>We will discuss and show the results obtained from an integrated SeismoGeodetic System, model SG160-09, installed in the Chilean National Network. The SG160-09 provides the user high rate GNSS and accelerometer data, full epoch-by-epoch measurement integrity and, using the Trimble Pivot™ SeismoGeodetic App, the ability to create combined GNSS and accelerometer high-rate (200Hz) displacement time series in real-time. The SG160-09 combines <span class="hlt">seismic</span> recording with GNSS geodetic measurement in a single compact, ruggedized package. The system includes a low-power, 220-channel GNSS receiver powered by the latest Trimble-precise Maxwell™6 technology and supports tracking GPS, GLONASS and Galileo signals. The receiver incorporates on-board GNSS point positioning using Real-Time Precise Point Positioning (PPP) technology with satellite clock and orbit corrections delivered over IP networks. The <span class="hlt">seismic</span> recording element includes an ANSS Class A, force balance triaxial accelerometer with the latest, low power, 24-bit A/D converter, which produces high-resolution <span class="hlt">seismic</span> data. The SG160-09 processor acquires and packetizes both <span class="hlt">seismic</span> and geodetic data and transmits it to the central station using an advanced, error-correction protocol with back fill capability providing data integrity between the field and the processing center. The SG160-09 has been installed in the <span class="hlt">seismic</span> station close to the area of the Iquique earthquake of April 1, 2014, in northern Chile, a <span class="hlt">seismically</span> prone area at the current time. The hardware includes the SG160-09 system, external Zephyr Geodetic-2 GNSS antenna, and high-speed Internet communication media. Both <span class="hlt">acceleration</span> and displacement data was transmitted in real-time to the National Seismological Center in Santiago for real-time data processing using Earthworm / Early Bird software. Command/Control of the field station and real-time GNSS position correction are provided via the Pivot software suite. Data from the SG160-09 system was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSeis.tmp...12R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSeis.tmp...12R"><span>Do French macroseismic intensity observations agree with expectations from the European <span class="hlt">Seismic</span> Hazard Model 2013?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rey, Julien; Beauval, Céline; Douglas, John</p> <p>2018-02-01</p> <p>Probabilistic <span class="hlt">seismic</span> hazard assessments are the basis of modern <span class="hlt">seismic</span> design codes. To test fully a <span class="hlt">seismic</span> hazard curve at the return periods of interest for engineering would require many thousands of years' worth of ground-motion recordings. Because strong-motion networks are often only a few decades old (e.g. in mainland France the first accelerometric network dates from the mid-1990s), data from such sensors can be used to test hazard estimates only at very short return periods. In this article, several hundreds of years of macroseismic intensity observations for mainland France are interpolated using a robust kriging-with-a-trend technique to establish the earthquake history of every French mainland municipality. At 24 selected cities representative of the French <span class="hlt">seismic</span> context, the number of exceedances of intensities IV, V and VI is determined over time windows considered complete. After converting these intensities to peak ground <span class="hlt">accelerations</span> using the global conversion equation of Caprio et al. (Ground motion to intensity conversion equations (GMICEs): a global relationship and evaluation of regional dependency, Bulletin of the Seismological Society of America 105:1476-1490, 2015), these exceedances are compared with those predicted by the European <span class="hlt">Seismic</span> Hazard Model 2013 (ESHM13). In half of the cities, the number of observed exceedances for low intensities (IV and V) is within the range of predictions of ESHM13. In the other half of the cities, the number of observed exceedances is higher than the predictions of ESHM13. For intensity VI, the match is closer, but the comparison is less meaningful due to a scarcity of data. According to this study, the ESHM13 underestimates hazard in roughly half of France, even when taking into account the uncertainty in the conversion from intensity to <span class="hlt">acceleration</span>. However, these results are valid only for the <span class="hlt">acceleration</span> range tested in this study (0.01 to 0.09 g).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSeis..22..589R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSeis..22..589R"><span>Do French macroseismic intensity observations agree with expectations from the European <span class="hlt">Seismic</span> Hazard Model 2013?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rey, Julien; Beauval, Céline; Douglas, John</p> <p>2018-05-01</p> <p>Probabilistic <span class="hlt">seismic</span> hazard assessments are the basis of modern <span class="hlt">seismic</span> design codes. To test fully a <span class="hlt">seismic</span> hazard curve at the return periods of interest for engineering would require many thousands of years' worth of ground-motion recordings. Because strong-motion networks are often only a few decades old (e.g. in mainland France the first accelerometric network dates from the mid-1990s), data from such sensors can be used to test hazard estimates only at very short return periods. In this article, several hundreds of years of macroseismic intensity observations for mainland France are interpolated using a robust kriging-with-a-trend technique to establish the earthquake history of every French mainland municipality. At 24 selected cities representative of the French <span class="hlt">seismic</span> context, the number of exceedances of intensities IV, V and VI is determined over time windows considered complete. After converting these intensities to peak ground <span class="hlt">accelerations</span> using the global conversion equation of Caprio et al. (Ground motion to intensity conversion equations (GMICEs): a global relationship and evaluation of regional dependency, Bulletin of the Seismological Society of America 105:1476-1490, 2015), these exceedances are compared with those predicted by the European <span class="hlt">Seismic</span> Hazard Model 2013 (ESHM13). In half of the cities, the number of observed exceedances for low intensities (IV and V) is within the range of predictions of ESHM13. In the other half of the cities, the number of observed exceedances is higher than the predictions of ESHM13. For intensity VI, the match is closer, but the comparison is less meaningful due to a scarcity of data. According to this study, the ESHM13 underestimates hazard in roughly half of France, even when taking into account the uncertainty in the conversion from intensity to <span class="hlt">acceleration</span>. However, these results are valid only for the <span class="hlt">acceleration</span> range tested in this study (0.01 to 0.09 g).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920064983&hterms=thermite&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthermite','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920064983&hterms=thermite&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthermite"><span>Probing the magnetosphere using chemical <span class="hlt">releases</span> from the Combined <span class="hlt">Release</span> and Radiation Effects Satellite</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bernhardt, P. A.</p> <p>1992-01-01</p> <p>An overview is presented of the chemical <span class="hlt">release</span> experiments from NASA's Combined <span class="hlt">Release</span> and Radiation Effects Satellite (CRRES) program. Preliminary results are given for the CRRES investigations of (1) stimulated electron and ion precipitation, (2) ion transport in the magnetotail, (3) critical ionization velocity, (4) field line tracing and parallel <span class="hlt">acceleration</span>, (5) diamagnetic cavity formation and collapse, and (6) plasma instabilities. The chemical vapor properties from a thermite <span class="hlt">release</span> mechanism are also briefly described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUSM.G11C..08D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUSM.G11C..08D"><span>Sumatra Megathrust Earthquakes Trigger Intraplate <span class="hlt">Seismicity</span> in the Indo-Australian Oceanic Lithosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delescluse, M.; Chamot-Rooke, N.; Cattin, R.</p> <p>2009-05-01</p> <p>The present-day intraplate deformation between India and Australia started 9 Myrs ago. In the Central Indian Basin (CIB), this deformation is recorded in the thick sediments of the Bengal fan. The equatorial, dense E-W thrust fault network in this region is the result of a massive reverse reactivation of normal faults at the onset of deformation. The Wharton Basin (WB), separated from the CIB by the NinetyEast Ridge (NyR), shows a contrasting style of deformation with mainly left-lateral strike-slip <span class="hlt">seismicity</span>. The WB finite deformation and <span class="hlt">seismicity</span> also involve pre-existing faults, in this case the N-S paleo-transforms of the fossile Wharton spreading-ridge system. The oceanic plate <span class="hlt">seismicity</span> after the December 2004 Aceh subduction earthquake shows strike-slip events with a clear intraplate P-axis. No thrust faults are detected. This indicates short-term reactivation of the transform faults near the trench. Spatial and temporal distribution of intraplate erthquakes, as well as their anomalous moment <span class="hlt">release</span> suggests triggering by the Aceh megathrust earthquake, which appears to have acted as an "<span class="hlt">accelerator</span>" for the oceanic intraplate deformation. In this study, we use Coulomb stress static variations to confirm our <span class="hlt">seismicity</span> observations. We first assume that the reactivated transform and the neoformed thrust fault plane families are present in the oceanic lithosphere. We then compute the coseismic stresses in the vicinity of the trench from the Aceh and Nias earthquakes slip distributions. Finally, we derive the normal and shear stresses on the fault planes. The results show that the strike-slip events are all favored by the subduction earthquakes coseismic stresses. They also show that the normal fault earthquakes at oceanic bulges are supported by the modeled coseismic stresses, except offshore Myanmar. The particularly interesting result is that all the possible neoformed thrust faults perpendicular to the intraplate P-axis are inhibited by the same</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH41A3770H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH41A3770H"><span>Broadband analysis of landslides <span class="hlt">seismic</span> signal : example of the Oso-Steelhead landslide and other recent events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hibert, C.; Stark, C. P.; Ekstrom, G.</p> <p>2014-12-01</p> <p>Landslide failures on the scale of mountains are spectacular, dangerous, and spontaneous, making direct observations hard to obtain. Measurement of their dynamic properties during runout is a high research priority, but a logistical and technical challenge. Seismology has begun to help in several important ways. Taking advantage of broadband <span class="hlt">seismic</span> stations, recent advances now allow: (i) the <span class="hlt">seismic</span> detection and location of large landslides in near-real-time, even for events in very remote areas that may have remain undetected, such as the 2014 Mt La Perouse supraglacial failure in Alaska; (ii) inversion of long-period waves generated by large landslides to yield an estimate of the forces imparted by the bulk <span class="hlt">accelerating</span> mass; (iii) inference of the landslide mass, its center-of-mass velocity over time, and its trajectory.Key questions persist, such as: What can the short-period <span class="hlt">seismic</span> data tell us about the high-frequency impacts taking place within the granular flow and along its boundaries with the underlying bedrock? And how does this <span class="hlt">seismicity</span> relate to the bulk <span class="hlt">acceleration</span> of the landslide and the long-period <span class="hlt">seismicity</span> generated by it?Our recent work on the joint analysis of short- and long-period <span class="hlt">seismic</span> signals generated by past and recent events, such as the Bingham Canyon Mine and the Oso-Steelhead landslides, provides new insights to tackle these issues. Qualitative comparison between short-period signal features and kinematic parameters inferred from long-period surface wave inversion helps to refine interpretation of the source dynamics and to understand the different mechanisms for the origin of the short-period wave radiation. Our new results also suggest that quantitative relationships can be derived from this joint analysis, in particular between the short-period <span class="hlt">seismic</span> signal envelope and the inferred momentum of the center-of-mass. In the future, these quantitative relationships may help to constrain and calibrate parameters used in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26759434','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26759434"><span><span class="hlt">Seismic</span> characterization and dynamic site response of a municipal solid waste landfill in Bangalore, India.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Anbazhagan, P; SivakumarBabu, G L; Lakshmikanthan, P; VivekAnand, K S</p> <p>2016-03-01</p> <p><span class="hlt">Seismic</span> design of landfills requires an understanding of the dynamic properties of municipal solid waste (MSW) and the dynamic site response of landfill waste during <span class="hlt">seismic</span> events. The dynamic response of the Mavallipura landfill situated in Bangalore, India, is investigated using field measurements, laboratory studies and recorded ground motions from the intraplate region. The dynamic shear modulus values for the MSW were established on the basis of field measurements of shear wave velocities. Cyclic triaxial testing was performed on reconstituted MSW samples and the shear modulus reduction and damping characteristics of MSW were studied. Ten ground motions were selected based on regional <span class="hlt">seismicity</span> and site response parameters have been obtained considering one-dimensional non-linear analysis in the DEEPSOIL program. The surface spectral response varied from 0.6 to 2 g and persisted only for a period of 1 s for most of the ground motions. The maximum peak ground <span class="hlt">acceleration</span> (PGA) obtained was 0.5 g and the minimum and maximum amplifications are 1.35 and 4.05. Amplification of the base <span class="hlt">acceleration</span> was observed at the top surface of the landfill underlined by a composite soil layer and bedrock for all ground motions. Dynamic <span class="hlt">seismic</span> properties with amplification and site response parameters for MSW landfill in Bangalore, India, are presented in this paper. This study shows that MSW has less shear stiffness and more amplification due to loose filling and damping, which need to be accounted for <span class="hlt">seismic</span> design of MSW landfills in India. © The Author(s) 2016.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70042220','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70042220"><span><span class="hlt">Seismic</span> hazard maps for Haiti</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Frankel, Arthur; Harmsen, Stephen; Mueller, Charles; Calais, Eric; Haase, Jennifer</p> <p>2011-01-01</p> <p>We have produced probabilistic <span class="hlt">seismic</span> hazard maps of Haiti for peak ground <span class="hlt">acceleration</span> and response spectral <span class="hlt">accelerations</span> that include the hazard from the major crustal faults, subduction zones, and background earthquakes. The hazard from the Enriquillo-Plantain Garden, Septentrional, and Matheux-Neiba fault zones was estimated using fault slip rates determined from GPS measurements. The hazard from the subduction zones along the northern and southeastern coasts of Hispaniola was calculated from slip rates derived from GPS data and the overall plate motion. Hazard maps were made for a firm-rock site condition and for a grid of shallow shear-wave velocities estimated from topographic slope. The maps show substantial hazard throughout Haiti, with the highest hazard in Haiti along the Enriquillo-Plantain Garden and Septentrional fault zones. The Matheux-Neiba Fault exhibits high hazard in the maps for 2% probability of exceedance in 50 years, although its slip rate is poorly constrained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S23A2751Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S23A2751Z"><span>RTX Correction Accuracy and Real-Time Data Processing of the New Integrated SeismoGeodetic System with Real-Time <span class="hlt">Acceleration</span> and Displacement Measurements for Earthquake Characterization Based on High-Rate <span class="hlt">Seismic</span> and GPS Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zimakov, L. G.; Raczka, J.; Barrientos, S. E.</p> <p>2016-12-01</p> <p>We will discuss and show the results obtained from an integrated SeismoGeodetic System, model SG160-09, installed in the Chile (Chilean National Network), Italy (University of Naples Network), and California. The SG160-09 provides the user high rate GNSS and accelerometer data, full epoch-by-epoch measurement integrity and the ability to create combined GNSS and accelerometer high-rate (200Hz) displacement time series in real-time. The SG160-09 combines <span class="hlt">seismic</span> recording with GNSS geodetic measurement in a single compact, ruggedized case. The system includes a low-power, 220-channel GNSS receiver powered by the latest Trimble-precise Maxwell™6 technology and supports tracking GPS, GLONASS and Galileo signals. The receiver incorporates on-board GNSS point positioning using Real-Time Precise Point Positioning (PPP) technology with satellite clock and orbit corrections delivered over IP networks. The <span class="hlt">seismic</span> recording includes an ANSS Class A, force balance accelerometer with the latest, low power, 24-bit A/D converter, producing high-resolution <span class="hlt">seismic</span> data. The SG160-09 processor acquires and packetizes both <span class="hlt">seismic</span> and geodetic data and transmits it to the central station using an advanced, error-correction protocol providing data integrity between the field and the processing center. The SG160-09 has been installed in three <span class="hlt">seismic</span> stations in different geographic locations with different Trimble global reference stations coverage The hardware includes the SG160-09 system, external Zephyr Geodetic-2 GNSS antenna, both radio and high-speed Internet communication media. Both <span class="hlt">acceleration</span> and displacement data was transmitted in real-time to the centralized Data Acquisition Centers for real-time data processing. Command/Control of the field station and real-time GNSS position correction are provided via the Pivot platform. Data from the SG160-09 system was used for <span class="hlt">seismic</span> event characterization along with data from traditional <span class="hlt">seismic</span> and geodetic stations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S33B0874D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S33B0874D"><span>Processing Approaches for DAS-Enabled Continuous <span class="hlt">Seismic</span> Monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dou, S.; Wood, T.; Freifeld, B. M.; Robertson, M.; McDonald, S.; Pevzner, R.; Lindsey, N.; Gelvin, A.; Saari, S.; Morales, A.; Ekblaw, I.; Wagner, A. M.; Ulrich, C.; Daley, T. M.; Ajo Franklin, J. B.</p> <p>2017-12-01</p> <p>Distributed Acoustic Sensing (DAS) is creating a "field as laboratory" capability for <span class="hlt">seismic</span> monitoring of subsurface changes. By providing unprecedented spatial and temporal sampling at a relatively low cost, DAS enables field-scale <span class="hlt">seismic</span> monitoring to have durations and temporal resolutions that are comparable to those of laboratory experiments. Here we report on <span class="hlt">seismic</span> processing approaches developed during data analyses of three case studies all using DAS-enabled <span class="hlt">seismic</span> monitoring with applications ranging from shallow permafrost to deep reservoirs: (1) 10-hour downhole monitoring of cement curing at Otway, Australia; (2) 2-month surface monitoring of controlled permafrost thaw at Fairbanks, Alaska; (3) multi-month downhole and surface monitoring of carbon sequestration at Decatur, Illinois. We emphasize the data management and processing components relevant to DAS-based <span class="hlt">seismic</span> monitoring, which include scalable approaches to data management, pre-processing, denoising, filtering, and wavefield decomposition. DAS has dramatically increased the data volume to the extent that terabyte-per-day data loads are now typical, straining conventional approaches to data storage and processing. To achieve more efficient use of disk space and network bandwidth, we explore improved file structures and data compression schemes. Because noise floor of DAS measurements is higher than that of conventional sensors, optimal processing workflow involving advanced denoising, deconvolution (of the source signatures), and stacking approaches are being established to maximize signal content of DAS data. The resulting workflow of data management and processing could <span class="hlt">accelerate</span> the broader adaption of DAS for continuous monitoring of critical processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJCMS...650025S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJCMS...650025S"><span><span class="hlt">Seismic</span> performance evaluation of RC frame-shear wall structures using nonlinear analysis methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Jialiang; Wang, Qiuwei</p> <p></p> <p>To further understand the <span class="hlt">seismic</span> performance of reinforced concrete (RC) frame-shear wall structures, a 1/8 model structure is scaled from a main factory structure with seven stories and seven bays. The model with four-stories and two-bays was pseudo-dynamically tested under six earthquake actions whose peak ground <span class="hlt">accelerations</span> (PGA) vary from 50gal to 400gal. The damage process and failure patterns were investigated. Furthermore, nonlinear dynamic analysis (NDA) and capacity spectrum method (CSM) were adopted to evaluate the <span class="hlt">seismic</span> behavior of the model structure. The top displacement curve, story drift curve and distribution of hinges were obtained and discussed. It is shown that the model structure had the characteristics of beam-hinge failure mechanism. The two methods can be used to evaluate the <span class="hlt">seismic</span> behavior of RC frame-shear wall structures well. What’s more, the NDA can be somewhat replaced by CSM for the <span class="hlt">seismic</span> performance evaluation of RC structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70015086','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70015086"><span>Earthquake recurrence and risk assessment in circum-Pacific <span class="hlt">seismic</span> gaps</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Thatcher, W.</p> <p>1989-01-01</p> <p>THE development of the concept of <span class="hlt">seismic</span> gaps, regions of low earthquake activity where large events are expected, has been one of the notable achievements of seismology and plate tectonics. Its application to long-term earthquake hazard assessment continues to be an active field of seismological research. Here I have surveyed well documented case histories of repeated rupture of the same segment of circum-Pacific plate boundary and characterized their general features. I find that variability in fault slip and spatial extent of great earthquakes rupturing the same plate boundary segment is typical rather than exceptional but sequences of major events fill identified <span class="hlt">seismic</span> gaps with remarkable order. Earthquakes are concentrated late in the <span class="hlt">seismic</span> cycle and occur with increasing size and magnitude. Furthermore, earthquake rup-ture starts near zones of concentrated moment <span class="hlt">release</span>, suggesting that high-slip regions control the timing of recurrent events. The absence of major earthquakes early in the <span class="hlt">seismic</span> cycle indicates a more complex behaviour for lower-slip regions, which may explain the observed cycle-to-cycle diversity of gap-filling sequences. ?? 1989 Nature Publishing Group.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JVGR..320...12G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JVGR..320...12G"><span>Changes in CO2 diffuse degassing induced by the passing of <span class="hlt">seismic</span> waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gresse, M.; Vandemeulebrouck, J.; Byrdina, S.; Chiodini, G.; Bruno, P. P.</p> <p>2016-06-01</p> <p>Solfatara crater, located in the Campi Flegrei caldera, is a volcano with one of the highest degassing rates on Earth, more than 1500 t of CO2 <span class="hlt">released</span> by diffusion or through vents. Here, we investigated how this gas <span class="hlt">release</span> can be disrupted by the passage of <span class="hlt">seismic</span> waves. We performed continuous soil CO2 flux measurements during the propagation of <span class="hlt">seismic</span> vibrations in the range of 5 Hz to 200 Hz induced by a vibroseis truck. The CO2 flux was continuously recorded using the accumulation chamber method. The data show a temporary and drastic (up to two-fold) increase in CO2 flux exclusively during the vibrations, before returning to the initial flux values. These transient variations are interpreted as fluidization of the surficial granular layer that <span class="hlt">releases</span> the stored gas. Similar degassing processes might occur at a larger scale during earthquakes, to cause temporary increases in the total gas outflow in volcanic or tectonic areas. Our findings are useful to better assess and monitor the potential hazard from sudden CO2 flux <span class="hlt">release</span> during earthquakes as several cases of intoxication or death have already been related to volcanic degassing.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.rintonpress.com/proceedings/0581.html','USGSPUBS'); return false;" href="http://www.rintonpress.com/proceedings/0581.html"><span>A deployment of broadband <span class="hlt">seismic</span> stations in two deep gold mines, South Africa</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McGarr, Arthur F.; Boettcher, Margaret S.; Fletcher, Jon Peter B.; Johnston, Malcolm J.; Durrheim, R.; Spottiswoode, S.; Milev, A.</p> <p>2009-01-01</p> <p>In-mine <span class="hlt">seismic</span> networks throughout the TauTona and Mponeng gold mines provide precise locations and <span class="hlt">seismic</span> source parameters of earthquakes. They also support small-scale experimental projects, including NELSAM (Natural Earthquake Laboratory in South African Mines), which is intended to record, at close hand, <span class="hlt">seismic</span> rupture of a geologic fault that traverses the project region near the deepest part of TauTona. To resolve some questions regarding the in-mine and NELSAM networks, we deployed four portable broadband <span class="hlt">seismic</span> stations at deep sites within TauTona and Mponeng for one week during September 2007 and recorded ground <span class="hlt">acceleration</span>. Moderately large earthquakes within our temporary network were recorded with sufficiently high signal-to-noise that we were able to integrate the <span class="hlt">acceleration</span> to ground velocity and displacement, from which moment tensors could be determined. We resolved the questions concerning the NELSAM and in-mine networks by using these moment tensors to calculate synthetic seismograms at various network recording sites for comparison with the ground motion recorded at the same locations. We also used the peak velocity of the S wave pulse, corrected for attenuation with distance, to estimate the maximum slip within the rupture zone of an earthquake. We then combined the maximum slip and <span class="hlt">seismic</span> moment with results from laboratory friction experiments to estimate maximum slip rates within the same high-slip patches of the rupture zone. For the four largest earthquakes recorded within our network, all with magnitudes near 2, these inferred maximum slips range from 4 to 27 mm and the corresponding maximum slip rates range from 1 to 6 m/s. These results, in conjunction with information from previous ground motion studies, indicate that underground support should be capable of withstanding peak ground velocities of at least 5 m/s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8765Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8765Z"><span>Hydro-mechanical modelling of induced <span class="hlt">seismicity</span> during the deep geothermal project in St. Gallen, Switzerland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zbinden, Dominik; Rinaldi, Antonio Pio; Kraft, Toni; Diehl, Tobias; Wiemer, Stefan</p> <p>2017-04-01</p> <p>The St. Gallen deep geothermal project in 2013 was the second geothermal project in Switzerland with the objective of power production after the Enhanced Geothermal System in Basel in 2006. In St. Gallen, the <span class="hlt">seismic</span> risk was expected to be smaller than in Basel, since the hydrothermal resource was an aquifer at a depth of about 4 km, not expected to require permeability enhancement and associated hydroshearing of the rock. However, after an injectivity test and two acid stimulations, unexpected gas <span class="hlt">release</span> from an unidentified source forced the operators to inject drilling mud into the well to fight the gas kick. Subsequently, several <span class="hlt">seismic</span> events were induced, the largest one having a local magnitude of 3.5, which was distinctly felt by the nearby living population. Even though the induced <span class="hlt">seismicity</span> could not be handled properly, the community still strongly supported the geothermal project. The project was however halted because the target formation was not as permeable as required to deliver sufficient power. Still, controlling induced <span class="hlt">seismicity</span> during deep geothermal projects is a key factor to successfully operate future geothermal projects. Hence, it is crucial to understand the physical relations of fluid injection, pressure and stress response at reservoir depth as well as associated induced <span class="hlt">seismicity</span>. To date, these processes are yet not fully understood. In this study, we aim at developing a hydro-mechanical model reproducing the main features of the induced <span class="hlt">seismic</span> sequence at the St. Gallen geothermal site. Here, we present the conceptual model and preliminary results accounting for hydraulic and mechanical parameters from the geothermal well, geological information from a <span class="hlt">seismic</span> survey conducted in the St. Gallen region, and actual fluid injection rates from the injectivity tests. In a future step, we are going to use this model to simulate the physical interaction of injected fluid, gas <span class="hlt">release</span>, hydraulic response of the rock, and induced</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S22B..06H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S22B..06H"><span>Combined GPS and <span class="hlt">seismic</span> monitoring of a 12-story structure in a region of induced <span class="hlt">seismicity</span> in Oklahoma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haase, J. S.; Soliman, M.; Kim, H.; Jaiswal, P.; Saunders, J. K.; Vernon, F.; Zhang, W.</p> <p>2017-12-01</p> <p>This work focuses on quantifying ground motions and their effects in Oklahoma near the location of the 2016 Mw 5.8 Pawnee earthquake, where <span class="hlt">seismicity</span> has been increasing due to wastewater injection related to oil and natural gas production. Much of the building inventory in Oklahoma was constructed before the increase in <span class="hlt">seismicity</span> and before the implementation of earthquake design and detailing provisions for reinforced concrete (RC) structures. We will use combined GPS/<span class="hlt">seismic</span> monitoring techniques to measure ground motion in the field and the response of structures to this ground motion. Several Oklahoma State University buildings experienced damage due to the Pawnee earthquake. The USGS Shake Map product estimated peak ground <span class="hlt">acceleration</span> (PGA) ranging from 0.12g to 0.15g at campus locations. We are deploying a high-rate GPS sensor and accelerometer on the roof and another accelerometer at ground level of a 12-story RC structure and at selected field sites in order to collect ambient noise data and nearby <span class="hlt">seismicity</span>. The longer period recording characteristics of the GPS/<span class="hlt">seismic</span> system are particularly well adapted to monitoring these large structures in the event of a significant earthquake. Gross characteristics of the structural system are described, which consists of RC columns and RC slabs in all stories. We conducted a preliminary structural analysis including modal analysis and response spectrum analysis based on a finite element (FE) simulation, which indicated that the period associated with the first X-axis bending, first torsional, and first Y-axis bending modes are 2.2 s, 2.1 s, and 1.8 s, respectively. Next, a preliminary analysis was conducted to estimate the range of expected deformation at the roof level for various earthquake excitations. The earthquake analysis shows a maximum roof displacement of 5 and 7 cm in the horizontal directions resulting from earthquake loads with PGA of 0.2g, well above the noise level of the combined GPS/<span class="hlt">seismic</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.175..685R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.175..685R"><span>Probabilistic <span class="hlt">Seismic</span> Hazard Assessment for Himalayan-Tibetan Region from Historical and Instrumental Earthquake Catalogs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rahman, M. Moklesur; Bai, Ling; Khan, Nangyal Ghani; Li, Guohui</p> <p>2018-02-01</p> <p>The Himalayan-Tibetan region has a long history of devastating earthquakes with wide-spread casualties and socio-economic damages. Here, we conduct the probabilistic <span class="hlt">seismic</span> hazard analysis by incorporating the incomplete historical earthquake records along with the instrumental earthquake catalogs for the Himalayan-Tibetan region. Historical earthquake records back to more than 1000 years ago and an updated, homogenized and declustered instrumental earthquake catalog since 1906 are utilized. The essential <span class="hlt">seismicity</span> parameters, namely, the mean <span class="hlt">seismicity</span> rate γ, the Gutenberg-Richter b value, and the maximum expected magnitude M max are estimated using the maximum likelihood algorithm assuming the incompleteness of the catalog. To compute the hazard value, three seismogenic source models (smoothed gridded, linear, and areal sources) and two sets of ground motion prediction equations are combined by means of a logic tree on accounting the epistemic uncertainties. The peak ground <span class="hlt">acceleration</span> (PGA) and spectral <span class="hlt">acceleration</span> (SA) at 0.2 and 1.0 s are predicted for 2 and 10% probabilities of exceedance over 50 years assuming bedrock condition. The resulting PGA and SA maps show a significant spatio-temporal variation in the hazard values. In general, hazard value is found to be much higher than the previous studies for regions, where great earthquakes have actually occurred. The use of the historical and instrumental earthquake catalogs in combination of multiple seismogenic source models provides better <span class="hlt">seismic</span> hazard constraints for the Himalayan-Tibetan region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2655D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2655D"><span>A one year long continuous record of <span class="hlt">seismic</span> activity and surface motion at the tongue of Rhonegletscher (Valais, Switzerland)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dalban Canassy, Pierre; Röösli, Claudia; Walter, Fabian; Gabbi, Jeannette</p> <p>2014-05-01</p> <p>A critical gap in our current understanding of glaciers is how high sub-glacial water pressure controls the coupling of the glacier to its bed. Processes at the base of a glacier are inherently difficult to investigate due to their remoteness. Investigation of the sub-glacial environment with passive <span class="hlt">seismic</span> methods is an innovative, rapidly growing interdisciplinary and promising endeavor. In combination with observations of surface motion and basal water pressure, this method is ideally suited to localize and quantify frictional and fracture processes which occur during periods of rapidly changing sub-glacial water pressure with consequent stress redistribution at the contact interface between ice and bed. Here we present the results of the first one-year-long glacier <span class="hlt">seismic</span> monitoring performed on an Alpine glacier to our knowledge. Together with records of surface motion and hydrological measurements, we examine whether seasonal changes can be captured by <span class="hlt">seismic</span> recording. Experiments were carried out from June 2012 to July 2013 on Rhonegletscher (Valais, Switzerland), by means of 3 three-components seismometers settled close to the tongue in 2 meters boreholes. An additional array of eleven sensors installed at the ice surface was also maintained during September 2012, in order to achieve more accurate icequakes locations. A high <span class="hlt">seismic</span> emission is observed on Rhonegletscher, with icequakes located close to the surface or in the vicinity of the bedrock. The temporal distribution of <span class="hlt">seismic</span> activity is shown to nicely reflect the seasonal evolution of the glacier hydrology, with a dramatic <span class="hlt">seismic</span> <span class="hlt">release</span> in early spring. During summer, <span class="hlt">released</span> <span class="hlt">seismic</span> activity is generally driven by diurnal ice/snow melting cycle. In winter, snow-cover conditions are associated with a reduced <span class="hlt">seismic</span> <span class="hlt">release</span>, with nevertheless some unexpected activity possibly related to snow-pack metamorphism. Based on icequake locations derived from data recorded in September, we discuss</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMIN41B3655T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMIN41B3655T"><span>National Archive of Marine <span class="hlt">Seismic</span> Surveys (NAMSS): A USGS-Boem Partnership to Provide Free and Easy Access to Previously Proprietary <span class="hlt">Seismic</span> Reflection Data on the U.S. Outer Continental Shelf</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Triezenberg, P. J.; Hart, P. E.; Childs, J. R.</p> <p>2014-12-01</p> <p>The National Archive of Marine <span class="hlt">Seismic</span> Surveys (NAMSS) was established by the USGS in 2004 in an effort to rescue marine <span class="hlt">seismic</span> reflection profile data acquired largely by the oil exploration industry throughout the US outer continental shelf (OCS). It features a Web interface for easy on-line geographic search and download. The commercial value of these data had decreased significantly because of drilling moratoria and newer acquisition technology, and large quantities were at risk of disposal. But, the data still had tremendous value for scientific research and education purposes, and an effort was undertaken to ensure that the data were preserved and publicly available. More recently, the USGS and Bureau of Ocean Energy Management (BOEM) have developed a partnership to make similarly available a much larger quantity of 2D and 3D <span class="hlt">seismic</span> data acquired by the U.S. government for assessment of resources in the OCS. Under Federal regulation, BOEM is required to publicly <span class="hlt">release</span> all processed geophysical data, including <span class="hlt">seismic</span> profiles, acquired under an exploration permit, purchased and retained by BOEM, no sooner than 25 years after issuance of the permit. Data acquired prior to 1989 are now eligible for <span class="hlt">release</span>. Currently these data are distributed on CD or DVD, but data discovery can be tedious. Inclusion of these data within NAMSS vastly increases the amount of <span class="hlt">seismic</span> data available for research purposes. A new NAMSS geographical interface provides easy and intuitive access to the data library. The interface utilizes OpenLayers, Mapnik, and the Django web framework. In addition, metadata capabilities have been greatly increased using a PostgresSQL/PostGIS database incorporating a community-developed ISO-compliant XML template. The NAMSS database currently contains 452 2D <span class="hlt">seismic</span> surveys comprising 1,645,956 line km and nine 3D <span class="hlt">seismic</span> surveys covering 9,385 square km. The 2D data holdings consist of stack, migrated and depth sections, most in SEG-Y format.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRB..123.2345I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRB..123.2345I"><span><span class="hlt">Seismicity</span> During Continental Breakup in the Red Sea Rift of Northern Afar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Illsley-Kemp, Finnigan; Keir, Derek; Bull, Jonathan M.; Gernon, Thomas M.; Ebinger, Cynthia; Ayele, Atalay; Hammond, James O. S.; Kendall, J.-Michael; Goitom, Berhe; Belachew, Manahloh</p> <p>2018-03-01</p> <p>Continental rifting is a fundamental component of plate tectonics. Recent studies have highlighted the importance of magmatic activity in accommodating extension during late-stage rifting, yet the mechanisms by which crustal thinning occurs are less clear. The Red Sea rift in Northern Afar presents an opportunity to study the final stages of continental rifting as these active processes are exposed subaerially. Between February 2011 and February 2013 two <span class="hlt">seismic</span> networks were installed in Ethiopia and Eritrea. We locate 4,951 earthquakes, classify them by frequency content, and calculate 31 focal mechanisms. Results show that <span class="hlt">seismicity</span> is focused at the rift axis and the western marginal graben. Rift axis <span class="hlt">seismicity</span> accounts for ˜64% of the <span class="hlt">seismic</span> moment <span class="hlt">release</span> and exhibits a swarm-like behavior. In contrast, <span class="hlt">seismicity</span> at the marginal graben is characterized by high-frequency earthquakes that occur at a constant rate. Results suggest that the rift axis remains the primary locus of <span class="hlt">seismicity</span>. Low-frequency earthquakes, indicative of magmatic activity, highlight the presence of a magma complex ˜12 km beneath Alu-Dalafilla at the rift axis. <span class="hlt">Seismicity</span> at the marginal graben predominantly occurs on westward dipping, antithetic faults. Focal mechanisms show that this <span class="hlt">seismicity</span> is accommodating E-W extension. We suggest that the <span class="hlt">seismic</span> activity at the marginal graben is either caused by upper crustal faulting accommodating enhanced crustal thinning beneath Northern Afar or as a result of flexural faulting between the rift and plateau. This <span class="hlt">seismicity</span> is occurring in conjunction with magmatic extension at the rift axis, which accommodates the majority of long-term extension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IAUS..327..113L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IAUS..327..113L"><span>What can He II 304 Å tell us about transient <span class="hlt">seismic</span> emission from solar flares?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lindsey, C.; Donea, A. C.</p> <p>2017-10-01</p> <p>After neary 20 years since their discovery by Kosovichev and Zharkova, the mechanics of the <span class="hlt">release</span> of <span class="hlt">seismic</span> transients into the solar interior from some flares remain a mystery. <span class="hlt">Seismically</span> emissive flares invariably show the signatures of intense chromosphere heating consistent with pressure variations sufficient to drive <span class="hlt">seismic</span> transients commensurate with helioseismic observations-under certain conditions. Magnetic observations show the signatures of apparent magnetic changes, suggesting Lorentz-force transients that could likewise drive <span class="hlt">seismic</span> transients-similarly subject to certain conditions. But, the diagnostic signatures of both of these prospective drivers are apparent over vast regions from which no significant <span class="hlt">seismic</span> emission emanates. What distinguishes the source regions of transient <span class="hlt">seismic</span> emission from the much vaster regions that show the signatures of both transient heating and magnetic variations but are acoustically unproductive? Observations of acoustically active flares in He II 304 Å by the Atomospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO) offer a promising new resource with which to address this question.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70020920','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70020920"><span><span class="hlt">Seismic</span> hazard map of North and Central America and the Caribbean</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Shedlock, K.M.</p> <p>1999-01-01</p> <p>Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of <span class="hlt">seismic</span> hazard. National, state, and local government, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require <span class="hlt">seismic</span> hazard estimates for land use planning, improved building design and construction (including adoption of building construction codes), emergency response preparedness plans, economic forecasts, housing and employment decisions, and many more types of risk mitigation. The <span class="hlt">seismic</span> hazard map of North and Central America and the Caribbean is the concatenation of various national and regional maps, involving a suite of approaches. The combined maps and documentation provide a useful regional <span class="hlt">seismic</span> hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This <span class="hlt">seismic</span> hazard map depicts Peak Ground <span class="hlt">Acceleration</span> (PGA) with a 10% chance of exceedance in 50 years. PGA, a short-period ground motion parameter that is proportional to force, is the most commonly mapped ground motion parameter because current building codes that include <span class="hlt">seismic</span> provisions specify the horizontal force a building should be able to withstand during an earthquake. This <span class="hlt">seismic</span> hazard map of North and Central America and the Caribbean depicts the likely level of short-period ground motion from earthquakes in a fifty-year window. Short-period ground motions effect short-period structures (e.g., one-to-two story buildings). The highest <span class="hlt">seismic</span> hazard values in the region generally occur in areas that have been, or are likely to be, the sites of the largest plate boundary earthquakes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812024N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812024N"><span>Using <span class="hlt">seismic</span> and tilt measurements simultaneously to forecast eruptions of silicic volcanoes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neuberg, Jurgen; Collinson, Amy; Mothes, Patricia</p> <p>2016-04-01</p> <p>Independent interpretations of <span class="hlt">seismic</span> swarms and tilt measurement on active silicic volcanoes have been successfully used to assess their eruption potential. Swarms of low-frequency <span class="hlt">seismic</span> events have been associated with brittle failure or stick-slip motion of magma during ascent and have been used to estimate qualitatively the magma ascent rate which typically <span class="hlt">accelerates</span> before lava dome collapses. Tilt signals are extremely sensitive indicators for volcano deformation and have been often modelled and interpreted as inflation or deflation of a shallow magma reservoir. Here we show that tilt in many cases does not represent inflation or deflation but is directly linked to magma ascent rate.This talk aims to combine these two independent observations, <span class="hlt">seismicity</span> and deformation, to design and implement a forecasting tool that can be deployed in volcano observatories on an operational level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011Tectp.507...47C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011Tectp.507...47C"><span>Arc segmentation and <span class="hlt">seismicity</span> in the Solomon Islands arc, SW Pacific</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Ming-Chu; Frohlich, Cliff; Taylor, Frederick W.; Burr, George; van Ufford, Andrew Quarles</p> <p>2011-07-01</p> <p>This paper evaluates neotectonic segmentation in the Solomon Islands forearc, and considers how it relates to regional tectonic evolution and the extent of ruptures of large megathrust earthquakes. We first consider regional geomorphology and Quaternary vertical displacements, especially uplifted coral reef terraces. Then we consider geographic <span class="hlt">seismicity</span> patterns, aftershock areas and vertical displacements for large earthquakes, focal mechanisms, and along-arc variations in <span class="hlt">seismic</span> moment <span class="hlt">release</span> to evaluate the relationship between neotectonically defined segments and <span class="hlt">seismicity</span>. Notably, one major limitation of using <span class="hlt">seismicity</span> to evaluate arc segmentation is the matter of accurately defining earthquake rupture zones. For example, shoreline uplifts associated with the 1 April 2007 M w 8.1 Western Solomons earthquake indicate that the along-arc extent of rupture was about 50 km smaller than the aftershock area. Thus if we had relied on aftershocks alone to identify the 2007 rupture zone, as we do for most historical earthquakes, we would have missed the rupture's relationship to a major morphologic feature. In many cases, the imprecision of defining rupture zones without surface deformation data may be largely responsible for the poor mismatches to neotectonic boundaries. However, when a precise paleoseismic vertical deformation history is absent, aftershocks are often the best available tool for inferring rupture geometries. Altogether we identify 16 segments in the Solomon Islands. These comprise three major tectonic regimes or supersegments that correspond respectively to the forearc areas of Guadalcanal-Makira, the New Georgia island group, and Bougainville Islands. Subduction of the young and relatively shallow and buoyant Woodlark Basin and spreading system distinguishes the central New Georgia supersegment from the two neighboring supersegments. The physiographic expression of the San Cristobal trench is largely absent, but bathymetric mapping of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986GeoRL..13.1003W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986GeoRL..13.1003W"><span>A <span class="hlt">seismically</span> active section of the Southwest Indian Ridge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wald, David J.; Wallace, Terry C.</p> <p>1986-10-01</p> <p>The section of the Southwest Indian Ocean Ridge west of the Prince Edward Fracture zone has a large ridge axis offset and a complicated ridge-transform morphology. We have determined the source mechanisms of transform earthquakes along this portion of the ridge from an inversion of long-period P and SH waveforms. The <span class="hlt">seismicity</span> is characterized by anomalous faulting mechanisms, source complexity and an unexpectedly large <span class="hlt">seismic</span> moment <span class="hlt">release</span>. Several earthquakes with dip-slip components of faulting have been recognized on the central section of the Andrew Bain and 32° E transforms suggesting geometrical complexity along the transform. This region has experienced a Mw = 8.0 transform earthquake in 1942, yet we observe a <span class="hlt">seismic</span> slip rate during the last 20 years that is still comparable to the predicted spreading rate (1.6 cm/yr). The calculated slip rate over a period of 60 years is three times greater than the expected rate of spreading.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1996/0011/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1996/0011/report.pdf"><span>Review of <span class="hlt">Seismic</span> Hazard Issues Associated with Auburn Dam Project, Sierra Nevada Foothills, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Schwartz, D.P.; Joyner, W.B.; Stein, R.S.; Brown, R.D.; McGarr, A.F.; Hickman, S.H.; Bakun, W.H.</p> <p>1996-01-01</p> <p>Summary -- The U.S. Geological Survey was requested by the U.S. Department of the Interior to review the design values and the issue of reservoir-induced <span class="hlt">seismicity</span> for a concrete gravity dam near the site of the previously-proposed Auburn Dam in the western foothills of the Sierra Nevada, central California. The dam is being planned as a flood-control-only dam with the possibility of conversion to a permanent water-storage facility. As a basis for planning studies the U.S. Army Corps of Engineers is using the same design values approved by the Secretary of the Interior in 1979 for the original Auburn Dam. These values were a maximum displacement of 9 inches on a fault intersecting the dam foundation, a maximum earthquake at the site of magnitude 6.5, a peak horizontal <span class="hlt">acceleration</span> of 0.64 g, and a peak vertical <span class="hlt">acceleration</span> of 0.39 g. In light of geological and seismological investigations conducted in the western Sierran foothills since 1979 and advances in the understanding of how earthquakes are caused and how faults behave, we have developed the following conclusions and recommendations: Maximum Displacement. Neither the pre-1979 nor the recent observations of faults in the Sierran foothills precisely define the maximum displacement per event on a fault intersecting the dam foundation. Available field data and our current understanding of surface faulting indicate a range of values for the maximum displacement. This may require the consideration of a design value larger than 9 inches. We recommend reevaluation of the design displacement using current <span class="hlt">seismic</span> hazard methods that incorporate uncertainty into the estimate of this design value. Maximum Earthquake Magnitude. There are no data to indicate that a significant change is necessary in the use of an M 6.5 maximum earthquake to estimate design ground motions at the dam site. However, there is a basis for estimating a range of maximum magnitudes using recent field information and new statistical fault</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7331G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7331G"><span><span class="hlt">Seismic</span> signal processing on heterogeneous supercomputers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gokhberg, Alexey; Ermert, Laura; Fichtner, Andreas</p> <p>2015-04-01</p> <p>The processing of <span class="hlt">seismic</span> signals - including the correlation of massive ambient noise data sets - represents an important part of a wide range of seismological applications. It is characterized by large data volumes as well as high computational input/output intensity. Development of efficient approaches towards <span class="hlt">seismic</span> signal processing on emerging high performance computing systems is therefore essential. Heterogeneous supercomputing systems introduced in the recent years provide numerous computing nodes interconnected via high throughput networks, every node containing a mix of processing elements of different architectures, like several sequential processor cores and one or a few graphical processing units (GPU) serving as <span class="hlt">accelerators</span>. A typical representative of such computing systems is "Piz Daint", a supercomputer of the Cray XC 30 family operated by the Swiss National Supercomputing Center (CSCS), which we used in this research. Heterogeneous supercomputers provide an opportunity for manifold application performance increase and are more energy-efficient, however they have much higher hardware complexity and are therefore much more difficult to program. The programming effort may be substantially reduced by the introduction of modular libraries of software components that can be reused for a wide class of seismology applications. The ultimate goal of this research is design of a prototype for such library suitable for implementing various <span class="hlt">seismic</span> signal processing applications on heterogeneous systems. As a representative use case we have chosen an ambient noise correlation application. Ambient noise interferometry has developed into one of the most powerful tools to image and monitor the Earth's interior. Future applications will require the extraction of increasingly small details from noise recordings. To meet this demand, more advanced correlation techniques combined with very large data volumes are needed. This poses new computational problems that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1052880-price-paid-two-metal-catalysis-magnesium-ions-accelerate-chemistry-unavoidably-limit-product-release-from-protein-kinase','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1052880-price-paid-two-metal-catalysis-magnesium-ions-accelerate-chemistry-unavoidably-limit-product-release-from-protein-kinase"><span>Price To Be Paid for Two-Metal Catalysis: Magnesium Ions That <span class="hlt">Accelerate</span> Chemistry Unavoidably Limit Product <span class="hlt">Release</span> from a Protein Kinase</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jacobsen, Douglas M.; Bao, Zhao-Qin; O'’Brien, Patrick</p> <p></p> <p>Incorporation of divalent metal ions into an active site is a fundamental catalytic tool used by diverse enzymes. Divalent cations are used by protein kinases to both stabilize ATP binding and <span class="hlt">accelerate</span> chemistry. Kinetic analysis establishes that Cyclin-dependent kinase 2 (CDK2) requires simultaneous binding of two Mg 2+ ions for catalysis of phosphoryl transfer. This tool, however, comes with a price: the rate-<span class="hlt">acceleration</span> effects are opposed by an unavoidable rate-limiting consequence of the use of two Mg 2+ ions by CDK2. The essential metal ions stabilize ADP product binding and limit the overall rate of the reaction. We demonstrate thatmore » product <span class="hlt">release</span> is rate limiting for activated CDK2 and evaluate the effects of the two catalytically essential Mg 2+ ions on the stability of the ADP product within the active site. We present two new crystal structures of CDK2 bound to ADP showing how the phosphate groups can be coordinated by either one or two Mg 2+ ions, with the occupancy of one site in a weaker equilibrium. Molecular dynamics simulations indicate that ADP phosphate mobility is more restricted when ADP is coordinated by two Mg 2+ ions compared to one. The structural similarity between the rigid ADP·2Mg product and the cooperatively assembled transition state provides a mechanistic rational for the rate-limiting ADP <span class="hlt">release</span> that is observed. We demonstrate that although the simultaneous binding of two Mg 2+ ions is essential for efficient phosphoryl transfer, the presence of both Mg 2+ ions in the active site also cooperatively increases ADP affinity and opposes its <span class="hlt">release</span>. Evolution of protein kinases must have involved careful tuning of the affinity for the second Mg 2+ ion in order to balance the needs to stabilize the chemical transition state and allow timely product <span class="hlt">release</span>. The link between Mg 2+ site affinity and activity presents a chemical handle that may be used by regulatory factors as well as explain some mutational effects.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011EEEV...10..253Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011EEEV...10..253Z"><span><span class="hlt">Seismic</span> analysis of a LNG storage tank isolated by a multiple friction pendulum system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Ruifu; Weng, Dagen; Ren, Xiaosong</p> <p>2011-06-01</p> <p>The <span class="hlt">seismic</span> response of an isolated vertical, cylindrical, extra-large liquefied natural gas (LNG) tank by a multiple friction pendulum system (MFPS) is analyzed. Most of the extra-large LNG tanks have a fundamental frequency which involves a range of resonance of most earthquake ground motions. It is an effective way to decrease the response of an isolation system used for extra-large LNG storage tanks under a strong earthquake. However, it is difficult to implement in practice with common isolation bearings due to issues such as low temperature, soft site and other severe environment factors. The extra-large LNG tank isolated by a MFPS is presented in this study to address these problems. A MFPS is appropriate for large displacements induced by earthquakes with long predominant periods. A simplified finite element model by Malhotra and Dunkerley is used to determine the usefulness of the isolation system. Data reported and statistically sorted include pile shear, wave height, impulsive <span class="hlt">acceleration</span>, convective <span class="hlt">acceleration</span> and outer tank <span class="hlt">acceleration</span>. The results show that the isolation system has excellent adaptability for different liquid levels and is very effective in controlling the <span class="hlt">seismic</span> response of extra-large LNG tanks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010Tectp.492..253W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010Tectp.492..253W"><span>An alternative approach to probabilistic <span class="hlt">seismic</span> hazard analysis in the Aegean region using Monte Carlo simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weatherill, Graeme; Burton, Paul W.</p> <p>2010-09-01</p> <p>The Aegean is the most <span class="hlt">seismically</span> active and tectonically complex region in Europe. Damaging earthquakes have occurred here throughout recorded history, often resulting in considerable loss of life. The Monte Carlo method of probabilistic <span class="hlt">seismic</span> hazard analysis (PSHA) is used to determine the level of ground motion likely to be exceeded in a given time period. Multiple random simulations of <span class="hlt">seismicity</span> are generated to calculate, directly, the ground motion for a given site. Within the <span class="hlt">seismic</span> hazard analysis we explore the impact of different <span class="hlt">seismic</span> source models, incorporating both uniform zones and distributed <span class="hlt">seismicity</span>. A new, simplified, <span class="hlt">seismic</span> source model, derived from seismotectonic interpretation, is presented for the Aegean region. This is combined into the epistemic uncertainty analysis alongside existing source models for the region, and models derived by a K-means cluster analysis approach. <span class="hlt">Seismic</span> source models derived using the K-means approach offer a degree of objectivity and reproducibility into the otherwise subjective approach of delineating <span class="hlt">seismic</span> sources using expert judgment. Similar review and analysis is undertaken for the selection of peak ground <span class="hlt">acceleration</span> (PGA) attenuation models, incorporating into the epistemic analysis Greek-specific models, European models and a Next Generation Attenuation model. Hazard maps for PGA on a "rock" site with a 10% probability of being exceeded in 50 years are produced and different source and attenuation models are compared. These indicate that Greek-specific attenuation models, with their smaller aleatory variability terms, produce lower PGA hazard, whilst recent European models and Next Generation Attenuation (NGA) model produce similar results. The Monte Carlo method is extended further to assimilate epistemic uncertainty into the hazard calculation, thus integrating across several appropriate source and PGA attenuation models. Site condition and fault-type are also integrated into the hazard</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920001515','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920001515"><span>Martian <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Phillips, Roger J.; Grimm, Robert E.</p> <p>1991-01-01</p> <p>The design and ultimate success of network seismology experiments on Mars depends on the present level of Martian <span class="hlt">seismicity</span>. Volcanic and tectonic landforms observed from imaging experiments show that Mars must have been a <span class="hlt">seismically</span> active planet in the past and there is no reason to discount the notion that Mars is <span class="hlt">seismically</span> active today but at a lower level of activity. Models are explored for present day Mars <span class="hlt">seismicity</span>. Depending on the sensitivity and geometry of a <span class="hlt">seismic</span> network and the attenuation and scattering properties of the interior, it appears that a reasonable number of Martian <span class="hlt">seismic</span> events would be detected over the period of a decade. The thermoelastic cooling mechanism as estimated is surely a lower bound, and a more refined estimate would take into account specifically the regional cooling of Tharsis and lead to a higher frequency of <span class="hlt">seismic</span> events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010089397&hterms=idea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Didea','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010089397&hterms=idea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Didea"><span>An Idea for an Active <span class="hlt">Seismic</span> Experiment on Mars in 2008</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lognonne, Ph.; Banerdt, B.; Giardini, D.; Costard, F.</p> <p>2001-01-01</p> <p>The detection of liquid water is of prime interest and should have deep implications in the understanding of the Martian hydrological cycle and also in exobiology. In the frame of the 2007 joint CNES-NASA mission to Mars, a set of 4 NETLANDERS developed by an European consortium is expected to be launched in June 2007. We propose to use a second spacecraft going or landing to Mars to <span class="hlt">release</span> near one of the Netlander a series of artificial metallic meteorites, in order to perform an active <span class="hlt">seismic</span> experiment providing a <span class="hlt">seismic</span> profile of the crust and subsurface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S23B0803C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S23B0803C"><span>Hydraulically Induced <span class="hlt">Seismicity</span> in South-Eastern Brazil Linked to Water Wells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Convers, J.; Assumpcao, M.; Barbosa, J. R.</p> <p>2017-12-01</p> <p>While hydraulic stimulus on <span class="hlt">seismic</span> activity is most commonly associated with hydraulic fracturing processes, we find in SE Brazil a rare case of <span class="hlt">seismicity</span> influenced by hydraulic stimulation linked to seasonal rain and water wells in a farming area. These are thought to be the main factors influencing the seasonal <span class="hlt">seismicity</span> activity in Jurupema, a farming town located in the interior of the state of Sao Paulo, southern Brazil. With temporary <span class="hlt">seismic</span> station deployments during 2016 and 2017, we analyze the <span class="hlt">seismicity</span> in this area, its temporal and spatial distribution, and its association with the drilling of ground water wells in this particular area. In a region where water wells are often drilled to provide irrigation for farming, these are often perforated down to about 100 m depth, penetrating below the uppermost sandstone rock layer ( 50 m) into a fractured basaltic rock layer, reaching the confined aquifer within it. While the wells are constantly pumped during the dry season, during the course of the rainy season (when these are not being used), a possible infiltration into the confined basaltic aquifer, from both the rainwater and the upper sandstone aquifer, adds changes to the pore pressure of the fractured rock, and modifies the tectonic pre-stress conditions, to facilitate stress <span class="hlt">release</span> mechanisms in pre-existing faults and cracks. With our temporary <span class="hlt">seismic</span> station deployments, we not only examine the <span class="hlt">seismicity</span> in this region during both 2016 and 2017, but we additionally compare its characteristics to the nearby Bebedouro case in an apparent induced <span class="hlt">seismic</span> case of analogous source, and <span class="hlt">seismic</span> activity with magnitudes up to 2.9 occurring between 2005 and 2010.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IzPSE..51..268N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IzPSE..51..268N"><span><span class="hlt">Seismic</span> hazard and <span class="hlt">seismic</span> risk assessment based on the unified scaling law for earthquakes: Himalayas and adjacent regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nekrasova, A. K.; Kossobokov, V. G.; Parvez, I. A.</p> <p>2015-03-01</p> <p>For the Himalayas and neighboring regions, the maps of <span class="hlt">seismic</span> hazard and <span class="hlt">seismic</span> risk are constructed with the use of the estimates for the parameters of the unified scaling law for earthquakes (USLE), in which the Gutenberg-Richter law for magnitude distribution of <span class="hlt">seismic</span> events within a given area is applied in the modified version with allowance for linear dimensions of the area, namely, log N( M, L) = A + B (5 - M) + C log L, where N( M, L) is the expected annual number of the earthquakes with magnitude M in the area with linear dimension L. The spatial variations in the parameters A, B, and C for the Himalayas and adjacent regions are studied on two time intervals from 1965 to 2011 and from 1980 to 2011. The difference in A, B, and C between these two time intervals indicates that <span class="hlt">seismic</span> activity experiences significant variations on a scale of a few decades. With a global consideration of the <span class="hlt">seismic</span> belts of the Earth overall, the estimates of coefficient A, which determines the logarithm of the annual average frequency of the earthquakes with a magnitude of 5.0 and higher in the zone with a linear dimension of 1 degree of the Earth's meridian, differ by a factor of 30 and more and mainly fall in the interval from -1.1 to 0.5. The values of coefficient B, which describes the balance between the number of earthquakes with different magnitudes, gravitate to 0.9 and range from less than 0.6 to 1.1 and higher. The values of coefficient C, which estimates the fractal dimension of the local distribution of epicenters, vary from 0.5 to 1.4 and higher. In the Himalayas and neighboring regions, the USLE coefficients mainly fall in the intervals of -1.1 to 0.3 for A, 0.8 to 1.3 for B, and 1.0 to 1.4 for C. The calculations of the local value of the expected peak ground <span class="hlt">acceleration</span> (PGA) from the maximal expected magnitude provided the necessary basis for mapping the <span class="hlt">seismic</span> hazards in the studied region. When doing this, we used the local estimates of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T33F..02D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T33F..02D"><span>Slab dehydration in Cascadia and its relationship to volcanism, <span class="hlt">seismicity</span>, and non-volcanic tremor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delph, J. R.; Levander, A.; Niu, F.</p> <p>2017-12-01</p> <p>The characteristics of subduction beneath the Pacific Northwest (Cascadia) are variable along strike, leading to the segmentation of Cascadia into 3 general zones: Klamath, Siletzia, and Wrangelia. These zones show marked differences in tremor density, earthquake density, <span class="hlt">seismicity</span> rates, and the locus and amount of volcanism in the subduction-related volcanic arc. To better understand what controls these variations, we have constructed a 3D shear-wave velocity model of the upper 80 km along the Cascadia margin from the joint inversion of CCP-derived receiver functions and ambient noise surface wave data using 900 temporary and permanent broadband <span class="hlt">seismic</span> stations. With this model, we can investigate variations in the <span class="hlt">seismic</span> structure of the downgoing oceanic lithosphere and overlying mantle wedge, the character of the crust-mantle transition beneath the volcanic arc, and local to regional variations in crustal structure. From these results, we infer the presence and distribution of fluids <span class="hlt">released</span> from the subducting slab and how they affect the <span class="hlt">seismic</span> structure of the overriding lithosphere. In the Klamath and Wrangelia zones, high <span class="hlt">seismicity</span> rates in the subducting plate and high tremor density correlate with low shear velocities in the overriding plate's forearc and relatively little arc volcanism. While the cause of tremor is debated, intermediate depth earthquakes are generally thought to be due to metamorphic dehydration reactions resulting from the dewatering of the downgoing slab. Thus, the <span class="hlt">seismic</span> characteristics of these zones combined with rather sparse arc volcanism may indicate that the slab has largely dewatered by the time it reaches sub-arc depths. Some of the water <span class="hlt">released</span> during earthquakes (and possibly tremor) may percolate into the overriding plate, leading to slow <span class="hlt">seismic</span> velocities in the forearc. In contrast, Siletzia shows relatively low <span class="hlt">seismicity</span> rates and tremor density, with relatively higher shear velocities in the forearc</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.1536S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.1536S"><span><span class="hlt">Seismic</span> Ecology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seleznev, V. S.; Soloviev, V. M.; Emanov, A. F.</p> <p></p> <p>The paper is devoted to researches of influence of <span class="hlt">seismic</span> actions for industrial and civil buildings and people. The <span class="hlt">seismic</span> actions bring influence directly on the people (vibration actions, force shocks at earthquakes) or indirectly through various build- ings and the constructions and can be strong (be felt by people) and weak (be fixed by sensing devices). The great number of work is devoted to influence of violent <span class="hlt">seismic</span> actions (first of all of earthquakes) on people and various constructions. This work is devoted to study weak, but long <span class="hlt">seismic</span> actions on various buildings and people. There is a need to take into account <span class="hlt">seismic</span> oscillations, acting on the territory, at construction of various buildings on urbanized territories. Essential influence, except for violent earthquakes, man-caused <span class="hlt">seismic</span> actions: the explosions, <span class="hlt">seismic</span> noise, emitted by plant facilities and moving transport, radiation from high-rise buildings and constructions under action of a wind, etc. can exert. Materials on increase of man- caused <span class="hlt">seismicity</span> in a number of regions in Russia, which earlier were not <span class="hlt">seismic</span>, are presented in the paper. Along with maps of <span class="hlt">seismic</span> microzoning maps to be built indicating a variation of amplitude spectra of <span class="hlt">seismic</span> noise within day, months, years. The presence of an information about amplitudes and frequencies of oscillations from possible earthquakes and man-caused oscillations in concrete regions allows carry- ing out soundly designing and construction of industrial and civil housing projects. The construction of buildings even in not <span class="hlt">seismically</span> dangerous regions, which have one from resonance frequencies coincident on magnitude to frequency of oscillations, emitted in this place by man-caused objects, can end in failure of these buildings and heaviest consequences for the people. The practical examples of detail of engineering- seismological investigation of large industrial and civil housing projects of Siberia territory (hydro power</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Icar..260..320Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Icar..260..320Y"><span>Experimental study on impact-induced <span class="hlt">seismic</span> wave propagation through granular materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yasui, Minami; Matsumoto, Eri; Arakawa, Masahiko</p> <p>2015-11-01</p> <p>Impact-induced <span class="hlt">seismic</span> waves are supposed to cause movements of regolith particles, resulting in modifications of asteroidal surfaces. The imparted <span class="hlt">seismic</span> energy is thus a key parameter to determining the scale and magnitude of this <span class="hlt">seismic</span> shaking process. It is important to study the propagation velocity, attenuation rate, and vibration period of the impact-induced <span class="hlt">seismic</span> wave to estimate the <span class="hlt">seismic</span> energy. Hence, we conducted impact cratering experiments at Kobe University using a 200-μm glass beads target to simulate a regolith layer, and measured the impact-induced <span class="hlt">seismic</span> wave using three accelerometers set on the target surface at differences ranging from 3.2 to 12.7 cm. The target was impacted with three kinds of projectiles at ∼100 m s-1 using a one-stage gas gun. The propagation velocity of the <span class="hlt">seismic</span> wave in the beads target was 108.9 m s-1, and the maximum <span class="hlt">acceleration</span>, gmax, in the unit of m s-2, measured by each accelerometer showed good correlation with the distance from the impact point normalized by the crater radius, x/R, irrespective of projectile type. They also were fitted by one power-law equation, gmax = 102.19 (x/R)-2.21. The half period of the first peak of the measured <span class="hlt">seismic</span> waves was ∼0.72 ms, and this duration was almost consistent with the penetration time of each projectile into the target. According to these measurements, we estimated the impact <span class="hlt">seismic</span> efficiency factor, that is, the ratio of <span class="hlt">seismic</span> energy to kinetic energy of the projectile, to be almost constant, 5.7 × 10-4 inside the crater rim, while it exponentially decreased with distance from the impact point outside the crater rim. At a distance quadruple of the crater radius, the efficiency factors were 4.4 × 10-5 for polycarbonate projectile and 9.5 × 10-5 for alumina and stainless steel projectiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.S43D..02P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.S43D..02P"><span>Open Source Tools for <span class="hlt">Seismicity</span> Analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Powers, P.</p> <p>2010-12-01</p> <p>The spatio-temporal analysis of <span class="hlt">seismicity</span> plays an important role in earthquake forecasting and is integral to research on earthquake interactions and triggering. For instance, the third version of the Uniform California Earthquake Rupture Forecast (UCERF), currently under development, will use Epidemic Type Aftershock Sequences (ETAS) as a model for earthquake triggering. UCERF will be a "living" model and therefore requires robust, tested, and well-documented ETAS algorithms to ensure transparency and reproducibility. Likewise, as earthquake aftershock sequences unfold, real-time access to high quality hypocenter data makes it possible to monitor the temporal variability of statistical properties such as the parameters of the Omori Law and the Gutenberg Richter b-value. Such statistical properties are valuable as they provide a measure of how much a particular sequence deviates from expected behavior and can be used when assigning probabilities of aftershock occurrence. To address these demands and provide public access to standard methods employed in statistical seismology, we present well-documented, open-source JavaScript and Java software libraries for the on- and off-line analysis of <span class="hlt">seismicity</span>. The Javascript classes facilitate web-based asynchronous access to earthquake catalog data and provide a framework for in-browser display, analysis, and manipulation of catalog statistics; implementations of this framework will be made available on the USGS Earthquake Hazards website. The Java classes, in addition to providing tools for <span class="hlt">seismicity</span> analysis, provide tools for modeling <span class="hlt">seismicity</span> and generating synthetic catalogs. These tools are extensible and will be <span class="hlt">released</span> as part of the open-source OpenSHA Commons library.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510426V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510426V"><span>Deformation and failure of single- and multi-phase silicate liquids: <span class="hlt">seismic</span> precursors and mechanical work</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vasseur, Jeremie; Lavallée, Yan; Hess, Kai-Uwe; Wassermann, Joachim; Dingwell, Donald B.</p> <p>2013-04-01</p> <p>Along with many others, volcanic unrest is regarded as a catastrophic material failure phenomenon and is often preceded by diverse precursory signals. Although a volcanic system intrinsically behave in a non-linear and stochastic way, these precursors display systematic evolutionary trends to upcoming eruptions. <span class="hlt">Seismic</span> signals in particular are in general dramatically increasing prior to an eruption and have been extensively reported to show <span class="hlt">accelerating</span> rates through time, as well as in the laboratory before failure of rock samples. At the lab-scale, acoustic emissions (AE) are high frequency transient stress waves used to track fracture initiation and propagation inside a rock sample. Synthesized glass samples featuring a range of porosities (0 - 30%) and natural rock samples from volcán de Colima, Mexico, have been failed under high temperature uniaxial compression experiments at constant stresses and strain rates. Using the monitored AEs and the generated mechanical work during deformation, we investigated the evolutionary trends of energy patterns associated to different degrees of heterogeneity. We observed that the failure of dense, poorly porous glasses is achieved by exceeding elevated strength and thus requires a significant accumulation of strain, meaning only pervasive small-scale cracking is occurring. More porous glasses as well as volcanic samples need much lower applied stress and deformation to fail, as fractures are nucleating, propagating and coalescing into localized large-scale cracks, taking the advantage of the existence of numerous defects (voids for glasses, voids and crystals for volcanic rocks). These observations demonstrate that the mechanical work generated through cracking is efficiently distributed inside denser and more homogeneous samples, as underlined by the overall lower AE energy <span class="hlt">released</span> during experiments. In contrast, the quicker and larger AE energy <span class="hlt">released</span> during the loading of heterogeneous samples shows that the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70018888','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70018888"><span>The cyclic and fractal <span class="hlt">seismic</span> series preceding an mb 4.8 earthquake on 1980 February 14 near the Virgin Islands</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Varnes, D.J.; Bufe, C.G.</p> <p>1996-01-01</p> <p><span class="hlt">Seismic</span> activity in the 10 months preceding the 1980 February 14, mb 4.8 earthquake in the Virgin Islands, reported on by Frankel in 1982, consisted of four principal cycles. Each cycle began with a relatively large event or series of closely spaced events, and the duration of the cycles progressively shortened by a factor of about 3/4. Had this regular shortening of the cycles been recognized prior to the earthquake, the time of the next episode of setsmicity (the main shock) might have been closely estimated 41 days in advance. That this event could be much larger than the previous events is indicated from time-to-failure analysis of the <span class="hlt">accelerating</span> rise in <span class="hlt">released</span> <span class="hlt">seismic</span> energy, using a non-linear time- and slip-predictable foreshock model. Examination of the timing of all events in the sequence shows an even higher degree of order. Rates of <span class="hlt">seismicity</span>, measured by consecutive interevent times, when plotted on an iteration diagram of a rate versus the succeeding rate, form a triangular circulating trajectory. The trajectory becomes an ascending helix if extended in a third dimension, time. This construction reveals additional and precise relations among the time intervals between times of relatively high or relatively low rates of <span class="hlt">seismic</span> activity, including period halving and doubling. The set of 666 time intervals between all possible pairs of the 37 recorded events appears to be a fractal; the set of time points that define the intervals has a finite, non-integer correlation dimension of 0.70. In contrast, the average correlation dimension of 50 random sequences of 37 events is significantly higher, dose to 1.0. In a similar analysis, the set of distances between pairs of epicentres has a fractal correlation dimension of 1.52. Well-defined cycles, numerous precise ratios among time intervals, and a non-random temporal fractal dimension suggest that the <span class="hlt">seismic</span> series is not a random process, but rather the product of a deterministic dynamic system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1371516','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1371516"><span>Nonlinear Time Domain <span class="hlt">Seismic</span> Soil-Structure Interaction (SSI) Deep Soil Site Methodology Development</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Spears, Robert Edward; Coleman, Justin Leigh</p> <p></p> <p>Currently the Department of Energy (DOE) and the nuclear industry perform <span class="hlt">seismic</span> soil-structure interaction (SSI) analysis using equivalent linear numerical analysis tools. For lower levels of ground motion, these tools should produce reasonable in-structure response values for evaluation of existing and new facilities. For larger levels of ground motion these tools likely overestimate the in-structure response (and therefore structural demand) since they do not consider geometric nonlinearities (such as gaping and sliding between the soil and structure) and are limited in the ability to model nonlinear soil behavior. The current equivalent linear SSI (SASSI) analysis approach either joins the soilmore » and structure together in both tension and compression or <span class="hlt">releases</span> the soil from the structure for both tension and compression. It also makes linear approximations for material nonlinearities and generalizes energy absorption with viscous damping. This produces the potential for inaccurately establishing where the structural concerns exist and/or inaccurately establishing the amplitude of the in-structure responses. <span class="hlt">Seismic</span> hazard curves at nuclear facilities have continued to increase over the years as more information has been developed on <span class="hlt">seismic</span> sources (i.e. faults), additional information gathered on <span class="hlt">seismic</span> events, and additional research performed to determine local site effects. <span class="hlt">Seismic</span> hazard curves are used to develop design basis earthquakes (DBE) that are used to evaluate nuclear facility response. As the <span class="hlt">seismic</span> hazard curves increase, the input ground motions (DBE’s) used to numerically evaluation nuclear facility response increase causing larger in-structure response. As ground motions increase so does the importance of including nonlinear effects in numerical SSI models. To include material nonlinearity in the soil and geometric nonlinearity using contact (gaping and sliding) it is necessary to develop a nonlinear time domain methodology</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EEEV...15..457B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EEEV...15..457B"><span>Tunnel flexibility effect on the ground surface <span class="hlt">acceleration</span> response</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baziar, Mohammad Hassan; Moghadam, Masoud Rabeti; Choo, Yun Wook; Kim, Dong-Soo</p> <p>2016-09-01</p> <p>Flexibility of underground structures relative to the surrounding medium, referred to as the flexibility ratio, is an important factor that influences their dynamic interaction. This study investigates the flexibility effect of a box-shaped subway tunnel, resting directly on bedrock, on the ground surface <span class="hlt">acceleration</span> response using a numerical model verified against dynamic centrifuge test results. A comparison of the ground surface <span class="hlt">acceleration</span> response for tunnel models with different flexibility ratios revealed that the tunnels with different flexibility ratios influence the <span class="hlt">acceleration</span> response at the ground surface in different ways. Tunnels with lower flexibility ratios have higher <span class="hlt">acceleration</span> responses at short periods, whereas tunnels with higher flexibility ratios have higher <span class="hlt">acceleration</span> responses at longer periods. The effect of the flexibility ratio on ground surface <span class="hlt">acceleration</span> is more prominent in the high range of frequencies. Furthermore, as the flexibility ratio of the tunnel system increases, the <span class="hlt">acceleration</span> response moves away from the free field response and shifts towards the longer periods. Therefore, the flexibility ratio of the underground tunnels influences the peak ground <span class="hlt">acceleration</span> (PGA) at the ground surface, and may need to be considered in the <span class="hlt">seismic</span> zonation of urban areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S41B0750L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S41B0750L"><span>Using Tectonic Tremor to Constrain <span class="hlt">Seismic</span>-wave Attenuation in Cascadia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Littel, G.; Thomas, A.; Baltay, A.</p> <p>2017-12-01</p> <p>In addition to fast, <span class="hlt">seismic</span> slip, many subduction zones also host slow, largely aseismic slip, accompanied by a weak <span class="hlt">seismic</span> signal known as tectonic tremor. Tremor is a small amplitude, low-frequency <span class="hlt">seismic</span> signal that originates at the plate interface, down-dip of where large earthquakes typically occur. The Cascadia subduction zone has not seen a large megathrust earthquake since 1700, yet its recurrence interval of 350-500 years motivates heightened interest in understanding the <span class="hlt">seismic</span> hazard of the region. Of great importance is to understand the degree to which waves are attenuated as they leave the plate interface and travel towards populated regions of interest. Ground motion prediction equations (GMPEs) relate ground motion to a number of parameters, including earthquake magnitude, depth, style of faulting, and anelastic attenuation, and are typically determined empirically from earthquake ground motion recordings. In Cascadia, however, earthquakes of the moderate size typically used to constrain GMPEs occur relatively infrequently compared to tectonic tremor events, which, in contrast, occur periodically approximately every 10-19 months. Studies have shown that the abundant tectonic tremor in Cascadia, despite its small amplitudes, can be used to constrain <span class="hlt">seismic</span> wave attenuation in GMPEs. Here we quantify <span class="hlt">seismic</span> wave attenuation and determine its spatial variations in Cascadia by performing an inversion using tremor ground motion amplitudes, taken as peak ground <span class="hlt">acceleration</span> (PGA) and peak ground velocity (PGV) from 1 min window waveforms of each individual tremor event. We estimate the anelastic attenuation parameter for varying regional sections along the Cascadia margin. Changes in <span class="hlt">seismic</span>-wave attenuation along the Cascadia Subduction Zone could result in significantly different ground motions in the event of a very large earthquake, hence quantifying attenuation may help to better estimate the severity of shaking in densely populated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.V41D2542S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.V41D2542S"><span><span class="hlt">Seismic</span> evidence for hydration of the Central American slab: Guatemala through Costa Rica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Syracuse, E. M.; Thurber, C. H.</p> <p>2011-12-01</p> <p>The Central American subduction zone exhibits a wide variability in along-arc slab hydration as indicated by geochemical studies. These studies generally show maximum slab contributions to magma beneath Nicaragua and minimum contributions beneath Costa Rica, while intermediate slab fluid contributions are found beneath El Salvador and Guatemala. Geophysical studies suggest strong slab serpentinization and fluid <span class="hlt">release</span> beneath Nicaragua, and little serpentinization beneath Costa Rica, but the remainder of the subduction zone is poorly characterized <span class="hlt">seismically</span>. To obtain an integrated <span class="hlt">seismic</span> model for the Central American subduction zone, we combine 250,000 local <span class="hlt">seismic</span> arrivals and 1,000,000 differential arrivals for 6,500 shallow and intermediate-depth earthquakes from the International <span class="hlt">Seismic</span> Centre, the Central American <span class="hlt">Seismic</span> Center, and the temporary PASSCAL TUCAN array. Using this dataset, we invert for Vp, Vs, and hypocenters using a variable-mesh double-difference tomography algorithm. By observing low-Vp areas within the normally high-Vp slab, we identify portions of the slab that are likely to contain serpentinized mantle, and thus contribute to higher degrees of melting and higher volatile components observable in arc lavas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EnOp...46.1553M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EnOp...46.1553M"><span>Optimization of <span class="hlt">seismic</span> isolation systems via harmony search</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Melih Nigdeli, Sinan; Bekdaş, Gebrail; Alhan, Cenk</p> <p>2014-11-01</p> <p>In this article, the optimization of isolation system parameters via the harmony search (HS) optimization method is proposed for <span class="hlt">seismically</span> isolated buildings subjected to both near-fault and far-fault earthquakes. To obtain optimum values of isolation system parameters, an optimization program was developed in Matlab/Simulink employing the HS algorithm. The objective was to obtain a set of isolation system parameters within a defined range that minimizes the <span class="hlt">acceleration</span> response of a <span class="hlt">seismically</span> isolated structure subjected to various earthquakes without exceeding a peak isolation system displacement limit. Several cases were investigated for different isolation system damping ratios and peak displacement limitations of <span class="hlt">seismic</span> isolation devices. Time history analyses were repeated for the neighbouring parameters of optimum values and the results proved that the parameters determined via HS were true optima. The performance of the optimum isolation system was tested under a second set of earthquakes that was different from the first set used in the optimization process. The proposed optimization approach is applicable to linear isolation systems. Isolation systems composed of isolation elements that are inherently nonlinear are the subject of a future study. Investigation of the optimum isolation system parameters has been considered in parametric studies. However, obtaining the best performance of a <span class="hlt">seismic</span> isolation system requires a true optimization by taking the possibility of both near-fault and far-fault earthquakes into account. HS optimization is proposed here as a viable solution to this problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990satx.symp....2L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990satx.symp....2L"><span>Proceedings of the 11th Annual DARPA/AFGL <span class="hlt">Seismic</span> Research symposium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lewkowicz, James F.; McPhetres, Jeanne M.</p> <p>1990-11-01</p> <p>The following subjects are covered: near source observations of quarry explosions; small explosion discrimination and yield estimation; Rg as a depth discriminant for earthquakes and explosions: a case study in New England; a comparative study of high frequency <span class="hlt">seismic</span> noise at selected sites in the USSR and USA; chemical explosions and the discrimination problem; application of simulated annealing to joint hypocenter determination; frequency dependence of Q(sub Lg) and Q in the continental crust; statistical approaches to testing for compliance with a threshold test ban treaty; broad-band studies of <span class="hlt">seismic</span> sources at regional and teleseismic distances using advanced time series analysis methods; effects of depth of burial and tectonic <span class="hlt">release</span> on regional and teleseismic explosion waveforms; finite difference simulations of <span class="hlt">seismic</span> wave excitation at Soviet test sites with deterministic structures; stochastic geologic effects on near-field ground motions; the damage mechanics of porous rock; nonlinear attenuation mechanism in salt at moderate strain; compressional- and shear-wave polarizations at the Anza <span class="hlt">seismic</span> array; and a generalized beamforming approach to real time network detection and phase association.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24649829','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24649829"><span>Structural and functional analysis of a FeoB A143S G5 loop mutant explains the <span class="hlt">accelerated</span> GDP <span class="hlt">release</span> rate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guilfoyle, Amy P; Deshpande, Chandrika N; Vincent, Kimberley; Pedroso, Marcelo M; Schenk, Gerhard; Maher, Megan J; Jormakka, Mika</p> <p>2014-05-01</p> <p>GTPases (G proteins) hydrolyze the conversion of GTP to GDP and free phosphate, comprising an integral part of prokaryotic and eukaryotic signaling, protein biosynthesis and cell division, as well as membrane transport processes. The G protein cycle is brought to a halt after GTP hydrolysis, and requires the <span class="hlt">release</span> of GDP before a new cycle can be initiated. For eukaryotic heterotrimeric Gαβγ proteins, the interaction with a membrane-bound G protein-coupled receptor catalyzes the <span class="hlt">release</span> of GDP from the Gα subunit. Structural and functional studies have implicated one of the nucleotide binding sequence motifs, the G5 motif, as playing an integral part in this <span class="hlt">release</span> mechanism. Indeed, a Gαs G5 mutant (A366S) was shown to have an <span class="hlt">accelerated</span> GDP <span class="hlt">release</span> rate, mimicking a G protein-coupled receptor catalyzed <span class="hlt">release</span> state. In the present study, we investigate the role of the equivalent residue in the G5 motif (residue A143) in the prokaryotic membrane protein FeoB from Streptococcus thermophilus, which includes an N-terminal soluble G protein domain. The structure of this domain has previously been determined in the apo and GDP-bound states and in the presence of a transition state analogue, revealing conformational changes in the G5 motif. The A143 residue was mutated to a serine and analyzed with respect to changes in GTPase activity, nucleotide <span class="hlt">release</span> rate, GDP affinity and structural alterations. We conclude that the identity of the residue at this position in the G5 loop plays a key role in the nucleotide <span class="hlt">release</span> rate by allowing the correct positioning and hydrogen bonding of the nucleotide base. © 2014 FEBS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008NHESS...8..805V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008NHESS...8..805V"><span>Rockfall induced <span class="hlt">seismic</span> signals: case study in Montserrat, Catalonia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vilajosana, I.; Suriñach, E.; Abellán, A.; Khazaradze, G.; Garcia, D.; Llosa, J.</p> <p>2008-08-01</p> <p>After a rockfall event, a usual post event survey includes qualitative volume estimation, trajectory mapping and determination of departing zones. However, quantitative measurements are not usually made. Additional relevant quantitative information could be useful in determining the spatial occurrence of rockfall events and help us in quantifying their size. <span class="hlt">Seismic</span> measurements could be suitable for detection purposes since they are non invasive methods and are relatively inexpensive. Moreover, <span class="hlt">seismic</span> techniques could provide important information on rockfall size and location of impacts. On 14 February 2007 the Avalanche Group of the University of Barcelona obtained the <span class="hlt">seismic</span> data generated by an artificially triggered rockfall event at the Montserrat massif (near Barcelona, Spain) carried out in order to purge a slope. Two 3 component <span class="hlt">seismic</span> stations were deployed in the area about 200 m from the explosion point that triggered the rockfall. <span class="hlt">Seismic</span> signals and video images were simultaneously obtained. The initial volume of the rockfall was estimated to be 75 m3 by laser scanner data analysis. After the explosion, dozens of boulders ranging from 10-4 to 5 m3 in volume impacted on the ground at different locations. The blocks fell down onto a terrace, 120 m below the <span class="hlt">release</span> zone. The impact generated a small continuous mass movement composed of a mixture of rocks, sand and dust that ran down the slope and impacted on the road 60 m below. Time, time-frequency evolution and particle motion analysis of the <span class="hlt">seismic</span> records and <span class="hlt">seismic</span> energy estimation were performed. The results are as follows: 1 A rockfall event generates <span class="hlt">seismic</span> signals with specific characteristics in the time domain; 2 the <span class="hlt">seismic</span> signals generated by the mass movement show a time-frequency evolution different from that of other seismogenic sources (e.g. earthquakes, explosions or a single rock impact). This feature could be used for detection purposes; 3 particle motion plot analysis shows</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/15002343','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/15002343"><span>Lawrence Livermore National Laboratory Site <span class="hlt">Seismic</span> Safety Program: Summary of Findings</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Savy, J B; Foxall, W</p> <p></p> <p> special effort was made to identify and quantify all types of uncertainties. The final <span class="hlt">seismic</span> hazard estimates were de-aggregated to determine the contribution of all the <span class="hlt">seismic</span> sources as well as the relative contributions of potential future earthquakes in terms of their magnitudes and distances from the site. It was found that, in agreement with previous studies, the Greenville Fault system contributes the most to the estimate of the <span class="hlt">seismic</span> hazard expressed in terms of the probability of exceedance of the peak ground <span class="hlt">acceleration</span> (PGA) at the center of the LLNL site (i.e., at high frequencies). It is followed closely by the Calaveras and Corral Hollow faults. The Mount Diablo thrust and the Springtown and Livermore faults were not considered in the hazard calculations in the 1991 study. In this study they contributed together approximately as much as the Greenville fault. At lower frequencies, more distant faults such as the Hayward and San Andreas faults begin to appear as substantial contributors to the total hazard. The results of this revision are presented in Figures 1 and 2. Figure 1 shows the estimated mean hazard curve in terms of the annual probability of exceedance of the peak ground <span class="hlt">acceleration</span> (average of the two horizontal orthogonal components) at the LLNL site, assuming that the local site conditions are similar to those of a generic soil. Figure 2 shows the results in terms of the uniform hazard spectra (pseudo-spectral <span class="hlt">accelerations</span> for 5% damping) for five return periods. Although this latest revision is based on a completely independent and in many respects very different set of data and methodology from the previous one, it gives essentially the same results for the prediction of the peak ground <span class="hlt">acceleration</span> (PGA), albeit with a reduced uncertainty. The Greenville fault being a dominant contributor to the hazard, a field investigation was performed to better characterize the probability distribution of the rate of slip on the fault. Samples were</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9906E..1NG','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9906E..1NG"><span>Nonlinear transient survival level <span class="hlt">seismic</span> finite element analysis of Magellan ground based telescope</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Griebel, Matt; Buleri, Christine; Baylor, Andrew; Gunnels, Steve; Hull, Charlie; Palunas, Povilas; Phillips, Mark</p> <p>2016-07-01</p> <p>The Magellan Telescopes are a set of twin 6.5 meter ground based optical/near-IR telescopes operated by the Carnegie Institution for Science at the Las Campanas Observatory (LCO) in Chile. The primary mirrors are f/1.25 paraboloids made of borosilicate glass and a honeycomb structure. The secondary mirror provides both f/11 and f/5 focal lengths with two Nasmyth, three auxiliary, and a Cassegrain port on the optical support structure (OSS). The telescopes have been in operation since 2000 and have experienced several small earthquakes with no damage. Measurement of in situ response of the telescopes to <span class="hlt">seismic</span> events showed significant dynamic amplification, however, the response of the telescopes to a survival level earthquake, including component level forces, displacements, <span class="hlt">accelerations</span>, and stresses were unknown. The telescopes are supported with hydrostatic bearings that can lift up under high <span class="hlt">seismic</span> loading, thus causing a nonlinear response. For this reason, the typical response spectrum analysis performed to analyze a survival level <span class="hlt">seismic</span> earthquake is not sufficient in determining the true response of the structure. Therefore, a nonlinear transient finite element analysis (FEA) of the telescope structure was performed to assess high risk areas and develop <span class="hlt">acceleration</span> responses for future instrument design. Several configurations were considered combining different installed components and altitude pointing directions. A description of the models, methodology, and results are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.3713A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.3713A"><span>Deterministic <span class="hlt">Seismic</span> Hazard Assessment of Center-East IRAN (55.5-58.5˚ E, 29-31˚ N)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Askari, M.; Ney, Beh</p> <p>2009-04-01</p> <p>Deterministic <span class="hlt">Seismic</span> Hazard Assessment of Center-East IRAN (55.5-58.5˚E, 29-31˚N) Mina Askari, Behnoosh Neyestani Students of Science and Research University,Iran. Deterministic <span class="hlt">seismic</span> hazard assessment has been performed in Center-East IRAN, including Kerman and adjacent regions of 100km is selected. A catalogue of earthquakes in the region, including historical earthquakes and instrumental earthquakes is provided. A total of 25 potential <span class="hlt">seismic</span> source zones in the region delineated as area sources for <span class="hlt">seismic</span> hazard assessment based on geological, seismological and geophysical information, then minimum distance for every <span class="hlt">seismic</span> sources until site (Kerman) and maximum magnitude for each source have been determined, eventually using the N. A. ABRAHAMSON and J. J. LITEHISER '1989 attenuation relationship, maximum <span class="hlt">acceleration</span> is estimated to be 0.38g, that is related to the movement of blind fault with maximum magnitude of this source is Ms=5.5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S32A..08K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S32A..08K"><span>MyShake: Initial Observations from a Global Smartphone <span class="hlt">Seismic</span> Network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kong, Q.; Allen, R. M.; Schreier, L.</p> <p>2016-12-01</p> <p>MyShake is a global smartphone <span class="hlt">seismic</span> network that harnesses the power of crowdsourcing. It has two component: an android application running on the personal smartphones to detect earthquake-like motion, and a network detection algorithm to aggregate results from multiple smartphones to detect earthquakes. The MyShake application was <span class="hlt">released</span> to the public on Feb 12th 2016. Within the first 5 months, there are more than 200 earthquakes recorded by the smartphones all over the world, including events in Chile, Argentina, Mexico, Morocco, Greece, Nepal, New Zealand, Taiwan, Japan, and across North America. In this presentation, we will show the waveforms we recorded from the smartphones for different earthquakes, and the evidences for using this data as a supplementary to the current earthquake early warning system. We will also show the performance of MyShake system during the some earthquakes in US. In short, MyShake smartphone <span class="hlt">seismic</span> network can be a nice complementary system to the current traditional <span class="hlt">seismic</span> network, at the same time, it can be a standalone system in places where few <span class="hlt">seismic</span> stations were installed to reduce the earthquake hazards.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001CRASE.333...45C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001CRASE.333...45C"><span>Pics d'accélération du mouvement sismique observés lors du séisme de Chichi à Taiwan : application à l'estimation de l'aléa sismiqueAnalysis of peak ground <span class="hlt">accelerations</span> during the Chichi earthquake, Taiwan: application to <span class="hlt">seismic</span> hazard evaluation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Tsui-Yu; Cotton, Fabrice; Angelier, Jacques; Shin, Tzay-Chyn</p> <p>2001-07-01</p> <p>Attenuation laws are widely used in order to estimate the peak ground <span class="hlt">acceleration</span> that may occur at a given locality during an earthquake, for hazard evaluation purposes. However, these simplified laws should be regarded acceptable only in the first approximation, because numerous significant parameters at the local and regional scales are often ignored. We examined the relationship between distance and peak <span class="hlt">acceleration</span> based on examples from the dense accelerometric network of Taiwan, specifically for the Chichi destructive earthquake. We thus observed significant discrepancies between the predicted and observed <span class="hlt">accelerations</span>, resulting from (1) near-field saturation, (2) amplification in sedimentary basins, and (3) hanging wall effect. We mapped the residual <span class="hlt">accelerations</span> (difference between observed and predicted peak ground <span class="hlt">accelerations</span>). This highlights the role of the regional structure, independently revealed by the geological analysis, as a significant factor that controls the transmission of the <span class="hlt">seismic</span> <span class="hlt">accelerations</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMDI21A0386P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMDI21A0386P"><span><span class="hlt">Seismic</span> signal and noise on Europa and how to use it</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panning, M. P.; Stähler, S. C.; Bills, B. G.; Castillo, J.; Huang, H. H.; Husker, A. L.; Kedar, S.; Lorenz, R. D.; Pike, W. T.; Schmerr, N. C.; Tsai, V. C.; Vance, S.</p> <p>2017-12-01</p> <p>Seismology is one of our best tools for detailing interior structure of planetary bodies, and a seismometer is included in the baseline and threshold mission design for a potential Europa lander mission. Guiding mission design and planning for adequate science return, though, requires modeling of both the anticipated signal and noise. Assuming ice <span class="hlt">seismicity</span> on Europa behaves according to statistical properties observed in Earth catalogs and scaling cumulative <span class="hlt">seismic</span> moment <span class="hlt">release</span> to the moon, we simulate long <span class="hlt">seismic</span> records and estimate background noise and peak signal amplitudes (Panning et al., 2017). This suggests a sensitive instrument comparable to many broadband terrestrial instruments or the SP instrument from the InSight mission to Mars will be able to record signals, while high frequency geophones are likely inadequate. We extend this analysis to also begin incorporation of spatial and temporal variation due to the tidal cycle, which can help inform landing site selection. We also begin exploration of how chaotic terrane at the bottom of the ice shell and inter-ice heterogeneities (i.e. internal melt structures) may affect predicted <span class="hlt">seismic</span> observations using 2D numerical <span class="hlt">seismic</span> simulations. We also show some of the key <span class="hlt">seismic</span> observations to determine interior properties of Europa (Stähler et al., 2017). M. P. Panning, S. C. Stähler, H.-H. Huang, S. D. Vance, S. Kedar, V. C. Tsai, W. T. Pike, R. D. Lorenz, "Expected <span class="hlt">seismicity</span> and the <span class="hlt">seismic</span> noise environment of Europa," J. Geophys. Res., in revision, 2017. S. C. Stähler, M. P. Panning, S. D. Vance, R. D. Lorenz, M. van Driel, T. Nissen-Meyer, S. Kedar, "<span class="hlt">Seismic</span> wave propagation in icy ocean worlds," J. Geophys. Res., in revision, 2017.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/11380','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/11380"><span><span class="hlt">Release</span> <span class="hlt">Accelerates</span> Growth of Yellow-Poplar -- an 18-Year Look</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Robert D. Williams</p> <p>1976-01-01</p> <p>Yellow-poplar seedlings that germinated and were completely <span class="hlt">released</span> from woody competition in 1957 (the first year after a harvest cut) were four times taller and five times larger in diameter after the 1973 growing season than seedlings that were not <span class="hlt">released</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.U23A0046B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.U23A0046B"><span>Accessing <span class="hlt">seismic</span> data through geological interpretation: Challenges and solutions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Butler, R. W.; Clayton, S.; McCaffrey, B.</p> <p>2008-12-01</p> <p>Between them, the world's research programs, national institutions and corporations, especially oil and gas companies, have acquired substantial volumes of <span class="hlt">seismic</span> reflection data. Although the vast majority are proprietary and confidential, significant data are <span class="hlt">released</span> and available for research, including those in public data libraries. The challenge now is to maximise use of these data, by providing routes to <span class="hlt">seismic</span> not simply on the basis of acquisition or processing attributes but via the geology they image. The Virtual <span class="hlt">Seismic</span> Atlas (VSA: www.seismicatlas.org) meets this challenge by providing an independent, free-to-use community based internet resource that captures and shares the geological interpretation of <span class="hlt">seismic</span> data globally. Images and associated documents are explicitly indexed by extensive metadata trees, using not only existing survey and geographical data but also the geology they portray. The solution uses a Documentum database interrogated through Endeca Guided Navigation, to search, discover and retrieve images. The VSA allows users to compare contrasting interpretations of clean data thereby exploring the ranges of uncertainty in the geometric interpretation of subsurface structure. The metadata structures can be used to link reports and published research together with other data types such as wells. And the VSA can link to existing data libraries. Searches can take different paths, revealing arrays of geological analogues, new datasets while providing entirely novel insights and genuine surprises. This can then drive new creative opportunities for research and training, and expose the contents of <span class="hlt">seismic</span> data libraries to the world.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.4462B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.4462B"><span>Reassessment of the <span class="hlt">Seismicity</span> and <span class="hlt">seismic</span> hazards of Libya</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ben Suleman, A.; Elmeladi, A.</p> <p>2009-04-01</p> <p>The tectonic evolution of Libya, located at the northern extreme of the African continent, has yielded a complex crustal structure that is composed of a series of basins and uplifts. The present day deformation of Libya is the result of the Eurasia-Africa continental collision. At the end of the year 2005, The Libyan National Seismological Network was established to monitor local, regional and teleseismic activities, as well as to provide high quality data for research projects both locally and on the regional and global scale. This study aims to discuss the <span class="hlt">seismicity</span> of Libya by using the new data from the Libyan national seismological network and to focus on the <span class="hlt">seismic</span> hazards. At first glance the <span class="hlt">seismic</span> activity map shows dominant trends of <span class="hlt">seismicity</span> with most of the <span class="hlt">seismic</span> activity concentrated along the northern coastal areas. Four major <span class="hlt">seismic</span> trends were quite noticeable. A first trend is a NW-SE direction coinciding with the eastern boarder of the Hun Graben. A second trend is also a NW-SE direction in the offshore area and might be a continuation of this trend. The other two trends were located in the western Gulf of Sirt and Cyrenaica platform. The rest of <span class="hlt">seismicity</span> is diffuse either offshore or in land, with no good correlation with well-mapped faults. Detailed investigations of the Libyan <span class="hlt">seismicity</span> indicates that the Libya has experienced earthquakes of varying magnitudes and that there is definitely a certain amount of <span class="hlt">seismic</span> risk involved in engineering projects, particularly in the northern regions. Detailed investigation of the distribution of the Libyan earthquakes in space and time along with all other geological considerations suggested the classification of the country into four <span class="hlt">seismic</span> zones with the Hun graben zone being the most <span class="hlt">seismically</span> active zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.T53A1407S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.T53A1407S"><span>Long Term <span class="hlt">Seismic</span> Observation in Mariana by OBSs : Double <span class="hlt">Seismic</span> Zone and Upper Mantle Structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shiobara, H.; Sugioka, H.; Mochizuki, K.; Oki, S.; Kanazawa, T.; Fukao, Y.; Suyehiro, K.</p> <p>2005-12-01</p> <p>In order to obtain the deep arc structural image of Mariana, a large-scale <span class="hlt">seismic</span> observation by using 58 long-term ocean bottom seismometers (LTOBS) had been performed from June 2003 until April 2004, which is a part of the MARGINS program funded by the NSF. Prior to this observation, a pilot long-term <span class="hlt">seismic</span> array observation was conducted in the same area by using 10 LTOBSs from Oct. 2001 until Feb. 2003. At that time, 8 LTOBSs were recovered but one had no data. Recently, 2 LTOBSs, had troubles in the <span class="hlt">releasing</span>, were recovered by the manned submersible (Shinkai 6500, Jamstec) for the research of the malfunction in July 2005. By using all 9 LTOBS's data, those are about 11 months long, hypocenter determination was performed and more than 3000 local events were found. Even with the 1D velocity structure based on the iasp91 model, double <span class="hlt">seismic</span> zones and a systematic shift of epicenters between the PDE and this study were observed. To investigate the detail of hypocenter distribution and the 3D velocity structure, the DD inversion (tomoDD: Zhang and Thurber, 2003) was applied for this data set with the 1D structure initial model except for the crust, which has been surveyed by using a dense airgun-OBS system (Takahashi et al., 2003). The result of relocated hypocenters shows clear double <span class="hlt">seismic</span> zones until about 200 km depth, a high activity area around the fore-arc serpentine sea-mount, the Big Blue, and a lined focuses along the current ridge axis in the back-arc basin, and the result of the tomography shows a image of subducting slab and a low-Vs region below the same sea-mount mentioned. The wedge mantle structure was not clearly resolved due to the inadequate source-receiver coverage, which will be done in the recent experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JIEIA.tmp..108M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JIEIA.tmp..108M"><span>Redistribution Principle Approach for Evaluation of <span class="hlt">Seismic</span> Active Earth Pressure Behind Retaining Wall</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maskar, A. D.; Madhekar, S. N.; Phatak, D. R.</p> <p>2017-11-01</p> <p>The knowledge of <span class="hlt">seismic</span> active earth pressure behind the rigid retaining wall is very essential in the design of retaining wall in earthquake prone regions. Commonly used Mononobe-Okabe (MO) method considers pseudo-static approach. Recently there are many pseudo-dynamic methods used to evaluate the <span class="hlt">seismic</span> earth pressure. However, available pseudo-static and pseudo-dynamic methods do not incorporate the effect of wall movement on the earth pressure distribution. Dubrova (Interaction between soils and structures, Rechnoi Transport, Moscow, 1963) was the first, who considered such effect and till date, it is used for cohesionless soil, without considering the effect of <span class="hlt">seismicity</span>. In this paper, Dubrova's model based on redistribution principle, considering the <span class="hlt">seismic</span> effect has been developed. It is further used to compute the distribution of <span class="hlt">seismic</span> active earth pressure, in a more realistic manner, by considering the effect of wall movement on the earth pressure, as it is displacement based method. The effects of a wide range of parameters like soil friction angle (ϕ), wall friction angle (δ), horizontal and vertical <span class="hlt">seismic</span> <span class="hlt">acceleration</span> coefficients (kh and kv); on <span class="hlt">seismic</span> active earth pressure (Kae) have been studied. Results are presented for comparison of pseudo-static and pseudo-dynamic methods, to highlight the realistic, non-linearity of <span class="hlt">seismic</span> active earth pressure distribution. The current study results in the variation of Kae with kh in the same manner as that of MO method and Choudhury and Nimbalkar (Geotech Geol Eng 24(5):1103-1113, 2006) study. To increase in ϕ, there is a reduction in static as well as <span class="hlt">seismic</span> earth pressure. Also, by keeping constant ϕ value, as kh increases from 0 to 0.3, earth pressure increases; whereas as δ increases, active earth pressure decreases. The <span class="hlt">seismic</span> active earth pressure coefficient (Kae) obtained from the present study is approximately same as that obtained by previous researchers. Though <span class="hlt">seismic</span> earth</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004LNES..104..671B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004LNES..104..671B"><span>Numerical Modelling of <span class="hlt">Seismic</span> Slope Stability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bourdeau, Céline; Havenith, Hans-Balder; Fleurisson, Jean-Alain; Grandjean, Gilles</p> <p></p> <p>Earthquake ground-motions recorded worldwide have shown that many morphological and geological structures (topography, sedimentary basin) are prone to amplify the <span class="hlt">seismic</span> shaking (San Fernando, 1971 [Davis and West 1973] Irpinia, 1980 [Del Pezzo et al. 1983]). This phenomenon, called site effects, was again recently observed in El Salvador when, on the 13th of January 2001, the country was struck by a M = 7.6 earthquake. Indeed, while horizontal <span class="hlt">accelerations</span> on a rock site at Berlin, 80 km from the epicentre, did not exceed 0.23 g, they reached 0.6 g at Armenia, 110 km from the epicentre. Armenia is located on a small hill underlaid by a few meters thick pyroclastic deposits. Both the local topography and the presence of surface layers are likely to have caused the observed amplification effects, which are supposed to have contributed to the triggering of some of the hundreds of landslides related to this <span class="hlt">seismic</span> event (Murphy et al. 2002). In order to better characterize the way site effects may influence the triggering of landslides along slopes, 2D numerical elastic and elasto-plastic models were developed. Various geometrical, geological and <span class="hlt">seismic</span> conditions were analysed and the dynamic behaviour of the slope under these con- ditions was studied in terms of creation and location of a sliding surface. Preliminary results suggest that the size of modelled slope failures is dependent on site effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9267G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9267G"><span>Constraints on Long-Term <span class="hlt">Seismic</span> Hazard From Vulnerable Stalagmites for the surroundings of Katerloch cave, Austria</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gribovszki, Katalin; Bokelmann, Götz; Mónus, Péter; Kovács, Károly; Kalmár, János</p> <p>2016-04-01</p> <p>Earthquakes hit urban centers in Europe infrequently, but occasionally with disastrous effects. This raises the important issue for society, how to react to the natural hazard: potential damages are huge, and infrastructure costs for addressing these hazards are huge as well. Obtaining an unbiased view of <span class="hlt">seismic</span> hazard (and risk) is very important therefore. In principle, the best way to test Probabilistic <span class="hlt">Seismic</span> Hazard Assessments (PSHA) is to compare with observations that are entirely independent of the procedure used to produce the PSHA models. Arguably, the most valuable information in this context should be information on long-term hazard, namely maximum intensities (or magnitudes) occurring over time intervals that are at least as long as a <span class="hlt">seismic</span> cycle. Such information would be very valuable, even if it concerned only a single site. Long-term information can in principle be gained from intact stalagmites in natural karstic caves. These have survived all earthquakes that have occurred, over thousands of years - depending on the age of the stalagmite. Their "survival" requires that the horizontal ground <span class="hlt">acceleration</span> has never exceeded a certain critical value within that period. We are focusing here on a case study from the Katerloch cave close to the city of Graz, Austria. A specially-shaped (candle stick style: high, slim, and more or less cylindrical form) intact and vulnerable stalagmites (IVSTM) in the Katerloch cave has been examined in 2013 and 2014. This IVSTM is suitable for estimating the upper limit for horizontal peak ground <span class="hlt">acceleration</span> generated by pre-historic earthquakes. For this cave, we have extensive information about ages (e.g., Boch et al., 2006, 2010). The approach, used in our study, yields significant new constraints on <span class="hlt">seismic</span> hazard, as the intactness of the stalagmites suggests that tectonic structures close to Katerloch cave, i.p. the Mur-Mürz fault did not generate very strong paleoearthquakes in the last few thousand years</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Tectp.682..147V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Tectp.682..147V"><span>Stress <span class="hlt">release</span> model and proxy measures of earthquake size. Application to Italian seismogenic sources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Varini, Elisa; Rotondi, Renata; Basili, Roberto; Barba, Salvatore</p> <p>2016-07-01</p> <p>This study presents a series of self-correcting models that are obtained by integrating information about <span class="hlt">seismicity</span> and fault sources in Italy. Four versions of the stress <span class="hlt">release</span> model are analyzed, in which the evolution of the system over time is represented by the level of strain, moment, <span class="hlt">seismic</span> energy, or energy scaled by the moment. We carry out the analysis on a regional basis by subdividing the study area into eight tectonically coherent regions. In each region, we reconstruct the <span class="hlt">seismic</span> history and statistically evaluate the completeness of the resulting <span class="hlt">seismic</span> catalog. Following the Bayesian paradigm, we apply Markov chain Monte Carlo methods to obtain parameter estimates and a measure of their uncertainty expressed by the simulated posterior distribution. The comparison of the four models through the Bayes factor and an information criterion provides evidence (to different degrees depending on the region) in favor of the stress <span class="hlt">release</span> model based on the energy and the scaled energy. Therefore, among the quantities considered, this turns out to be the measure of the size of an earthquake to use in stress <span class="hlt">release</span> models. At any instant, the time to the next event turns out to follow a Gompertz distribution, with a shape parameter that depends on time through the value of the conditional intensity at that instant. In light of this result, the issue of forecasting is tackled through both retrospective and prospective approaches. Retrospectively, the forecasting procedure is carried out on the occurrence times of the events recorded in each region, to determine whether the stress <span class="hlt">release</span> model reproduces the observations used in the estimation procedure. Prospectively, the estimates of the time to the next event are compared with the dates of the earthquakes that occurred after the end of the learning catalog, in the 2003-2012 decade.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.S42B..05M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.S42B..05M"><span>Modelling induced <span class="hlt">seismicity</span> due to fluid injection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murphy, S.; O'Brien, G. S.; Bean, C. J.; McCloskey, J.; Nalbant, S. S.</p> <p>2011-12-01</p> <p>Injection of fluid into the subsurface alters the stress in the crust and can induce earthquakes. The science of assessing the risk of induced <span class="hlt">seismicity</span> from such ventures is still in its infancy despite public concern. We plan to use a fault network model in which stress perturbations due to fluid injection induce earthquakes. We will use this model to investigate the role different operational and geological factors play in increasing <span class="hlt">seismicity</span> in a fault system due to fluid injection. The model is based on a quasi-dynamic relationship between stress and slip coupled with a rate and state fiction law. This allows us to model slip on fault interfaces over long periods of time (i.e. years to 100's years). With the use of the rate and state friction law the nature of stress <span class="hlt">release</span> during slipping can be altered through variation of the frictional parameters. Both <span class="hlt">seismic</span> and aseismic slip can therefore be simulated. In order to add heterogeneity along the fault plane a fractal variation in the frictional parameters is used. Fluid injection is simulated using the lattice Boltzmann method whereby pore pressure diffuses throughout a permeable layer from the point of injection. The stress perturbation this causes on the surrounding fault system is calculated using a quasi-static solution for slip dislocation in an elastic half space. From this model we can generate slip histories and <span class="hlt">seismicity</span> catalogues covering 100's of years for predefined fault networks near fluid injection sites. Given that rupture is a highly non-linear process, comparison between models with different input parameters (e.g. fault network statistics and injection rates) will be based on system wide features (such as the Gutenberg-Richter b-values), rather than specific <span class="hlt">seismic</span> events. Our ultimate aim is that our model produces <span class="hlt">seismic</span> catalogues similar to those observed over real injection sites. Such validation would pave the way to probabilistic estimation of reactivation risk for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.175..149K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.175..149K"><span><span class="hlt">Seismic</span> Microzonation of Islamabad-Rawalpindi Metropolitan Area, Pakistan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khan, Sarfraz; Khan, M. Asif</p> <p>2018-01-01</p> <p>Microzonation deals with classifying <span class="hlt">seismic</span> hazards in terms of ground motions resulting from amplification of <span class="hlt">seismic</span> waves by nature of soil profiles underlying a site, town or city. This paper presents the results of microzonation study for Islamabad metropolitan, the capital of Pakistan. Cumulative SPT- N values from geophysical borehole and microtremor (Tromino Engy Plus) data were used to classify the soils into classes C (very dense soil profile and soft rock) and D (stiff soil profile) as devised by the National Earthquake Hazard Reduction Program (NEHRP). Soil response analyses were carried out based on scaled time histories of Kashmir earthquake (2005, 0.02 g), Mangla earthquake (2006, 0.031 g) and Haripur earthquake (2010, 0.13 g) corresponding to return periods of 150, 475, 975 and 2475 years. Spectral <span class="hlt">accelerations</span> on the ground surface are calculated by two different approaches (1) soil response analysis performed using one dimensional shear wave propagation method (equivalent linear approach); and (2) NEHRP and Borcherdt amplification factors. Microzonation maps are produced with respect to ground shaking intensity for the return periods of 150, 475, 975 and 2475 years taking into account the variation of the spectral <span class="hlt">accelerations</span> calculated based on these two procedures. The results show that the <span class="hlt">accelerations</span> at the ground surface in the Islamabad-Rawalpindi metropolitan are in the range of 0.40-0.48 g (for 150 years), 0.59-0.65 g (for 475 years), 0.71-0.77 g (for 975 years), and 0.92-0.94 g (for 2475 years). The amplification factors for these four hazard levels range from 0.96 to 1.38 (150 years), 0.90-1.14 (475 years), 0.85-1.04 (975 years) and 0.84-1.00 (2475 years).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JGE.....4..362A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JGE.....4..362A"><span>Application of wavelet multi-resolution analysis for correction of <span class="hlt">seismic</span> <span class="hlt">acceleration</span> records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ansari, Anooshiravan; Noorzad, Assadollah; Zare, Mehdi</p> <p>2007-12-01</p> <p>During an earthquake, many stations record the ground motion, but only a few of them could be corrected using conventional high-pass and low-pass filtering methods and the others were identified as highly contaminated by noise and as a result useless. There are two major problems associated with these noisy records. First, since the signal to noise ratio (S/N) is low, it is not possible to discriminate between the original signal and noise either in the frequency domain or in the time domain. Consequently, it is not possible to cancel out noise using conventional filtering methods. The second problem is the non-stationary characteristics of the noise. In other words, in many cases the characteristics of the noise are varied over time and in these situations, it is not possible to apply frequency domain correction schemes. When correcting <span class="hlt">acceleration</span> signals contaminated with high-level non-stationary noise, there is an important question whether it is possible to estimate the state of the noise in different bands of time and frequency. Wavelet multi-resolution analysis decomposes a signal into different time-frequency components, and besides introducing a suitable criterion for identification of the noise among each component, also provides the required mathematical tool for correction of highly noisy <span class="hlt">acceleration</span> records. In this paper, the characteristics of the wavelet de-noising procedures are examined through the correction of selected real and synthetic <span class="hlt">acceleration</span> time histories. It is concluded that this method provides a very flexible and efficient tool for the correction of very noisy and non-stationary records of ground <span class="hlt">acceleration</span>. In addition, a two-step correction scheme is proposed for long period correction of the <span class="hlt">acceleration</span> records. This method has the advantage of stable results in displacement time history and response spectrum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRB..121.6009K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRB..121.6009K"><span>Validating induced <span class="hlt">seismicity</span> forecast models—Induced <span class="hlt">Seismicity</span> Test Bench</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Király-Proag, Eszter; Zechar, J. Douglas; Gischig, Valentin; Wiemer, Stefan; Karvounis, Dimitrios; Doetsch, Joseph</p> <p>2016-08-01</p> <p>Induced earthquakes often accompany fluid injection, and the <span class="hlt">seismic</span> hazard they pose threatens various underground engineering projects. Models to monitor and control induced <span class="hlt">seismic</span> hazard with traffic light systems should be probabilistic, forward-looking, and updated as new data arrive. In this study, we propose an Induced <span class="hlt">Seismicity</span> Test Bench to test and rank such models; this test bench can be used for model development, model selection, and ensemble model building. We apply the test bench to data from the Basel 2006 and Soultz-sous-Forêts 2004 geothermal stimulation projects, and we assess forecasts from two models: Shapiro and Smoothed <span class="hlt">Seismicity</span> (SaSS) and Hydraulics and <span class="hlt">Seismics</span> (HySei). These models incorporate a different mix of physics-based elements and stochastic representation of the induced sequences. Our results show that neither model is fully superior to the other. Generally, HySei forecasts the <span class="hlt">seismicity</span> rate better after shut-in but is only mediocre at forecasting the spatial distribution. On the other hand, SaSS forecasts the spatial distribution better and gives better <span class="hlt">seismicity</span> rate estimates before shut-in. The shut-in phase is a difficult moment for both models in both reservoirs: the models tend to underpredict the <span class="hlt">seismicity</span> rate around, and shortly after, shut-in.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5010128','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5010128"><span>Precursory changes in <span class="hlt">seismic</span> velocity for the spectrum of earthquake failure modes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Scuderi, M.M.; Marone, C.; Tinti, E.; Di Stefano, G.; Collettini, C.</p> <p>2016-01-01</p> <p>Temporal changes in <span class="hlt">seismic</span> velocity during the earthquake cycle have the potential to illuminate physical processes associated with fault weakening and connections between the range of fault slip behaviors including slow earthquakes, tremor and low frequency earthquakes1. Laboratory and theoretical studies predict changes in <span class="hlt">seismic</span> velocity prior to earthquake failure2, however tectonic faults fail in a spectrum of modes and little is known about precursors for those modes3. Here we show that precursory changes of wave speed occur in laboratory faults for the complete spectrum of failure modes observed for tectonic faults. We systematically altered the stiffness of the loading system to reproduce the transition from slow to fast stick-slip and monitored ultrasonic wave speed during frictional sliding. We find systematic variations of elastic properties during the <span class="hlt">seismic</span> cycle for both slow and fast earthquakes indicating similar physical mechanisms during rupture nucleation. Our data show that <span class="hlt">accelerated</span> fault creep causes reduction of <span class="hlt">seismic</span> velocity and elastic moduli during the preparatory phase preceding failure, which suggests that real time monitoring of active faults may be a means to detect earthquake precursors. PMID:27597879</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8756Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8756Z"><span>3D Numerical Simulation on the Sloshing Waves Excited by the <span class="hlt">Seismic</span> Shacking</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Lin; Wu, Tso-Ren</p> <p>2016-04-01</p> <p>In the event of 2015 Nepal earthquake, a video clip broadcasted worldwide showed a violent water spilling in a hotel swimming pool. This sloshing phenomenon indicates a potential water loss in the sensitive facilities, e.g. the spent fuel pools in nuclear power plant, has to be taken into account carefully under the consideration of <span class="hlt">seismic</span>-induced ground <span class="hlt">acceleration</span>. In the previous studies, the simulation of sloshing mainly focused on the pressure force on the structure by using a simplified Spring-Mass Method developed in the field of solid mechanics. However, restricted by the assumptions of plane water surface and limited wave height, significant error will be made in evaluating the amount of water loss in the tank. In this paper, the computational fluid dynamical model, Splash3D, was adopted for studying the sloshing problem accurately. Splash3D solved 3D Navier-Stokes Equation directly with Large-Eddy Simulation (LES) turbulent closure. The Volume-of-fluid (VOF) method with piecewise linear interface calculation (PLIC) was used to track the complex breaking water surface. The time series <span class="hlt">acceleration</span> of a design <span class="hlt">seismic</span> was loaded to excite the water. With few restrictions from the assumptions, the accuracy of the simulation results were improved dramatically. A series model validations were conducted by compared to a 2D theoretical solution, and a 3D experimental data. Good comparisons can be seen. After the validation, we performed the simulation for considering a sloshing case in a rectangular water tank with a dimension of 12 m long, 8 m wide, 8 m deep, which contained water with 7 m in depth. The <span class="hlt">seismic</span> movement was imported by considering time-series <span class="hlt">acceleration</span> in three dimensions, which were about 0.5 g to 1.2 g in the horizontal directions, and 0.3 g to 1 g in the vertical direction. We focused the discussions on the kinematics of the water surface, wave breaking, velocity field, pressure field, water force on the side walls, and, most</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.7088S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.7088S"><span>Added-value joint source modelling of <span class="hlt">seismic</span> and geodetic data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sudhaus, Henriette; Heimann, Sebastian; Walter, Thomas R.; Krueger, Frank</p> <p>2013-04-01</p> <p>In tectonically active regions earthquake source studies strongly support the analysis of the current faulting processes as they reveal the location and geometry of active faults, the average slip <span class="hlt">released</span> or more. For source modelling of shallow, moderate to large earthquakes often a combination of geodetic (GPS, InSAR) and <span class="hlt">seismic</span> data is used. A truly joint use of these data, however, usually takes place only on a higher modelling level, where some of the first-order characteristics (time, centroid location, fault orientation, moment) have been fixed already. These required basis model parameters have to be given, assumed or inferred in a previous, separate and highly non-linear modelling step using one of the these data sets alone. We present a new earthquake rupture model implementation that realizes a fully combined data integration of surface displacement measurements and <span class="hlt">seismic</span> data in a non-linear optimization of simple but extended planar ruptures. The model implementation allows for fast forward calculations of full seismograms and surface deformation and therefore enables us to use Monte Carlo global search algorithms. Furthermore, we benefit from the complementary character of <span class="hlt">seismic</span> and geodetic data, e. g. the high definition of the source location from geodetic data and the sensitivity of the resolution of the <span class="hlt">seismic</span> data on moment <span class="hlt">releases</span> at larger depth. These increased constraints from the combined dataset make optimizations efficient, even for larger model parameter spaces and with a very limited amount of a priori assumption on the source. A vital part of our approach is rigorous data weighting based on the empirically estimated data errors. We construct full data error variance-covariance matrices for geodetic data to account for correlated data noise and also weight the <span class="hlt">seismic</span> data based on their signal-to-noise ratio. The estimation of the data errors and the fast forward modelling opens the door for Bayesian inferences of the source</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSeis..22..575R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSeis..22..575R"><span>Application of Gumbel I and Monte Carlo methods to assess <span class="hlt">seismic</span> hazard in and around Pakistan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rehman, Khaista; Burton, Paul W.; Weatherill, Graeme A.</p> <p>2018-05-01</p> <p>A proper assessment of <span class="hlt">seismic</span> hazard is of considerable importance in order to achieve suitable building construction criteria. This paper presents probabilistic <span class="hlt">seismic</span> hazard assessment in and around Pakistan (23° N-39° N; 59° E-80° E) in terms of peak ground <span class="hlt">acceleration</span> (PGA). Ground motion is calculated in terms of PGA for a return period of 475 years using a seismogenic-free zone method of Gumbel's first asymptotic distribution of extreme values and Monte Carlo simulation. Appropriate attenuation relations of universal and local types have been used in this study. The results show that for many parts of Pakistan, the expected <span class="hlt">seismic</span> hazard is relatively comparable with the level specified in the existing PGA maps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70014006','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70014006"><span>A//r//m//s AND <span class="hlt">SEISMIC</span> SOURCE STUDIES.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hanks, T.C.; ,</p> <p>1984-01-01</p> <p>This paper briefly summarizes some recent developments in studies of <span class="hlt">seismic</span> source parameter estimation, emphasizing the essential similarities between mining-induced seismogenic-failure and naturally occurring, tectonically driven earthquakes. The root-mean-square <span class="hlt">acceleration</span>, a//r//m//s, shows much promise as an observational measure of high-frequency ground motion; it is very stable observationally, is insensitive to radiation pattern, and can be related linearly to the dynamic stress differences arising in the faulting process. To interpret a//r//m//s correctly, however, requires knowledge of f//m//a//x, the high-frequency band-limitation of the radiated field of earthquakes. As a practical matter, f//m//a//x can be due to any number of causes, but an essential ambiguity is whether or not f//m//a//x can arise from source properties alone. The interaction of the aftershocks of the Oroville, California, earthquake illustrates how a//r//m//s stress drops may be connected to detailed <span class="hlt">seismicity</span> patterns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013CG.....58....8H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013CG.....58....8H"><span>A spatio-temporal model for probabilistic <span class="hlt">seismic</span> hazard zonation of Tehran</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hashemi, Mahdi; Alesheikh, Ali Asghar; Zolfaghari, Mohammad Reza</p> <p>2013-08-01</p> <p>A precondition for all disaster management steps, building damage prediction, and construction code developments is a hazard assessment that shows the exceedance probabilities of different ground motion levels at a site considering different near- and far-field earthquake sources. The <span class="hlt">seismic</span> sources are usually categorized as time-independent area sources and time-dependent fault sources. While the earlier incorporates the small and medium events, the later takes into account only the large characteristic earthquakes. In this article, a probabilistic approach is proposed to aggregate the effects of time-dependent and time-independent sources on <span class="hlt">seismic</span> hazard. The methodology is then applied to generate three probabilistic <span class="hlt">seismic</span> hazard maps of Tehran for 10%, 5%, and 2% exceedance probabilities in 50 years. The results indicate an increase in peak ground <span class="hlt">acceleration</span> (PGA) values toward the southeastern part of the study area and the PGA variations are mostly controlled by the shear wave velocities across the city. In addition, the implementation of the methodology takes advantage of GIS capabilities especially raster-based analyses and representations. During the estimation of the PGA exceedance rates, the emphasis has been placed on incorporating the effects of different attenuation relationships and <span class="hlt">seismic</span> source models by using a logic tree.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730013015&hterms=mortar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmortar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730013015&hterms=mortar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmortar"><span>Active <span class="hlt">seismic</span> experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kovach, R. L.; Watkins, J. S.; Talwani, P.</p> <p>1972-01-01</p> <p>The Apollo 16 active <span class="hlt">seismic</span> experiment (ASE) was designed to generate and monitor <span class="hlt">seismic</span> waves for the study of the lunar near-surface structure. Several <span class="hlt">seismic</span> energy sources are used: an astronaut-activated thumper device, a mortar package that contains rocket-launched grenades, and the impulse produced by the lunar module ascent. Analysis of some <span class="hlt">seismic</span> signals recorded by the ASE has provided data concerning the near-surface structure at the Descartes landing site. Two compressional <span class="hlt">seismic</span> velocities have so far been recognized in the <span class="hlt">seismic</span> data. The deployment of the ASE is described, and the significant results obtained are discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70020087','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70020087"><span><span class="hlt">Seismicity</span> associated with dome growth and collapse at the Soufriere Hills Volcano, Montserrat</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Miller, A.D.; Stewart, R.C.; White, R.A.; Luckett, R.; Baptie, B.J.; Aspinall, W.P.; Latchman, J.L.; Lynch, L.L.; Voight, B.</p> <p>1998-01-01</p> <p>Varied <span class="hlt">seismicity</span> has accompanied growth and collapse of the lava dome of the Soufriere Hills Volcano, Montserrat. Earthquakes have been classified as either volcano-tectonic, long-period or hybrid, and daily variations in the numbers of events have mapped changes in the style of eruption. Repetitive hybrid earthquakes were common during the first months of dome growth. In July 1996 the style of <span class="hlt">seismicity</span> changed and regular short-lived hybrid earthquake swarms became common. This change was probably caused by an increase in the magma flux. Earthquake swarms have preceded almost all major dome collapses, and have accompanied cyclical deformation, thought to be due to a built-up of pressure in the upper conduit which is later <span class="hlt">released</span> by magma moving into the dome.Varied <span class="hlt">seismicity</span> has accompanied growth and collapse of the lava dome of the Soufriere Hills Volcano, Montserrat. Earthquakes have been classified as either volcano-tectonic, long-period or hybrid, and daily variations in the numbers of events have mapped changes in the style of eruption. Repetitive hybrid earthquakes were common during the first months of dome growth. In July 1996 the style of <span class="hlt">seismicity</span> changed and regular, short-lived hybrid earthquake swarms became common. This change was probably caused by an increase in the magma flux. Earthquake swarms have preceded almost all major dome collapses, and have accompanied cyclical deformation, thought to be due to a build-up of pressure in the upper conduit which is later <span class="hlt">released</span> by magma moving into the dome.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/2889','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/2889"><span>Probabilistic <span class="hlt">seismic</span> hazard characterization and design parameters for the Pantex Plant</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bernreuter, D. L.; Foxall, W.; Savy, J. B.</p> <p>1998-10-19</p> <p>The Hazards Mitigation Center at Lawrence Livermore National Laboratory (LLNL) updated the <span class="hlt">seismic</span> hazard and design parameters at the Pantex Plant. The probabilistic <span class="hlt">seismic</span> hazard (PSH) estimates were first updated using the latest available data and knowledge from LLNL (1993, 1998), Frankel et al. (1996), and other relevant recent studies from several consulting companies. Special attention was given to account for the local <span class="hlt">seismicity</span> and for the system of potentially active faults associated with the Amarillo-Wichita uplift. Aleatory (random) uncertainty was estimated from the available data and the epistemic (knowledge) uncertainty was taken from results of similar studies. Special attentionmore » was given to soil amplification factors for the site. Horizontal Peak Ground <span class="hlt">Acceleration</span> (PGA) and 5% damped uniform hazard spectra were calculated for six return periods (100 yr., 500 yr., 1000 yr., 2000 yr., 10,000 yr., and 100,000 yr.). The design parameters were calculated following DOE standards (DOE-STD-1022 to 1024). Response spectra for design or evaluation of Performance Category 1 through 4 structures, systems, and components are presented.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S23A4476Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S23A4476Y"><span>Progressive <span class="hlt">Seismic</span> Failure, <span class="hlt">Seismic</span> Gap, and Great <span class="hlt">Seismic</span> Risk across the Densely Populated North China Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yin, A.; Yu, X.; Shen, Z.</p> <p>2014-12-01</p> <p>Although the <span class="hlt">seismically</span> active North China basin has the most complete written records of pre-instrumentation earthquakes in the world, this information has not been fully utilized for assessing potential earthquake hazards of this densely populated region that hosts ~200 million people. In this study, we use the historical records to document the earthquake migration pattern and the existence of a 180-km <span class="hlt">seismic</span> gap along the 600-km long right-slip Tangshan-Hejian-Cixian (THC) fault zone that cuts across the North China basin. The newly recognized <span class="hlt">seismic</span> gap, which is centered at Tianjin with a population of 11 million people and ~120 km from Beijing (22 million people) and Tangshan (7 million people), has not been ruptured in the past 1000 years by M≥6 earthquakes. The <span class="hlt">seismic</span> migration pattern in the past millennium suggests that the epicenters of major earthquakes have shifted towards this <span class="hlt">seismic</span> gap along the THC fault, which implies that the 180- km gap could be the site of the next great earthquake with M≈7.6 if it is ruptured by a single event. Alternatively, the <span class="hlt">seismic</span> gap may be explained by aseismic creeping or <span class="hlt">seismic</span> strain transfer between active faults.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH21A0159M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH21A0159M"><span>Time-Independent Annual <span class="hlt">Seismic</span> Rates, Based on Faults and Smoothed <span class="hlt">Seismicity</span>, Computed for <span class="hlt">Seismic</span> Hazard Assessment in Italy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murru, M.; Falcone, G.; Taroni, M.; Console, R.</p> <p>2017-12-01</p> <p>In 2015 the Italian Department of Civil Protection, started a project for upgrading the official Italian <span class="hlt">seismic</span> hazard map (MPS04) inviting the Italian scientific community to participate in a joint effort for its realization. We participated providing spatially variable time-independent (Poisson) long-term annual occurrence rates of <span class="hlt">seismic</span> events on the entire Italian territory, considering cells of 0.1°x0.1° from M4.5 up to M8.1 for magnitude bin of 0.1 units. Our final model was composed by two different models, merged in one ensemble model, each one with the same weight: the first one was realized by a smoothed <span class="hlt">seismicity</span> approach, the second one using the seismogenic faults. The spatial smoothed <span class="hlt">seismicity</span> was obtained using the smoothing method introduced by Frankel (1995) applied to the historical and instrumental <span class="hlt">seismicity</span>. In this approach we adopted a tapered Gutenberg-Richter relation with a b-value fixed to 1 and a corner magnitude estimated with the bigger events in the catalogs. For each seismogenic fault provided by the Database of the Individual Seismogenic Sources (DISS), we computed the annual rate (for each cells of 0.1°x0.1°) for magnitude bin of 0.1 units, assuming that the <span class="hlt">seismic</span> moments of the earthquakes generated by each fault are distributed according to the same tapered Gutenberg-Richter relation of the smoothed <span class="hlt">seismicity</span> model. The annual rate for the final model was determined in the following way: if the cell falls within one of the <span class="hlt">seismic</span> sources, we merge the respective value of rate determined by the <span class="hlt">seismic</span> moments of the earthquakes generated by each fault and the value of the smoothed <span class="hlt">seismicity</span> model with the same weight; if instead the cells fall outside of any <span class="hlt">seismic</span> source we considered the rate obtained from the spatial smoothed <span class="hlt">seismicity</span>. Here we present the final results of our study to be used for the new Italian <span class="hlt">seismic</span> hazard map.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMDI43A2661L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMDI43A2661L"><span>A first step to compare geodynamical models and <span class="hlt">seismic</span> observations of the inner core</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lasbleis, M.; Waszek, L.; Day, E. A.</p> <p>2016-12-01</p> <p> to <span class="hlt">release</span> our codes to broader scientific community, allowing researchers from all disciplines to test their models of inner core growth against <span class="hlt">seismic</span> observations or create a kinematic model for the evolution of the inner core which matches new geophysical observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1815962F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1815962F"><span><span class="hlt">Seismicity</span> and seismogenic structures of Central Apennines (Italy): constraints on the present-day stress field from focal mechanisms - The SLAM (<span class="hlt">Seismicity</span> of Lazio-Abruzzo and Molise) project</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frepoli, Alberto; Battista Cimini, Giovanni; De Gori, Pasquale; De Luca, Gaetano; Marchetti, Alessandro; Montuori, Caterina; Pagliuca, Nicola</p> <p>2016-04-01</p> <p>We present new results for the microseismic activity in the Central Apennines recorded from a total of 81<span class="hlt">seismic</span> stations. The large number of recording sites derives from the combination of temporary and permanent <span class="hlt">seismic</span> networks operating in the study region. Between January 2009 and October 2013 we recorded 6923 earthquakes with local magnitudes ML ranging from 0.1 to 4.8. We located hypocentres by using a refined 1D crustal velocity model. The majority of the hypocenters are located beneath the axes of the Apenninic chain, while the <span class="hlt">seismic</span> activity observed along the peri-Tyrrhenian margin is lower. The <span class="hlt">seismicity</span> extends to a depth of 32 km; the hypocentral depth distribution exhibits a pronounced peak of <span class="hlt">seismic</span> energy <span class="hlt">release</span> in the depth range between 8 and 20 km. During the observation period we recorded two major <span class="hlt">seismic</span> swarms and one <span class="hlt">seismic</span> sequence in the Marsica-Sorano area in which we have had the largest detected magnitude (ML = 4.8). Fault plane solutions for a total of 600 earthquakes were derived from P-polarities. This new data set consists of a number of focal plane solutions that is about four times the data so far available for regional stress field study. The majority of the focal mechanisms show predominantly normal fault solutions. T-axis trends are oriented NE-SW confirming that the area is in extension. We also derived the azimuths of the principal stress axes by inverting the fault plane solutions and calculated the direction of the maximum horizontal stress, which is mainly sub-vertical oriented. The study region has been historically affected by many strong earthquakes, some of them very destructive. This work can give an important contribution to the <span class="hlt">seismic</span> hazard assessment in an area densely populated as the city of Rome which is distant around 60 km from the main seismogenic structures of Central Apennine.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMNH13A1139D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMNH13A1139D"><span>Solar-terrestrial effect controls <span class="hlt">seismic</span> activity to a large extent (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Duma, G.</p> <p>2010-12-01</p> <p>Several observational results and corresponding publications in the 20 century indicate that earthquakes in many regions happen systematically in dependence on the time of day and on the season as well. In the recent decade, studies on this topic have also been intensively performed at the Central Institute for Meteorology and Geodynamics (ZAMG), Vienna. Any natural effect on Earth which systematically appears at certain hours of the day or at a special season can solely be caused by a solar or lunar influence. And actually, statistic results on <span class="hlt">seismic</span> activity reveal a correlation with the solar cycles. Examples of this <span class="hlt">seismic</span> performance are shown. To gain more clarity about these effects, the three-hour magnetic index Kp, which characterizes the magnetic field disturbances, mainly caused by the solar particle radiation, the solar wind, was correlated with the <span class="hlt">seismic</span> energy <span class="hlt">released</span> by earthquakes over decades. Kp is determined from magnetic records of 13 observatories worldwide and continuously published by ISGI, France. It is demonstrated that a highly significant correlation between the geomagnetic index Kp and the annual <span class="hlt">seismic</span> energy <span class="hlt">release</span> in regions at latitudes between 35 and 60° N exists. Three regions of continental size were investigated, using the USGS (PDE) earthquake catalogue data. In the period 1974-2009 the Kp cycle periods range between 9 and 12 years, somewhat different to the sunspot number cycles of 11 years. <span class="hlt">Seismicity</span> follows the Kp cycles with high coincidence. A detailed analysis of this correlation for N-America reveals, that the sum of <span class="hlt">released</span> energy by earthquakes per year changes by a factor up to 100 with Kp. It is shown that during years of high Kp there happen e.g. 1 event M7, 4 events M6 and 30 events M5 per year, instead of only 10 events M5 in years with lowest Kp. Almost the same relation appears in other regions of continental size, with the same significance. The <span class="hlt">seismicity</span> in S-America clearly follows the Kp cycles</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMMR43B0472V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMMR43B0472V"><span>A Discrete Element Method Approach to Progressive Localization of Damage in Granular Rocks and Associated <span class="hlt">Seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vora, H.; Morgan, J.</p> <p>2017-12-01</p> <p>Brittle failure in rock under confined biaxial conditions is accompanied by <span class="hlt">release</span> of <span class="hlt">seismic</span> energy, known as acoustic emissions (AE). The objective our study is to understand the influence of elastic properties of rock and its stress state on deformation patterns, and associated <span class="hlt">seismicity</span> in granular rocks. Discrete Element Modeling is used to simulate biaxial tests on granular rocks of defined grain size distribution. Acoustic Energy and <span class="hlt">seismic</span> moments are calculated from microfracture events as rock is taken to conditions of failure under different confining pressure states. Dimensionless parameters such as <span class="hlt">seismic</span> b-value and fractal parameter for deformation, D-value, are used to quantify <span class="hlt">seismic</span> character and distribution of damage in rock. Initial results suggest that confining pressure has the largest control on distribution of induced microfracturing, while fracture energy and <span class="hlt">seismic</span> magnitudes are highly sensitive to elastic properties of rock. At low confining pressures, localized deformation (low D-values) and high <span class="hlt">seismic</span> b-values are observed. Deformation at high confining pressures is distributed in nature (high D-values) and exhibit low <span class="hlt">seismic</span> b-values as shearing becomes the dominant mode of microfracturing. <span class="hlt">Seismic</span> b-values and fractal D-values obtained from microfracturing exhibit a linear inverse relationship, similar to trends observed in earthquakes. Mode of microfracturing in our simulations of biaxial compression tests show mechanistic similarities to propagation of fractures and faults in nature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/549187-overview-seismic-potential-central-eastern-united-states','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/549187-overview-seismic-potential-central-eastern-united-states"><span>Overview of <span class="hlt">seismic</span> potential in the central and eastern United States</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Schweig, E.S.</p> <p>1995-12-31</p> <p>The <span class="hlt">seismic</span> potential of any region can be framed in terms the locations of source zones, the frequency of earthquake occurrence for each source, and the maximum size earthquake that can be expect from each source. As delineated by modern and historical <span class="hlt">seismicity</span>, the most important <span class="hlt">seismic</span> source zones affecting the eastern United States include the New Madrid and Wabash Valley <span class="hlt">seismic</span> zones of the central U.S., the southern Appalachians and Charleston, South Carolina, areas in the southeast, and the northern Appalachians and Adirondacks in the northeast. The most prominant of these in terms of current <span class="hlt">seismicity</span> and historical seismicmore » moment <span class="hlt">release</span> in the New Madrid <span class="hlt">seismic</span> zone, which produced three earthquakes of moment magnitude {ge} 8 in 1811 and 1812. The frequency of earthquake recurrence can be examined using the instrumental record, the historical record, and the geological record. Each record covers a unique time period and has a different scale of temporal resolution and completeness of the data set. The Wabash Valley is an example where the long-term geological record indicates a greater potential than the instrumental and historical records. This points to the need to examine all of the evidence in any region in order to obtain a credible estimates of earthquake hazards. Although earthquake hazards may be dominated by mid-magnitude 6 earthquakes within the mapped <span class="hlt">seismic</span> source zones, the 1994 Northridge, California, earthquake is just the most recent example of the danger of assuming future events will occur on faults known to have had past events and how destructive such an earthquake can be.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JSeis..11..453G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JSeis..11..453G"><span><span class="hlt">Seismic</span> hazard assessment of the Province of Murcia (SE Spain): analysis of source contribution to hazard</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>García-Mayordomo, J.; Gaspar-Escribano, J. M.; Benito, B.</p> <p>2007-10-01</p> <p>A probabilistic <span class="hlt">seismic</span> hazard assessment of the Province of Murcia in terms of peak ground <span class="hlt">acceleration</span> (PGA) and spectral <span class="hlt">accelerations</span> [SA( T)] is presented in this paper. In contrast to most of the previous studies in the region, which were performed for PGA making use of intensity-to-PGA relationships, hazard is here calculated in terms of magnitude and using European spectral ground-motion models. Moreover, we have considered the most important faults in the region as specific <span class="hlt">seismic</span> sources, and also comprehensively reviewed the earthquake catalogue. Hazard calculations are performed following the Probabilistic <span class="hlt">Seismic</span> Hazard Assessment (PSHA) methodology using a logic tree, which accounts for three different <span class="hlt">seismic</span> source zonings and three different ground-motion models. Hazard maps in terms of PGA and SA(0.1, 0.2, 0.5, 1.0 and 2.0 s) and coefficient of variation (COV) for the 475-year return period are shown. Subsequent analysis is focused on three sites of the province, namely, the cities of Murcia, Lorca and Cartagena, which are important industrial and tourism centres. Results at these sites have been analysed to evaluate the influence of the different input options. The most important factor affecting the results is the choice of the attenuation relationship, whereas the influence of the selected <span class="hlt">seismic</span> source zonings appears strongly site dependant. Finally, we have performed an analysis of source contribution to hazard at each of these cities to provide preliminary guidance in devising specific risk scenarios. We have found that local source zones control the hazard for PGA and SA( T ≤ 1.0 s), although contribution from specific fault sources and long-distance north Algerian sources becomes significant from SA(0.5 s) onwards.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70037251','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70037251"><span>The influence of maximum magnitude on <span class="hlt">seismic</span>-hazard estimates in the Central and Eastern United States</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Mueller, C.S.</p> <p>2010-01-01</p> <p>I analyze the sensitivity of <span class="hlt">seismic</span>-hazard estimates in the central and eastern United States (CEUS) to maximum magnitude (mmax) by exercising the U.S. Geological Survey (USGS) probabilistic hazard model with several mmax alternatives. <span class="hlt">Seismicity</span>-based sources control the hazard in most of the CEUS, but data seldom provide an objective basis for estimating mmax. The USGS uses preferred mmax values of moment magnitude 7.0 and 7.5 for the CEUS craton and extended margin, respectively, derived from data in stable continental regions worldwide. Other approaches, for example analysis of local <span class="hlt">seismicity</span> or judgment about a source's seismogenic potential, often lead to much smaller mmax. Alternative models span the mmax ranges from the 1980s Electric Power Research Institute/<span class="hlt">Seismicity</span> Owners Group (EPRI/SOG) analysis. Results are presented as haz-ard ratios relative to the USGS national <span class="hlt">seismic</span> hazard maps. One alternative model specifies mmax equal to moment magnitude 5.0 and 5.5 for the craton and margin, respectively, similar to EPRI/SOG for some sources. For 2% probability of exceedance in 50 years (about 0.0004 annual probability), the strong mmax truncation produces hazard ratios equal to 0.35-0.60 for 0.2-sec spectral <span class="hlt">acceleration</span>, and 0.15-0.35 for 1.0-sec spectral <span class="hlt">acceleration</span>. Hazard-controlling earthquakes interact with mmax in complex ways. There is a relatively weak dependence on probability level: hazardratios increase 0-15% for 0.002 annual exceedance probability and decrease 5-25% for 0.00001 annual exceedance probability. Although differences at some sites are tempered when faults are added, mmax clearly accounts for some of the discrepancies that are seen in comparisons between USGS-based and EPRI/SOG-based hazard results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014acm..conf..595Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014acm..conf..595Y"><span>Experimental study on the impact-induced <span class="hlt">seismic</span> wave propagating through granular materials: Implications for a future asteroid mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yasui, M.; Matsumoto, E.; Arakawa, M.; Matsue, K.; Kobayashi, N.</p> <p>2014-07-01</p> <p> with a diameter of 10 mm and a height of 10 mm, and stainless steel and alumina balls with a diameter of 3 mm. The stainless steel and alumina projectiles were <span class="hlt">accelerated</span> with a sabot made of polyethylene. The impact velocity was from 20 to 100 m/s. The target was a non-cohesive glass bead with a mean particle diameter of 200 μ m prepared by putting the particles into a container with a diameter of 300 mm and a height of 100 mm, up to 80 mm depth. The target porosity was about 40%. A chamber that we set the target in was evacuated below 1000 Pa. Three accelerometers (response frequency < 10 kHz) were set on the target surface at different distances from the impact point. The observed <span class="hlt">seismic</span> waves were recorded on a data logger (A/D conversion rate 100 kHz). Experimental results: First, we examined the propagation velocity of the <span class="hlt">seismic</span> wave by using the traveling time from the impact point to the site of the accelerometer, then the impact velocity was obtained to be 105 ± 15 m/s. Next, we discovered that the maximum <span class="hlt">acceleration</span>, g_max, had a good relationship to the normalized distance, x/R (x: distance from impact point, R: crater radius) and it was fitted by the following equation, g_max=268(x/R)^{-2.8}, irrespective of projectile types. These results mean that the <span class="hlt">seismic</span> wave attenuates with a similar waveform scaled by the crater radius on the same target. The duration keeping the maximum <span class="hlt">acceleration</span> was measured to have a half width of g_max peak on the waveform, and it was estimated to be ˜0.3 ms. This value is almost consistent with the penetration time of projectiles estimated by the model proposed by Niimi et al. (2011). McGarr et al. (1969) studied the momentum conversion efficiency from the projectile momentum to the target momentum transferred by the <span class="hlt">seismic</span> wave and obtained it as the ratio of the momentum calculated by the particle motion, I, to the projectile momentum, I_p. In our study, the I/I_p was obtained to be 0.23-1.56. This range was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH53B1995D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH53B1995D"><span>Single station monitoring of volcanoes using <span class="hlt">seismic</span> ambient noise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De Plaen, R. S.; Lecocq, T.; Caudron, C.; Ferrazzini, V.; Francis, O.</p> <p>2016-12-01</p> <p>During volcanic eruptions, magma transport causes gas <span class="hlt">release</span>, pressure perturbations and fracturing in the plumbing system. The potential subsequent surface deformation that can be detected using geodetic techniques and deep mechanical processes associated with magma pressurization and/or migration and their spatial-temporal evolution can be monitored with volcanic <span class="hlt">seismicity</span>. However, these techniques respectively suffer from limited sensitivity to deep changes and a too short-term temporal distribution to expose early aseismic processes such as magma pressurisation. <span class="hlt">Seismic</span> ambient noise cross-correlation uses the multiple scattering of <span class="hlt">seismic</span> vibrations by heterogeneities in the crust to retrieves the Green's function for surface waves between two stations by cross-correlating these diffuse wavefields. <span class="hlt">Seismic</span> velocity changes are then typically measured from the cross-correlation functions with applications for volcanoes, large magnitude earthquakes in the far field and smaller magnitude earthquakes at smaller distances. This technique is increasingly used as a non-destructive way to continuously monitor small <span class="hlt">seismic</span> velocity changes ( 0.1%) associated with volcanic activity, although it is usually limited to volcanoes equipped with large and dense networks of broadband stations. The single-station approach may provide a powerful and reliable alternative to the classical "cross-stations" approach when measuring variation of <span class="hlt">seismic</span> velocities. We implemented it on the Piton de la Fournaise in Reunion Island, a very active volcano with a remarkable multi-disciplinary continuous monitoring. Over the past decade, this volcano was increasingly studied using the traditional cross-station approach and therefore represents a unique laboratory to validate our approach. Our results, tested on stations located up to 3.5 km from the eruptive site, performed as well as the classical approach to detect the volcanic eruption in the 1-2 Hz frequency band. This opens new</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.4559K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.4559K"><span>Are <span class="hlt">seismic</span> hazard assessment errors and earthquake surprises unavoidable?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kossobokov, Vladimir</p> <p>2013-04-01</p> <p>Why earthquake occurrences bring us so many surprises? The answer seems evident if we review the relationships that are commonly used to assess <span class="hlt">seismic</span> hazard. The time-span of physically reliable <span class="hlt">Seismic</span> History is yet a small portion of a rupture recurrence cycle at an earthquake-prone site, which makes premature any kind of reliable probabilistic statements about narrowly localized <span class="hlt">seismic</span> hazard. Moreover, <span class="hlt">seismic</span> evidences accumulated to-date demonstrate clearly that most of the empirical relations commonly accepted in the early history of instrumental seismology can be proved erroneous when testing statistical significance is applied. <span class="hlt">Seismic</span> events, including mega-earthquakes, cluster displaying behaviors that are far from independent or periodic. Their distribution in space is possibly fractal, definitely, far from uniform even in a single segment of a fault zone. Such a situation contradicts generally accepted assumptions used for analytically tractable or computer simulations and complicates design of reliable methodologies for realistic earthquake hazard assessment, as well as search and definition of precursory behaviors to be used for forecast/prediction purposes. As a result, the conclusions drawn from such simulations and analyses can MISLEAD TO SCIENTIFICALLY GROUNDLESS APPLICATION, which is unwise and extremely dangerous in assessing expected societal risks and losses. For example, a systematic comparison of the GSHAP peak ground <span class="hlt">acceleration</span> estimates with those related to actual strong earthquakes, unfortunately, discloses gross inadequacy of this "probabilistic" product, which appears UNACCEPTABLE FOR ANY KIND OF RESPONSIBLE <span class="hlt">SEISMIC</span> RISK EVALUATION AND KNOWLEDGEABLE DISASTER PREVENTION. The self-evident shortcomings and failures of GSHAP appeals to all earthquake scientists and engineers for an urgent revision of the global <span class="hlt">seismic</span> hazard maps from the first principles including background methodologies involved, such that there becomes: (a) a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812496H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812496H"><span>Analysis of the <span class="hlt">seismic</span> signals generated by controlled single-block rockfalls on soft clay shales sediments: the Rioux Bourdoux slope experiment (French Alps).</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hibert, Clément; Provost, Floriane; Malet, Jean-Philippe; Bourrier, Franck; Berger, Frédéric; Bornemann, Pierrick; Borgniet, Laurent; Tardif, Pascal; Mermin, Eric</p> <p>2016-04-01</p> <p>Understanding the dynamics of rockfalls is critical to mitigate the associated hazards but is made very difficult by the nature of these natural disasters that makes them hard to observe directly. Recent advances in seismology allow to determine the dynamics of the largest landslides on Earth from the very low-frequency <span class="hlt">seismic</span> waves they generate. However, the vast majority of rockfalls that occur worldwide are too small to generate such low-frequency <span class="hlt">seismic</span> waves and thus these methods cannot be used to reconstruct their dynamics. However, if <span class="hlt">seismic</span> sensors are close enough, these events will generate high-frequency <span class="hlt">seismic</span> signals. Unfortunately we cannot yet use these high-frequency <span class="hlt">seismic</span> records to infer parameters synthetizing the rockfall dynamics as the source of these waves is not well understood. One of the first steps towards understanding the physical processes involved in the generation of high-frequency <span class="hlt">seismic</span> waves by rockfalls is to study the link between the dynamics of a single block propagating along a well-known path and the features of the <span class="hlt">seismic</span> signal generated. We conducted controlled <span class="hlt">releases</span> of single blocks of limestones in a gully of clay-shales (e.g. black marls) in the Rioux Bourdoux torrent (French Alps). 28 blocks, with masses ranging from 76 kg to 472 kg, were <span class="hlt">released</span>. A monitoring network combining high-velocity cameras, a broadband seismometer and an array of 4 high-frequency seismometers was deployed near the <span class="hlt">release</span> area and along the travel path. The high-velocity cameras allow to reconstruct the 3D trajectories of the blocks, to estimate their velocities and the position of the different impacts with the slope surface. These data are compared to the <span class="hlt">seismic</span> signals recorded. As the distance between the block and the <span class="hlt">seismic</span> sensors at the time of each impact is known, we can determine the associated <span class="hlt">seismic</span> signal amplitude corrected from propagation and attenuation effects. We can further compare the velocity, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S13D4490N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S13D4490N"><span>Angola <span class="hlt">Seismicity</span> MAP</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neto, F. A. P.; Franca, G.</p> <p>2014-12-01</p> <p>The purpose of this job was to study and document the Angola natural <span class="hlt">seismicity</span>, establishment of the first database <span class="hlt">seismic</span> data to facilitate consultation and search for information on <span class="hlt">seismic</span> activity in the country. The study was conducted based on query reports produced by National Institute of Meteorology and Geophysics (INAMET) 1968 to 2014 with emphasis to the work presented by Moreira (1968), that defined six seismogenic zones from macro <span class="hlt">seismic</span> data, with highlighting is Zone of Sá da Bandeira (Lubango)-Chibemba-Oncócua-Iona. This is the most important of Angola <span class="hlt">seismic</span> zone, covering the epicentral Quihita and Iona regions, geologically characterized by transcontinental structure tectono-magmatic activation of the Mesozoic with the installation of a wide variety of intrusive rocks of ultrabasic-alkaline composition, basic and alkaline, kimberlites and carbonatites, strongly marked by intense tectonism, presenting with several faults and fractures (locally called corredor de Lucapa). The earthquake of May 9, 1948 reached intensity VI on the Mercalli-Sieberg scale (MCS) in the locality of Quihita, and <span class="hlt">seismic</span> active of Iona January 15, 1964, the main shock hit the grade VI-VII. Although not having significant <span class="hlt">seismicity</span> rate can not be neglected, the other five zone are: Cassongue-Ganda-Massano de Amorim; Lola-Quilengues-Caluquembe; Gago Coutinho-zone; Cuima-Cachingues-Cambândua; The Upper Zambezi zone. We also analyzed technical reports on the <span class="hlt">seismicity</span> of the middle Kwanza produced by Hidroproekt (GAMEK) region as well as international <span class="hlt">seismic</span> bulletins of the International Seismological Centre (ISC), United States Geological Survey (USGS), and these data served for instrumental location of the epicenters. All compiled information made possible the creation of the First datbase of <span class="hlt">seismic</span> data for Angola, preparing the map of <span class="hlt">seismicity</span> with the reconfirmation of the main <span class="hlt">seismic</span> zones defined by Moreira (1968) and the identification of a new <span class="hlt">seismic</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983PhDT........44S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983PhDT........44S"><span>Strain <span class="hlt">release</span> along ocean transform faults</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stewart, L. M.</p> <p></p> <p>A global study of the nature of <span class="hlt">seismic</span> rupture along oceanic transform faults (TFs) is presented, and many aspects of fault behavior and Mid-Ocean Ridge processes are discussed. A classification of TF earthquakes is developed based on their relative excitation of short period body waves to long period surface waves. Since the ways in which transform faults <span class="hlt">release</span> their accumulated strain varies, for more than 50 earthquakes occurring on 30 TFs since 1963 form the database for a comparison of rupture processes. The variation of TF rupture processes is not related to spreading rate or TF offset. A study of <span class="hlt">seismicity</span> of the Eltanin Fracture Zone system shows that unlike many TFs, the Eltanin FZ realizes more than 90% of its slip aseismically. This identifies a major portion of plate boundary whose motion persists undetected by <span class="hlt">seismic</span> instruments. The global variations in rupture patterns are discussed in terms of current models of fault behavior. The versatility of the asperity model accommodates the entire range of observed patterns. Variations in physical properties within TF contact zones (asperities) are documented in the petrology and geochemistry of rocks from ophiolite sections and TFs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70003857','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70003857"><span>Recent faulting in western Nevada revealed by multi-scale <span class="hlt">seismic</span> reflection</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Frary, Roxanna N.; Louie, John N.; Stephenson, William J.; Odum, Jackson K.; Kell, Annie; Eisses, Amy; Kent, Graham M.; Driscoll, Neal W.; Karlin, Robert; Baskin, Robert L.; Pullammanappallil, Satish; Liberty, Lee M.</p> <p>2011-01-01</p> <p>The main goal of this study is to compare different reflection methods used to image subsurface structure within different physical environments in western Nevada. With all the methods employed, the primary goal is fault imaging for structural information toward geothermal exploration and <span class="hlt">seismic</span> hazard estimation. We use <span class="hlt">seismic</span> CHIRP (a swept-frequency marine acquisition system), weight drop (an <span class="hlt">accelerated</span> hammer source), and two different vibroseis systems to characterize fault structure. We focused our efforts in the Reno metropolitan area and the area within and surrounding Pyramid Lake in northern Nevada. These different methods have provided valuable constraints on the fault geometry and activity, as well as associated fluid movement. These are critical in evaluating the potential for large earthquakes in these areas, and geothermal exploration possibilities near these structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70033959','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70033959"><span>Recent faulting in western Nevada revealed by multi-scale <span class="hlt">seismic</span> reflection</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Frary, R.N.; Louie, J.N.; Stephenson, W.J.; Odum, J.K.; Kell, A.; Eisses, A.; Kent, G.M.; Driscoll, N.W.; Karlin, R.; Baskin, R.L.; Pullammanappallil, S.; Liberty, L.M.</p> <p>2011-01-01</p> <p>The main goal of this study is to compare different reflection methods used to image subsurface structure within different physical environments in western Nevada. With all the methods employed, the primary goal is fault imaging for structural information toward geothermal exploration and <span class="hlt">seismic</span> hazard estimation. We use <span class="hlt">seismic</span> CHIRP a swept-frequency marine acquisition system, weight drop an <span class="hlt">accelerated</span> hammer source, and two different vibroseis systems to characterize fault structure. We focused our efforts in the Reno metropolitan area and the area within and surrounding Pyramid Lake in northern Nevada. These different methods have provided valuable constraints on the fault geometry and activity, as well as associated fluid movement. These are critical in evaluating the potential for large earthquakes in these areas, and geothermal exploration possibilities near these structures. ?? 2011 Society of Exploration Geophysicists.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S13A2527Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S13A2527Z"><span>An integrated analysis on source parameters, seismogenic structure and <span class="hlt">seismic</span> hazard of the 2014 Ms 6.3 Kangding earthquake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zheng, Y.</p> <p>2016-12-01</p> <p>On November 22, 2014, the Ms6.3 Kangding earthquake ended 30 years of history of no strong earthquake at the Xianshuihe fault zone. The focal mechanism and centroid depth of the Kangding earthquake are inverted by teleseismic waveforms and regional seismograms with CAP method. The result shows that the two nodal planes of focal mechanism are 235°/82°/-173° and 144°/83°/-8° respectively, the latter nodal plane should be the ruptured fault plane with a focal depth of 9 km. The rupture process model of the Kangding earthquake is obtained by joint inversion of teleseismic data and regional seismograms. The Kangding earthquake is a bilateral earthquake, and the major rupture zone is within a depth range of 5-15 km, spanning 10 km and 12 km along dip and strike directions, and maximum slip is about 0.5m. Most <span class="hlt">seismic</span> moment was <span class="hlt">released</span> during the first 5 s and the magnitude is Mw6.01, smaller than the model determined by InSAR data. The discrepancy between co-<span class="hlt">seismic</span> rupture models of the Kangding and its Ms 5.8 aftershock and the InSAR model implies significant afterslip deformation occurred in the two weeks after the mainshock. The afterslip <span class="hlt">released</span> energy equals to an Mw5.9 earthquake and mainly concentrates in the northwest side and the shallower side to the rupture zone. The CFS accumulation near the epicenter of the 2014 Kangding earthquake is increased by the 2008 Wenchuan earthquake, implying that the Kangding earthquake could be triggered by the Wenchuan earthquake. The CFS at the northwest section of the <span class="hlt">seismic</span> gap along the Kangding-daofu segment is increased by the Kanding earthquake, and the rupture slip of the Kangding earthquake sequence is too small to <span class="hlt">release</span> the accumulated strain in the <span class="hlt">seismic</span> gap. Consequently, the northwest section of the Kangding-daofu <span class="hlt">seismic</span> gap is under high <span class="hlt">seismic</span> hazard in the future.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998Tectp.289..239C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998Tectp.289..239C"><span>Induced <span class="hlt">seismicity</span> and the potential for liability under U.S. law</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cypser, Darlene A.; Davis, Scott D.</p> <p>1998-04-01</p> <p> United States owners of land owe a duty of lateral support to adjacent landowners, and, in some states, mineral estate owners and lessees owe a duty of subjacent support to the surface owners. Failure to meet those duties of support can result in liability. <span class="hlt">Seismicity</span> induced by one source might <span class="hlt">accelerate</span> failure of support originating from another source, leaving both of the parties at fault proportionally liable to the injured parties. Geoscientists can use their roles as investigators, educators and advisors to help companies in the petroleum, mining and geothermal fields avoid liability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S51A2320F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S51A2320F"><span><span class="hlt">Seismic</span> Noise Analysis and Reduction through Utilization of Collocated <span class="hlt">Seismic</span> and Atmospheric Sensors at the GRO Chile <span class="hlt">Seismic</span> Network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farrell, M. E.; Russo, R. M.</p> <p>2013-12-01</p> <p>The installation of Earthscope Transportable Array-style geophysical observatories in Chile expands open data <span class="hlt">seismic</span> recording capabilities in the southern hemisphere by nearly 30%, and has nearly tripled the number of <span class="hlt">seismic</span> stations providing freely-available data in southern South America. Through the use of collocated <span class="hlt">seismic</span> and atmospheric sensors at these stations we are able to analyze how local atmospheric conditions generate <span class="hlt">seismic</span> noise, which can degrade data in <span class="hlt">seismic</span> frequency bands at stations in the ';roaring forties' (S latitudes). <span class="hlt">Seismic</span> vaults that are climate-controlled and insulated from the local environment are now employed throughout the world in an attempt to isolate seismometers from as many noise sources as possible. However, this is an expensive solution that is neither practical nor possible for all <span class="hlt">seismic</span> deployments; and also, the increasing number and scope of temporary <span class="hlt">seismic</span> deployments has resulted in the collection and archiving of terabytes of <span class="hlt">seismic</span> data that is affected to some degree by natural <span class="hlt">seismic</span> noise sources such as wind and atmospheric pressure changes. Changing air pressure can result in a depression and subsequent rebound of Earth's surface - which generates low frequency noise in <span class="hlt">seismic</span> frequency bands - and even moderate winds can apply enough force to ground-coupled structures or to the surface above the seismometers themselves, resulting in significant noise. The 10 stations of the permanent Geophysical Reporting Observatories (GRO Chile), jointly installed during 2011-12 by IRIS and the Chilean Servicio Sismológico, include instrumentation in addition to the standard three <span class="hlt">seismic</span> components. These stations, spaced approximately 300 km apart along the length of the country, continuously record a variety of atmospheric data including infrasound, air pressure, wind speed, and wind direction. The collocated <span class="hlt">seismic</span> and atmospheric sensors at each station allow us to analyze both datasets together, to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GMDD....8.4487G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GMDD....8.4487G"><span>SiSeRHMap v1.0: a simulator for mapped <span class="hlt">seismic</span> response using a hybrid model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grelle, G.; Bonito, L.; Lampasi, A.; Revellino, P.; Guerriero, L.; Sappa, G.; Guadagno, F. M.</p> <p>2015-06-01</p> <p>SiSeRHMap is a computerized methodology capable of drawing up prediction maps of <span class="hlt">seismic</span> response. It was realized on the basis of a hybrid model which combines different approaches and models in a new and non-conventional way. These approaches and models are organized in a code-architecture composed of five interdependent modules. A GIS (Geographic Information System) Cubic Model (GCM), which is a layered computational structure based on the concept of lithodynamic units and zones, aims at reproducing a parameterized layered subsoil model. A metamodeling process confers a hybrid nature to the methodology. In this process, the one-dimensional linear equivalent analysis produces <span class="hlt">acceleration</span> response spectra of shear wave velocity-thickness profiles, defined as trainers, which are randomly selected in each zone. Subsequently, a numerical adaptive simulation model (Spectra) is optimized on the above trainer <span class="hlt">acceleration</span> response spectra by means of a dedicated Evolutionary Algorithm (EA) and the Levenberg-Marquardt Algorithm (LMA) as the final optimizer. In the final step, the GCM Maps Executor module produces a serial map-set of a stratigraphic <span class="hlt">seismic</span> response at different periods, grid-solving the calibrated Spectra model. In addition, the spectra topographic amplification is also computed by means of a numerical prediction model. This latter is built to match the results of the numerical simulations related to isolate reliefs using GIS topographic attributes. In this way, different sets of <span class="hlt">seismic</span> response maps are developed, on which, also maps of <span class="hlt">seismic</span> design response spectra are defined by means of an enveloping technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PApGe.167...63B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PApGe.167...63B"><span>Coal Mining Induced <span class="hlt">Seismicity</span> in the Ruhr Area, Germany</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bischoff, Monika; Cete, Alpan; Fritschen, Ralf; Meier, Thomas</p> <p>2010-02-01</p> <p>Over the last 25 years mining-induced <span class="hlt">seismicity</span> in the Ruhr area has continuously been monitored by the Ruhr-University Bochum. About 1,000 <span class="hlt">seismic</span> events with local magnitudes between 0.7 ≤ M L ≤ 3.3 are located every year. For example, 1,336 events were located in 2006. General characteristics of induced <span class="hlt">seismicity</span> in the entire Ruhr area are spatial and temporal correlation with mining activity and a nearly constant energy <span class="hlt">release</span> per unit time. This suggests that induced stresses are <span class="hlt">released</span> rapidly by many small events. The magnitude-frequency distribution follows a Gutenberg-Richter relation which is a result from combining distributions of single longwalls that themselves show large variability. A high b-value of about 2 was found indicating a lack of large magnitude events. Local analyses of single longwalls indicate that various factors such as local geology and mine layout lead to significant differences in <span class="hlt">seismicity</span>. Stress redistribution acts very locally since differences on a small scale of some hundreds of meters are observed. A regional relation between <span class="hlt">seismic</span> moment M 0 and local magnitude M L was derived. The magnitude-frequency distribution of a single longwall in Hamm was studied in detail and shows a maximum at M L = 1.4 corresponding to an estimated characteristic source area of about 2,200 m2. Sandstone layers in the hanging or foot wall of the active longwall might fail in these characteristic events. Source mechanisms can mostly be explained by shear failure of two different types above and below the longwall. Fault plane solutions of typical events are consistent with steeply dipping fracture planes parallel to the longwall face and nearly vertical dislocation in direction towards the goaf. We also derive an empirical relation for the decay of ground velocity with epicenter distance and compare maximum observed ground velocity to local magnitude. This is of considerable public interest because about 30 events larger than M L ≥ 1</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSeis..21.1067D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSeis..21.1067D"><span>Probabilistic <span class="hlt">seismic</span> hazard assessment for the two layer fault system of Antalya (SW Turkey) area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dipova, Nihat; Cangir, Bülent</p> <p>2017-09-01</p> <p>Southwest Turkey, along Mediterranean coast, is prone to large earthquakes resulting from subduction of the African plate under the Eurasian plate and shallow crustal faults. Maximum observed magnitude of subduction earthquakes is Mw = 6.5 whereas that of crustal earthquakes is Mw = 6.6. Crustal earthquakes are sourced from faults which are related with Isparta Angle and Cyprus Arc tectonic structures. The primary goal of this study is to assess <span class="hlt">seismic</span> hazard for Antalya area (SW Turkey) using a probabilistic approach. A new earthquake catalog for Antalya area, with unified moment magnitude scale, was prepared in the scope of the study. <span class="hlt">Seismicity</span> of the area has been evaluated by the Gutenberg-Richter recurrence relationship. For hazard computation, CRISIS2007 software was used following the standard Cornell-McGuire methodology. Attenuation model developed by Youngs et al. Seismol Res Lett 68(1):58-73, (1997) was used for deep subduction earthquakes and Chiou and Youngs Earthq Spectra 24(1):173-215, (2008) model was used for shallow crustal earthquakes. A <span class="hlt">seismic</span> hazard map was developed for peak ground <span class="hlt">acceleration</span> and for rock ground with a hazard level of a 10% probability of exceedance in 50 years. Results of the study show that peak ground <span class="hlt">acceleration</span> values on bedrock change between 0.215 and 0.23 g in the center of Antalya.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRF..117.3004C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRF..117.3004C"><span><span class="hlt">Seismic</span> multiplet response triggered by melt at Blood Falls, Taylor Glacier, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carmichael, Joshua D.; Pettit, Erin C.; Hoffman, Matt; Fountain, Andrew; Hallet, Bernard</p> <p>2012-09-01</p> <p>Meltwater input often triggers a <span class="hlt">seismic</span> response from glaciers and ice sheets. It is difficult, however, to measure melt production on glaciers directly, while subglacial water storage is not directly observable. Therefore, we document temporal changes in <span class="hlt">seismicity</span> from a dry-based polar glacier (Taylor Glacier, Antarctica) during a melt season using a synthesis of <span class="hlt">seismic</span> observation and melt modeling. We record icequakes using a dense six-receiver network of three-component geophones and compare this with melt input generated from a calibrated surface energy balance model. In the absence of modeled surface melt, we find that <span class="hlt">seismicity</span> is well-described by a diurnal signal composed of microseismic events in lake and glacial ice. During melt events, the diurnal signal is suppressed and <span class="hlt">seismicity</span> is instead characterized by large glacial icequakes. We perform network-based correlation and clustering analyses of <span class="hlt">seismic</span> record sections and determine that 18% of melt-season icequakes are repetitive (multiplets). The epicentral locations for these multiplets suggest that they are triggered by meltwater produced near a brine seep known as Blood Falls. Our observations of the correspondingp-wave first motions are consistent with volumetric source mechanisms. We suggest that surface melt enables a persistent pathway through this cold ice to an englacial fracture system that is responsible for brine <span class="hlt">release</span> episodes from the Blood Falls seep. The scalar moments for these events suggest that the volumetric increase at the source region can be explained by melt input.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70023365','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70023365"><span><span class="hlt">Seismic</span> hazard in Hawaii: High rate of large earthquakes and probabilistics ground-motion maps</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Klein, F.W.; Frankel, A.D.; Mueller, C.S.; Wesson, R.L.; Okubo, P.G.</p> <p>2001-01-01</p> <p>The <span class="hlt">seismic</span> hazard and earthquake occurrence rates in Hawaii are locally as high as that near the most hazardous faults elsewhere in the United States. We have generated maps of peak ground <span class="hlt">acceleration</span> (PGA) and spectral <span class="hlt">acceleration</span> (SA) (at 0.2, 0.3 and 1.0 sec, 5% critical damping) at 2% and 10% exceedance probabilities in 50 years. The highest hazard is on the south side of Hawaii Island, as indicated by the MI 7.0, MS 7.2, and MI 7.9 earthquakes, which occurred there since 1868. Probabilistic values of horizontal PGA (2% in 50 years) on Hawaii's south coast exceed 1.75g. Because some large earthquake aftershock zones and the geometry of flank blocks slipping on subhorizontal decollement faults are known, we use a combination of spatially uniform sources in active flank blocks and smoothed <span class="hlt">seismicity</span> in other areas to model <span class="hlt">seismicity</span>. Rates of earthquakes are derived from magnitude distributions of the modem (1959-1997) catalog of the Hawaiian Volcano Observatory's <span class="hlt">seismic</span> network supplemented by the historic (1868-1959) catalog. Modern magnitudes are ML measured on a Wood-Anderson seismograph or MS. Historic magnitudes may add ML measured on a Milne-Shaw or Bosch-Omori seismograph or MI derived from calibrated areas of MM intensities. Active flank areas, which by far account for the highest hazard, are characterized by distributions with b slopes of about 1.0 below M 5.0 and about 0.6 above M 5.0. The kinked distribution means that large earthquake rates would be grossly under-estimated by extrapolating small earthquake rates, and that longer catalogs are essential for estimating or verifying the rates of large earthquakes. Flank earthquakes thus follow a semicharacteristic model, which is a combination of background <span class="hlt">seismicity</span> and an excess number of large earthquakes. Flank earthquakes are geometrically confined to rupture zones on the volcano flanks by barriers such as rift zones and the seaward edge of the volcano, which may be expressed by a magnitude</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EEEV...16..487L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EEEV...16..487L"><span>Accuracy of three-dimensional <span class="hlt">seismic</span> ground response analysis in time domain using nonlinear numerical simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, Fayun; Chen, Haibing; Huang, Maosong</p> <p>2017-07-01</p> <p>To provide appropriate uses of nonlinear ground response analysis for engineering practice, a three-dimensional soil column with a distributed mass system and a time domain numerical analysis were implemented on the OpenSees simulation platform. The standard mesh of a three-dimensional soil column was suggested to be satisfied with the specified maximum frequency. The layered soil column was divided into multiple sub-soils with a different viscous damping matrix according to the shear velocities as the soil properties were significantly different. It was necessary to use a combination of other one-dimensional or three-dimensional nonlinear <span class="hlt">seismic</span> ground analysis programs to confirm the applicability of nonlinear <span class="hlt">seismic</span> ground motion response analysis procedures in soft soil or for strong earthquakes. The accuracy of the three-dimensional soil column finite element method was verified by dynamic centrifuge model testing under different peak <span class="hlt">accelerations</span> of the earthquake. As a result, nonlinear <span class="hlt">seismic</span> ground motion response analysis procedures were improved in this study. The accuracy and efficiency of the three-dimensional <span class="hlt">seismic</span> ground response analysis can be adapted to the requirements of engineering practice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1612959G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1612959G"><span>Pyroclast <span class="hlt">acceleration</span> and energy partitioning in fake explosive eruptions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gaudin, Damien; Taddeucci, Jacopo; Scheu, Bettina; Valentine, Greg; Capponi, Antonio; Kueppers, Ulrich; Graettiger, Allison; Sonder, Ingo</p> <p>2014-05-01</p> <p>Explosive eruptions are characterized by the fast <span class="hlt">release</span> of energy, with gas expansion playing a lead role. An excess of pressure may be generated either by the exsolution and accumulation of volatiles (e.g., vulcanian and strombolian explosions) or by in situ vaporization of water (e.g., phreato-magmatic explosions). The <span class="hlt">release</span> of pressurized gas ejects magma and country rock pyroclasts at velocities that can reach several hundred of meters per second. The amount and velocity of pyroclasts is determined not only by the total <span class="hlt">released</span> energy, but also by the system-specific dynamics of the energy transfer from gas to pyroclasts. In this context, analogue experiments are crucial, since the amount of available energy is determined. Here, we analyze three different experiments, designed to reproduce different aspects of explosive volcanism, focusing on the <span class="hlt">acceleration</span> phase of the pyroclasts, in order to compare how the potential energy is transferred to the pyroclasts in different systems. In the first, shock-tube-type experiment, salt crystals resting in a pressurized Plexiglas cylinder are <span class="hlt">accelerated</span> when a diaphragm set is suddenly opened, <span class="hlt">releasing</span> the gas. In the second experiment, a pressurized air bubble is <span class="hlt">released</span> in a water-filled Plexiglas pipe; diaphragm opening causes sudden expansion and bursting of the bubble and ejection of water droplets. In the last experiment, specifically focusing on phreatomagmatic eruptions, buried explosive charges <span class="hlt">accelerate</span> the overlying loose material. All experiments were monitored by multiple high speed cameras and a variety of sensors. Despite the largely differing settings and processes, particle ejection velocity above the vent from the three experiments share a non-linear decay over time. Fitting this decay allows to estimate a characteristic depth that is related to the specific <span class="hlt">acceleration</span> processes. Given that the initial available energy is experimentally controlled a priori, the information on the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812319K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812319K"><span>Evaluation of induced <span class="hlt">seismicity</span> forecast models in the Induced <span class="hlt">Seismicity</span> Test Bench</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Király, Eszter; Gischig, Valentin; Zechar, Jeremy; Doetsch, Joseph; Karvounis, Dimitrios; Wiemer, Stefan</p> <p>2016-04-01</p> <p>Induced earthquakes often accompany fluid injection, and the <span class="hlt">seismic</span> hazard they pose threatens various underground engineering projects. Models to monitor and control induced <span class="hlt">seismic</span> hazard with traffic light systems should be probabilistic, forward-looking, and updated as new data arrive. Here, we propose an Induced <span class="hlt">Seismicity</span> Test Bench to test and rank such models. We apply the test bench to data from the Basel 2006 and Soultz-sous-Forêts 2004 geothermal stimulation projects, and we assess forecasts from two models that incorporate a different mix of physical understanding and stochastic representation of the induced sequences: Shapiro in Space (SiS) and Hydraulics and <span class="hlt">Seismics</span> (HySei). SiS is based on three pillars: the <span class="hlt">seismicity</span> rate is computed with help of the seismogenic index and a simple exponential decay of the <span class="hlt">seismicity</span>; the magnitude distribution follows the Gutenberg-Richter relation; and <span class="hlt">seismicity</span> is distributed in space based on smoothing <span class="hlt">seismicity</span> during the learning period with 3D Gaussian kernels. The HySei model describes <span class="hlt">seismicity</span> triggered by pressure diffusion with irreversible permeability enhancement. Our results show that neither model is fully superior to the other. HySei forecasts the <span class="hlt">seismicity</span> rate well, but is only mediocre at forecasting the spatial distribution. On the other hand, SiS forecasts the spatial distribution well but not the <span class="hlt">seismicity</span> rate. The shut-in phase is a difficult moment for both models in both reservoirs: the models tend to underpredict the <span class="hlt">seismicity</span> rate around, and shortly after, shut-in. Ensemble models that combine HySei's rate forecast with SiS's spatial forecast outperform each individual model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70025504','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70025504"><span>Post-<span class="hlt">seismic</span> relaxation theory on laterally heterogeneous viscoelastic model</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pollitz, F.F.</p> <p>2003-01-01</p> <p>Investigation was carried out into the problem of relaxation of a laterally heterogeneous viscoelastic Earth following an impulsive moment <span class="hlt">release</span> event. The formal solution utilizes a semi-analytic solution for post-<span class="hlt">seismic</span> deformation on a laterally homogeneous Earth constructed from viscoelastic normal modes, followed by application of mode coupling theory to derive the response on the aspherical Earth. The solution is constructed in the Laplace transform domain using the correspondence principle and is valid for any linear constitutive relationship between stress and strain. The specific implementation described in this paper is a semi-analytic discretization method which assumes isotropic elastic structure and a Maxwell constitutive relation. It accounts for viscoelastic-gravitational coupling under lateral variations in elastic parameters and viscosity. For a given viscoelastic structure and minimum wavelength scale, the computational effort involved with the numerical algorithm is proportional to the volume of the laterally heterogeneous region. Examples are presented of the calculation of post-<span class="hlt">seismic</span> relaxation with a shallow, laterally heterogeneous volume following synthetic impulsive <span class="hlt">seismic</span> events, and they illustrate the potentially large effect of regional 3-D heterogeneities on regional deformation patterns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.3680R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.3680R"><span><span class="hlt">Seismic</span> monitoring of the unstable rock slope at Aaknes, Norway</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roth, M.; Blikra, L. H.</p> <p>2009-04-01</p> <p>The unstable rock slope at Aaknes has an estimated volume of about 70 million cubic meters, and parts of the slope are moving at a rate between 2-15 cm/year. Amongst many other direct monitoring systems we have installed a small-scale <span class="hlt">seismic</span> network (8 three-component geophones over an area of 250 x 150 meters) in order to monitor microseismic events related to the movement of the slope. The network has been operational since November 2005 with only a few short-term outages. <span class="hlt">Seismic</span> data are transferred in real-time from the site to NORSAR for automatic detection processing. The resulting detection lists and charts and the associated waveform are forwarded immediately to the early warning centre of the Municipality of Stranda. Furthermore, we make them available after a delay of about 10-15 minutes on our public project web page (http://www.norsar.no/pc-47-48-Latest-Data.aspx). <span class="hlt">Seismic</span> monitoring provides independent and complementary data to the more direct monitoring systems at Aaknes. We observe increased <span class="hlt">seismic</span> activity in periods of heavy rain fall or snow melt, when laser ranging data and extensometer readings indicate temporary <span class="hlt">acceleration</span> phases of the slope. The <span class="hlt">seismic</span> network is too small and the velocity structure is too heterogeneous in order to obtain reliable localizations of the microseismic events. In summer 2009 we plan to install a high-sensitive broadband seismometer (60 s - 100 Hz) in the middle of the unstable slope. This will allow us to better constrain the locations of the microseismic events and to investigate potential low-frequency signals associated with the slope movement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.4122B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.4122B"><span><span class="hlt">Seismic</span> signature of crustal magma and fluid from deep <span class="hlt">seismic</span> sounding data across Tengchong volcanic area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bai, Z. M.; Zhang, Z. Z.; Wang, C. Y.; Klemperer, S. L.</p> <p>2012-04-01</p> <p>The weakened lithosphere around eastern syntax of Tibet plateau has been revealed by the Average Pn and Sn velocities, the 3D upper mantle velocity variations of P wave and S wave, and the iimaging results of magnetotelluric data. Tengchong volcanic area is neighboring to core of eastern syntax and famous for its springs, volcanic-geothermal activities and remarkable <span class="hlt">seismicity</span> in mainland China. To probe the deep environment for the Tengchong volcanic-geothermal activity a deep <span class="hlt">seismic</span> sounding (DSS) project was carried out across the this area in 1999. In this paper the <span class="hlt">seismic</span> signature of crustal magma and fluid is explored from the DSS data with the <span class="hlt">seismic</span> attribute fusion (SAF) technique, hence four possible positions for magma generation together with some locations for porous and fractured fluid beneath the Tengchong volcanic area were disclosed from the final fusion image of multi <span class="hlt">seismic</span> attributes. The adopted attributes include the Vp, Vs and Vp/Vs results derived from a new inversion method based on the No-Ray-Tomography technique, and the migrated instantaneous attributes of central frequency, bandwidth and high frequency energy of pressure wave. Moreover, the back-projected ones which are mainly consisted by the attenuation factor Qp , the delay-time of shear wave splitting, and the amplitude ratio between S wave and P wave + S wave were also considered in this fusion process. Our fusion image indicates such a mechanism for the surface springs: a large amount of heat and the fluid <span class="hlt">released</span> by the crystallization of magma were transmitted upward into the fluid-filled rock, and the fluid upwells along some pipeline since the high pressure in deep, thus the widespread springs of Tengchong volcanic area were developed. Moreover, the fusion image, regional volcanic and geothermal activities, and the <span class="hlt">seismicity</span> suggest that the main risk of volcanic eruption was concentrated to the south of Tengchong city, especially around the shot point (SP) Tuantian</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PApGe.161.2405Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PApGe.161.2405Y"><span>Load-Unload Response Ratio (LURR), <span class="hlt">Accelerating</span> Moment/Energy <span class="hlt">Release</span> (AM/ER) and State Vector Saltation as Precursors to Failure of Rock Specimens</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yin, Xiang-Chu; Yu, Huai-Zhong; Kukshenko, Victor; Xu, Zhao-Yong; Wu, Zhishen; Li, Min; Peng, Keyin; Elizarov, Surgey; Li, Qi</p> <p>2004-12-01</p> <p>In order to verify some precursors such as LURR (Load/Unload Response Ratio) and AER (<span class="hlt">Accelerating</span> Energy <span class="hlt">Release</span>) before large earthquakes or macro-fracture in heterogeneous brittle media, four acoustic emission experiments involving large rock specimens under tri-axial stress, have been conducted. The specimens were loaded in two ways: monotonous or cycling. The experimental results confirm that LURR and AER are precursors of macro-fracture in brittle media. A new measure called the state vector has been proposed to describe the damage evolution of loaded rock specimens.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29717139','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29717139"><span>Gas and <span class="hlt">seismicity</span> within the Istanbul <span class="hlt">seismic</span> gap.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Géli, L; Henry, P; Grall, C; Tary, J-B; Lomax, A; Batsi, E; Riboulot, V; Cros, E; Gürbüz, C; Işık, S E; Sengör, A M C; Le Pichon, X; Ruffine, L; Dupré, S; Thomas, Y; Kalafat, D; Bayrakci, G; Coutellier, Q; Regnier, T; Westbrook, G; Saritas, H; Çifçi, G; Çağatay, M N; Özeren, M S; Görür, N; Tryon, M; Bohnhoff, M; Gasperini, L; Klingelhoefer, F; Scalabrin, C; Augustin, J-M; Embriaco, D; Marinaro, G; Frugoni, F; Monna, S; Etiope, G; Favali, P; Bécel, A</p> <p>2018-05-01</p> <p>Understanding micro-<span class="hlt">seismicity</span> is a critical question for earthquake hazard assessment. Since the devastating earthquakes of Izmit and Duzce in 1999, the <span class="hlt">seismicity</span> along the submerged section of North Anatolian Fault within the Sea of Marmara (comprising the "Istanbul <span class="hlt">seismic</span> gap") has been extensively studied in order to infer its mechanical behaviour (creeping vs locked). So far, the <span class="hlt">seismicity</span> has been interpreted only in terms of being tectonic-driven, although the Main Marmara Fault (MMF) is known to strike across multiple hydrocarbon gas sources. Here, we show that a large number of the aftershocks that followed the M 5.1 earthquake of July, 25 th 2011 in the western Sea of Marmara, occurred within a zone of gas overpressuring in the 1.5-5 km depth range, from where pressurized gas is expected to migrate along the MMF, up to the surface sediment layers. Hence, gas-related processes should also be considered for a complete interpretation of the micro-<span class="hlt">seismicity</span> (~M < 3) within the Istanbul offshore domain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940013359','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940013359"><span>Generalized <span class="hlt">seismic</span> analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Butler, Thomas G.</p> <p>1993-01-01</p> <p>There is a constant need to be able to solve for enforced motion of structures. Spacecraft need to be qualified for <span class="hlt">acceleration</span> inputs. Truck cargoes need to be safeguarded from road mishaps. Office buildings need to withstand earthquake shocks. Marine machinery needs to be able to withstand hull shocks. All of these kinds of enforced motions are being grouped together under the heading of <span class="hlt">seismic</span> inputs. Attempts have been made to cope with this problem over the years and they usually have ended up with some limiting or compromise conditions. The crudest approach was to limit the problem to <span class="hlt">acceleration</span> occurring only at a base of a structure, constrained to be rigid. The analyst would assign arbitrarily outsized masses to base points. He would then calculate the magnitude of force to apply to the base mass (or masses) in order to produce the specified <span class="hlt">acceleration</span>. He would of necessity have to sacrifice the determination of stresses in the vicinity of the base, because of the artificial nature of the input forces. The author followed the lead of John M. Biggs by using relative coordinates for a rigid base in a 1975 paper, and again in a 1981 paper . This method of relative coordinates was extended and made operational as DMAP ALTER packets to rigid formats 9, 10, 11, and 12 under contract N60921-82-C-0128. This method was presented at the twelfth NASTRAN Colloquium. Another analyst in the field developed a method that computed the forces from enforced motion then applied them as a forcing to the remaining unknowns after the knowns were partitioned off. The method was translated into DMAP ALTER's but was never made operational. All of this activity jelled into the current effort. Much thought was invested in working out ways to unshakle the analysis of enforced motions from the limitations that persisted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993co21.coll...60B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993co21.coll...60B"><span>Generalized <span class="hlt">seismic</span> analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Butler, Thomas G.</p> <p>1993-09-01</p> <p>There is a constant need to be able to solve for enforced motion of structures. Spacecraft need to be qualified for <span class="hlt">acceleration</span> inputs. Truck cargoes need to be safeguarded from road mishaps. Office buildings need to withstand earthquake shocks. Marine machinery needs to be able to withstand hull shocks. All of these kinds of enforced motions are being grouped together under the heading of <span class="hlt">seismic</span> inputs. Attempts have been made to cope with this problem over the years and they usually have ended up with some limiting or compromise conditions. The crudest approach was to limit the problem to <span class="hlt">acceleration</span> occurring only at a base of a structure, constrained to be rigid. The analyst would assign arbitrarily outsized masses to base points. He would then calculate the magnitude of force to apply to the base mass (or masses) in order to produce the specified <span class="hlt">acceleration</span>. He would of necessity have to sacrifice the determination of stresses in the vicinity of the base, because of the artificial nature of the input forces. The author followed the lead of John M. Biggs by using relative coordinates for a rigid base in a 1975 paper, and again in a 1981 paper . This method of relative coordinates was extended and made operational as DMAP ALTER packets to rigid formats 9, 10, 11, and 12 under contract N60921-82-C-0128. This method was presented at the twelfth NASTRAN Colloquium. Another analyst in the field developed a method that computed the forces from enforced motion then applied them as a forcing to the remaining unknowns after the knowns were partitioned off. The method was translated into DMAP ALTER's but was never made operational. All of this activity jelled into the current effort. Much thought was invested in working out ways to unshakle the analysis of enforced motions from the limitations that persisted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983aifo.reptQ....J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983aifo.reptQ....J"><span><span class="hlt">Seismic</span> hazard study for selected sites in New Mexico and Nevada</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnston, J. C.</p> <p>1983-12-01</p> <p><span class="hlt">Seismic</span> hazard evaluations were conducted for specific sites in New Mexico and Nevada. For New Mexico, a model of <span class="hlt">seismicity</span> was developed from historical accounts of medium to large shocks and the current microactivity record from local networks. Ninety percent confidence levels at Albuquerque and Roswell were computed to be 56 gals for a 10-year period and 77 gals for a 20-year period. Values of ground motion for Clovis were below these values. Peak velocity and displacement were also computed for each site. Deterministic spectra based on the estimated maximum credible earthquake for the zones which the sites occupy were also computed. For the sites in Nevada, the regionalizations used in Battis (1982) for the uniform <span class="hlt">seismicity</span> model were slightly modified. For 10- and 20-year time periods, peak <span class="hlt">acceleration</span> values for Indian Springs were computed to be 94 gals and 123 gals and for Hawthorne 206 gals and 268 gals. Deterministic spectra were also computed. The input parameters were well determined for the analysis for the Nevada sites because of the abundance of data. The values computed for New Mexico, however, are likely upper limits. As more data are collected from the area of the Rio Grande rift zone, the pattern of <span class="hlt">seismicity</span> will become better understood. At this time a more detailed, and thus more accurate, model may emerge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSM.S52A..07B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSM.S52A..07B"><span><span class="hlt">Seismic</span> Catalogue and <span class="hlt">Seismic</span> Network in Haiti</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Belizaire, D.; Benito, B.; Carreño, E.; Meneses, C.; Huerfano, V.; Polanco, E.; McCormack, D.</p> <p>2013-05-01</p> <p>The destructive earthquake occurred on January 10, 2010 in Haiti, highlighted the lack of preparedness of the country to address <span class="hlt">seismic</span> phenomena. At the moment of the earthquake, there was no <span class="hlt">seismic</span> network operating in the country, and only a partial control of the past <span class="hlt">seismicity</span> was possible, due to the absence of a national catalogue. After the 2010 earthquake, some advances began towards the installation of a national network and the elaboration of a <span class="hlt">seismic</span> catalogue providing the necessary input for <span class="hlt">seismic</span> Hazard Studies. This paper presents the state of the works carried out covering both aspects. First, a <span class="hlt">seismic</span> catalogue has been built, compiling data of historical and instrumental events occurred in the Hispaniola Island and surroundings, in the frame of the SISMO-HAITI project, supported by the Technical University of Madrid (UPM) and Developed in cooperation with the Observatoire National de l'Environnement et de la Vulnérabilité of Haiti (ONEV). Data from different agencies all over the world were gathered, being relevant the role of the Dominican Republic and Puerto Rico seismological services which provides local data of their national networks. Almost 30000 events recorded in the area from 1551 till 2011 were compiled in a first catalogue, among them 7700 events with Mw ranges between 4.0 and 8.3. Since different magnitude scale were given by the different agencies (Ms, mb, MD, ML), this first catalogue was affected by important heterogeneity in the size parameter. Then it was homogenized to moment magnitude Mw using the empirical equations developed by Bonzoni et al (2011) for the eastern Caribbean. At present, this is the most exhaustive catalogue of the country, although it is difficult to assess its degree of completeness. Regarding the <span class="hlt">seismic</span> network, 3 stations were installed just after the 2010 earthquake by the Canadian Government. The data were sent by telemetry thought the Canadian System CARINA. In 2012, the Spanish IGN together</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1919586F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1919586F"><span>Communication of <span class="hlt">Seismic</span> Risk in the Kyrgyz Republic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fourniadis, Yannis; Free, Matthew; Coates, Katherine; Moldobekov, Bolot; Fleming, Kevin; Parolai, Stefano; Pittore, Massimiliano; Ormukov, Cholponbek; Takeuchi, Ko</p> <p>2017-04-01</p> <p> of challenges were addressed when developing and implementing the risk communication strategy, and these will be discussed in this presentation. This includes the need for the engineering seismology community of the Kyrgyz Republic to reconsider some of the measures used to describe <span class="hlt">seismic</span>, such as the ongoing use of macroseismic intensity instead of such measures as peak ground <span class="hlt">acceleration</span> (PGA).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70029890','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70029890"><span>Probabilistic <span class="hlt">seismic</span> demand analysis using advanced ground motion intensity measures</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Tothong, P.; Luco, N.</p> <p>2007-01-01</p> <p>One of the objectives in performance-based earthquake engineering is to quantify the <span class="hlt">seismic</span> reliability of a structure at a site. For that purpose, probabilistic <span class="hlt">seismic</span> demand analysis (PSDA) is used as a tool to estimate the mean annual frequency of exceeding a specified value of a structural demand parameter (e.g. interstorey drift). This paper compares and contrasts the use, in PSDA, of certain advanced scalar versus vector and conventional scalar ground motion intensity measures (IMs). One of the benefits of using a well-chosen IM is that more accurate evaluations of <span class="hlt">seismic</span> performance are achieved without the need to perform detailed ground motion record selection for the nonlinear dynamic structural analyses involved in PSDA (e.g. record selection with respect to <span class="hlt">seismic</span> parameters such as earthquake magnitude, source-to-site distance, and ground motion epsilon). For structural demands that are dominated by a first mode of vibration, using inelastic spectral displacement (Sdi) can be advantageous relative to the conventionally used elastic spectral <span class="hlt">acceleration</span> (Sa) and the vector IM consisting of Sa and epsilon (??). This paper demonstrates that this is true for ordinary and for near-source pulse-like earthquake records. The latter ground motions cannot be adequately characterized by either Sa alone or the vector of Sa and ??. For structural demands with significant higher-mode contributions (under either of the two types of ground motions), even Sdi (alone) is not sufficient, so an advanced scalar IM that additionally incorporates higher modes is used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AIPC.1020.1563M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AIPC.1020.1563M"><span><span class="hlt">Seismic</span> Rehabilitation of RC Frames by Using Steel Panels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mowrtage, Waiel</p> <p>2008-07-01</p> <p>Every major earthquake in Turkey causes a large number of building suffer moderate damage due to poor construction. If a proper and fast retrofit is not applied, the aftershocks, which may sometimes come days or weeks after the main shock, can push a moderately damaged building into a major damage or even total collapse. This paper presents a practical retrofit method for moderately damaged buildings, which increases the <span class="hlt">seismic</span> performance of the structural system by reducing the displacement demand. Fabricated steel panels are used for the retrofit. They are light-weight, easy to handle, and can be constructed very quickly. Moreover, they are cheap, and do not need formwork or skilled workers. They can be designed to compensate for the stiffness and strength degradation, and to fit easily inside a moderately damaged reinforced concrete frame. To test the concept, a half-scale, single-story 3D reinforced concrete frame specimen was constructed at the shake-table laboratories of the Kandilli Observatory and Earthquake Research Institute of Bogazici University, and subjected to recorded real earthquake base <span class="hlt">accelerations</span>. The amplitudes of base <span class="hlt">accelerations</span> were increased until a moderate damage level is reached. Then, the damaged RC frames was retrofitted by means of steel panels and tested under the same earthquake. The <span class="hlt">seismic</span> performance of the specimen before and after the retrofit was evaluated using FEMA356 standards, and the results were compared in terms of stiffness, strength, and deformability. The results have confirmed effectiveness of the proposed retrofit scheme.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.7225A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.7225A"><span>Annually-layered lake sediments reveal strongly increased <span class="hlt">release</span> of persistent chemicals due to <span class="hlt">accelerated</span> glacier melting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anselmetti, Flavio S.; Blüthgen, Nancy; Bogdal, Christian; Schmid, Peter</p> <p>2010-05-01</p> <p>Melting glaciers may represent a secondary source of chemical pollutants that have previously been incorporated and stored in the ice. Of particular concern are persistent organic pollutants (POPs), such as the insecticide dichlorodiphenyl trichloroethane (DDT) and industrial chemicals like polychlorinated biphenyls (PCBs), which are hazardous environmental contaminants due to their persistent, bioaccumulative and toxic properties. They were introduced in the 1930s and eventually banned in the 1970s. After <span class="hlt">release</span> into the environment these chemicals were atmospherically transported to even remote areas such as the Alps and were deposited and stored in glaciers. Ongoing drastic glacier melting due to global warming, which is expected to further <span class="hlt">accelerate</span>, implies the significance of studying the fate of these 'legacy pollutants'. Proglacial lake sediments provide well-dated and high-resolution archives to reconstruct timing and quantities of such a potentially hazardous remobilization. The goal of this study is to reconstruct the historical inputs of POPs into remote alpine lakes and to investigate the <span class="hlt">accelerated</span> <span class="hlt">release</span> of POPs from melting glaciers. Due to their lipophilic character, these chemicals exhibit a high tendency to adsorb to particles whereas concentrations in water are expected to be low. Therefore, quantitative determination in annually-layered lake sediment provides an excellent way to investigate the temporal trend of inputs into lakes that act as particle sinks. For this purpose, sediment cores were sampled from proglacial lakes in the Bernese Alps (Switzerland), which are exclusively fed by glacial melt waters. For comparison, cores were also taken from nearby high-alpine lakes located in non-glaciated catchments, which only should record the initial atmospheric fall-out. Sediment layers were dated by annual varve counting and radionuclide measurements; they cover the time period from the mid 20th century to today. The measured time series of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JVGR..128..187S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JVGR..128..187S"><span>The effects of a decompression on <span class="hlt">seismic</span> parameter profiles in a gas-charged magma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sturton, Susan; Neuberg, Jürgen</p> <p>2003-11-01</p> <p><span class="hlt">Seismic</span> velocities in a gas-charged magma vary with depth and time. Relationships between pressure, density, exsolved gas content, and <span class="hlt">seismic</span> velocity are derived and used in conjunction with expressions describing diffusive bubble growth to find a series of velocity profiles which depend on time. An equilibrium solution is obtained by considering a column of magma in which the gas distribution corresponds to the magmastatic pressure profile with depth. Decompression events of various sizes are simulated, and the resulting disequilibrium between the gas pressure and magmastatic pressure leads to bubble growth and therefore to a change of <span class="hlt">seismic</span> velocity and density with time. Bubble growth stops when the system reaches a new equilibrium. The corresponding volume increase is accommodated by <span class="hlt">accelerating</span> the magma column upwards and an extrusion of lava. A timescale for the system to return to equilibrium can be obtained. The effect of changes in magma viscosity and bubble number density is examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70020685','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70020685"><span>Observation of the <span class="hlt">seismic</span> nucleation phase in the Ridgecrest, California, earthquake sequence</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ellsworth, W.L.; Beroza, G.C.</p> <p>1998-01-01</p> <p>Near-source observations of five M 3.8-5.2 earthquakes near Ridgecrest, California are consistent with the presence of a <span class="hlt">seismic</span> nucleation phase. These earthquakes start abruptly, but then slow or stop before rapidly growing again toward their maximum rate of moment <span class="hlt">release</span>. Deconvolution of instrument and path effects by empirical Green's functions demonstrates that the initial complexity at the start of the earthquake is a source effect. The rapid growth of the P-wave arrival at the start of the <span class="hlt">seismic</span> nucleation phase supports the conclusion of Mori and Kanamori [1996] that these earthquakes begin without a magnitude-scaled slow initial phase of the type observed by Iio [1992, 1995].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1918881R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1918881R"><span>A quantitative analysis of global intermediate and deep <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ruscic, Marija; Becker, Dirk; Le Pourhiet, Laetitita; Agard, Philippe; Meier, Thomas</p> <p>2017-04-01</p> <p> exhibiting higher ratios indicating stronger hydration of older slabs and consequently stronger <span class="hlt">seismic</span> activity at depth in older and thicker slabs. Furthermore, older slabs show the tendency to larger b-values. This indicates stronger fragmentation of older slabs favoring smaller events. Between 50 km and 300 km depth, <span class="hlt">seismicity</span> in subduction zones decays nearly exponentially with depth. However, the majority of subduction zones show between about 60 km and 100 km lower <span class="hlt">seismic</span> activity than expected by an exponential decay. This observation correlates well with findings from petrological studies that rocks are rarely scraped off from the downgoing plate at these depths indicating low <span class="hlt">seismic</span> coupling and low stresses at the plate interface in a depth range below the seismogenic zone and above 100 km depth were dehydration reactions become virulent. Interestingly, the percentage of this deficit becomes larger with plate age for event frequency (reduced number of events), but decreases for moment <span class="hlt">release</span> (events have larger magnitudes). It is observed that the forearc high is located above the plate interface with reduced <span class="hlt">seismic</span> coupling. The forearc high is thus an indication of upward directed return flow along the <span class="hlt">seismically</span> decoupled plate interface. In addition, it is found that the topography of the forearc high is larger above shallow dipping slabs. A correlation of the depth dependent <span class="hlt">seismic</span> behavior with the subduction or trench velocity is not observed for the investigated subduction zones. Plate age seems to be the dominating factor for properties of intermediate deep and deep <span class="hlt">seismicity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoJI.209.1168D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoJI.209.1168D"><span><span class="hlt">Seismic</span> gradiometry using ambient <span class="hlt">seismic</span> noise in an anisotropic Earth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Ridder, S. A. L.; Curtis, A.</p> <p>2017-05-01</p> <p>We introduce a wavefield gradiometry technique to estimate both isotropic and anisotropic local medium characteristics from short recordings of <span class="hlt">seismic</span> signals by inverting a wave equation. The method exploits the information in the spatial gradients of a <span class="hlt">seismic</span> wavefield that are calculated using dense deployments of <span class="hlt">seismic</span> arrays. The application of the method uses the surface wave energy in the ambient <span class="hlt">seismic</span> field. To estimate isotropic and anisotropic medium properties we invert an elliptically anisotropic wave equation. The spatial derivatives of the recorded wavefield are evaluated by calculating finite differences over nearby recordings, which introduces a systematic anisotropic error. A two-step approach corrects this error: finite difference stencils are first calibrated, then the output of the wave-equation inversion is corrected using the linearized impulse response to the inverted velocity anomaly. We test the procedure on ambient <span class="hlt">seismic</span> noise recorded in a large and dense ocean bottom cable array installed over Ekofisk field. The estimated azimuthal anisotropy forms a circular geometry around the production-induced subsidence bowl. This conforms with results from studies employing controlled sources, and with interferometry correlating long records of <span class="hlt">seismic</span> noise. Yet in this example, the results were obtained using only a few minutes of ambient <span class="hlt">seismic</span> noise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUSM.S34A..03A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSM.S34A..03A"><span>Adding <span class="hlt">seismic</span> broadband analysis to characterize Andean backarc <span class="hlt">seismicity</span> in Argentina</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alvarado, P.; Giuliano, A.; Beck, S.; Zandt, G.</p> <p>2007-05-01</p> <p>Characterization of the highly <span class="hlt">seismically</span> active Andean backarc is crucial for assessment of earthquake hazards in western Argentina. Moderate-to-large crustal earthquakes have caused several deaths, damage and drastic economic consequences in Argentinean history. We have studied the Andean backarc crust between 30°S and 36°S using <span class="hlt">seismic</span> broadband data available from a previous ("the CHARGE") IRIS-PASSCAL experiment. We collected more than 12 terabytes of continuous <span class="hlt">seismic</span> data from 22 broadband instruments deployed across Chile and Argentina during 1.5 years. Using free software we modeled full regional broadband waveforms and obtained <span class="hlt">seismic</span> moment tensor inversions of crustal earthquakes testing for the best focal depth for each event. We also mapped differences in the Andean backarc crustal structure and found a clear correlation with different types of crustal <span class="hlt">seismicity</span> (i.e. focal depths, focal mechanisms, magnitudes and frequencies of occurrence) and previously mapped terrane boundaries. We now plan to use the same methodology to study other regions in Argentina using near-real time broadband data available from the national <span class="hlt">seismic</span> (INPRES) network and global <span class="hlt">seismic</span> networks operating in the region. We will re-design the national <span class="hlt">seismic</span> network to optimize short-period and broadband <span class="hlt">seismic</span> station coverage for different network purposes. This work is an international effort that involves researchers and students from universities and national government agencies with the goal of providing more information about earthquake hazards in western Argentina.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.3320N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.3320N"><span>Romanian Data Center: A modern way for <span class="hlt">seismic</span> monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neagoe, Cristian; Marius Manea, Liviu; Ionescu, Constantin</p> <p>2014-05-01</p> <p>The main <span class="hlt">seismic</span> survey of Romania is performed by the National Institute for Earth Physics (NIEP) which operates a real-time digital <span class="hlt">seismic</span> network. The NIEP real-time network currently consists of 102 stations and two <span class="hlt">seismic</span> arrays equipped with different high quality digitizers (Kinemetrics K2, Quanterra Q330, Quanterra Q330HR, PS6-26, Basalt), broadband and short period seismometers (CMG3ESP, CMG40T, KS2000, KS54000, KS2000, CMG3T,STS2, SH-1, S13, Mark l4c, Ranger, gs21, Mark l22) and <span class="hlt">acceleration</span> sensors (Episensor Kinemetrics). The data are transmitted at the National Data Center (NDC) and Eforie Nord (EFOR) <span class="hlt">Seismic</span> Observatory. EFOR is the back-up for the NDC and also a monitoring center for the Black Sea tsunami events. NIEP is a data acquisition node for the <span class="hlt">seismic</span> network of Moldova (FDSN code MD) composed of five <span class="hlt">seismic</span> stations. NIEP has installed in the northern part of Bulgaria eight <span class="hlt">seismic</span> stations equipped with broadband sensors and Episensors and nine accelerometers (Episensors) installed in nine districts along the Danube River. All the data are acquired at NIEP for Early Warning System and for primary estimation of the earthquake parameters. The real-time acquisition (RT) and data exchange is done by Antelope software and Seedlink (from Seiscomp3). The real-time data communication is ensured by different types of transmission: GPRS, satellite, radio, Internet and a dedicated line provided by a governmental network. For data processing and analysis at the two data centers Antelope 5.2 TM is being used running on 3 workstations: one from a CentOS platform and two on MacOS. Also a Seiscomp3 server stands as back-up for Antelope 5.2 Both acquisition and analysis of <span class="hlt">seismic</span> data systems produce information about local and global parameters of earthquakes. In addition, Antelope is used for manual processing (event association, calculation of magnitude, creating a database, sending <span class="hlt">seismic</span> bulletins, calculation of PGA and PGV, etc.), generating</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70141641','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70141641"><span>Sea-level-induced <span class="hlt">seismicity</span> and submarine landslide occurrence</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Brothers, Daniel S.; Luttrell, Karen M.; Chaytor, Jason D.</p> <p>2013-01-01</p> <p>The temporal coincidence between rapid late Pleistocene sea-level rise and large-scale slope failures is widely documented. Nevertheless, the physical mechanisms that link these phenomena are poorly understood, particularly along nonglaciated margins. Here we investigate the causal relationships between rapid sea-level rise, flexural stress loading, and increased <span class="hlt">seismicity</span> rates along passive margins. We find that Coulomb failure stress across fault systems of passive continental margins may have increased more than 1 MPa during rapid late Pleistocene–early Holocene sea-level rise, an amount sufficient to trigger fault reactivation and rupture. These results suggest that sea-level–modulated <span class="hlt">seismicity</span> may have contributed to a number of poorly understood but widely observed phenomena, including (1) increased frequency of large-scale submarine landslides during rapid, late Pleistocene sea-level rise; (2) emplacement of coarse-grained mass transport deposits on deep-sea fans during the early stages of marine transgression; and (3) the unroofing and <span class="hlt">release</span> of methane gas sequestered in continental slope sediments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994shkm.rept.....K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994shkm.rept.....K"><span><span class="hlt">Seismic</span> hazards at Kilauea and Mauna Loa volcanoes, Hawaii</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klein, Fred W.</p> <p>1994-04-01</p> <p>A significant <span class="hlt">seismic</span> hazard exists in south Hawaii from large tectonic earthquakes that can reach magnitude 8 and intensity XII. This paper quantifies the hazard by estimating the horizontal peak ground <span class="hlt">acceleration</span> (PGA) in south Hawaii which occurs with a 90% probability of not being exceeded during exposure times from 10 to 250 years. The largest earthquakes occur beneath active, unbuttressed and mobile flanks of volcanos in their shield building stage. The flanks are compressed and pushed laterally by rift zone intrusions. The largest earthquakes are thus not directly caused by volcanic activity. Historic earthquakes (since 1823) and the best Hawaiian Volcano Observatory catalog (since 1970) under the south side of the island define linear frequency-magnitude distributions that imply average recurrence intervals for M greater than 5.5 earthquakes of 3.4-5 years, for M greater than 7 events of 29-44 years, and for M greater than 8 earthquakes of 120-190 years. These estimated recurrences are compatable with the 107 year interval between the two major April 2, 1868 (M(approximately)7.9) and November 29, 1975 (M=7.2) earthquakes. Frequency-magnitude distributions define the activity levels of 19 different <span class="hlt">seismic</span> source zones for probabilistic ground motion estimations. The available measurements of PGA (33 from 7 moderate earthquakes) are insufficient to define a new attenuation curve. We use the Boore et al. (1993) curve shifted upward by a factor of 1.2 to fit Hawaiian data. Amplification of sites on volcanic ash or unconsolidated soil are about two times those of hard lava sites. On a map for a 50 year exposure time with a 90% probability of not being exceeded, the peak ground <span class="hlt">accelerations</span> are 1.0 g Kilauea's and Mauna Loa's mobile south flanks and 0.9 g in the Kaoiki <span class="hlt">seismic</span> zone. This hazard from strong ground shaking is comparable to that near the San Andreas Fault in California or the subduction zone in the Gulf of Alaska.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH53D..06J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH53D..06J"><span>Exploring the interior of Venus with <span class="hlt">seismic</span> and infrasonic techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jackson, J. M.; Cutts, J. A.; Pauken, M.; Komjathy, A.; Smrekar, S. E.; Kedar, S.; Mimoun, D.; Garcia, R.; Schubert, G.; Lebonnois, S.; Stevenson, D. J.; Lognonne, P. H.; Zhan, Z.; Ko, J. Y. T.; Tsai, V. C.</p> <p>2016-12-01</p> <p>The dense atmosphere of Venus, which efficiently couples <span class="hlt">seismic</span> energy into the atmosphere as infrasonic waves, enables an alternative to conventional seismology: detection of infrasonic waves in the upper atmosphere using either high altitude balloons or orbiting spacecraft. Infrasonic techniques for probing the interior of Venus can be implemented without exposing sensors to the severe surface environments on Venus. This approach takes advantage of the fact that approximately sixty-times the energy from a <span class="hlt">seismic</span> event on Venus is coupled into the atmosphere on Venus as would occur for a comparable event on Earth. The direct or epicentral wave propagates vertically above the event, and the indirect wave propagates through the planet as a Rayleigh wave and then couples to an infrasonic wave. Although there is abundant evidence of tectonic activity on Venus, questions remain as to whether the planet is still active and whether energy <span class="hlt">releases</span> are <span class="hlt">seismic</span> or aseismic. In recent years, seismologists have developed techniques for probing crustal and interior structure in parts of the Earth where there are very few quakes. We have begun an effort to determine if this is also possible for Venus. Just as <span class="hlt">seismic</span> energy propagates more efficiently upward across the surface atmosphere interface, equally acoustic energy originating in the atmosphere will propagate downwards more effectively. Measurements from a balloon platform in the atmosphere of Venus could assess the nature and spectral content of such sources, while having the ability to identify and discriminate signatures from volcanic events, storm activity, and meteor impacts. We will discuss our ongoing assessment on the feasibility of a balloon acoustic monitoring system. In particular, we will highlight our results of the flight experiment on Earth that will focus on using barometer instruments on a tethered helium-filled balloon in the vicinity of a known <span class="hlt">seismic</span> source generated by a <span class="hlt">seismic</span> hammer</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615081S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615081S"><span>The <span class="hlt">Seismic</span> Strong Motion Array Project (SSMAP) and the September 5, 2012 Mw=7.6 Nicoya, Costa Rica Earthquake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Simila, Gerald; Mohammadebrahim, Ehsan; McNally, Karen; Quintero, Ronnie; Segura, Juan</p> <p>2014-05-01</p> <p><span class="hlt">Seismic</span> gaps along the subduction zones are locations where large earthquakes have not occurred in a long time. The Cocos plate is subducting beneath the Caribbean plate in Costa Rica, and the Nicoya Peninsula, located in northwestern Costa Rica, has been identified as a <span class="hlt">seismic</span> gap. The previous major earthquakes in Nicoya occurred on 1853, 1900 and 1950, which indicates about a 50-year recurrence interval for the characteristic earthquake cycle. Since 2006, the <span class="hlt">seismic</span> strong motion array project (SSMAP) for the Nicoya Peninsula in northwestern Costa Rica has been composed of 10 sites with Geotech A900/A800 accelerographs (three-component) and GPS timing. Our digital accelerographs array has been deployed as part of our ongoing research on large earthquakes, including the potential Nicoya event, in conjunction with the Earthquake and Volcano Observatory (OVSICORI) at the Universidad Nacional in Costa Rica. From 2006 to 2012, 28 events were relocated using the SSMAP and OVSICORI data with moderate magnitudes (4 < Mw< 6.5), and were mainly located in Nicoya Peninsula region. On September 5, 2012, a Mw=7.6 earthquake occurred in the <span class="hlt">seismic</span> gap and appears to be the expected event based on the 50 years recurrence interval, but was instead 62 years later. The main shock focal mechanism was thrust faulting, propagating downdip, of the Cocos plate in the Middle America trench with strike N54W and dip 20 degrees NE. The mainshock and 15 early aftershocks were relocated by using SSMAP, OVSICORI, and UCSC networks. The final location of the mainshock is 9.671 N and 85.878 W with a depth of 18 km. The maximum <span class="hlt">accelerations</span> from two A900 stations perpendicular to the trench, Fortuna (distance 112km) and Pedernal (distance 128 km) are: 13.8% and 8.9 % g, respectively. In addition, the October 10 (MW 5.3) and 24(Mw 6.6) aftershocks recorded at Tamarindo (distances 40 km and 70 km, respectively) showed <span class="hlt">accelerations</span> of 2.4% and 8.2% g; respectively. The mainshock <span class="hlt">acceleration</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E%26ES...95b2004S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26ES...95b2004S"><span>On-line Data Transmission, as Part of the <span class="hlt">Seismic</span> Evaluation Process in the Buildings Field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sorin Dragomir, Claudiu; Dobre, Daniela; Craifaleanu, Iolanda; Georgescu, Emil-Sever</p> <p>2017-12-01</p> <p>The thorough analytical modelling of <span class="hlt">seismic</span> actions, of the structural system and of the foundation soil is essential for a proper dynamic analysis of a building. However, the validation of the used models should be made, whenever possible, with reference to results obtained from experimental investigations, building instrumentation and monitoring of vibrations generated by various <span class="hlt">seismic</span> or non-<span class="hlt">seismic</span> sources. In Romania, the permanent <span class="hlt">seismic</span> instrumentation/monitoring of buildings is part of a special follow-up activity, performed in accordance with the P130/1999 code for the time monitoring of building behaviour and with the <span class="hlt">seismic</span> design code, P100-2013. By using the state-of-the-art modern equipment (GeoSIG and Kinemetrics digital accelerographs) in the <span class="hlt">seismic</span> network of the National Institute for Research and Development URBAN-INCERC, the instrumented buildings can be monitored remotely, with recorded data being sent to authorities or to research institutes in the field by a real-time data transmission system. The obtained records are processed, computing the Fourier amplitude spectra and the response spectra, and the modal parameters of buildings are determined. The paper presents some of the most important results of the institute in the field of building monitoring, focusing on the situation of some significant instrumented buildings located in different parts of the country. In addition, maps with data received from <span class="hlt">seismic</span> stations after the occurrence of two recent Vrancea (Romania) earthquakes, showing the spatial distribution of ground <span class="hlt">accelerations</span>, are presented, together with a comparative analysis, performed with reference to previous studies in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70029867','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70029867"><span>Developments in <span class="hlt">seismic</span> monitoring for risk reduction</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Celebi, M.</p> <p>2007-01-01</p> <p>This paper presents recent state-of-the-art developments to obtain displacements and drift ratios for <span class="hlt">seismic</span> monitoring and damage assessment of buildings. In most cases, decisions on safety of buildings following <span class="hlt">seismic</span> events are based on visual inspections of the structures. Real-time instrumental measurements using GPS or double integration of <span class="hlt">accelerations</span>, however, offer a viable alternative. Relevant parameters, such as the type of connections and structural characteristics (including storey geometry), can be estimated to compute drifts corresponding to several pre-selected threshold stages of damage. Drift ratios determined from real-time monitoring can then be compared to these thresholds in order to estimate damage conditions drift ratios. This approach is demonstrated in three steel frame buildings in San Francisco, California. Recently recorded data of strong shaking from these buildings indicate that the monitoring system can be a useful tool in rapid assessment of buildings and other structures following an earthquake. Such systems can also be used for risk monitoring, as a method to assess performance-based design and analysis procedures, for long-term assessment of structural characteristics of a building, and as a possible long-term damage detection tool.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.epa.gov/environmental-geophysics/seismic-methods','PESTICIDES'); return false;" href="https://www.epa.gov/environmental-geophysics/seismic-methods"><span><span class="hlt">Seismic</span> Methods</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p><span class="hlt">Seismic</span> methods are the most commonly conducted geophysical surveys for engineering investigations. <span class="hlt">Seismic</span> refraction provides engineers and geologists with the most basic of geologic data via simple procedures with common equipment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EP%26S...68..180U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EP%26S...68..180U"><span>The 2016 Kumamoto-Oita earthquake sequence: aftershock <span class="hlt">seismicity</span> gap and dynamic triggering in volcanic areas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Uchide, Takahiko; Horikawa, Haruo; Nakai, Misato; Matsushita, Reiken; Shigematsu, Norio; Ando, Ryosuke; Imanishi, Kazutoshi</p> <p>2016-11-01</p> <p>The 2016 Kumamoto-Oita earthquake sequence involving three large events ( M w ≥ 6) in the central Kyushu Island, southwest Japan, activated <span class="hlt">seismicities</span> in two volcanic areas with unusual and puzzling spatial gaps after the largest earthquake ( M w 7.0) of April 16, 2016. We attempt to reveal the <span class="hlt">seismic</span> process during the sequence by following seismological data analyses. Our hypocenter relocation result implies that the large events ruptured different faults of a complex fault system. A slip inversion analysis of the largest event indicates a large slip in the <span class="hlt">seismicity</span> gap (Aso gap) in the caldera of Mt. Aso, which probably <span class="hlt">released</span> accumulated stress and resulted in little aftershock production. We identified that the largest event dynamically triggered a mid-M6 event at Yufuin (80 km northeast of the epicenter), which is consistent with existence of the 20-km long zone where <span class="hlt">seismicity</span> was activated and surface offset was observed. These findings will help us study the contribution of the identified complexity in fault geometries and the geotherm in the volcanic areas to the revealed <span class="hlt">seismic</span> process and consequently improve our understanding of the seismo-volcano tectonics.[Figure not available: see fulltext.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1978/0287/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1978/0287/"><span>FORTRAN programs for calculating nonlinear <span class="hlt">seismic</span> ground response in two dimensions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Joyner, W.B.</p> <p>1978-01-01</p> <p>The programs described here were designed for calculating the nonlinear <span class="hlt">seismic</span> response of a two-dimensional configuration of soil underlain by a semi-infinite elastic medium representing bedrock. There are two programs. One is for plane strain motions, that is, motions in the plane perpendicular to the long axis of the structure, and the other is for antiplane strain motions, that is motions parallel to the axis. The <span class="hlt">seismic</span> input is provided by specifying what the motion of the rock-soil boundary would be if the soil were absent and the boundary were a free surface. This may be done by supplying a magnetic tape containing the values of particle velocity for every boundary point at every instant of time. Alternatively, a punch card deck may be supplied giving <span class="hlt">acceleration</span> values at every instant of time. In the plane strain program it is assumed that the <span class="hlt">acceleration</span> values apply simultaneously to every point on the boundary; in the antiplane strain program it is assumed that the <span class="hlt">acceleration</span> values characterize a plane shear wave propagating upward in the underlying elastic medium at a specified angle with the vertical. The nonlinear hysteretic behavior of the soil is represented by a three-dimensional rheological model. A boundary condition is used which takes account of finite rigidity in the elastic substratum. The computations are performed by an explicit finite-difference scheme that proceeds step by step in space and time. Computations are done in terms of stress departures from an unspecified initial state. Source listings are provided here along with instructions for preparing the input. A more detailed discussion of the method is presented elsewhere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S11F4410A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S11F4410A"><span>Neural Models: An Option to Estimate <span class="hlt">Seismic</span> Parameters of Accelerograms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alcántara, L.; García, S.; Ovando-Shelley, E.; Macías, M. A.</p> <p>2014-12-01</p> <p><span class="hlt">Seismic</span> instrumentation for recording strong earthquakes, in Mexico, goes back to the 60´s due the activities carried out by the Institute of Engineering at Universidad Nacional Autónoma de México. However, it was after the big earthquake of September 19, 1985 (M=8.1) when the project of <span class="hlt">seismic</span> instrumentation assumes a great importance. Currently, strong ground motion networks have been installed for monitoring <span class="hlt">seismic</span> activity mainly along the Mexican subduction zone and in Mexico City. Nevertheless, there are other major regions and cities that can be affected by strong earthquakes and have not yet begun their <span class="hlt">seismic</span> instrumentation program or this is still in development.Because of described situation some relevant earthquakes (e.g. Huajuapan de León Oct 24, 1980 M=7.1, Tehuacán Jun 15, 1999 M=7 and Puerto Escondido Sep 30, 1999 M= 7.5) have not been registered properly in some cities, like Puebla and Oaxaca, and that were damaged during those earthquakes. Fortunately, the good maintenance work carried out in the <span class="hlt">seismic</span> network has permitted the recording of an important number of small events in those cities. So in this research we present a methodology based on the use of neural networks to estimate significant duration and in some cases the response spectra for those <span class="hlt">seismic</span> events. The neural model developed predicts significant duration in terms of magnitude, epicenter distance, focal depth and soil characterization. Additionally, for response spectra we used a vector of spectral <span class="hlt">accelerations</span>. For training the model we selected a set of accelerogram records obtained from the small events recorded in the strong motion instruments installed in the cities of Puebla and Oaxaca. The final results show that neural networks as a soft computing tool that use a multi-layer feed-forward architecture provide good estimations of the target parameters and they also have a good predictive capacity to estimate strong ground motion duration and response spectra.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH41B1794M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH41B1794M"><span>Numerical modeling of landslides and generated <span class="hlt">seismic</span> waves: The Bingham Canyon Mine landslides</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miallot, H.; Mangeney, A.; Capdeville, Y.; Hibert, C.</p> <p>2016-12-01</p> <p>Landslides are important natural hazards and key erosion processes. They create long period surface waves that can be recorded by regional and global <span class="hlt">seismic</span> networks. The <span class="hlt">seismic</span> signals are generated by <span class="hlt">acceleration</span>/deceleration of the mass sliding over the topography. They consist in a unique and powerful tool to detect, characterize and quantify the landslide dynamics. We investigate here the processes at work during the two massive landslides that struck the Bingham Canyon Mine on the 10th April 2013. We carry a combined analysis of the generated <span class="hlt">seismic</span> signals and the landslide processes computed with a 3D modeling on a complex topography. Forces computed by broadband <span class="hlt">seismic</span> waveform inversion are used to constrain the study and particularly the force-source and the bulk dynamic. The source time function are obtained by a 3D model (Shaltop) where rheological parameters can be adjusted. We first investigate the influence of the initial shape of the sliding mass which strongly affects the whole landslide dynamic. We also see that the initial shape of the source mass of the first landslide constrains pretty well the second landslide source mass. We then investigate the effect of a rheological parameter, the frictional angle, that strongly influences the resulted computed <span class="hlt">seismic</span> source function. We test here numerous friction laws as the frictional Coulomb law and a velocity-weakening friction law. Our results show that the force waveform fitting the observed data is highly variable depending on these different choices.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70037543','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70037543"><span><span class="hlt">Seismic</span> performance assessment of base-isolated safety-related nuclear structures</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Huang, Y.-N.; Whittaker, A.S.; Luco, N.</p> <p>2010-01-01</p> <p><span class="hlt">Seismic</span> or base isolation is a proven technology for reducing the effects of earthquake shaking on buildings, bridges and infrastructure. The benefit of base isolation has been presented in terms of reduced <span class="hlt">accelerations</span> and drifts on superstructure components but never quantified in terms of either a percentage reduction in <span class="hlt">seismic</span> loss (or percentage increase in safety) or the probability of an unacceptable performance. Herein, we quantify the benefits of base isolation in terms of increased safety (or smaller loss) by comparing the safety of a sample conventional and base-isolated nuclear power plant (NPP) located in the Eastern U.S. Scenario- and time-based assessments are performed using a new methodology. Three base isolation systems are considered, namely, (1) Friction Pendulum??? bearings, (2) lead-rubber bearings and (3) low-damping rubber bearings together with linear viscous dampers. Unacceptable performance is defined by the failure of key secondary systems because these systems represent much of the investment in a new build power plant and ensure the safe operation of the plant. For the scenario-based assessments, the probability of unacceptable performance is computed for an earthquake with a magnitude of 5.3 at a distance 7.5 km from the plant. For the time-based assessments, the annual frequency of unacceptable performance is computed considering all potential earthquakes that may occur. For both assessments, the implementation of base isolation reduces the probability of unacceptable performance by approximately four orders of magnitude for the same NPP superstructure and secondary systems. The increase in NPP construction cost associated with the installation of <span class="hlt">seismic</span> isolators can be offset by substantially reducing the required <span class="hlt">seismic</span> strength of secondary components and systems and potentially eliminating the need to <span class="hlt">seismically</span> qualify many secondary components and systems. ?? 2010 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V21B2707C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V21B2707C"><span>Sub-crustal <span class="hlt">seismic</span> activity beneath Klyuchevskoy Volcano</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carr, M. J.; Droznina, S.; Levin, V. L.; Senyukov, S.</p> <p>2013-12-01</p> <p> events observed at a site closest to the epicenter to delay times of Ps phases in RFs that we associate with the crust-mantle transition. Both observations are essentially differences between travel times of S and P waves originating at the same place, and traversing the same velocity structure. Consequently, the uncertainty of the velocity structure beneath the KVG does not influence the comparison. For all events nominally located at 28-30 km beneath KVG the S-P time at the nearest site (CIR) significantly exceeds 4 seconds. Given that crust-mantle boundary Ps times at nearby sites are ~3 s, these earthquakes take place in the upper mantle. Both recent RFs and wide-angle reflection (Deep <span class="hlt">Seismic</span> Sounding) studies in the late 1970s identified additional boundaries beneath KVG at depths in excess of 40 km. The nature of these boundaries is unclear, however their sharpness suggests chemical changes or the presence of fluids or melts. Chemistry of Klyuchevskoy lavas suggests sub-crustal origin with no clear magma chamber within the crust. Sub-crustal earthquakes we describe show that processes in the magma conduit at the base of the crust beneath KVG are vigorous enough to promote brittle failure in the surrounding mantle rock. The complex <span class="hlt">seismic</span> structure of the uppermost mantle beneath KVG may reflect a history of magma injection that is accompanied by <span class="hlt">seismic</span> energy <span class="hlt">release</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.U13B..19M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.U13B..19M"><span>Geometric and thermal controls on normal fault <span class="hlt">seismicity</span> from rate-and-state friction models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mark, H. F.; Behn, M. D.; Olive, J. A. L.; Liu, Y.</p> <p>2017-12-01</p> <p><span class="hlt">Seismic</span> and geodetic observations from the last two decades have led to a growing realization that a significant amount of fault slip at plate boundaries occurs aseismically, and that the amount of aseismic displacement varies across settings. Here we investigate controls on the seismogenic behavior of crustal-scale normal faults that accommodate extensional strain at mid-ocean ridges and continental rifts. <span class="hlt">Seismic</span> moment <span class="hlt">release</span> rates measured along the fast-spreading East Pacific Rise suggest that the majority of fault growth occurs aseismically with almost no <span class="hlt">seismic</span> slip. In contrast, at the slow-spreading Mid-Atlantic Ridge <span class="hlt">seismic</span> slip may represent up to 60% of the total fault displacement. Potential explanations for these variations include heterogeneous distributions of frictional properties on fault surfaces, effects of variable magma supply associated with seafloor spreading, and/or differences in fault geometry and thermal structure. In this study, we use rate-and-state friction models to study the <span class="hlt">seismic</span> coupling coefficient (the fraction of total fault slip that occurs <span class="hlt">seismically</span>) for normal faults at divergent plate boundaries, and investigate controls on fault behavior that might produce the variations in the coupling coefficient observed in natural systems. We find that the <span class="hlt">seismic</span> coupling coefficient scales with W/h*, where W is the downdip width of the seismogenic area of the fault and h* is the critical earthquake nucleation size. At mid-ocean ridges, W is expected to increase with decreasing spreading rate. Thus, the observed relationship between <span class="hlt">seismic</span> coupling and W/h* explains to first order variations in <span class="hlt">seismic</span> coupling coefficient as a function of spreading rate. Finally, we use catalog data from the Gulf of Corinth to show that this scaling relationship can be extended into the thicker lithosphere of continental rift systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S43F..08M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S43F..08M"><span>Using <span class="hlt">Seismic</span> Interferometry to Investigate <span class="hlt">Seismic</span> Swarms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matzel, E.; Morency, C.; Templeton, D. C.</p> <p>2017-12-01</p> <p><span class="hlt">Seismicity</span> provides a direct means of measuring the physical characteristics of active tectonic features such as fault zones. Hundreds of small earthquakes often occur along a fault during a <span class="hlt">seismic</span> swarm. This <span class="hlt">seismicity</span> helps define the tectonically active region. When processed using novel geophysical techniques, we can isolate the energy sensitive to the fault, itself. Here we focus on two methods of <span class="hlt">seismic</span> interferometry, ambient noise correlation (ANC) and the virtual seismometer method (VSM). ANC is based on the observation that the Earth's background noise includes coherent energy, which can be recovered by observing over long time periods and allowing the incoherent energy to cancel out. The cross correlation of ambient noise between a pair of stations results in a waveform that is identical to the seismogram that would result if an impulsive source located at one of the stations was recorded at the other, the Green function (GF). The calculation of the GF is often stable after a few weeks of continuous data correlation, any perturbations to the GF after that point are directly related to changes in the subsurface and can be used for 4D monitoring.VSM is a style of <span class="hlt">seismic</span> interferometry that provides fast, precise, high frequency estimates of the Green's function (GF) between earthquakes. VSM illuminates the subsurface precisely where the pressures are changing and has the potential to image the evolution of <span class="hlt">seismicity</span> over time, including changes in the style of faulting. With hundreds of earthquakes, we can calculate thousands of waveforms. At the same time, VSM collapses the computational domain, often by 2-3 orders of magnitude. This allows us to do high frequency 3D modeling in the fault region. Using data from a swarm of earthquakes near the Salton Sea, we demonstrate the power of these techniques, illustrating our ability to scale from the far field, where sources are well separated, to the near field where their locations fall within each other</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA376853','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA376853"><span>A High Resolution <span class="hlt">Seismic</span> Sequence Analysis of the Malta Plateau</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1999-05-01</p> <p>the SACLANTCEN Programme of Work. The document has been approved for <span class="hlt">release</span> by The Director, SACLANTCEN. Jan L . Spoelstra Director NATO...the Plio- Quatemary. To the southwest of Sicily, Di Stefano et al. (1993) identified six sequence boundaries and estimated the ages by the...the location of the <span class="hlt">seismic</span> reflection profiles in Di Stefano et al. (1993) do not overlap any of the profiles in this study and use a lower frequency</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.S41B2430B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.S41B2430B"><span>Study on Frequency content in <span class="hlt">seismic</span> hazard analysis in West Azarbayjan and East Azarbayjan provinces (Iran)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Behzadafshar, K.; Abbaszadeh Shahri, A.; Isfandiari, K.</p> <p>2012-12-01</p> <p>ABSTRACT: Iran plate is prone to earthquake, occurrence of destructive earthquakes approximately every 5 years certify it. Due to existence of happened great earthquakes and large number of potential <span class="hlt">seismic</span> sources (active faults) which some of them are responsible for great earthquakes the North-West of Iran which is located in junction of Alborz and Zagros seismotectonic provinces (Mirzaii et al, 1998) is an interesting area for seismologists. Considering to population and existence of large cities like Tabriz, Ardabil and Orumiyeh which play crucial role in industry and economy of Iran, authors decided to focus on study of <span class="hlt">seismic</span> hazard assessment in these two provinces to achieve ground <span class="hlt">acceleration</span> in different frequency content and indicate critical frequencies in the studied area. It is important to note that however lots of studies have been done in North -West of Iran, but building code modifications also need frequency content analysis to asses <span class="hlt">seismic</span> hazard more precisely which has been done in the present study. Furthermore, in previous studies have been applied free download softwares which were provided before 2000 but the most important advantage of this study is applying professional industrial software which has been written in 2009 and provided by authors. This applied software can cover previous software weak points very well such as gridding potential sources, attention to the seismogenic zone and applying attenuation relationships directly. Obtained hazard maps illustrate that maximum <span class="hlt">accelerations</span> will be experienced in North West to South East direction which increased by frequency reduction from 100 Hz to 10 Hz then decreased by frequency reduce (to 0.25 Hz). Maximum <span class="hlt">acceleration</span> will be occurred in the basement in 10 HZ frequency content. Keywords: hazard map, Frequency content, seismogenic zone, Iran</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615287B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615287B"><span>Reevaluation of the <span class="hlt">Seismicity</span> and <span class="hlt">seismic</span> hazards of Northeastern Libya</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ben Suleman, abdunnur; Aousetta, Fawzi</p> <p>2014-05-01</p> <p>Libya, located at the northern margin of the African continent, underwent many episodes of orogenic activities. These episodes of orogenic activities affected and shaped the geological setting of the country. This study represents a detailed investigation that aims to focus on the <span class="hlt">seismicity</span> and its implications on earthquake hazards of Northeastern Libya. At the end of year 2005 the Libyan National Seismological Network starts functioning with 15 stations. The <span class="hlt">Seismicity</span> of the area under investigation was reevaluated using data recorded by the recently established network. The Al-Maraj earthquake occurred in May 22nd 2005was analyzed. This earthquake was located in a known <span class="hlt">seismically</span> active area. This area was the sight of the well known 1963 earthquake that kills over 200 people. Earthquakes were plotted and resulting maps were interpreted and discussed. The level of <span class="hlt">seismic</span> activity is higher in some areas, such as the city of Al-Maraj. The offshore areas north of Al-Maraj seem to have higher <span class="hlt">seismic</span> activity. It is highly recommended that the recent earthquake activity is considered in the <span class="hlt">seismic</span> hazard assessments for the northeastern part of Libya.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9771G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9771G"><span>Modeling continuous <span class="hlt">seismic</span> velocity changes due to ground shaking in Chile</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gassenmeier, Martina; Richter, Tom; Sens-Schönfelder, Christoph; Korn, Michael; Tilmann, Frederik</p> <p>2015-04-01</p> <p>In order to investigate temporal <span class="hlt">seismic</span> velocity changes due to earthquake related processes and environmental forcing, we analyze 8 years of ambient <span class="hlt">seismic</span> noise recorded by the Integrated Plate Boundary Observatory Chile (IPOC) network in northern Chile between 18° and 25° S. The Mw 7.7 Tocopilla earthquake in 2007 and the Mw 8.1 Iquique earthquake in 2014 as well as numerous smaller events occurred in this area. By autocorrelation of the ambient <span class="hlt">seismic</span> noise field, approximations of the Green's functions are retrieved. The recovered function represents backscattered or multiply scattered energy from the immediate neighborhood of the station. To detect relative changes of the <span class="hlt">seismic</span> velocities we apply the stretching method, which compares individual autocorrelation functions to stretched or compressed versions of a long term averaged reference autocorrelation function. We use time windows in the coda of the autocorrelations, that contain scattered waves which are highly sensitive to minute changes in the velocity. At station PATCX we observe seasonal changes in <span class="hlt">seismic</span> velocity as well as temporary velocity reductions in the frequency range of 4-6 Hz. The seasonal changes can be attributed to thermal stress changes in the subsurface related to variations of the atmospheric temperature. This effect can be modeled well by a sine curve and is subtracted for further analysis of short term variations. Temporary velocity reductions occur at the time of ground shaking usually caused by earthquakes and are followed by a recovery. We present an empirical model that describes the <span class="hlt">seismic</span> velocity variations based on continuous observations of the local ground <span class="hlt">acceleration</span>. Our hypothesis is that not only the shaking of earthquakes provokes velocity drops, but any small vibrations continuously induce minor velocity variations that are immediately compensated by healing in the steady state. We show that the shaking effect is accumulated over time and best described by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJASE...8....1M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJASE...8....1M"><span><span class="hlt">Seismic</span> fragility analysis of typical pre-1990 bridges due to near- and far-field ground motions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mosleh, Araliya; Razzaghi, Mehran S.; Jara, José; Varum, Humberto</p> <p>2016-03-01</p> <p>Bridge damages during the past earthquakes caused several physical and economic impacts to transportation systems. Many of the existing bridges in earthquake prone areas are pre-1990 bridges and were designed with out of date regulation codes. The occurrences of strong motions in different parts of the world show every year the vulnerability of these structures. Nonlinear dynamic time history analyses were conducted to assess the <span class="hlt">seismic</span> vulnerability of typical pre-1990 bridges. A family of existing concrete bridge representative of the most common bridges in the highway system in Iran is studied. The <span class="hlt">seismic</span> demand consists in a set of far-field and near-field strong motions to evaluate the likelihood of exceeding the <span class="hlt">seismic</span> capacity of the mentioned bridges. The peak ground <span class="hlt">accelerations</span> (PGAs) were scaled and applied incrementally to the 3D models to evaluate the <span class="hlt">seismic</span> performance of the bridges. The superstructure was assumed to remain elastic and the nonlinear behavior in piers was modeled by assigning plastic hinges in columns. In this study the displacement ductility and the PGA are selected as a <span class="hlt">seismic</span> performance indicator and intensity measure, respectively. The results show that pre-1990 bridges subjected to near-fault ground motions reach minor and moderate damage states.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.1344B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.1344B"><span>GIA induced intraplate <span class="hlt">seismicity</span> in northern Central Europe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brandes, Christian; Steffen, Holger; Steffen, Rebekka; Wu, Patrick</p> <p>2015-04-01</p> <p>Though northern Central Europe is regarded as a low <span class="hlt">seismicity</span> area (Leydecker and Kopera, 1999), several historic earthquakes with intensities of up to VII affected the area in the last 1200 years (Leydecker, 2011). The trigger for these <span class="hlt">seismic</span> events is not sufficiently investigated yet. Based on the combination of historic earthquake epicentres with the most recent fault maps we show that the historic <span class="hlt">seismicity</span> concentrated at major reverse faults. There is no evidence for significant historic earthquakes along normal faults in northern Central Europe. The spatial and temporal distribution of earthquakes (clusters that shift from time to time) implies that northern Central Europe behaves like a typical intraplate tectonic region as demonstrated for other intraplate settings (Liu et al., 2000) We utilized Finite Element models that describe the process of glacial isostatic adjustment to analyse the fault behaviour. We use the change in Coulomb Failure Stress (dCFS) to represent the minimum stress required to reach faulting. A negative dCFS value indicates that the fault is stable, while a positive value means that GIA stress is potentially available to induce faulting or cause fault instability or failure unless <span class="hlt">released</span> temporarily by an earthquake. The results imply that many faults in Central Europe are postglacial faults, though they developed outside the glaciated area. This is supported by the characteristics of the dCFS graphs, which indicate the likelihood that an earthquake is related to GIA. Almost all graphs show a change from negative to positive values during the deglaciation phase. This observation sheds new light on the distribution of post-glacial faults in general. Based on field data and the numerical simulations we developed the first consistent model that can explain the occurrence of deglaciation <span class="hlt">seismicity</span> and more recent historic earthquakes in northern Central Europe. Based on our model, the historic <span class="hlt">seismicity</span> in northern Central Europe</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004EOSTr..85..218H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004EOSTr..85..218H"><span>U.S. Quaternary Fault and Fold Database <span class="hlt">Released</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haller, Kathleen M.; Machette, Michael N.; Dart, Richard L.; Rhea, B. Susan</p> <p>2004-06-01</p> <p>A comprehensive online compilation of Quaternary-age faults and folds throughout the United States was recently <span class="hlt">released</span> by the U.S. Geological Survey, with cooperation from state geological surveys, academia, and the private sector. The Web site at http://Qfaults.cr.usgs.gov/ contains searchable databases and related geo-spatial data that characterize earthquake-related structures that could be potential <span class="hlt">seismic</span> sources for large-magnitude (M > 6) earthquakes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991ESRv...31...11P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991ESRv...31...11P"><span>Geomorphology and <span class="hlt">seismic</span> risk</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panizza, Mario</p> <p>1991-07-01</p> <p>The author analyses the contributions provided by geomorphology in studies suited to the assessment of <span class="hlt">seismic</span> risk: this is defined as function of the <span class="hlt">seismic</span> hazard, of the <span class="hlt">seismic</span> susceptibility, and of the vulnerability. The geomorphological studies applicable to <span class="hlt">seismic</span> risk assessment can be divided into two sectors: (a) morpho-neotectonic investigations conducted to identify active tectonic structures; (b) geomorphological and morphometric analyses aimed at identifying the particular situations that amplify or reduce <span class="hlt">seismic</span> susceptibility. The morpho-neotectonic studies lead to the identification, selection and classification of the lineaments that can be linked with active tectonic structures. The most important geomorphological situations that can condition <span class="hlt">seismic</span> susceptibility are: slope angle, debris, morphology, degradational slopes, paleo-landslides and underground cavities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060050243&hterms=quarks&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dquarks','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060050243&hterms=quarks&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dquarks"><span>Using the Moon As A Low-Noise <span class="hlt">Seismic</span> Detector For Strange Quark Nuggets</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Banerdt, W. Bruce; Chui, Talso; Griggs, Cornelius E.; Herrin, Eugene T.; Nakamura, Yosio; Paik, Ho Jung; Penanen, Konstantin; Rosenbaum, Doris; Teplitz, Vigdor L.; Young, Joseph</p> <p>2006-01-01</p> <p>Strange quark matter made of up, down and strange quarks has been postulated by Witten [1]. Strange quark matter would be nearly charge neutral and would have density of nuclear matter (10(exp 14) gm/cu cm). Witten also suggested that nuggets of strange quark matter, or strange quark nuggets (SQNs), could have formed shortly after the Big Bang, and that they would be viable candidates for cold dark matter. As suggested by de Rujula and Glashow [2], an SQN may pass through a celestial body <span class="hlt">releasing</span> detectable <span class="hlt">seismic</span> energy along a straight line. The Moon, being much quieter <span class="hlt">seismically</span> than the Earth, would be a favorable place to search for such events. We review previous searches for SQNs to illustrate the parameter space explored by using the Moon as a low-noise detector of SQNs. We also discuss possible detection schemes using a single seismometer, and using an International Lunar <span class="hlt">Seismic</span> Network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNS23A1929K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNS23A1929K"><span>Imaging the Danish Chalk Group with high resolution, 3-component <span class="hlt">seismics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kammann, J.; Rasmussen, S. L.; Nielsen, L.; Malehmir, A.; Stemmerik, L.</p> <p>2016-12-01</p> <p>The Chalk Group in the Danish Basin forms important reservoirs to hydrocarbons as well as water resources, and it has been subject to several <span class="hlt">seismic</span> studies to determine e.g. structural elements, deposition and burial history. This study focuses on the high quality <span class="hlt">seismic</span> response of a survey acquired with an <span class="hlt">accelerated</span> 45 kg weight drop and 3-component MEMS-based sensors and additional wireless vertical-type sensors. The 500 m long profile was acquired during one day close to a chalk quarry and chalk cliffs of the Stevns peninsula in eastern Denmark where the well-known K-T (Cretaceous-Tertiary) boundary and different chalk lithologies are well-exposed. With this simple and fast procedure we were able to achieve deep P-wave penetration to the base of the Chalk Group at about 900 m depth. Additionally, the CMP-processed <span class="hlt">seismic</span> image of the vertical component stands out by its high resolution. Sedimentary features are imaged in the near-surface Danian, as well as in the deeper Maastrichtian and Upper Campanian parts of the Chalk Group. Integration with borehole data suggests that changes in composition, in particular clay content, correlate with changes in reflectivity of the <span class="hlt">seismic</span> data set. While the pure chalk in the Maastrichtian deposits shows rather low reflectivity, succession enriched in clay appear to be more reflective. The integration of the mentioned methods gives the opportunity to connect changes in facies to the elastic response of the Chalk Group in its natural environmental conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSeis..21.1559P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSeis..21.1559P"><span>Neo-deterministic <span class="hlt">seismic</span> hazard scenarios for India—a preventive tool for disaster mitigation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parvez, Imtiyaz A.; Magrin, Andrea; Vaccari, Franco; Ashish; Mir, Ramees R.; Peresan, Antonella; Panza, Giuliano Francesco</p> <p>2017-11-01</p> <p>Current computational resources and physical knowledge of the <span class="hlt">seismic</span> wave generation and propagation processes allow for reliable numerical and analytical models of waveform generation and propagation. From the simulation of ground motion, it is easy to extract the desired earthquake hazard parameters. Accordingly, a scenario-based approach to <span class="hlt">seismic</span> hazard assessment has been developed, namely the neo-deterministic <span class="hlt">seismic</span> hazard assessment (NDSHA), which allows for a wide range of possible <span class="hlt">seismic</span> sources to be used in the definition of reliable scenarios by means of realistic waveforms modelling. Such reliable and comprehensive characterization of expected earthquake ground motion is essential to improve building codes, particularly for the protection of critical infrastructures and for land use planning. Parvez et al. (Geophys J Int 155:489-508, 2003) published the first ever neo-deterministic <span class="hlt">seismic</span> hazard map of India by computing synthetic seismograms with input data set consisting of structural models, seismogenic zones, focal mechanisms and earthquake catalogues. As described in Panza et al. (Adv Geophys 53:93-165, 2012), the NDSHA methodology evolved with respect to the original formulation used by Parvez et al. (Geophys J Int 155:489-508, 2003): the computer codes were improved to better fit the need of producing realistic ground shaking maps and ground shaking scenarios, at different scale levels, exploiting the most significant pertinent progresses in data acquisition and modelling. Accordingly, the present study supplies a revised NDSHA map for India. The <span class="hlt">seismic</span> hazard, expressed in terms of maximum displacement (Dmax), maximum velocity (Vmax) and design ground <span class="hlt">acceleration</span> (DGA), has been extracted from the synthetic signals and mapped on a regular grid over the studied territory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.C14A..01L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.C14A..01L"><span>Simultaneous observations of ice motion, calving and <span class="hlt">seismicity</span> on the Yahtse Glacier, Alaska. (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Larsen, C. F.; Bartholomaus, T. C.; O'Neel, S.; West, M. E.</p> <p>2010-12-01</p> <p>We observe ice motion, calving and <span class="hlt">seismicity</span> simultaneously and with high-resolution on an advancing tidewater glacier in Icy Bay, Alaska. Icy Bay’s tidewater glaciers dominate regional glacier-generated <span class="hlt">seismicity</span> in Alaska. Yahtse emanates from the St. Elias Range near the Bering-Bagley-Seward-Malaspina Icefield system, the most extensive glacier cover outside the polar regions. Rapid rates of change and fast flow (>16 m/d near the terminus) at Yahtse Glacier provide a direct analog to the disintegrating outlet systems in Greenland. Our field experiment co-locates GPS and seismometers on the surface of the glacier, with a greater network of bedrock seismometers surrounding the glacier. Time-lapse photogrammetry, fjord wave height sensors, and optical survey methods monitor iceberg calving and ice velocity near the terminus. This suite of geophysical instrumentation enables us to characterize glacier motion and geometry changes while concurrently listening for <span class="hlt">seismic</span> energy <span class="hlt">release</span>. We are performing a close examination of calving as a <span class="hlt">seismic</span> source, and the associated mechanisms of energy transfer to <span class="hlt">seismic</span> waves. Detailed observations of ice motion (GPS and optical surveying), glacier geometry and iceberg calving (direct observations and timelapse photogrammetry) have been made in concert with a passive <span class="hlt">seismic</span> network. Combined, the observations form the basis of a rigorous analysis exploring the relationship between glacier-generated <span class="hlt">seismic</span> events and motion, glacier-fiord interactions, calving and hydraulics. Our work is designed to demonstrate the applicability and utility of seismology to study the impact of climate forcing on calving glaciers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.C43B0803C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.C43B0803C"><span>Laboratory investigations of <span class="hlt">seismicity</span> caused by iceberg calving and capsize</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cathles, L. M. M., IV; Kaluzienski, L. M.; Burton, J. C.</p> <p>2015-12-01</p> <p>The calving and capsize of cubic kilometer-sized icebergs in both Greenland and Antarctica are known to be the source of long-period <span class="hlt">seismic</span> events classified as glacial earthquakes. The ability to monitor both calving events and the mass of ice calved using the Global Seismographic Network is quite attractive, however, the basic physics of these large calving events must be understood to develop a robust relationship between <span class="hlt">seismic</span> magnitude and mass of ice calved. The amplitude and duration of the <span class="hlt">seismic</span> signal is expected to be related to the mass of the calved iceberg and the magnitude of the <span class="hlt">acceleration</span> of the iceberg's center of mass, yet a simple relationship between these quantities has proved difficult to develop from in situ observations or numerical models. To address this, we developed and carried out a set of experiments on a laboratory scale model of iceberg calving. These experiments were designed to measure several aspects of the post-fracture calving process. Our results show that a combination of mechanical contact forces and hydrodynamic pressure forces are generated by the capsize of an iceberg adjacent to a glacier's terminus. These forces combine to produce the net horizontal centroid single force (CSF) which is often used to model glacial earthquake sources. We find that although the amplitude and duration of the force applied to the terminus generally increases with the iceberg mass, the details depend on the geometry of the iceberg and the depth of the water. The resulting <span class="hlt">seismic</span> signal is thus crucially dependent on hydrodynamics of the capsize process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://seismic.alaska.gov','SCIGOVWS'); return false;" href="http://seismic.alaska.gov"><span>Alaska <span class="hlt">Seismic</span> Hazards Safety Commission</span></a></p> <p><a target="_blank" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a></p> <p></p> <p></p> <p>State Employees ASHSC State of Alaska search Alaska <span class="hlt">Seismic</span> Hazards <em>Safety</em> Commission View of Anchorage and Commissions Alaska <span class="hlt">Seismic</span> Hazards <em>Safety</em> Commission (ASHSC) main contant Alaska <span class="hlt">Seismic</span> Hazards <em>Safety</em> Commission logo Alaska <span class="hlt">Seismic</span> Hazards <em>Safety</em> Commission (ASHSC) - Mission The Alaska <span class="hlt">Seismic</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LNP...778..157V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LNP...778..157V"><span>The Solar Flare: A Strongly Turbulent Particle <span class="hlt">Accelerator</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vlahos, L.; Krucker, S.; Cargill, P.</p> <p></p> <p>The topics of explosive magnetic energy <span class="hlt">release</span> on a large scale (a solar flare) and particle <span class="hlt">acceleration</span> during such an event are rarely discussed together in the same article. Many discussions of magnetohydrodynamic (MHD) mod- eling of solar flares and/or CMEs have appeared (see [143] and references therein) and usually address large-scale destabilization of the coronal mag- netic field. Particle <span class="hlt">acceleration</span> in solar flares has also been discussed exten- sively [74, 164, 116, 166, 87, 168, 95, 122, 35] with the main emphasis being on the actual mechanisms for <span class="hlt">acceleration</span> (e.g., shocks, turbulence, DC electric fields) rather than the global magnetic context in which the <span class="hlt">acceleration</span> takes place.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S51A2642V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S51A2642V"><span><span class="hlt">Seismic</span> Scenario in the Acambay Graben and Possible Affectations in the Miguel Hidalgo Refinery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valderrama Membrillo, S.; Aguirre, J.</p> <p>2015-12-01</p> <p>In this paper we presented synthetic <span class="hlt">acceleration</span> records in the Miguel Hidalgo refinery, Hidalgo due to a <span class="hlt">seismic</span> scenario originated in the graben Acambay, such as occurred in 1912 (70 km distance to it). This earthquake had a magnitude of 6.9 and caused extensive damage, according to reports caused 164 deaths and numerous houses collapsing. To simulate the event of M = 6.9 we used the empirical Greeńs function method proposed by Irikura (1986). Due to the low <span class="hlt">seismic</span> activity we have not any small earthquake record or an "element earthquake" so that we generated a synthetic seismogram of M = 4.1 to be used as empirical Greeńs function. The seismogram was constructed in two parts. For low frequencies we constructed from cross-correlations of <span class="hlt">seismic</span> noise, while for high frequencies we made a stochastic simulation. Subsequently, we applied a "matched filter" to join the two frequency bands of synthetic earthquake. For the construction of <span class="hlt">seismic</span> scenario the method of Irikura (1986) was used. We consider a square fault of 47.75 km long, a radial rupture propagation, rupture velocity of 3.06 m/s, and with the following focal mechanism: strike of 280°, dip of 66 ° and rake of -138 °. With these parameters we obtained the synthetic seismograms. Since there was not any observed earthquake to validate the model, the 1912 event was simulated and then from relationships of intensity (obtained Wald et al.,2005; Sandoval et al., 2013; and Arias, 1969), we estimated the Modified Mercalli Intensity (MMI) for the refinery. We compare our result with isoseismal map obtained by Suter et al. (1996) for the earthquake of 1912. In agreement with Suter, our results shown a MMI V-VI for the Miguel Hidalgo refinery. With this qualitative validation we search the <span class="hlt">seismic</span> scenario with the higher <span class="hlt">accelerations</span> and from this synthetic seismogram, we obtained parameters that are of interest in engineering to estimate the possible affectations to the Miguel Hidalgo refinery, such as</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S43C2877M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S43C2877M"><span>Tectonic history in the Fort Worth Basin, north Texas, derived from well-log integration with multiple 3D <span class="hlt">seismic</span> reflection surveys: implications for paleo and present-day <span class="hlt">seismicity</span> in the basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Magnani, M. B.; Hornbach, M. J.</p> <p>2016-12-01</p> <p>Oil and gas exploration and production in the Fort Worth Basin (FWB) in north Texas have <span class="hlt">accelerated</span> in the last 10 years due to the success of unconventional gas production. Here, hydraulic fracturing wastewater is disposed via re-injection into deep wells that penetrate Ordovician carbonate formations. The rise in wastewater injection has coincided with a marked rise in earthquake rates, suggesting a causal relationship between industry practices and <span class="hlt">seismicity</span>. Most studies addressing this relationship in intraplate regions like the FWB focus on current <span class="hlt">seismicity</span>, which provides an a-posteriori assessment of the processes involved. 3D <span class="hlt">seismic</span> reflection data contribute complementary information on the existence, distribution, orientation and long-term deformation history of faults that can potentially become reactivated by the injection process. Here we present new insights into the tectonic evolution of faults in the FWB using multiple 3D <span class="hlt">seismic</span> reflection surveys in the basin, west of the Dallas Fort-Worth Metroplex, where high-volume wastewater injection wells have increased most significantly in number in the past few years. The datasets image with remarkable clarity the 3,300 m-thick sedimentary rocks of the basin, from the crystalline basement to the Cretaceous cover, with particular detail of the Paleozoic section. The data, interpreted using coincident and nearby wells to correlate <span class="hlt">seismic</span> reflections with stratigraphic markers, allow us to identify faults, extract their orientation, length and displacements at several geologic time intervals, and therefore, reconstruct the long-term deformation history. Throughout the basin, the data show that all <span class="hlt">seismically</span> detectable faults were active during the Mississippian and Pennsylvanian, but that displacement amounts drop below data resolution ( 7 m) in the post-Pennsylvanian deposits. These results indicate that faults have been inactive for at least the past 300 Ma, until the recent 2008 surge in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S23A2469S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S23A2469S"><span>Effect of strong elastic contrasts on the propagation of <span class="hlt">seismic</span> wave in hard-rock environments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saleh, R.; Zheng, L.; Liu, Q.; Milkereit, B.</p> <p>2013-12-01</p> <p>Understanding the propagation of <span class="hlt">seismic</span> waves in a presence of strong elastic contrasts, such as topography, tunnels and ore-bodies is still a challenge. Safety in mining is a major concern and <span class="hlt">seismic</span> monitoring is the main tool here. For engineering purposes, amplitudes (peak particle velocity/<span class="hlt">acceleration</span>) and travel times of <span class="hlt">seismic</span> events (mostly blasts or microseismic events) are critical parameters that have to be determined at various locations in a mine. These parameters are useful in preparing risk maps or to better understand the process of spatial and temporal stress distributions in a mine. Simple constant velocity models used for monitoring studies in mining, cannot explain the observed complexities in scattered <span class="hlt">seismic</span> waves. In hard-rock environments modeling of elastic <span class="hlt">seismic</span> wavefield require detailed 3D petrophysical, infrastructure and topographical data to simulate the propagation of <span class="hlt">seismic</span> wave with a frequencies up to few kilohertz. With the development of efficient numerical techniques, and parallel computation facilities, a solution for such a problem is achievable. In this study, the effects of strong elastic contrasts such as ore-bodies, rough topography and tunnels will be illustrated using 3D modeling method. The main tools here are finite difference code (SOFI3D)[1] that has been benchmarked for engineering studies, and spectral element code (SPECFEM) [2], which was, developed for global seismology problems. The modeling results show locally enhanced peak particle velocity due to presence of strong elastic contrast and topography in models. [1] Bohlen, T. Parallel 3-D viscoelastic finite difference <span class="hlt">seismic</span> modeling. Computers & Geosciences 28 (2002) 887-899 [2] Komatitsch, D., and J. Tromp, Introduction to the spectral-element method for 3-D <span class="hlt">seismic</span> wave propagation, Geophys. J. Int., 139, 806-822, 1999.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGE....15...13K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGE....15...13K"><span>Probabilistic <span class="hlt">seismic</span> hazard assessments of Sabah, east Malaysia: accounting for local earthquake activity near Ranau</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khalil, Amin E.; Abir, Ismail A.; Ginsos, Hanteh; Abdel Hafiez, Hesham E.; Khan, Sohail</p> <p>2018-02-01</p> <p>Sabah state in eastern Malaysia, unlike most of the other Malaysian states, is characterized by common seismological activity; generally an earthquake of moderate magnitude is experienced at an interval of roughly every 20 years, originating mainly from two major sources, either a local source (e.g. Ranau and Lahad Dato) or a regional source (e.g. Kalimantan and South Philippines subductions). The <span class="hlt">seismicity</span> map of Sabah shows the presence of two zones of distinctive <span class="hlt">seismicity</span>, these zones are near Ranau (near Kota Kinabalu) and Lahad Datu in the southeast of Sabah. The <span class="hlt">seismicity</span> record of Ranau begins in 1991, according to the international <span class="hlt">seismicity</span> bulletins (e.g. United States Geological Survey and the International Seismological Center), and this short record is not sufficient for <span class="hlt">seismic</span> source characterization. Fortunately, active Quaternary fault systems are delineated in the area. Henceforth, the <span class="hlt">seismicity</span> of the area is thus determined as line sources referring to these faults. Two main fault systems are believed to be the source of such activities; namely, the Mensaban fault zone and the Crocker fault zone in addition to some other faults in their vicinity. <span class="hlt">Seismic</span> hazard assessments became a very important and needed study for the extensive developing projects in Sabah especially with the presence of earthquake activities. Probabilistic <span class="hlt">seismic</span> hazard assessments are adopted for the present work since it can provide the probability of various ground motion levels during expected from future large earthquakes. The output results are presented in terms of spectral <span class="hlt">acceleration</span> curves and uniform hazard curves for periods of 500, 1000 and 2500 years. Since this is the first time that a complete hazard study has been done for the area, the output will be a base and standard for any future strategic plans in the area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70045047','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70045047"><span>Challenges in making a <span class="hlt">seismic</span> hazard map for Alaska and the Aleutians</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wesson, R.L.; Boyd, O.S.; Mueller, C.S.; Frankel, A.D.; Freymueller, J.T.</p> <p>2008-01-01</p> <p>We present a summary of the data and analyses leading to the revision of the time-independent probabilistic <span class="hlt">seismic</span> hazard maps of Alaska and the Aleutians. These maps represent a revision of existing maps based on newly obtained data, and reflect best current judgments about methodology and approach. They have been prepared following the procedures and assumptions made in the preparation of the 2002 National <span class="hlt">Seismic</span> Hazard Maps for the lower 48 States, and will be proposed for adoption in future revisions to the International Building Code. We present example maps for peak ground <span class="hlt">acceleration</span>, 0.2 s spectral amplitude (SA), and 1.0 s SA at a probability level of 2% in 50 years (annual probability of 0.000404). In this summary, we emphasize issues encountered in preparation of the maps that motivate or require future investigation and research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1001364','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1001364"><span>Neuromuscular Control of Rapid Linear <span class="hlt">Accelerations</span> in Fish</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2016-06-22</p> <p>2014 30-Apr-2015 Approved for Public <span class="hlt">Release</span>; Distribution Unlimited Final Report: Neuromuscular Control of Rapid Linear <span class="hlt">Accelerations</span> in Fish The...it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. Tufts University Research... Control of Rapid Linear <span class="hlt">Accelerations</span> in Fish Report Title In this project, we measured muscle activity, body movements, and flow patterns during linear</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PApGe.169.1519R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PApGe.169.1519R"><span><span class="hlt">Seismic</span> Hazard and Ground Motion Characterization at the Itoiz Dam (Northern Spain)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rivas-Medina, A.; Santoyo, M. A.; Luzón, F.; Benito, B.; Gaspar-Escribano, J. M.; García-Jerez, A.</p> <p>2012-08-01</p> <p>This paper presents a new hazard-consistent ground motion characterization of the Itoiz dam site, located in Northern Spain. Firstly, we propose a methodology with different approximation levels to the expected ground motion at the dam site. Secondly, we apply this methodology taking into account the particular characteristics of the site and of the dam. Hazard calculations were performed following the Probabilistic <span class="hlt">Seismic</span> Hazard Assessment method using a logic tree, which accounts for different <span class="hlt">seismic</span> source zonings and different ground-motion attenuation relationships. The study was done in terms of peak ground <span class="hlt">acceleration</span> and several spectral <span class="hlt">accelerations</span> of periods coinciding with the fundamental vibration periods of the dam. In order to estimate these ground motions we consider two different dam conditions: when the dam is empty ( T = 0.1 s) and when it is filled with water to its maximum capacity ( T = 0.22 s). Additionally, <span class="hlt">seismic</span> hazard analysis is done for two return periods: 975 years, related to the project earthquake, and 4,975 years, identified with an extreme event. Soil conditions were also taken into account at the site of the dam. Through the proposed methodology we deal with different forms of characterizing ground motion at the study site. In a first step, we obtain the uniform hazard response spectra for the two return periods. In a second step, a disaggregation analysis is done in order to obtain the controlling earthquakes that can affect the dam. Subsequently, we characterize the ground motion at the dam site in terms of specific response spectra for target motions defined by the expected values SA ( T) of T = 0.1 and 0.22 s for the return periods of 975 and 4,975 years, respectively. Finally, synthetic <span class="hlt">acceleration</span> time histories for earthquake events matching the controlling parameters are generated using the discrete wave-number method and subsequently analyzed. Because of the short relative distances between the controlling</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9803E..4IL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9803E..4IL"><span>Analysis of longitudinal <span class="hlt">seismic</span> response of bridge with magneto-rheological elastomeric bearings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Rui; Li, Xi; Wu, Yueyuan; Chen, Shiwei; Wang, Xiaojie</p> <p>2016-04-01</p> <p>As the weakest part in the bridge system, traditional bridge bearing is incapable of isolating the impact load such as earthquake. A magneto-rheological elastomeric bearing (MRB) with adjustable stiffness and damping parameters is designed, tested and modeled. The developed Bouc-Wen model is adopted to represent the constitutive relation and force-displacement behavior of an MRB. Then, the lead rubber bearing (LRB), passive MRB and controllable MRB are modeled by finite element method (FEM). Furthermore, two typical <span class="hlt">seismic</span> waves are adopted as inputs for the isolation system of bridge <span class="hlt">seismic</span> response. The experiments are carried out to investigate the different response along the bridge with on-off controlled MRBs. The results show that the isolating performance of MRB is similar to that of traditional LRB, which ensures the fail-safe capability of bridge with MRBs under <span class="hlt">seismic</span> excitation. In addition, the controllable bridge with MRBs demonstrated the advantage of isolating capacity and energy dissipation, because it restrains the <span class="hlt">acceleration</span> peak of bridge beam by 33.3%, and the displacement of bearing decrease by 34.1%. The shear force of the pier top is also alleviated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S41B4485S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S41B4485S"><span>Effect of Velocity of Detonation of Explosives on <span class="hlt">Seismic</span> Radiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stroujkova, A. F.; Leidig, M.; Bonner, J. L.</p> <p>2014-12-01</p> <p>We studied <span class="hlt">seismic</span> body wave generation from four fully contained explosions of approximately the same yields (68 kg of TNT equivalent) conducted in anisotropic granite in Barre, VT. The explosions were detonated using three types of explosives with different velocities of detonation (VOD): Black Powder (BP), Ammonium Nitrate Fuel Oil/Emulsion (ANFO), and Composition B (COMP B). The main objective of the experiment was to study differences in <span class="hlt">seismic</span> wave generation among different types of explosives, and to determine the mechanism responsible for these differences. The explosives with slow burn rate (BP) produced lower P-wave amplitude and lower corner frequency, which resulted in lower <span class="hlt">seismic</span> efficiency (0.35%) in comparison with high burn rate explosives (2.2% for ANFO and 3% for COMP B). The <span class="hlt">seismic</span> efficiency estimates for ANFO and COMP B agree with previous studies for nuclear explosions in granite. The body wave radiation pattern is consistent with an isotropic explosion with an added azimuthal component caused by vertical tensile fractures oriented along pre-existing micro-fracturing in the granite, although the complexities in the P- and S-wave radiation patterns suggest that more than one fracture orientation could be responsible for their generation. High S/P amplitude ratios and low P-wave amplitudes suggest that a significant fraction of the BP source mechanism can be explained by opening of the tensile fractures as a result of the slow energy <span class="hlt">release</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1113807R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1113807R"><span>Application of a time probabilistic approach to <span class="hlt">seismic</span> landslide hazard estimates in Iran</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rajabi, A. M.; Del Gaudio, V.; Capolongo, D.; Khamehchiyan, M.; Mahdavifar, M. R.</p> <p>2009-04-01</p> <p>Iran is a country located in a tectonic active belt and is prone to earthquake and related phenomena. In the recent years, several earthquakes caused many fatalities and damages to facilities, e.g. the Manjil (1990), Avaj (2002), Bam (2003) and Firuzabad-e-Kojur (2004) earthquakes. These earthquakes generated many landslides. For instance, catastrophic landslides triggered by the Manjil Earthquake (Ms = 7.7) in 1990 buried the village of Fatalak, killed more than 130 peoples and cut many important road and other lifelines, resulting in major economic disruption. In general, earthquakes in Iran have been concentrated in two major zones with different <span class="hlt">seismicity</span> characteristics: one is the region of Alborz and Central Iran and the other is the Zagros Orogenic Belt. Understanding where <span class="hlt">seismically</span> induced landslides are most likely to occur is crucial in reducing property damage and loss of life in future earthquakes. For this purpose a time probabilistic approach for earthquake-induced landslide hazard at regional scale, proposed by Del Gaudio et al. (2003), has been applied to the whole Iranian territory to provide the basis of hazard estimates. This method consists in evaluating the recurrence of <span class="hlt">seismically</span> induced slope failure conditions inferred from the Newmark's model. First, by adopting Arias Intensity to quantify <span class="hlt">seismic</span> shaking and using different Arias attenuation relations for Alborz - Central Iran and Zagros regions, well-established methods of <span class="hlt">seismic</span> hazard assessment, based on the Cornell (1968) method, were employed to obtain the occurrence probabilities for different levels of <span class="hlt">seismic</span> shaking in a time interval of interest (50 year). Then, following Jibson (1998), empirical formulae specifically developed for Alborz - Central Iran and Zagros, were used to represent, according to the Newmark's model, the relation linking Newmark's displacement Dn to Arias intensity Ia and to slope critical <span class="hlt">acceleration</span> ac. These formulae were employed to evaluate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70023610','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70023610"><span>Geographic deaggregation of <span class="hlt">seismic</span> hazard in the United States</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Harmsen, S.; Frankel, A.</p> <p>2001-01-01</p> <p>The <span class="hlt">seismic</span> hazard calculations for the 1996 national <span class="hlt">seismic</span> hazard maps have been geographically deaggregated to assist in the understanding of the relative contributions of sources. These deaggregations are exhibited as maps with vertical bars whose heights are proportional to the contribution that each geographical cell makes to the ground-motion exceedance hazard. Bar colors correspond to average source magnitudes. We also extend the deaggregation analysis reported in Harmsen et al. (1999) to the western conterminous United States. In contrast to the central and eastern United States (CEUS); the influence of specific faults or characteristic events can be clearly identified. Geographic deaggregation for 0.2-sec and 1.0-sec pseudo spectral <span class="hlt">acceleration</span> (SA) is performed for 10% probability of exceedance (PE) in 50 yr (475-yr mean return period) and 2% PE in 50 yr (2475-yr mean return period) for four western U.S. cities, Los Angeles, Salt Lake City, San Francisco, and Seattle, and for three central and eastern U.S. cities, Atlanta, Boston, and Saint Louis. In general, as the PE is lowered, the sources of hazard closer to the site dominate. Larger, more distant earthquakes contribute more significantly to hazard for 1.0-sec SA than for 0.2-sec SA. Additional maps of geographically deaggregated <span class="hlt">seismic</span> hazard are available on the Internet for 120 cities in the conterminous United States (http://geohazards. cr.usgs.gov/eq/) for 1-sec SA and for 0.2-sec SA with a 2% PE in 50 yr. Examination of these maps of hazard contributions enables the investigator to determine the distance and azimuth to predominant sources, and their magnitudes. This information can be used to generate scenario earthquakes and corresponding time histories for <span class="hlt">seismic</span> design and retrofit. Where fault density is lower than deaggregation cell dimensions, we can identify specific faults that contribute significantly to the <span class="hlt">seismic</span> hazard at a given site. Detailed fault information enables</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992seas.rept.....K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992seas.rept.....K"><span>A semi-empirical analysis of strong-motion peaks in terms of <span class="hlt">seismic</span> source, propagation path, and local site conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kamiyama, M.; Orourke, M. J.; Flores-Berrones, R.</p> <p>1992-09-01</p> <p>A new type of semi-empirical expression for scaling strong-motion peaks in terms of <span class="hlt">seismic</span> source, propagation path, and local site conditions is derived. Peak <span class="hlt">acceleration</span>, peak velocity, and peak displacement are analyzed in a similar fashion because they are interrelated. However, emphasis is placed on the peak velocity which is a key ground motion parameter for lifeline earthquake engineering studies. With the help of <span class="hlt">seismic</span> source theories, the semi-empirical model is derived using strong motions obtained in Japan. In the derivation, statistical considerations are used in the selection of the model itself and the model parameters. Earthquake magnitude M and hypocentral distance r are selected as independent variables and the dummy variables are introduced to identify the amplification factor due to individual local site conditions. The resulting semi-empirical expressions for the peak <span class="hlt">acceleration</span>, velocity, and displacement are then compared with strong-motion data observed during three earthquakes in the U.S. and Mexico.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.S44C..04T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.S44C..04T"><span><span class="hlt">Seismic</span> Hazard Assessment of Middle East Region: Based on the Example to Georgia (Preliminary results)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsereteli, N. S.; Akkar, S.; Askan, A.; Varazanashvili, O.; Adamia, S.; Chkhitunidze, M.</p> <p>2012-12-01</p> <p>The country of Georgia is located between Russia and Turkey. The main morphological units of Georgia are the mountain ranges of the Greater and Lesser Caucasus separated by the Black Sea-Rioni and Kura (Mtkvari)-South Caspian intermountain troughs. Recent geodynamics of Georgia and adjacent territories of the Black Sea-Caspian Sea region, as a whole, are determined by its position between the still-converging Eurasian and Africa-Arabian plates. That caused moderate <span class="hlt">seismicity</span> in the region. However, the risk resulting from these earthquakes is considerably high, as recent events during the last two decades have shown. <span class="hlt">Seismic</span> hazard and risk assessment is a major research topic in various recent international and national projects. Despite the current efforts, estimation of regional <span class="hlt">seismic</span> hazard assessment remains as a major problem. Georgia is one of the partners of ongoing regional project EMME (Earthquake Model for Middle East region). The main objective of EMME is calculation of Earthquake hazard uniformly with heights standards. One approach used in the project is the probabilistic <span class="hlt">seismic</span> hazard assessment PSHA. In this study, we present the preliminary results of PSHA for Georgia in this project attempting to improve gaps especially in such steps as: determination of <span class="hlt">seismic</span> sources; selection or derivation of ground motion prediction equations models; estimation of maximum magnitude Mmax. <span class="hlt">Seismic</span> sources (SS) were obtained on the bases of structural geology, parameters of <span class="hlt">seismicity</span> and seismotectonics. Finely new SS have been developed for Georgia and adjacent region. Each zone was defined with the following parameters: the magnitude-frequency parameters, maximum magnitude, and depth distribution as well as modern dynamical characteristics widely used for complex processes. As the ground motion dataset is absolutely insufficient by itself to derive a ground motion prediction model for Georgia, two approaches were taken in defining ground motions. First</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1185183-self-replenishing-vascularized-fouling-release-surfaces','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1185183-self-replenishing-vascularized-fouling-release-surfaces"><span>Self-Replenishing Vascularized Fouling-<span class="hlt">Release</span> Surfaces</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Howell, Caitlin; Vu, Thy L.; Lin, Jennifer J.; ...</p> <p>2014-08-13</p> <p>Inspired by the long-term effectiveness of living antifouling materials, we have developed a method for the selfreplenishment of synthetic biofouling-<span class="hlt">release</span> surfaces. These surfaces are created by either molding or directly embedding 3D vascular systems into polydimethylsiloxane (PDMS) and filling them with a silicone oil to generate a nontoxic oil-infused material. When replenished with silicone oil from an outside source, these materials are capable of self-lubrication and continuous renewal of the interfacial fouling-<span class="hlt">release</span> layer. Under <span class="hlt">accelerated</span> lubricant loss conditions, fully infused vascularized samples retained significantly more lubricant than equivalent nonvascularized controls. Tests of lubricant-infused PDMS in static cultures of the infectiousmore » bacteria Staphylococcus aureus and Escherichia coli as well as the green microalgae Botryococcus braunii, Chlamydomonas reinhardtii, Dunaliella salina, and Nannochloropsis oculata showed a significant reduction in biofilm adhesion compared to PDMS and glass controls containing no lubricant. Further experiments on vascularized versus nonvascularized samples that had been subjected to <span class="hlt">accelerated</span> lubricant evaporation conditions for up to 48 h showed significantly less biofilm adherence on the vascularized surfaces. These results demonstrate the ability of an embedded lubricant-filled vascular network to improve the longevity of fouling-<span class="hlt">release</span> surfaces.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70189628','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70189628"><span>St. Louis area earthquake hazards mapping project; <span class="hlt">seismic</span> and liquefaction hazard maps</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cramer, Chris H.; Bauer, Robert A.; Chung, Jae-won; Rogers, David; Pierce, Larry; Voigt, Vicki; Mitchell, Brad; Gaunt, David; Williams, Robert; Hoffman, David; Hempen, Gregory L.; Steckel, Phyllis; Boyd, Oliver; Watkins, Connor M.; Tucker, Kathleen; McCallister, Natasha</p> <p>2016-01-01</p> <p>We present probabilistic and deterministic <span class="hlt">seismic</span> and liquefaction hazard maps for the densely populated St. Louis metropolitan area that account for the expected effects of surficial geology on earthquake ground shaking. Hazard calculations were based on a map grid of 0.005°, or about every 500 m, and are thus higher in resolution than any earlier studies. To estimate ground motions at the surface of the model (e.g., site amplification), we used a new detailed near‐surface shear‐wave velocity model in a 1D equivalent‐linear response analysis. When compared with the 2014 U.S. Geological Survey (USGS) National <span class="hlt">Seismic</span> Hazard Model, which uses a uniform firm‐rock‐site condition, the new probabilistic seismic‐hazard estimates document much more variability. Hazard levels for upland sites (consisting of bedrock and weathered bedrock overlain by loess‐covered till and drift deposits), show up to twice the ground‐motion values for peak ground <span class="hlt">acceleration</span> (PGA), and similar ground‐motion values for 1.0 s spectral <span class="hlt">acceleration</span> (SA). Probabilistic ground‐motion levels for lowland alluvial floodplain sites (generally the 20–40‐m‐thick modern Mississippi and Missouri River floodplain deposits overlying bedrock) exhibit up to twice the ground‐motion levels for PGA, and up to three times the ground‐motion levels for 1.0 s SA. Liquefaction probability curves were developed from available standard penetration test data assuming typical lowland and upland water table levels. A simplified liquefaction hazard map was created from the 5%‐in‐50‐year probabilistic ground‐shaking model. The liquefaction hazard ranges from low (60% of area expected to liquefy) in the lowlands. Because many transportation routes, power and gas transmission lines, and population centers exist in or on the highly susceptible lowland alluvium, these areas in the St. Louis region are at significant potential risk from <span class="hlt">seismically</span> induced liquefaction and associated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996EOSTr..77..289H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996EOSTr..77..289H"><span>Multi-Use <span class="hlt">seismic</span> stations offer strong deterrent to clandestine nuclear weapons testing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hennet, C. B.; Van der Vink, G. E.; Richards, P. G.; Adushkin, V. V.; Kopnichev, Y. F.; Geary, R.</p> <p></p> <p>As the United States and other nations push for the signing of a Comprehensive Test Ban Treaty, representatives are meeting in Geneva this year to develop an International <span class="hlt">Seismic</span> Monitoring System to verify compliance with the treaty's restrictions. In addition to the official monitoring system, regional networks developed for earthquake studies and basic research can provide a strong deterrent against clandestine testing. The recent <span class="hlt">release</span> of information by the U.S. Department of Energy (DoE) on previously unannounced nuclear tests provides an opportunity to assess the ability of multi-use <span class="hlt">seismic</span> networks to help monitor nuclear testing across the globe.Here we look at the extent to which the formerly unannounced tests were recorded and identified on the basis of publicly available seismographic data recorded by five <span class="hlt">seismic</span> networks. The data were recorded by networks in southern Nevada and northern California at stations less than 1500 km from the Nevada Test Site (NTS), and two networks in the former Soviet Union at stations farther than 1500 km from the NTS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1917395S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1917395S"><span>On the use of faults and background <span class="hlt">seismicity</span> in <span class="hlt">Seismic</span> Probabilistic Tsunami Hazard Analysis (SPTHA)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Selva, Jacopo; Lorito, Stefano; Basili, Roberto; Tonini, Roberto; Tiberti, Mara Monica; Romano, Fabrizio; Perfetti, Paolo; Volpe, Manuela</p> <p>2017-04-01</p> <p>Most of the SPTHA studies and applications rely on several working assumptions: i) the - mostly offshore - tsunamigenic faults are sufficiently well known; ii) the subduction zone earthquakes dominate the hazard; iii) and their location and geometry is sufficiently well constrained. Hence, a probabilistic model is constructed as regards the magnitude-frequency distribution and sometimes the slip distribution of earthquakes occurring on assumed known faults. Then, tsunami scenarios are usually constructed for all earthquakes location, sizes, and slip distributions included in the probabilistic model, through deterministic numerical modelling of tsunami generation, propagation and impact on realistic bathymetries. Here, we adopt a different approach (Selva et al., GJI, 2016) that <span class="hlt">releases</span> some of the above assumptions, considering that i) also non-subduction earthquakes may contribute significantly to SPTHA, depending on the local tectonic context; ii) that not all the offshore faults are known or sufficiently well constrained; iii) and that the faulting mechanism of future earthquakes cannot be considered strictly predictable. This approach uses as much as possible information from known faults which, depending on the amount of available information and on the local tectonic complexity, among other things, are either modelled as Predominant <span class="hlt">Seismicity</span> (PS) or as Background <span class="hlt">Seismicity</span> (BS). PS is used when it is possible to assume sufficiently known geometry and mechanism (e.g. for the main subduction zones). Conversely, within the BS approach information on faults is merged with that on past <span class="hlt">seismicity</span>, dominant stress regime, and tectonic characterisation, to determine a probability density function for the faulting mechanism. To illustrate the methodology and its impact on the hazard estimates, we present an application in the NEAM region (Northeast Atlantic, Mediterranean and connected seas), initially designed during the ASTARTE project and now applied for the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.S14B..08S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.S14B..08S"><span>Mineral, Virginia earthquake illustrates <span class="hlt">seismicity</span> of a passive-aggressive margin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stein, S. A.; Pazzaglia, F. J.; Meltzer, A.; Berti, C.; Wolin, E.; Kafka, A. L.</p> <p>2011-12-01</p> <p>The August 2011 M5.8 Virginia earthquake illustrated again that "passive" continental margins, at which the continent and neighboring seafloor are part of the same plate, are often <span class="hlt">seismically</span> active. This phenomenon occurs worldwide, with the east coast of North America a prime example. Examples from North to South include the 1933 M 7.3 Baffin Bay, 1929 M 7.2 Grand Banks of Newfoundland, 1755 M 6 Cape Ann, Massachusetts, and 1886 M 7 Charleston earthquakes. The mechanics of these earthquakes remains unclear. Their overall alignment along the margin suggests that they reflect reactivation of generally margin-parallel faults remaining from continental convergence and later rifting by the modern stress field. This view accords with the occurrence of the Virginia earthquake by reverse faulting on a margin-parallel NE-SW striking fault. However, it occurred on the northern edge of the central Virginia <span class="hlt">seismic</span> zone, a <span class="hlt">seismic</span> trend normal to the fault plane, margin, and associated structures, that has no clear geologic expression. Hence it is unclear why this and similar <span class="hlt">seismic</span> zones have the geometry they do. Although it is tempting to correlate these zones with extensions of Atlantic fracture zones, this correlation has little explanatory power given the large number of such zones. It is similarly unclear whether these zones and the intervening <span class="hlt">seismic</span> gaps reflect areas that are relatively more active over time, or are instead the present loci of activity that migrates. It is also possible that the presently-active zones reflect long-lived aftershocks of large prehistoric earthquakes. The forces driving the <span class="hlt">seismicity</span> are also unclear. In general, <span class="hlt">seismic</span> moment <span class="hlt">release</span> decreases southward along the margin, consistent with the variation in vertical motion rates observed by GPS, suggesting that glacial-isostatic adjustment (GIA) provides some of the stresses involved. However, in the mid-Atlantic region - south of the area of significant GIA - deformed stratigraphic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S21B0702N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S21B0702N"><span><span class="hlt">Seismic</span> dynamics in advance and after the recent strong earthquakes in Italy and New Zealand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nekrasova, A.; Kossobokov, V. G.</p> <p>2017-12-01</p> <p>We consider <span class="hlt">seismic</span> events as a sequence of avalanches in self-organized system of blocks-and-faults of the Earth lithosphere and characterize earthquake series with the distribution of the control parameter, η = τ × 10B × (5-M) × L C of the Unified Scaling Law for Earthquakes, USLE (where τ is inter-event time, B is analogous to the Gutenberg-Richter b-value, and C is fractal dimension of <span class="hlt">seismic</span> locus). A systematic analysis of earthquake series in Central Italy and New Zealand, 1993-2017, suggests the existence, in a long-term, of different rather steady levels of <span class="hlt">seismic</span> activity characterized with near constant values of η, which, in mid-term, intermittently switch at times of transitions associated with the strong catastrophic events. On such a transition, <span class="hlt">seismic</span> activity, in short-term, may follow different scenarios with inter-event time scaling of different kind, including constant, logarithmic, power law, exponential rise/decay or a mixture of those. The results do not support the presence of universality in <span class="hlt">seismic</span> energy <span class="hlt">release</span>. The observed variability of <span class="hlt">seismic</span> activity in advance and after strong (M6.0+) earthquakes in Italy and significant (M7.0+) earthquakes in New Zealand provides important constraints on modelling realistic earthquake sequences by geophysicists and can be used to improve local <span class="hlt">seismic</span> hazard assessments including earthquake forecast/prediction methodologies. The transitions of <span class="hlt">seismic</span> regime in Central Italy and New Zealand started in 2016 are still in progress and require special attention and geotechnical monitoring. It would be premature to make any kind of definitive conclusions on the level of <span class="hlt">seismic</span> hazard which is evidently high at this particular moment of time in both regions. The study supported by the Russian Science Foundation Grant No.16-17-00093.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JSeis..19..667A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JSeis..19..667A"><span>Ghana's experience in the establishment of a national digital <span class="hlt">seismic</span> network observatory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahulu, Sylvanus; Danuor, Sylvester Kojo</p> <p>2015-07-01</p> <p>The Government of Ghana has established a National Digital <span class="hlt">Seismic</span> Network Observatory in Ghana with the aim of monitoring events such as earthquakes, blasts from mining and quarrying, nuclear tests, etc. The Digital Observatory was commissioned on 19 December 2012, and was dedicated to Geosciences in Ghana. Previously Ghana did not have any operational, digital <span class="hlt">seismic</span> network acquisition system with the capability of monitoring and analysing data for planning and research purposes. The Ghana Geological Survey has been monitoring <span class="hlt">seismic</span> events with an analogue system which was not efficient and does not deliver real-time data. Hence, the importance of setting up the National Digital <span class="hlt">Seismic</span> Network System which would enable the Geological Survey to constantly monitor, manage and coordinate both natural and man-made <span class="hlt">seismic</span> activities in the country and around the globe, to some extent on real-time basis. The Network System is made up of six remote digital stations that transmit data via satellite to the central observatory. Sensors used are 3× Trillium Compact and 3× Trillium 120PA with Trident digitizers. The department has also acquired strong motion equipment: Titan accelerometers with Taurus digitizers from Nanometrics. Three of each of these instruments have been installed at the Akosombo and Kpong hydrodams, and also at the Weija water supply dam. These instruments are used to monitor dams. The peak ground <span class="hlt">acceleration</span> (PGA) values established from the analysed data from the accelerometers will be used to retrofit or carry out maintenance work of the dam structures to avoid collapse. Apart from these, the observatory also assesses and analyses <span class="hlt">seismic</span> waveforms relevant to its needs from the Global Seismographic Network (GSN) system operated by the US Geological Survey. The Ghana Geological Survey, through its <span class="hlt">Seismic</span> Network Observatory makes data available to its stakeholder institutions for earthquake disaster mitigation; reports on all aspects of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S11E4395S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S11E4395S"><span>Linking <span class="hlt">Seismicity</span> at Depth to the Mechanics of a Lava Dome Failure - a Forecasting Approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salvage, R. O.; Neuberg, J. W.; Murphy, W.</p> <p>2014-12-01</p> <p>Soufriere Hills volcano (SHV), Montserrat has been in a state of ongoing unrest since 1995. Prior to eruptions, an increase in the number of <span class="hlt">seismic</span> events has been observed. We use the Material Failure Law (MFL) (Voight, 1988) to investigate how an <span class="hlt">accelerating</span> number of low frequency <span class="hlt">seismic</span> events are related to the timing of a large scale dome collapse in June 1997. We show that although the forecasted timing of a dome collapse may coincide with the known timing, the accuracy of the application of the MFL to the data is poor. Using a cross correlation technique we show how characterising <span class="hlt">seismicity</span> into similar waveform "families'' allows us to focus on a single process at depth and improve the reliability of our forecast. A number of families are investigated to assess their relative importance. We show that despite the timing of a forecasted dome collapse ranging between several hours of the known timing of collapse, each of the families produces a better forecast in terms of fit to the <span class="hlt">seismic</span> <span class="hlt">acceleration</span> data than when using all low frequency <span class="hlt">seismicity</span>. In addition, we investigate the stability of such families between major dome collapses (1997 and 2003), assessing their potential for use in real-time forecasting. Initial application of Grey's Incidence Analysis suggests that a key parameter influencing the potential for a large scale slumping on the dome of SHV is the rate of low frequency <span class="hlt">seismicity</span> associated with magma movement and dome growth. We undertook numerical modelling of an andesitic dome with a hydrothermally altered layer down to 800m. The geometry of the dome is based on SHV prior to the collapse of 2003. We show that a critical instability is reached once slope angles exceed 25°, corresponding to a summit height of just over 1100m a.s.l.. The geometry of failure is in close agreement with the identified failure plane suggesting that the input mechanical properties are broadly consistent with reality. We are therefore able to compare</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S41A0742W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S41A0742W"><span>Regional Characteristics of Stress State of Main <span class="hlt">Seismic</span> Active Faults in Mid-Northern Part of Sichuan-Yunnan Block</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weiwei, W.; Yaling, W.</p> <p>2017-12-01</p> <p>We restore the <span class="hlt">seismic</span> source spectrums of 1012 earthquakes(2.0 ≤ ML ≤ 5.0) in the mid-northern part of Sichuan-Yunnan <span class="hlt">seismic</span> block(26 ° N-33 ° N, 99 ° E-104 ° E),then calculate the source parameters.Based on the regional <span class="hlt">seismic</span> tectonic background, the distribution of active faults and <span class="hlt">seismicity</span>, the study area is divided into four statistical units (Z1 Jinshajiang and Litang fault zone, Z2 Xianshuihe fault zone, Z3 Anninghe-Zemuhe fault zone, Z4 Lijiang-Xiaojinhe fault zone). <span class="hlt">Seismic</span> source stress drop results show the following, (1)The stress at the end of the Jinshajiang fault is low, strong earthquake activity rare.Stress-strain loading deceases gradually from northwest to southeast along Litang fault, the northwest section which is relatively locked is more likely to accumulate strain than southeast section. (2)Stress drop of Z2 is divided by Kangding, the southern section is low and northern section is high. Southern section (Kangding-Shimian) is difficult to accumulate higher strain in the short term, but in northern section (Garzê-Kangding), moderate and strong earthquakes have not filled the gaps of <span class="hlt">seismic</span> moment <span class="hlt">release</span>, there is still a high stress accumulation in partial section. (3)High stress-drop events were concentrated on Z3, strain accumulation of this unit is strong, and stress level is the highest, earthquake risk is high. (4)On Z4, stress drop characteristics of different magnitude earthquakes are not the same, which is related to complex tectonic setting, the specific reasons still need to be discussed deeply.The study also show that, (1)Stress drops display a systematic change with different faults and locations, high stress-drop events occurs mostly on the fault intersection area. Faults without locking condition and mainly creep, are mainly characterized by low stress drop. (2)Contrasting to what is commonly thought that "strike-slip faults are not easy to accumulate stress ", Z2 and Z3 all exhibit high stress levels, which</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9437E..2LC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9437E..2LC"><span>Damage detection and quantification in a structural model under <span class="hlt">seismic</span> excitation using time-frequency analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chan, Chun-Kai; Loh, Chin-Hsiung; Wu, Tzu-Hsiu</p> <p>2015-04-01</p> <p>In civil engineering, health monitoring and damage detection are typically carry out by using a large amount of sensors. Typically, most methods require global measurements to extract the properties of the structure. However, some sensors, like LVDT, cannot be used due to in situ limitation so that the global deformation remains unknown. An experiment is used to demonstrate the proposed algorithms: a one-story 2-bay reinforce concrete frame under weak and strong <span class="hlt">seismic</span> excitation. In this paper signal processing techniques and nonlinear identification are used and applied to the response measurements of <span class="hlt">seismic</span> response of reinforced concrete structures subject to different level of earthquake excitations. Both modal-based and signal-based system identification and feature extraction techniques are used to study the nonlinear inelastic response of RC frame using both input and output response data or output only measurement. From the signal-based damage identification method, which include the enhancement of time-frequency analysis of <span class="hlt">acceleration</span> responses and the estimation of permanent deformation using directly from <span class="hlt">acceleration</span> response data. Finally, local deformation measurement from dense optical tractor is also use to quantify the damage of the RC frame structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSeis.tmp...48N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSeis.tmp...48N"><span>Angola <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neto, Francisco António Pereira; França, George Sand; Condori, Cristobal; Sant'Anna Marotta, Giuliano; Chimpliganond, Cristiano Naibert</p> <p>2018-05-01</p> <p>This work describes the development of the Angolan earthquake catalog and <span class="hlt">seismicity</span> distribution in the Southwestern African Plate, in Angola. This region is one of the least <span class="hlt">seismically</span> active, even for stable continental regions (SCRs) in the world. The maximum known earthquake had a magnitude of 6.0 Ms, while events with magnitudes of 4.5 have return period of about 10 years. Events with magnitude 5 and above occur with return period of about 20 years. Five <span class="hlt">seismic</span> zones can be confirmed in Angola, within and along craton edges and in the sedimentary basins including offshore. Overall, the exposed cratonic regions tend to have more earthquakes compared to other regions such as sedimentary basins. Earthquakes tend to occur in Archaic rocks, especially inside preexisting weakness zones and in tectonic-magmatic reactivation zones of Mesozoic and Meso-Cenozoic, associated with the installation of a wide variety of intrusive rocks, strongly marked by intense tectonism. This fact can be explained by the models of preexisting weakness zones and stress concentration near intersecting structures. The Angolan passive margin is also a new region where <span class="hlt">seismic</span> activity occurs. Although clear differences are found between different areas along the passive margin, in the middle near Porto Amboim city, <span class="hlt">seismic</span> activity is more frequent compared with northwestern and southwestern regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoJI.204.1490G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoJI.204.1490G"><span>Field observations of <span class="hlt">seismic</span> velocity changes caused by shaking-induced damage and healing due to mesoscopic nonlinearity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gassenmeier, M.; Sens-Schönfelder, C.; Eulenfeld, T.; Bartsch, M.; Victor, P.; Tilmann, F.; Korn, M.</p> <p>2016-03-01</p> <p>To investigate temporal <span class="hlt">seismic</span> velocity changes due to earthquake related processes and environmental forcing in Northern Chile, we analyse 8 yr of ambient <span class="hlt">seismic</span> noise recorded by the Integrated Plate Boundary Observatory Chile (IPOC). By autocorrelating the ambient <span class="hlt">seismic</span> noise field measured on the vertical components, approximations of the Green's functions are retrieved and velocity changes are measured with Coda Wave Interferometry. At station PATCX, we observe seasonal changes in <span class="hlt">seismic</span> velocity caused by thermal stress as well as transient velocity reductions in the frequency range of 4-6 Hz. Sudden velocity drops occur at the time of mostly earthquake-induced ground shaking and recover over a variable period of time. We present an empirical model that describes the <span class="hlt">seismic</span> velocity variations based on continuous observations of the local ground <span class="hlt">acceleration</span>. The model assumes that not only the shaking of large earthquakes causes velocity drops, but any small vibrations continuously induce minor velocity variations that are immediately compensated by healing in the steady state. We show that the shaking effect is accumulated over time and best described by the integrated envelope of the ground <span class="hlt">acceleration</span> over the discretization interval of the velocity measurements, which is one day. In our model, the amplitude of the velocity reduction as well as the recovery time are proportional to the size of the excitation. This model with two free scaling parameters fits the data of the shaking induced velocity variation in remarkable detail. Additionally, a linear trend is observed that might be related to a recovery process from one or more earthquakes before our measurement period. A clear relationship between ground shaking and induced velocity reductions is not visible at other stations. We attribute the outstanding sensitivity of PATCX to ground shaking and thermal stress to the special geological setting of the station, where the subsurface material</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ExG....48..272E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ExG....48..272E"><span>New comprehensive standard <span class="hlt">seismic</span> noise models and 3D <span class="hlt">seismic</span> noise variation for Morocco territory, North Africa, obtained using <span class="hlt">seismic</span> broadband stations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El Fellah, Younes; El-Aal, Abd El-Aziz Khairy Abd; Harnafi, Mimoun; Villaseñor, Antonio</p> <p>2017-05-01</p> <p>In the current work, we constructed new comprehensive standard <span class="hlt">seismic</span> noise models and 3D temporal-spatial <span class="hlt">seismic</span> noise level cubes for Morocco in north-west Africa to be used for seismological and engineering purposes. Indeed, the original global standard <span class="hlt">seismic</span> noise models published by Peterson (1993) and their following updates by Astiz and Creager (1995), Ekström (2001) and Berger et al. (2003) had no contributing <span class="hlt">seismic</span> stations deployed in North Africa. Consequently, this preliminary study was conducted to shed light on <span class="hlt">seismic</span> noise levels specific to north-west Africa. For this purpose, 23 broadband <span class="hlt">seismic</span> stations recently installed in different structural domains throughout Morocco are used to study the nature and characteristics of <span class="hlt">seismic</span> noise and to create <span class="hlt">seismic</span> noise models for Morocco. Continuous data recorded during 2009, 2010 and 2011 were processed and analysed to construct these new noise models and 3D noise levels from all stations. We compared the Peterson new high-noise model (NHNM) and low-noise model (NLNM) with the Moroccan high-noise model (MHNM) and low-noise model (MLNM). These new noise models are comparable to the United States Geological Survey (USGS) models in the short period band; however, in the period range 1.2 s to 1000 s for MLNM and 10 s to 1000 s for MHNM display significant variations. This variation is attributed to differences in the nature of <span class="hlt">seismic</span> noise sources that dominate Morocco in these period bands. The results of this study have a new perception about permanent <span class="hlt">seismic</span> noise models for this spectacular region and can be considered a significant contribution because it supplements the Peterson models and can also be used to site future permanent <span class="hlt">seismic</span> stations in Morocco.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036303','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036303"><span><span class="hlt">Seismic</span> and geodetic signatures of fault slip at the Slumgullion Landslide Natural Laboratory</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gomberg, J.; Schulz, W.; Bodin, P.; Kean, J.</p> <p>2011-01-01</p> <p>We tested the hypothesis that the Slumgullion landslide is a useful natural laboratory for observing fault slip, specifically that slip along its basal surface and side-bounding strike-slip faults occurs with comparable richness of aseismic and <span class="hlt">seismic</span> modes as along crustal- and plate-scale boundaries. Our study provides new constraints on models governing landslide motion. We monitored landslide deformation with temporary deployments of a 29-element prism array surveyed by a robotic theodolite and an 88-station <span class="hlt">seismic</span> network that complemented permanent extensometers and environmental instrumentation. Aseismic deformation observations show that large blocks of the landslide move steadily at approximately centimeters per day, possibly punctuated by variations of a few millimeters, while localized transient slip episodes of blocks less than a few tens of meters across occur frequently. We recorded a rich variety of <span class="hlt">seismic</span> signals, nearly all of which originated outside the monitoring network boundaries or from the side-bounding strike-slip faults. The landslide basal surface beneath our <span class="hlt">seismic</span> network likely slipped almost completely aseismically. Our results provide independent corroboration of previous inferences that dilatant strengthening along sections of the side-bounding strike-slip faults controls the overall landslide motion, acting as <span class="hlt">seismically</span> radiating brakes that limit <span class="hlt">acceleration</span> of the aseismically slipping basal surface. Dilatant strengthening has also been invoked in recent models of transient slip and tremor sources along crustal- and plate-scale faults suggesting that the landslide may indeed be a useful natural laboratory for testing predictions of specific mechanisms that control fault slip at all scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21973353','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21973353"><span>Two applications of time reversal mirrors: <span class="hlt">seismic</span> radio and <span class="hlt">seismic</span> radar.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hanafy, Sherif M; Schuster, Gerard T</p> <p>2011-10-01</p> <p>Two <span class="hlt">seismic</span> applications of time reversal mirrors (TRMs) are introduced and tested with field experiments. The first one is sending, receiving, and decoding coded messages similar to a radio except <span class="hlt">seismic</span> waves are used. The second one is, similar to radar surveillance, detecting and tracking a moving object(s) in a remote area, including the determination of the objects speed of movement. Both applications require the prior recording of calibration Green's functions in the area of interest. This reference Green's function will be used as a codebook to decrypt the coded message in the first application and as a moving sensor for the second application. Field tests show that <span class="hlt">seismic</span> radar can detect the moving coordinates (x(t), y(t), z(t)) of a person running through a calibration site. This information also allows for a calculation of his velocity as a function of location. Results with the <span class="hlt">seismic</span> radio are successful in <span class="hlt">seismically</span> detecting and decoding coded pulses produced by a hammer. Both <span class="hlt">seismic</span> radio and radar are highly robust to signals in high noise environments due to the super-stacking property of TRMs. © 2011 Acoustical Society of America</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH23C1876S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH23C1876S"><span>Temblor, an App to Transform <span class="hlt">Seismic</span> Science into Personal Risk Reduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sevilgen, V.; Jacobson, D. S.; Stein, R. S.; Lotto, G. C.; Sevilgen, S.; Kim, A.</p> <p>2016-12-01</p> <p>Government agencies and academic researchers provide a rich stream of <span class="hlt">seismic</span> and engineering data. In addition to rapid earthquake notifications and damage assessments, these form the basis of probabilistic <span class="hlt">seismic</span> hazard assessments and loss evaluations used by emergency management agencies, practicing engineers and geologists, and the insurance industry. But the data and the assessments that grow out of them are notoriously difficult for the public to comprehend. For example, who but the cognoscenti understands what "2% exceedance probability in 50 years," "0.5 g peak ground <span class="hlt">acceleration</span>," or "moment-magnitude" mean? Nowhere is this divide more stark than in earthquake insurance. Using proprietary models, insurers calculate the probability of a payout above the deductible for your home policy, but sell the policy as "peace of mind" or "the strength to rebuild." How can a homeowner act in her best financial interests under these circumstances? Temblor (temblor.net) is our attempt to make <span class="hlt">seismic</span> risk lucid, personal, and actionable. Free and ad-free, Temblor uses the best available public data and methods. Temblor gives you the <span class="hlt">seismic</span> hazard rank of your location anywhere in the U.S. In its maps, you can see the active faults and recent quakes, and the landslide, liquefaction, tsunami inundation, and flood zones around you. Temblor also displays the Global Earthquake Activity Rate (GEAR) model of Bird et al. (2015). By entering the construction year and square footage for homes within the U.S., you learn the likely cost for <span class="hlt">seismic</span> damage, and how that cost could be reduced by retrofit or covered by insurance. To give context to this decision, the app compares your <span class="hlt">seismic</span> risk to other risks homeowners protect themselves against or insure for. Temblor estimates the cost and the most probable financial and safety benefits of a retrofit based on your location, home age and size, so you can decide if the expenditure makes sense. Seeking to make quakes more</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/862663','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/862663"><span><span class="hlt">Seismic</span> intrusion detector system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hawk, Hervey L.; Hawley, James G.; Portlock, John M.; Scheibner, James E.</p> <p>1976-01-01</p> <p>A system for monitoring man-associated <span class="hlt">seismic</span> movements within a control area including a geophone for generating an electrical signal in response to <span class="hlt">seismic</span> movement, a bandpass amplifier and threshold detector for eliminating unwanted signals, pulse counting system for counting and storing the number of <span class="hlt">seismic</span> movements within the area, and a monitoring system operable on command having a variable frequency oscillator generating an audio frequency signal proportional to the number of said <span class="hlt">seismic</span> movements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.S31D..08R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.S31D..08R"><span>CAFE: a <span class="hlt">seismic</span> investigation of water percolation in the Cascadia subduction zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rondenay, S.; Abers, G. A.; Creager, K. C.; Malone, S. D.; MacKenzie, L.; Zhang, Z.; van Keken, P. E.; Wech, A. G.; Sweet, J. R.; Melbourne, T. I.; Hacker, B. R.</p> <p>2008-12-01</p> <p>Subduction zones transport water into the Earth's interior. The subsequent <span class="hlt">release</span> of this water through dehydration reactions may trigger intraslab earthquakes and arc volcanism, regulate slip on the plate interface, control plate buoyancy, and regulate the long-term budget of water on the planet's surface. As part of Earthscope, we have undertaken an experiment named CAFE (Cascadia Arrays for Earthscope) seeking to better constrain these effects in the Cascadia subduction zone. The basic experiment has four components: (1) a 47-element broadband imaging array of Flexible Array instruments integrated with Bigfoot; (2) three small-aperture <span class="hlt">seismic</span> arrays with 15 additional short-period instruments near known sources of Episodic Tremor and Slip (ETS) events; (3) analysis of the PBO and PANGA GPS data sets to define the details of episodic slip events; and (4) integrative modeling with complementary constraints from petrology and geodynamics. Here, we present a summary of the results that have been obtained to date by CAFE, with a focus on high-resolution <span class="hlt">seismic</span> imaging. A 250 km-long by 120 km-deep <span class="hlt">seismic</span> profile extending eastward from the Washington coast was generated by 2-D Generalized Radon Transform Inversion of the broadband data. It images the subducted crust as a shallow-dipping, low-velocity layer from 20km depth beneath the coast to 40km depth beneath the forearc. The termination of the low-velocity layer is consistent with the depth at which hydrated metabasalts of the subducted crust are expected to undergo eclogitization, a reaction that is accompanied by the <span class="hlt">release</span> of water and an increase in <span class="hlt">seismic</span> velocities. Slab earthquakes are located in both the oceanic crust and mantle at depths <40 km, and exclusively in the oceanic mantle at greater depth, as would be expected if they are related to slab dehydration. Two ETS events have occurred during the course of the deployment. They were precisely located and are confined to the region above which the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.bssaonline.org/content/84/3/835.abstract','USGSPUBS'); return false;" href="http://www.bssaonline.org/content/84/3/835.abstract"><span>Triggered <span class="hlt">seismicity</span> and deformation between the Landers, California, and Little Skull Mountain, Nevada, earthquakes</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bodin, Paul; Gomberg, Joan</p> <p>1994-01-01</p> <p>This article presents evidence for the channeling of strain energy <span class="hlt">released</span> by the Ms = 7.4 Landers, California, earthquake within the eastern California shear zone (ECSZ). We document an increase in <span class="hlt">seismicity</span> levels during the 22-hr period starting with the Landers earthquake and culminating 22 hr later with the Ms = 5.4 Little Skull Mountain (LSM), Nevada, earthquake. We evaluate the completeness of regional <span class="hlt">seismicity</span> catalogs during this period and find that the continuity of post-Landers strain <span class="hlt">release</span> within the ECSZ is even more pronounced than is evident from the catalog data. We hypothesize that regional-scale connectivity of faults within the ECSZ and LSM region is a critical ingredient in the unprecedented scale and distribution of remotely triggered earthquakes and geodetically manifest strain changes that followed the Landers earthquake. The viability of static strain changes as triggering agents is tested using numerical models. Modeling results illustrate that regional-scale fault connectivity can increase the static strain changes by approximately an order of magnitude at distances of at least 280 km, the distance between the Landers and LSM epicenters. This is possible for models that include both a network of connected faults that slip “sympathetically” and realistic levels of tectonic prestrain. Alternatively, if dynamic strains are a more significant triggering agent than static strains, ECSZ structure may still be important in determining the distribution of triggered <span class="hlt">seismic</span> and aseismic deformation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018RMRE...51..893O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018RMRE...51..893O"><span><span class="hlt">Seismic</span> Design of a Single Bored Tunnel: Longitudinal Deformations and <span class="hlt">Seismic</span> Joints</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oh, J.; Moon, T.</p> <p>2018-03-01</p> <p>The large diameter bored tunnel passing through rock and alluvial deposits subjected to <span class="hlt">seismic</span> loading is analyzed for estimating longitudinal deformations and member forces on the segmental tunnel liners. The project site has challenges including high hydrostatic pressure, variable ground profile and high <span class="hlt">seismic</span> loading. To ensure the safety of segmental tunnel liner from the <span class="hlt">seismic</span> demands, the performance-based two-level design earthquake approach, Functional Evaluation Earthquake and Safety Evaluation Earthquake, has been adopted. The longitudinal tunnel and ground response <span class="hlt">seismic</span> analyses are performed using a three-dimensional quasi-static linear elastic and nonlinear elastic discrete beam-spring elements to represent segmental liner and ground spring, respectively. Three components (longitudinal, transverse and vertical) of free-field ground displacement-time histories evaluated from site response analyses considering wave passage effects have been applied at the end support of the strain-compatible ground springs. The result of the longitudinal <span class="hlt">seismic</span> analyses suggests that <span class="hlt">seismic</span> joint for the mitigation measure requiring the design deflection capacity of 5-7.5 cm is to be furnished at the transition zone between hard and soft ground condition where the maximum member forces on the segmental liner (i.e., axial, shear forces and bending moments) are induced. The paper illustrates how detailed numerical analyses can be practically applied to evaluate the axial and curvature deformations along the tunnel alignment under difficult ground conditions and to provide the <span class="hlt">seismic</span> joints at proper locations to effectively reduce the <span class="hlt">seismic</span> demands below the allowable levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Tectp.724..137M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Tectp.724..137M"><span>Earthquake damage orientation to infer <span class="hlt">seismic</span> parameters in archaeological sites and historical earthquakes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martín-González, Fidel</p> <p>2018-01-01</p> <p>Studies to provide information concerning <span class="hlt">seismic</span> parameters and <span class="hlt">seismic</span> sources of historical and archaeological <span class="hlt">seismic</span> events are used to better evaluate the <span class="hlt">seismic</span> hazard of a region. This is of especial interest when no surface rupture is recorded or the seismogenic fault cannot be identified. The orientation pattern of the earthquake damage (ED) (e.g., fallen columns, dropped key stones) that affected architectonic elements of cities after earthquakes has been traditionally used in historical and archaeoseismological studies to infer <span class="hlt">seismic</span> parameters. However, in the literature depending on the authors, the parameters that can be obtained are contradictory (it has been proposed: the epicenter location, the orientation of the P-waves, the orientation of the compressional strain and the fault kinematics) and authors even question these relations with the earthquake damage. The earthquakes of Lorca in 2011, Christchurch in 2011 and Emilia Romagna in 2012 present an opportunity to measure systematically a large number and wide variety of earthquake damage in historical buildings (the same structures that are used in historical and archaeological studies). The damage pattern orientation has been compared with modern instrumental data, which is not possible in historical and archaeoseismological studies. From measurements and quantification of the orientation patterns in the studied earthquakes, it is observed that there is a systematic pattern of the earthquake damage orientation (EDO) in the proximity of the <span class="hlt">seismic</span> source (fault trace) (<10 km). The EDO in these earthquakes is normal to the fault trend (±15°). This orientation can be generated by a pulse of motion that in the near fault region has a distinguishable <span class="hlt">acceleration</span> normal to the fault due to the polarization of the S-waves. Therefore, the earthquake damage orientation could be used to estimate the seismogenic fault trend of historical earthquakes studies where no instrumental data are available.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/872840','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/872840"><span>Method of migrating <span class="hlt">seismic</span> records</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ober, Curtis C.; Romero, Louis A.; Ghiglia, Dennis C.</p> <p>2000-01-01</p> <p>The present invention provides a method of migrating <span class="hlt">seismic</span> records that retains the information in the <span class="hlt">seismic</span> records and allows migration with significant reductions in computing cost. The present invention comprises phase encoding <span class="hlt">seismic</span> records and combining the encoded <span class="hlt">seismic</span> records before migration. Phase encoding can minimize the effect of unwanted cross terms while still allowing significant reductions in the cost to migrate a number of <span class="hlt">seismic</span> records.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.T11D..05S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.T11D..05S"><span>Deep <span class="hlt">Seismic</span> Reflection Images of the Sumatra <span class="hlt">Seismic</span> and Aseismic Gaps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, S. C.; Hananto, N. D.; Chauhan, A.; Carton, H. D.; Midenet, S.; Djajadihardja, Y.</p> <p>2009-12-01</p> <p>The Sumatra subduction zone is <span class="hlt">seismically</span> most active region on the Earth, and has been the site of three great earthquakes only in the last four years. The first of the series, the 2004 Boxing Day earthquake, broke 1300 km of the plate boundary and produced the devastating tsunami around the Indian Ocean. The second great earthquake occurred three months later in March 2005, about 150 km SE of the 2004 event. The Earth waited for three years, and then broke again in September 2007 at 1300 km SE of the 2004 event producing a twin earthquake of magnitudes of 8.5 and 7.9 at an interval of 12 hours, leaving a <span class="hlt">seismic</span> gap of about 600 km between the second and third earthquake, the Sumatra <span class="hlt">Seismic</span> Gap. Seismological and geodetic studies suggest that this gap is fully locked and may break any time. In order to study the <span class="hlt">seismic</span> and tsunami risk in this locked region, a deep <span class="hlt">seismic</span> reflection survey (Tsunami Investigation Deep Evaluation <span class="hlt">Seismic</span> -TIDES) was carried out in May 2009 using the CGGVeritas vessel Geowave Champion towing a 15 long streamer, the longest ever used during a <span class="hlt">seismic</span> survey, to image the nature of the subducting plate and associated features, including the seismogenic zone, from seafloor down to 50 km depth. A total of 1700 km of deep <span class="hlt">seismic</span> reflection data were acquired. Three dip lines traverse the Sumatra subduction zone; one going through the Sumatra <span class="hlt">Seismic</span> Gap, one crossing the region that broke during the 2007 great earthquake, and one going through the aseismic zone. These three dip profiles should provide insight about the locking mechanism and help us to understand why an earthquake occurs in one zone and not in aseismic zone. A strike-line was shot in the forearc basin connecting the locked zone with broken zone profiles, which should provide insight about barriers that might have stopped propagation of 2007 earthquake rupture further northward.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25583865','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25583865"><span><span class="hlt">Seismic</span> analysis of offshore wind turbines on bottom-fixed support structures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alati, Natale; Failla, Giuseppe; Arena, Felice</p> <p>2015-02-28</p> <p>This study investigates the <span class="hlt">seismic</span> response of a horizontal axis wind turbine on two bottom-fixed support structures for transitional water depths (30-60 m), a tripod and a jacket, both resting on pile foundations. Fully coupled, nonlinear time-domain simulations on full system models are carried out under combined wind-wave-earthquake loadings, for different load cases, considering fixed and flexible foundation models. It is shown that earthquake loading may cause a significant increase of stress resultant demands, even for moderate peak ground <span class="hlt">accelerations</span>, and that fully coupled nonlinear time-domain simulations on full system models are essential to capture relevant information on the moment demand in the rotor blades, which cannot be predicted by analyses on simplified models allowed by existing standards. A comparison with some typical design load cases substantiates the need for an accurate <span class="hlt">seismic</span> assessment in sites at risk from earthquakes. © 2015 The Author(s) Published by the Royal Society. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH43D..05O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH43D..05O"><span>Probabilistic, <span class="hlt">Seismically</span>-Induced Landslide Hazard Mapping of Western Oregon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Olsen, M. J.; Sharifi Mood, M.; Gillins, D. T.; Mahalingam, R.</p> <p>2015-12-01</p> <p>Earthquake-induced landslides can generate significant damage within urban communities by damaging structures, obstructing lifeline connection routes and utilities, generating various environmental impacts, and possibly resulting in loss of life. Reliable hazard and risk maps are important to assist agencies in efficiently allocating and managing limited resources to prepare for such events. This research presents a new methodology in order to communicate site-specific landslide hazard assessments in a large-scale, regional map. Implementation of the proposed methodology results in <span class="hlt">seismic</span>-induced landslide hazard maps that depict the probabilities of exceeding landslide displacement thresholds (e.g. 0.1, 0.3, 1.0 and 10 meters). These maps integrate a variety of data sources including: recent landslide inventories, LIDAR and photogrammetric topographic data, geology map, mapped NEHRP site classifications based on available shear wave velocity data in each geologic unit, and USGS probabilistic <span class="hlt">seismic</span> hazard curves. Soil strength estimates were obtained by evaluating slopes present along landslide scarps and deposits for major geologic units. Code was then developed to integrate these layers to perform a rigid, sliding block analysis to determine the amount and associated probabilities of displacement based on each bin of peak ground <span class="hlt">acceleration</span> in the <span class="hlt">seismic</span> hazard curve at each pixel. The methodology was applied to western Oregon, which contains weak, weathered, and often wet soils at steep slopes. Such conditions have a high landslide hazard even without <span class="hlt">seismic</span> events. A series of landslide hazard maps highlighting the probabilities of exceeding the aforementioned thresholds were generated for the study area. These output maps were then utilized in a performance based design framework enabling them to be analyzed in conjunction with other hazards for fully probabilistic-based hazard evaluation and risk assessment. a) School of Civil and Construction</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985Tectp.116..335M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985Tectp.116..335M"><span>Evaluation of a <span class="hlt">seismic</span> quiescence pattern in southeastern sicily</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mulargia, F.; Broccio, F.; Achilli, V.; Baldi, P.</p> <p>1985-07-01</p> <p>Southeastern Sicily experienced a very peculiar <span class="hlt">seismic</span> activity in historic times, with a long series of ruinous earthquakes. A last large event, with magnitude probably in excess of 7.5, occurred on Jan., 11, 1693, totally destroying the city of Catania and killing 60,000 people. Only a few moderate events were reported since then, and a <span class="hlt">seismic</span> gap issue has been proposed on this basis. A close scrutiny of the available data further shows that all significant <span class="hlt">seismic</span> activity ceased after year 1850, suggesting one of the largest quiescence patterns ever encountered. This is examined together with the complex tectonic setting of the region, characterized by a wrenching mechanism with most significant <span class="hlt">seismicity</span> located in its northern graben structure. An attempt to ascertain the imminence and the size of a future earthquake through commonly accepted empirical relations based on size and duration of the quiescence pattern did not provide any feasible result. A precision levelling survey which we recently completed yielded a relative subsidence of ~ 3 mm/yr, consistent with an aseismic slip on the northern graben structure at a rate of ~ 15 mm/yr. Comparing these results with sedimentological and tidal data suggests that the area is undergoing an <span class="hlt">accelerated</span> deformation process; this issue is further supported by Rikitake's ultimate strain statistics. If the imminence of a damaging ( M = 5.4) event is strongly favoured by Weibull statistics applied to the time series of occurrence of large events, the accumulated strain does not appear sufficient for a large earthquake ( M ⪸ 7.0). Within the limits of reliability of present semi-empirical approaches we conclude that the available evidence is consistent with the occurrence of a moderate-to-large ( M ≅ 6.0) event in the near future. Several questions regarding the application of simple models to real (and complex) tectonic settings remain nevertheless unanswered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1713325E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1713325E"><span>Results from the latest SN-4 multi-parametric benthic observatory experiment (MARsite EU project) in the Gulf of Izmit, Turkey: oceanographic, chemical and <span class="hlt">seismic</span> monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Embriaco, Davide; Marinaro, Giuditta; Frugoni, Francesco; Giovanetti, Gabriele; Monna, Stephen; Etiope, Giuseppe; Gasperini, Luca; Çağatay, Namık; Favali, Paolo</p> <p>2015-04-01</p> <p>An autonomous and long-term multiparametric benthic observatory (SN-4) was designed to study gas seepage and <span class="hlt">seismic</span> energy <span class="hlt">release</span> along the submerged segment of the North Anatolian Fault (NAF). Episodic gas seepage occurs at the seafloor in the Gulf of Izmit (Sea of Marmara, NW Turkey) along this submerged segment of the NAF, which ruptured during the 1999 Mw7.4 Izmit earthquake. The SN-4 observatory already operated in the Gulf of Izmit at the western end of the 1999 Izmit earthquake rupture for about one-year at 166 m water depth during the 2009-2010 experiment (EGU2014-13412-1, EGU General Assembly 2014). SN-4 was re-deployed in the same site for a new long term mission (September 2013 - April 2014) in the framework of MARsite (New Directions in <span class="hlt">Seismic</span> Hazard assessment through Focused Earth Observation in the Marmara Supersite, http://marsite.eu/ ) EC project, which aims at evaluating <span class="hlt">seismic</span> risk and managing of long-term monitoring activities in the Marmara Sea. A main scientific objective of the SN-4 experiment is to investigate the possible correlations between seafloor methane seepage and <span class="hlt">release</span> of <span class="hlt">seismic</span> energy. We used the same site of the 2009-2010 campaign to verify both the occurrence of previously observed phenomena and the reliability of results obtained in the previous experiment (Embriaco et al., 2014, doi:10.1093/gji/ggt436). In particular, we are interested in the detection of gas <span class="hlt">release</span> at the seafloor, in the role played by oceanographic phenomena in this detection, and in the association of gas and <span class="hlt">seismic</span> energy <span class="hlt">release</span>. The scientific payload included, among other instruments, a three-component broad-band seismometer, and gas and oceanographic sensors. We present a technical description of the observatory, including the data acquisition and control system, results from the preliminary analysis of this new multidisciplinary data set, and a comparison with the previous experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.T43B2223C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.T43B2223C"><span>South-Central Tibetan <span class="hlt">Seismicity</span> from HiCLIMB <span class="hlt">Seismic</span> Array Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carpenter, S.; Nabelek, J.; Braunmiller, J.</p> <p>2010-12-01</p> <p>The HiCLIMB broadband passive <span class="hlt">seismic</span> experiment (2002-2005) operated 233 sites along a 800-km long north-south array extending from the Himalayan foreland into the Central Tibetan Plateau and a flanking 350x350 km lateral array in southern Tibet and eastern Nepal. We use data from the experiment’s second phase (June 2004 to August 2005), when stations operated in Tibet, to locate earthquakes in south-central Tibet, a region with no permanent <span class="hlt">seismic</span> network where little is known about its <span class="hlt">seismicity</span>. We used the Antelope software for automatic detection and arrival time picking, event-arrival association and event location. Requiring a low detection and event association threshold initially resulted in ~110,000 declared events. The large database size rendered manual inspection unfeasible and we developed automated post-processing modules to weed out spurious detections and erroneous phase and event associations, which stemmed, e.g., from multiple coincident earthquakes within the array or misplaced <span class="hlt">seismicity</span> from the great 2004 Sumatra earthquake. The resulting database contains ~32,000 events within 5° distance from the closest station. We consider ~7,600 events defined by more than 30 P and S arrivals well located and discuss them here. <span class="hlt">Seismicity</span> in the subset correlates well with mapped faults and structures seen on satellite imagery attesting to high location quality. This is confirmed by non-systematic, kilometer-scale differences between automatic and manual locations for selected events. <span class="hlt">Seismicity</span> in south-central Tibet is intense north of the Yarlung-Tsangpo Suture. Almost 90% of events occurred in the Lhasa Terrane mainly along north-south trending rifts. Vigorous activity (>4,800 events) accompanied two M>6 earthquakes in the Payang Basin (84°E), ~100 km west of the linear array. The Tangra-Yum Co (86.5°E) and Pumqu-Xianza (88°E) rifts were very active (~1,000 events) without dominant main shocks indicating swarm like-behavior possibly related</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70016211','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70016211"><span><span class="hlt">Seismic</span>-wave attenuation associated with crustal faults in the New Madrid <span class="hlt">seismic</span> zone</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hamilton, R.M.; Mooney, W.D.</p> <p>1990-01-01</p> <p>The attenuation of upper crustal <span class="hlt">seismic</span> waves that are refracted with a velocity of about 6 kilometers per second varies greatly among profiles in the area of the New Madrid <span class="hlt">seismic</span> zone in the central Mississippi Valley. The waves that have the strongest attenuation pass through the <span class="hlt">seismic</span> trend along the axis of the Reelfoot rift in the area of the Blytheville arch. Defocusing of the waves in a low-velocity zone and/ or <span class="hlt">seismic</span> scattering and absorption could cause the attenuation; these effects are most likely associated with the highly deformed rocks along the arch. Consequently, strong <span class="hlt">seismic</span>-wave attenuation may be a useful criterion for identifying seismogenic fault zones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/31119','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/31119"><span><span class="hlt">Seismic</span> site coefficients and <span class="hlt">acceleration</span> design response spectra based on conditions in South Carolina : final report.</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>2014-11-15</p> <p>The simplified procedure in design codes for determining earthquake response spectra involves : estimating site coefficients to adjust available rock <span class="hlt">accelerations</span> to site <span class="hlt">accelerations</span>. Several : investigators have noted concerns with the site coeff...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T51I..07F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T51I..07F"><span>Reconciling Pre- and Co-<span class="hlt">Seismic</span> Deformation at Megathrusts: Tohoku Informing Cascadia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Furlong, K. P.; Govers, R. M.</p> <p>2013-12-01</p> <p>One of the outstanding goals of earthquake science is to effectively anticipate the earthquake characteristics of a future event - magnitude, rupture area, slip history - through the judicious application of models that use observations of inter-earthquake deformation and the history of earthquakes along that plate boundary segment. The series of great earthquakes over the past decade since the 2004 Mw 9.2 Sumatra earthquake have demonstrated both the sobering reality that our current models of subduction zone earthquake genesis are insufficient but more positively have provided a wealth of data and observations that can be used to develop improved framework models of the lithospheric behavior through the earthquake cycle in subduction zones. Some of the issues that recent observations raise are straightforward, while others imply aspects of the subduction process that have not been previously considered important. Based on observations of a range of great earthquakes since 2004, and with a particular focus on the 2011 Mw 9.0 Tohoku event we can identify a suite of key issues that include: (1) Patterns of inter-<span class="hlt">seismic</span> deformation (strain accumulation) are not simply the converse of the co-<span class="hlt">seismic</span> elastic strain <span class="hlt">release</span>. (2) Deformation of the slab during the earthquake cycle is a common occurrence and its role in buffering upper-plate deformation is a key consideration in the potential tsunamigenic character of a subduction system. (3) Rates of pre-earthquake deformation (e.g. observed upper-plate GPS displacements) and inferred slip deficit accumulation on the megathrust are inconsistent with co-<span class="hlt">seismic</span> displacements/fault slip and recurrence intervals. (4) Patterns of megathrust locked patches, degrees of coupling and other parameterizations that are used to define earthquake potential have only a loose agreement with the actual patterns of slip and moment <span class="hlt">release</span> seen in the ensuing great earthquake. Simple elastic models do provide a general agreement between</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1982/0293/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1982/0293/report.pdf"><span>SEISRISK II; a computer program for <span class="hlt">seismic</span> hazard estimation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bender, Bernice; Perkins, D.M.</p> <p>1982-01-01</p> <p>The computer program SEISRISK II calculates probabilistic ground motion values for use in <span class="hlt">seismic</span> hazard mapping. SEISRISK II employs a model that allows earthquakes to occur as points within source zones and as finite-length ruptures along faults. It assumes that earthquake occurrences have a Poisson distribution, that occurrence rates remain constant during the time period considered, that ground motion resulting from an earthquake is a known function of magnitude and distance, that <span class="hlt">seismically</span> homogeneous source zones are defined, that fault locations are known, that fault rupture lengths depend on magnitude, and that earthquake rates as a function of magnitude are specified for each source. SEISRISK II calculates for each site on a grid of sites the level of ground motion that has a specified probability of being exceeded during a given time period. The program was designed to process a large (essentially unlimited) number of sites and sources efficiently and has been used to produce regional and national maps of <span class="hlt">seismic</span> hazard.}t is a substantial revision of an earlier program SEISRISK I, which has never been documented. SEISRISK II runs considerably [aster and gives more accurate results than the earlier program and in addition includes rupture length and <span class="hlt">acceleration</span> variability which were not contained in the original version. We describe the model and how it is implemented in the computer program and provide a flowchart and listing of the code.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70033979','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70033979"><span><span class="hlt">Seismic</span> hazard assessment: Issues and alternatives</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wang, Z.</p> <p>2011-01-01</p> <p><span class="hlt">Seismic</span> hazard and risk are two very important concepts in engineering design and other policy considerations. Although <span class="hlt">seismic</span> hazard and risk have often been used inter-changeably, they are fundamentally different. Furthermore, <span class="hlt">seismic</span> risk is more important in engineering design and other policy considerations. <span class="hlt">Seismic</span> hazard assessment is an effort by earth scientists to quantify <span class="hlt">seismic</span> hazard and its associated uncertainty in time and space and to provide <span class="hlt">seismic</span> hazard estimates for <span class="hlt">seismic</span> risk assessment and other applications. Although <span class="hlt">seismic</span> hazard assessment is more a scientific issue, it deserves special attention because of its significant implication to society. Two approaches, probabilistic <span class="hlt">seismic</span> hazard analysis (PSHA) and deterministic <span class="hlt">seismic</span> hazard analysis (DSHA), are commonly used for <span class="hlt">seismic</span> hazard assessment. Although PSHA has been pro-claimed as the best approach for <span class="hlt">seismic</span> hazard assessment, it is scientifically flawed (i.e., the physics and mathematics that PSHA is based on are not valid). Use of PSHA could lead to either unsafe or overly conservative engineering design or public policy, each of which has dire consequences to society. On the other hand, DSHA is a viable approach for <span class="hlt">seismic</span> hazard assessment even though it has been labeled as unreliable. The biggest drawback of DSHA is that the temporal characteristics (i.e., earthquake frequency of occurrence and the associated uncertainty) are often neglected. An alternative, <span class="hlt">seismic</span> hazard analysis (SHA), utilizes earthquake science and statistics directly and provides a <span class="hlt">seismic</span> hazard estimate that can be readily used for <span class="hlt">seismic</span> risk assessment and other applications. ?? 2010 Springer Basel AG.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ESuD....5..653D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ESuD....5..653D"><span><span class="hlt">Seismic</span> monitoring of small alpine rockfalls - validity, precision and limitations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dietze, Michael; Mohadjer, Solmaz; Turowski, Jens M.; Ehlers, Todd A.; Hovius, Niels</p> <p>2017-10-01</p> <p>Rockfall in deglaciated mountain valleys is perhaps the most important post-glacial geomorphic process for determining the rates and patterns of valley wall erosion. Furthermore, rockfall poses a significant hazard to inhabitants and motivates monitoring efforts in populated areas. Traditional rockfall detection methods, such as aerial photography and terrestrial laser scanning (TLS) data evaluation, provide constraints on the location and <span class="hlt">released</span> volume of rock but have limitations due to significant time lags or integration times between surveys, and deliver limited information on rockfall triggering mechanisms and the dynamics of individual events. Environmental seismology, the study of <span class="hlt">seismic</span> signals emitted by processes at the Earth's surface, provides a complementary solution to these shortcomings. However, this approach is predominantly limited by the strength of the signals emitted by a source and their transformation and attenuation towards receivers. To test the ability of <span class="hlt">seismic</span> methods to identify and locate small rockfalls, and to characterise their dynamics, we surveyed a 2.16 km2 large, near-vertical cliff section of the Lauterbrunnen Valley in the Swiss Alps with a TLS device and six broadband seismometers. During 37 days in autumn 2014, 10 TLS-detected rockfalls with volumes ranging from 0.053 ± 0.004 to 2.338 ± 0.085 m3 were independently detected and located by the <span class="hlt">seismic</span> approach, with a deviation of 81-29+59 m (about 7 % of the average inter-station distance of the seismometer network). Further potential rockfalls were detected outside the TLS-surveyed cliff area. The onset of individual events can be determined within a few milliseconds, and their dynamics can be resolved into distinct phases, such as detachment, free fall, intermittent impact, fragmentation, arrival at the talus slope and subsequent slope activity. The small rockfall volumes in this area require significant supervision during data processing: 2175 initially picked</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850034466&hterms=barium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dbarium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850034466&hterms=barium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dbarium"><span><span class="hlt">Acceleration</span> of barium ions near 8000 km above an aurora</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stenbaek-Nielsen, H. C.; Hallinan, T. J.; Wescott, E. M.; Foeppl, H.</p> <p>1984-01-01</p> <p>A barium shaped charge, named Limerick, was <span class="hlt">released</span> from a rocket launched from Poker Flat Research Range, Alaska, on March 30, 1982, at 1033 UT. The <span class="hlt">release</span> took place in a small auroral breakup. The jet of ionized barium reached an altitude of 8100 km 14.5 min after <span class="hlt">release</span>, indicating that there were no parallel electric fields below this altitude. At 8100 km the jet appeared to stop. Analysis shows that the barium at this altitude was effectively removed from the tip. It is concluded that the barium was actually <span class="hlt">accelerated</span> upward, resulting in a large decrease in the line-of-sight density and hence the optical intensity. The parallel electric potential in the <span class="hlt">acceleration</span> region must have been greater than 1 kV over an altitude interval of less than 200 km. The <span class="hlt">acceleration</span> region, although presumably auroral in origin, did not seem to be related to individual auroral structures, but appeared to be a large-scale horizontal structure. The perpendicular electric field below, as deduced from the drift of the barium, was temporally and spatially very uniform and showed no variation related to individual auroral structures passing through.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511011N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511011N"><span>Very-long-period <span class="hlt">seismic</span> signals - filling the gap between deformation and <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neuberg, Jurgen; Smith, Paddy</p> <p>2013-04-01</p> <p>Good broadband <span class="hlt">seismic</span> sensors are capable to record <span class="hlt">seismic</span> transients with dominant wavelengths of several tens or even hundreds of seconds. This allows us to generate a multi-component record of <span class="hlt">seismic</span> volcanic events that are located in between the conventional high to low-frequency <span class="hlt">seismic</span> spectrum and deformation signals. With a much higher temporal resolution and accuracy than e.g. GPS records, these signals fill the gap between <span class="hlt">seismicity</span> and deformation studies. In this contribution we will review the non-trivial processing steps necessary to retrieve ground deformation from the original velocity seismogram and explore which role the resulting displacement signals have in the analysis of volcanic events. We use examples from Soufriere Hills volcano in Montserrat, West Indies, to discuss the benefits and shortcomings of such methods regarding new insights into volcanic processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S51A2312G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S51A2312G"><span><span class="hlt">Seismic</span> microzoning in the metropolitan area of Port - au-Prince - complexity of the subsoil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gilles, R.; Bertil, D.; Belvaux, M.; Roulle, A.; Noury, G.; Prepetit, C.; Jean-Philippe, J.</p> <p>2013-12-01</p> <p> accelerograms (2 real and 2 altered real) having a spectral response close to the spectrum of <span class="hlt">acceleration</span> to the rock. In sum, the <span class="hlt">seismic</span> microzoning presents a better perspective for the preparation of the plan for the prevention of <span class="hlt">seismic</span> risk (PPRS) and for the establishment of <span class="hlt">seismic</span> rules in the metropolitan area of Port-au-Prince.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70022054','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70022054"><span><span class="hlt">Seismic</span> subduction of the Nazca Ridge as shown by the 1996-97 Peru earthquakes</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Spence, W.; Mendoza, C.; Engdahl, E.R.; Choy, G.L.; Norabuena, E.</p> <p>1999-01-01</p> <p>By rupturing more than half of the shallow subduction interface of the Nazca Ridge, the great November 12, 1996 Peruvian earthquake contradicts the hypothesis that oceanic ridges subduct aseismically. The mainshock's rupture has a length of about 200 km and has an average slip of about 1.4 m. Its moment is 1.5 x 1028 dyne-cm and the corresponding M(w) is 8.0. The mainshock registered three major episodes of moment <span class="hlt">release</span> as shown by a finite fault inversion of teleseismically recorded broadband body waves. About 55% of the mainshock's total moment <span class="hlt">release</span> occurred south of the Nazca Ridge, and the remaining moment <span class="hlt">release</span> occurred at the southern half of the subduction interface of the Nazca Ridge. The rupture south of the Nazca Ridge was elongated parallel to the ridge axis and extended from a shallow depth to about 65 km depth. Because the axis of the Nazca Ridge is at a high angle to the plate convergence direction, the subducting Nazca Ridge has a large southwards component of motion, 5 cm/yr parallel to the coast. The 900-1200 m relief of the southwards sweeping Nazca Ridge is interpreted to act as a 'rigid indenter,' causing the greatest coupling south of the ridge's leading edge and leading to the large observed slip. The mainshock and aftershock hypocenters were relocated using a new procedure that simultaneously inverts local and teleseismic data. Most aftershocks were within the outline of the Nazca Ridge. A three-month delayed aftershock cluster' occurred at the northern part of the subducting Nazca Ridge. Aftershocks were notably lacking at the zone of greatest moment <span class="hlt">release</span>, to the south of the Nazca Ridge. However, a lone foreshock at the southern end of this zone, some 140 km downstrike of the mainshock's epicenter, implies that conditions existed for rupture into that zone. The 1996 earthquake ruptured much of the inferred source zone of the M(w) 7.9-8.2 earthquake of 1942, although the latter was a slightly larger earthquake. The rupture zone of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S41A2764I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S41A2764I"><span><span class="hlt">Seismic</span> Structure of Perth Basin (Australia) and surroundings from Passive <span class="hlt">Seismic</span> Deployments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Issa, N.; Saygin, E.; Lumley, D. E.; Hoskin, T. E.</p> <p>2016-12-01</p> <p>We image the subsurface structure of Perth Basin, Western Australia and surroundings by using ambient <span class="hlt">seismic</span> noise data from 14 <span class="hlt">seismic</span> stations recently deployed by University of Western Australia (UWA) and other available permanent stations from Geoscience Australia <span class="hlt">seismic</span> network and the Australian Seismometers in Schools program. Each of these 14 UWA <span class="hlt">seismic</span> stations comprises a broadband sensor and a high fidelity 3-component 10 Hz geophone, recording in tandem at 250 Hz and 1000 Hz. The other stations used in this study are equipped with short period and broadband sensors. In addition, one shallow borehole station is operated with eight 3 component geophones at depths of between 2 and 44 m. The network is deployed to characterize natural <span class="hlt">seismicity</span> in the basin and to try and identify any microseismic activity across Darling Fault Zone (DFZ), bounding the basin to the east. The DFZ stretches to approximately 1000 km north-south in Western Australia, and is one of the longest fault zones on the earth with a limited number of detected earthquakes. We use <span class="hlt">seismic</span> noise cross- and auto-correlation methods to map <span class="hlt">seismic</span> velocity perturbations across the basin and the transition from DFZ to the basin. Retrieved Green's functions are stable and show clear dispersed waveforms. Travel times of the surface wave Green's functions from noise cross-correlations are inverted with a two-step probabilistic framework to map the absolute shear wave velocities as a function of depth. The single station auto-correlations from the <span class="hlt">seismic</span> noise yields P wave reflectivity under each station, marking the major discontinuities. Resulting images show the shear velocity perturbations across the region. We also quantify the variation of ambient <span class="hlt">seismic</span> noise at different depths in the near surface using the geophones in the shallow borehole array.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoJI.213.1113K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoJI.213.1113K"><span>The 2014, MW6.9 North Aegean earthquake: <span class="hlt">seismic</span> and geodetic evidence for coseismic slip on persistent asperities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Konca, Ali Ozgun; Cetin, Seda; Karabulut, Hayrullah; Reilinger, Robert; Dogan, Ugur; Ergintav, Semih; Cakir, Ziyadin; Tari, Ergin</p> <p>2018-05-01</p> <p>We report that asperities with the highest coseismic slip in the 2014 MW6.9 North Aegean earthquake persisted through the interseismic, coseismic and immediate post-<span class="hlt">seismic</span> periods. We use GPS and <span class="hlt">seismic</span> data to obtain the source model of the 2014 earthquake, which is located on the western extension of the North Anatolian Fault (NAF). The earthquake ruptured a bilateral, 90 km strike-slip fault with three slip patches: one asperity located west of the hypocentre and two to the east with a rupture duration of 40 s. Relocated pre-earthquake <span class="hlt">seismicity</span> and aftershocks show that zones with significant coseismic slip were relatively quiet during both the 7 yr of interseismic and the 3-month aftershock periods, while the surrounding regions generated significant <span class="hlt">seismicity</span> during both the interseismic and post-<span class="hlt">seismic</span> periods. We interpret the unusually long fault length and source duration, and distribution of pre- and post-main-shock <span class="hlt">seismicity</span> as evidence for a rupture of asperities that persisted through strain accumulation and coseismic strain <span class="hlt">release</span> in a partially coupled fault zone. We further suggest that the association of <span class="hlt">seismicity</span> with fault creep may characterize the adjacent Izmit, Marmara Sea and Saros segments of the NAF. Similar behaviour has been reported for sections of the San Andreas Fault, and some large subduction zones, suggesting that the association of <span class="hlt">seismicity</span> with creeping fault segments and rapid relocking of asperities may characterize many large earthquake faults.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3616606','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3616606"><span><span class="hlt">Accelerated</span> drug <span class="hlt">release</span> and clearance of PEGylated epirubicin liposomes following repeated injections: a new challenge for sequential low-dose chemotherapy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yang, Qiang; Ma, Yanling; Zhao, Yongxue; She, Zhennan; Wang, Long; Li, Jie; Wang, Chunling; Deng, Yihui</p> <p>2013-01-01</p> <p>Background Sequential low-dose chemotherapy has received great attention for its unique advantages in attenuating multidrug resistance of tumor cells. Nevertheless, it runs the risk of producing new problems associated with the <span class="hlt">accelerated</span> blood clearance phenomenon, especially with multiple injections of PEGylated liposomes. Methods Liposomes were labeled with fluorescent phospholipids of 1,2-dipalmitoyl-snglycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl) and epirubicin (EPI). The pharmacokinetics profile and biodistribution of the drug and liposome carrier following multiple injections were determined. Meanwhile, the antitumor effect of sequential low-dose chemotherapy was tested. To clarify this unexpected phenomenon, the production of polyethylene glycol (PEG)-specific immunoglobulin M (IgM), drug <span class="hlt">release</span>, and residual complement activity experiments were conducted in serum. Results The first or sequential injections of PEGylated liposomes within a certain dose range induced the rapid clearance of subsequently injected PEGylated liposomal EPI. Of note, the clearance of EPI was two- to three-fold faster than the liposome itself, and a large amount of EPI was <span class="hlt">released</span> from liposomes in the first 30 minutes in a complement-activation, direct-dependent manner. The therapeutic efficacy of liposomal EPI following 10 days of sequential injections in S180 tumor-bearing mice of 0.75 mg EPI/kg body weight was almost completely abolished between the sixth and tenth day of the sequential injections, even although the subsequently injected doses were doubled. The level of PEG-specific IgM in the blood increased rapidly, with a larger amount of complement being activated while the concentration of EPI in blood and tumor tissue was significantly reduced. Conclusion Our investigation implied that the <span class="hlt">accelerated</span> blood clearance phenomenon and its accompanying rapid leakage and clearance of drug following sequential low-dose injections may reverse the unique</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EEEV...16..219K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EEEV...16..219K"><span>Spring tube braces for <span class="hlt">seismic</span> isolation of buildings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karayel, V.; Yuksel, Ercan; Gokce, T.; Sahin, F.</p> <p>2017-01-01</p> <p>A new low-cost <span class="hlt">seismic</span> isolation system based on spring tube bracings has been proposed and studied at the Structural and Earthquake Engineering Laboratory of Istanbul Technical University. Multiple compression-type springs are positioned in a special cylindrical tube to obtain a symmetrical response in tension and compression-type axial loading. An isolation floor, which consists of pin-ended steel columns and spring tube bracings, is constructed at the foundation level or any intermediate level of the building. An experimental campaign with three stages was completed to evaluate the capability of the system. First, the behavior of the spring tubes subjected to axial displacement reversals with varying frequencies was determined. In the second phase, the isolation floor was assessed in the quasi-static tests. Finally, a ¼ scaled 3D steel frame was tested on the shake table using actual <span class="hlt">acceleration</span> records. The transmitted <span class="hlt">acceleration</span> to the floor levels is greatly diminished because of the isolation story, which effects longer period and higher damping. There are no stability and self-centering problems in the isolation floor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S44B..04L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S44B..04L"><span>Comprehensive Studies on the <span class="hlt">Seismic</span> Gap between the Wenchuan and Lushan Earthquakes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, C.</p> <p>2016-12-01</p> <p>An array of 20 short-period and 15 broadband seismometers were deployed to monitor the <span class="hlt">seismic</span> gap between the 2008 Ms8.0 Wenchuan earthquake and the 2013 Ms7.0 Lushan earthquake. The Wenchuan earthquake ruptured from epicenter at (31.01°N, 103.42°E) largely northeastward while the Lushan earthquake ruptured from epicenter at (30.3°N, 103.0°E) largely southwestward. The region between the two earthquakes has recorded very few aftershocks and cataloged <span class="hlt">seismicity</span> before and after the two big earthquakes compared to neighboring segments. As one small segment of the 500KM long Longmen Shan fault system, its absence of <span class="hlt">seismicity</span> draws hot debate on whether a big one is still in brewing or steady creeping is in control of the strain energy <span class="hlt">release</span>. The dense array is deployed primarily aimed to detect events that are much smaller than cataloged events and to determine if the segment is experiencing constantly creeping. The preliminary findings include: (1) source mechanisms show that the <span class="hlt">seismic</span> gap appears to be a transitional zone between north and south segment. The events to the south are primarily thrust while events to north have more or less striking-slip components. This is also the case for both Lushan and Wenchuan earthquake; (2) The receiver function analysis shows that the Moho beneath the <span class="hlt">seismic</span> Gap is less defined than its adjacent region with relatively weaker Ps conversion phases; (3) Both receiver function and ambient noise tomography show that the velocities in the upper crust is relatively lower in the Gap region than surrounding regions; (4) significant number of small earthquakes are located near surface in the gap region. Further examinations should be conducted before we can make a sounding conclusion on what mechanism is in control of the <span class="hlt">seismicity</span> in this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFM.V21A1188S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFM.V21A1188S"><span>Modelling the Effects of Magma Properties, Pressure and Conduit Dimensions on the <span class="hlt">Seismic</span> Signature</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sturton, S.; Neuberg, J.</p> <p>2002-12-01</p> <p>A finite-difference scheme is used to model the <span class="hlt">seismic</span> radiation pattern for a fluid filled conduit surrounded by a solid medium. <span class="hlt">Seismic</span> waves travel slower than the acoustic velocity inside the conduit and the propagation velocity is frequency dependent. At the ends of the conduit the waves are partly reflected back along the conduit and also leak into the solid medium. The seismometer signal obtained is therefore composed of a series of events <span class="hlt">released</span> from the ends of the conduit. Each signal can be characterised by the repeat time of the events and the dispersion seen within each event. These characteristics are dependent on the <span class="hlt">seismic</span> parameters and the conduit dimensions. For a gas-charged magma, increasing the pressure with depth reduces the volume of gas exsolved, thereby increasing the <span class="hlt">seismic</span> velocity lower in the conduit. From the volume of gas exsolved, profiles of <span class="hlt">seismic</span> parameters within the conduit and their evolution with time can be obtained. The differences between a varying velocity with depth and a constant velocity with depth are seen in the synthetic seismograms and spectrograms. At Soufriere Hills Volcano, Montserrat, single hybrid events merge into tremor and occasionally gliding lines are observed in the spectra indicating changes in the <span class="hlt">seismic</span> parameters with time or varying triggering rates of single events. The synthetic seismograms are compared to the observational data and used to constrain the magnitude of pressure changes necessary to produce the gliding lines. Further constraints are obtained from the dispersion patterns in both the synthetic seismograms and the observed data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S13B0658J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S13B0658J"><span>xQuake: A Modern Approach to <span class="hlt">Seismic</span> Network Analytics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnson, C. E.; Aikin, K. E.</p> <p>2017-12-01</p> <p>While <span class="hlt">seismic</span> networks have expanded over the past few decades, and social needs for accurate and timely information has increased dramatically, approaches to the operational needs of both global and regional <span class="hlt">seismic</span> observatories have been slow to adopt new technologies. This presentation presents the xQuake system that provides a fresh approach to <span class="hlt">seismic</span> network analytics based on complexity theory and an adaptive architecture of streaming connected microservices as diverse data (picks, beams, and other data) flow into a final, curated catalog of events. The foundation for xQuake is the xGraph (executable graph) framework that is essentially a self-organizing graph database. An xGraph instance provides both the analytics as well as the data storage capabilities at the same time. Much of the analytics, such as synthetic annealing in the detection process and an evolutionary programing approach for event evolution, draws from the recent GLASS 3.0 <span class="hlt">seismic</span> associator developed by and for the USGS National Earthquake Information Center (NEIC). In some respects xQuake is reminiscent of the Earthworm system, in that it comprises processes interacting through store and forward rings; not surprising as the first author was the lead architect of the original Earthworm project when it was known as "Rings and Things". While Earthworm components can easily be integrated into the xGraph processing framework, the architecture and analytics are more current (e.g. using a Kafka Broker for store and forward rings). The xQuake system is being <span class="hlt">released</span> under an unrestricted open source license to encourage and enable sthe eismic community support in further development of its capabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1212412D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1212412D"><span><span class="hlt">Seismic</span> swarms and fluid flow offshore Central America</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dzierma, Yvonne; Thorwart, Martin; Hensen, Christian; Rabbel, Wolfgang; Wolf, Florian</p> <p>2010-05-01</p> <p>Offshore Nicaragua and Northern Costa Rica, the Cocos Plate subducts beneath the Caribbean Plate, carrying with it a large amount of fluids and volatiles. While some of these are set free at great depth beneath the volcanic arc, causing the extremely high water content observed in Nicaraguan mafic magmas (Carr et al., 2003; Kutterolf et al., 2007), some early dehydration reactions already <span class="hlt">release</span> fluids from the subducting plate underneath the continental slope. Unlike in accretionary margins, where these fluids migrate up along the decollement towards the deformation front, fluid <span class="hlt">release</span> at erosional margins seems to occur through fractures in the overriding plate (Ranero et al., 2008). Fluid seeps in this region have be observed at seafloor mounds, appearing as side-scan sonar backscatter anomalies or revealed by the presence of chemosynthetic communities (Sahling et al., 2008). In the framework of the General Research Area SFB 574 "Volatiles and Fluids in Subduction Zones", a network of 20 ocean-bottom-stations was deployed offshore Sta Elena Peninsula, Northern Costa Rica, from December 2005 to June 2006. Several distinct swarms of small earthquakes were observed at the <span class="hlt">seismic</span> stations, which occurred clustered over a time period of several days and have very similar <span class="hlt">seismic</span> waveforms. Since a correlation of fluid-<span class="hlt">release</span> sites with the occurrence of sporadic <span class="hlt">seismic</span> swarms would indicate that fluid migration and fracturing is the mechanism responsible for triggering the earthquake swarms, the events are re-analysed by double-difference localisation to enhance the resolution of the earthquake locations. The results are then considered to estimate the migration velocity and direction and compare the localisations with the known mound sites. Carr, M., Feigenson, M. D., Patino, L. C., and Walker, J. A., 2003: Volcanism and geochemistry in Central America: Progress and problems, in Eiler, J. (ed.), Inside the subduction factory, pp. 153-179, American Geophysical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.U23B..04G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.U23B..04G"><span>Improvement of real-time <span class="hlt">seismic</span> magnitude estimation by combining <span class="hlt">seismic</span> and geodetic instrumentation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goldberg, D.; Bock, Y.; Melgar, D.</p> <p>2017-12-01</p> <p>Rapid <span class="hlt">seismic</span> magnitude assessment is a top priority for earthquake and tsunami early warning systems. For the largest earthquakes, <span class="hlt">seismic</span> instrumentation tends to underestimate the magnitude, leading to an insufficient early warning, particularly in the case of tsunami evacuation orders. GPS instrumentation provides more accurate magnitude estimations using near-field stations, but isn't sensitive enough to detect the first <span class="hlt">seismic</span> wave arrivals, thereby limiting solution speed. By optimally combining collocated <span class="hlt">seismic</span> and GPS instruments, we demonstrate improved solution speed of earthquake magnitude for the largest <span class="hlt">seismic</span> events. We present a real-time implementation of magnitude-scaling relations that adapts to consider the length of the recording, reflecting the observed evolution of ground motion with time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1815305C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1815305C"><span>The influence of climatically-driven surface loading variations on continental strain and <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Craig, Tim; Calais, Eric; Fleitout, Luce; Bollinger, Laurent; Scotti, Oona</p> <p>2016-04-01</p> <p>In slowly deforming regions of plate interiors, secondary sources of stress and strain can result in transient deformation rates comparable to, or greater than, the background tectonic rates. Highly variable in space and time, these transients have the potential to influence the spatio-temporal distribution of <span class="hlt">seismicity</span>, interfering with any background tectonic effects to either promote or inhibit the failure of pre-existing faults, and potentially leading to a clustered, or 'pulse-like', <span class="hlt">seismic</span> history. Here, we investigate the ways in which the large-scale deformation field resulting from climatically-controlled changes in surface ice mass over the Pleistocene and Holocene may have influenced not only the <span class="hlt">seismicity</span> of glaciated regions, but also the wider <span class="hlt">seismicity</span> around the ice periphery. We first use a set of geodynamic models to demonstrate that a major pulse of <span class="hlt">seismic</span> activity occurring in Fennoscandia, coincident with the time of end-glaciation, occurred in a setting where the contemporaneous horizontal strain-rate resulting from the changing ice mass, was extensional - opposite to the reverse sense of coseismic displacement accommodated on these faults. Therefore, faulting did not <span class="hlt">release</span> extensional elastic strain that was building up at the time of failure, but compressional elastic strain that had accumulated in the lithosphere on timescales longer than the glacial cycle, illustrating the potential for a non-tectonic trigger to tap in to the background tectonic stress-state. We then move on to investigate the more distal influence that changing ice (and ocean) volumes may have had on the evolving strain field across intraplate Europe, how this is reflected in the <span class="hlt">seismicity</span> across intraplate Europe, and what impact this might have on the paleoseismic record.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S53E..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S53E..05L"><span>MSNoise: a Python Package for Monitoring <span class="hlt">Seismic</span> Velocity Changes using Ambient <span class="hlt">Seismic</span> Noise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lecocq, T.; Caudron, C.; Brenguier, F.</p> <p>2013-12-01</p> <p>Earthquakes occur every day all around the world and are recorded by thousands of <span class="hlt">seismic</span> stations. In between earthquakes, stations are recording "noise". In the last 10 years, the understanding of this noise and its potential usage have been increasing rapidly. The method, called "<span class="hlt">seismic</span> interferometry", uses the principle that <span class="hlt">seismic</span> waves travel between two recorders and are multiple-scattered in the medium. By cross-correlating the two records, one gets an information on the medium below/between the stations. The cross-correlation function (CCF) is a proxy to the Green Function of the medium. Recent developments of the technique have shown those CCF can be used to image the earth at depth (3D <span class="hlt">seismic</span> tomography) or study the medium changes with time. We present MSNoise, a complete software suite to compute relative <span class="hlt">seismic</span> velocity changes under a <span class="hlt">seismic</span> network, using ambient <span class="hlt">seismic</span> noise. The whole is written in Python, from the monitoring of data archives, to the production of high quality figures. All steps have been optimized to only compute the necessary steps and to use 'job'-based processing. We present a validation of the software on a dataset acquired during the UnderVolc[1] project on the Piton de la Fournaise Volcano, La Réunion Island, France, for which precursory relative changes of <span class="hlt">seismic</span> velocity are visible for three eruptions betwee 2009 and 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JSeis..16..169H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JSeis..16..169H"><span>Monitoring the West Bohemian earthquake swarm in 2008/2009 by a temporary small-aperture <span class="hlt">seismic</span> array</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hiemer, Stefan; Roessler, Dirk; Scherbaum, Frank</p> <p>2012-04-01</p> <p>The most recent intense earthquake swarm in West Bohemia lasted from 6 October 2008 to January 2009. Starting 12 days after the onset, the University of Potsdam monitored the swarm by a temporary small-aperture <span class="hlt">seismic</span> array at 10 km epicentral distance. The purpose of the installation was a complete monitoring of the swarm including micro-earthquakes ( M L < 0). We identify earthquakes using a conventional short-term average/long-term average trigger combined with sliding-window frequency-wavenumber and polarisation analyses. The resulting earthquake catalogue consists of 14,530 earthquakes between 19 October 2008 and 18 March 2009 with magnitudes in the range of - 1.2 ≤ M L ≤ 2.7. The small-aperture <span class="hlt">seismic</span> array substantially lowers the detection threshold to about M c = - 0.4, when compared to the regional networks operating in West Bohemia ( M c > 0.0). In the course of this work, the main temporal features (frequency-magnitude distribution, propagation of back azimuth and horizontal slowness, occurrence rate of aftershock sequences and interevent-time distribution) of the recent 2008/2009 earthquake swarm are presented and discussed. Temporal changes of the coefficient of variation (based on interevent times) suggest that the swarm earthquake activity of the 2008/2009 swarm terminates by 12 January 2009. During the main phase in our studied swarm period after 19 October, the b value of the Gutenberg-Richter relation decreases from 1.2 to 0.8. This trend is also reflected in the power-law behavior of the <span class="hlt">seismic</span> moment <span class="hlt">release</span>. The corresponding total <span class="hlt">seismic</span> moment <span class="hlt">release</span> of 1.02×1017 Nm is equivalent to M L,max = 5.4.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.9372G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.9372G"><span>High temporal resolution mapping of <span class="hlt">seismic</span> noise sources using heterogeneous supercomputers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gokhberg, Alexey; Ermert, Laura; Paitz, Patrick; Fichtner, Andreas</p> <p>2017-04-01</p> <p>Time- and space-dependent distribution of <span class="hlt">seismic</span> noise sources is becoming a key ingredient of modern real-time monitoring of various geo-systems. Significant interest in <span class="hlt">seismic</span> noise source maps with high temporal resolution (days) is expected to come from a number of domains, including natural resources exploration, analysis of active earthquake fault zones and volcanoes, as well as geothermal and hydrocarbon reservoir monitoring. Currently, knowledge of noise sources is insufficient for high-resolution subsurface monitoring applications. Near-real-time <span class="hlt">seismic</span> data, as well as advanced imaging methods to constrain <span class="hlt">seismic</span> noise sources have recently become available. These methods are based on the massive cross-correlation of <span class="hlt">seismic</span> noise records from all available <span class="hlt">seismic</span> stations in the region of interest and are therefore very computationally intensive. Heterogeneous massively parallel supercomputing systems introduced in the recent years combine conventional multi-core CPU with GPU <span class="hlt">accelerators</span> and provide an opportunity for manifold increase and computing performance. Therefore, these systems represent an efficient platform for implementation of a noise source mapping solution. We present the first results of an ongoing research project conducted in collaboration with the Swiss National Supercomputing Centre (CSCS). The project aims at building a service that provides <span class="hlt">seismic</span> noise source maps for Central Europe with high temporal resolution (days to few weeks depending on frequency and data availability). The service is hosted on the CSCS computing infrastructure; all computationally intensive processing is performed on the massively parallel heterogeneous supercomputer "Piz Daint". The solution architecture is based on the Application-as-a-Service concept in order to provide the interested external researchers the regular access to the noise source maps. The solution architecture includes the following sub-systems: (1) data acquisition responsible for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.epa.gov/environmental-geophysics/seismic-reflection-methods','PESTICIDES'); return false;" href="https://www.epa.gov/environmental-geophysics/seismic-reflection-methods"><span><span class="hlt">Seismic</span> Reflection Methods</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p><span class="hlt">Seismic</span> methods are the most commonly conducted geophysical surveys for engineering investigations. <span class="hlt">Seismic</span> refraction provides engineers and geologists with the most basic of geologic data via simple procedures with common equipment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998Natur.394..356W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998Natur.394..356W"><span>Escape tectonics in the Los Angeles metropolitan region and implications for <span class="hlt">seismic</span> risk</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walls, Christian; Rockwell, Thomas; Mueller, Karl; Bock, Yehuda; Williams, Simon; Pfanner, John; Dolan, James; Fang, Peng</p> <p>1998-07-01</p> <p>Recent damaging earthquakes in California, including the 1971 San Fernando, 1983 Coalinga, 1987 Whittier Narrows and 1994 Northridge events, have drawn attention to thrust faults as both potentially hazardous <span class="hlt">seismic</span> sources and as a mechanism for accommodating shortening in many regions of southern California. Consequently, many geological studies, have concluded that thrust faults in Southern California pose the greatest <span class="hlt">seismic</span> hazard, and also account for most of the estimated 5-7mmyr-1 of contraction across the greater Los Angeles metropolitan area, indicated by Global Positioning System geodetic measurements. Our study demonstrates, however, that less than 50% of the geodetically observed contraction is accommodated on the principal thrust systems across the Los Angeles region. We integrate the most recent geological, geodetic and seismological data to assess the spatial distribution of strain across the Los Angeles metropolitan region. We then demonstrate that a significant component of <span class="hlt">seismic</span> moment <span class="hlt">release</span> and shortening in this region is accommodated by east-west crustal escape `extrusion' along known strike-slip and oblique-slip faults.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T21A0545V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T21A0545V"><span><span class="hlt">Seismic</span> and Aseismic Behavior of the Altotiberina Low-angle Normal Fault System (Northern Apennines, Italy) through High-resolution Earthquake Locations and Repeating Events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valoroso, L.; Chiaraluce, L.</p> <p>2017-12-01</p> <p>Low-angle normal faults (dip < 30°) are geologically widely documented and considered responsible for accommodating the crustal extension within the brittle crust although their mechanical behavior and seismogenic potential is enigmatic. We study the anatomy and slip-behavior of the actively slipping Altotiberina low-angle (ATF) normal fault system using a high-resolution 5-years-long (2010-2014) earthquake catalogue composed of 37k events (ML<3.9 and completeness magnitude MC=0.5 ML), recorded by a dense permanent <span class="hlt">seismic</span> network of the Altotiberina Near Fault Observatory (TABOO). The <span class="hlt">seismic</span> activity defines the fault system dominated at depth by the low-angle ATF surface (15-20°) coinciding to the ATF geometry imaged through <span class="hlt">seismic</span> reflection data. The ATF extends for 50km along-strike and between 4-5 to 16km of depth. <span class="hlt">Seismicity</span> also images the geometry of a set of higher angle faults (35-50°) located in the ATF hanging-wall (HW). The ATF-related <span class="hlt">seismicity</span> accounts for 10% of the whole <span class="hlt">seismicity</span> (3,700 events with ML<2.4), occurring at a remarkably constant rate of 2.2 events/day. This <span class="hlt">seismicity</span> describes an about 1.5-km-thick fault zone composed by multiple sub-parallel slipping planes. The remaining events are instead organized in multiple mainshocks (MW>3) <span class="hlt">seismic</span> sequences lasting from weeks to months, activating a contiguous network of 3-5-km-long syn- and antithetic fault segments within the ATF-HW. The space-time evolution of these minor sequences is consistent with subsequence failures promoted by fluid flow. The ATF-<span class="hlt">seismicity</span> pattern includes 97 clusters of repeating events (RE) made of 299 events with ML<1.9. RE are located around locked patches identified by geodetic modeling, suggesting a mixed-mode (stick-slip and stable-sliding) slip-behavior along the fault plane in accommodating most of the NE-trending tectonic deformation with creeping dominating below 5 km depth. Consistently, the <span class="hlt">seismic</span> moment <span class="hlt">released</span> by the ATF-<span class="hlt">seismicity</span> accounts</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NHESS..17.1725H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NHESS..17.1725H"><span>A procedure to select ground-motion time histories for deterministic <span class="hlt">seismic</span> hazard analysis from the Next Generation Attenuation (NGA) database</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Duruo; Du, Wenqi; Zhu, Hong</p> <p>2017-10-01</p> <p>In performance-based <span class="hlt">seismic</span> design, ground-motion time histories are needed for analyzing dynamic responses of nonlinear structural systems. However, the number of ground-motion data at design level is often limited. In order to analyze <span class="hlt">seismic</span> performance of structures, ground-motion time histories need to be either selected from recorded strong-motion database or numerically simulated using stochastic approaches. In this paper, a detailed procedure to select proper <span class="hlt">acceleration</span> time histories from the Next Generation Attenuation (NGA) database for several cities in Taiwan is presented. Target response spectra are initially determined based on a local ground-motion prediction equation under representative deterministic <span class="hlt">seismic</span> hazard analyses. Then several suites of ground motions are selected for these cities using the Design Ground Motion Library (DGML), a recently proposed interactive ground-motion selection tool. The selected time histories are representatives of the regional <span class="hlt">seismic</span> hazard and should be beneficial to earthquake studies when comprehensive <span class="hlt">seismic</span> hazard assessments and site investigations are unavailable. Note that this method is also applicable to site-specific motion selections with the target spectra near the ground surface considering the site effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S43A2495N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S43A2495N"><span><span class="hlt">Seismicity</span> detection around the subduting seamount off Ibaraki the Japan Trench using dense OBS array data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakatani, Y.; Mochizuki, K.; Shinohara, M.; Yamada, T.; Hino, R.; Ito, Y.; Murai, Y.; Sato, T.</p> <p>2013-12-01</p> <p>A subducting seamount which has a height of about 3 km was revealed off Ibaraki in the Japan Trench by a <span class="hlt">seismic</span> survey (Mochizuki et al., 2008). Mochizuki et al. (2008) also interpreted that interplate coupling was weak over the seamount because <span class="hlt">seismicity</span> was low and the slip of the recent large earthquake did not propagate over it. To carry out further investigation, we deployed dense ocean bottom seismometers (OBSs) array around the seamount for about a year. During the observation period, <span class="hlt">seismicity</span> off Ibaraki was activated due to the occurrence of the 2011 Tohoku earthquake. The southern edge of the mainshock rupture area was considered to be located around off Ibaraki by many source analyses. Moreover, Kubo et al. (2013) proposes the seamount played an important role in the rupture termination of the largest aftershock. Therefore, in this study, we try to understand about spatiotemporal variation of <span class="hlt">seismicity</span> around the seamount before and after the Mw 9.0 event as a first step to elucidate relationship between the subducting seamount and seismogenic behavior. We used velocity waveforms of 1 Hz long-term OBSs which were densely deployed at station intervals of about 6 km. The sampling rate is 200 Hz and the observation period is from October 16, 2010 to September 19, 2011. Because of the ambient noise and effects of thick seafloor sediments, it is difficult to apply methods which have been used to on-land observational data for detecting <span class="hlt">seismicity</span> to OBS data and to handle continuous waveforms automatically. We therefore apply back-projection method (e.g., Kiser and Ishii, 2012) to OBS waveform data which estimate energy-<span class="hlt">release</span> source by stacking waveforms. Among many back-projection methods, we adopt a semblance analysis (e.g., Honda et al., 2008) which can detect feeble waves. First of all, we constructed a 3-D velocity structure model off Ibaraki by compiling the results of marine <span class="hlt">seismic</span> surveys (e.g., Nakahigashi et al., 2012). Then, we divided a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMDI23A2069L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMDI23A2069L"><span>a method of gravity and <span class="hlt">seismic</span> sequential inversion and its GPU implementation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, G.; Meng, X.</p> <p>2011-12-01</p> <p>In this abstract, we introduce a gravity and <span class="hlt">seismic</span> sequential inversion method to invert for density and velocity together. For the gravity inversion, we use an iterative method based on correlation imaging algorithm; for the <span class="hlt">seismic</span> inversion, we use the full waveform inversion. The link between the density and velocity is an empirical formula called Gardner equation, for large volumes of data, we use the GPU to <span class="hlt">accelerate</span> the computation. For the gravity inversion method , we introduce a method based on correlation imaging algorithm,it is also a interative method, first we calculate the correlation imaging of the observed gravity anomaly, it is some value between -1 and +1, then we multiply this value with a little density ,this value become the initial density model. We get a forward reuslt with this initial model and also calculate the correaltion imaging of the misfit of observed data and the forward data, also multiply the correaltion imaging result a little density and add it to the initial model, then do the same procedure above , at last ,we can get a inversion density model. For the <span class="hlt">seismic</span> inveron method ,we use a mothod base on the linearity of acoustic wave equation written in the frequency domain,with a intial velociy model, we can get a good velocity result. In the sequential inversion of gravity and <span class="hlt">seismic</span> , we need a link formula to convert between density and velocity ,in our method , we use the Gardner equation. Driven by the insatiable market demand for real time, high-definition 3D images, the programmable NVIDIA Graphic Processing Unit (GPU) as co-processor of CPU has been developed for high performance computing. Compute Unified Device Architecture (CUDA) is a parallel programming model and software environment provided by NVIDIA designed to overcome the challenge of using traditional general purpose GPU while maintaining a low learn curve for programmers familiar with standard programming languages such as C. In our inversion processing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.S41B2446G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.S41B2446G"><span><span class="hlt">Seismic</span> databases of The Caucasus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gunia, I.; Sokhadze, G.; Mikava, D.; Tvaradze, N.; Godoladze, T.</p> <p>2012-12-01</p> <p>The Caucasus is one of the active segments of the Alpine-Himalayan collision belt. The region needs continues <span class="hlt">seismic</span> monitoring systems for better understanding of tectonic processes going in the region. <span class="hlt">Seismic</span> Monitoring Center of Georgia (Ilia State University) is operating the digital <span class="hlt">seismic</span> network of the country and is also collecting and exchanging data with neighboring countries. The main focus of our study was to create <span class="hlt">seismic</span> database which is well organized, easily reachable and is convenient for scientists to use. The seismological database includes the information about more than 100 000 earthquakes from the whole Caucasus. We have to mention that it includes data from analog and digital <span class="hlt">seismic</span> networks. The first analog <span class="hlt">seismic</span> station in Georgia was installed in 1899 in the Caucasus in Tbilisi city. The number of analog <span class="hlt">seismic</span> stations was increasing during next decades and in 1980s about 100 analog stations were operated all over the region. From 1992 due to political and economical situation the number of stations has been decreased and in 2002 just two analog equipments was operated. New digital <span class="hlt">seismic</span> network was developed in Georgia since 2003. The number of digital <span class="hlt">seismic</span> stations was increasing and in current days there are more than 25 digital stations operating in the country. The database includes the detailed information about all equipments installed on <span class="hlt">seismic</span> stations. Database is available online. That will make convenient interface for <span class="hlt">seismic</span> data exchange data between Caucasus neighboring countries. It also makes easier both the <span class="hlt">seismic</span> data processing and transferring them to the database and decreases the operator's mistakes during the routine work. The database was created using the followings: php, MySql, Javascript, Ajax, GMT, Gmap, Hypoinverse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70035565','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70035565"><span>Integrated geologic and geophysical studies of North American continental intraplate <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Van Lanen, X.; Mooney, W.D.</p> <p>2007-01-01</p> <p>The origin of earthquakes within stable continental regions has been the subject of debate over the past thirty years. Here, we examine the correlation of North American stable continental region earthquakes using five geologic and geophysical data sets: (1) a newly compiled age-province map; (2) Bouguer gravity data; (3) aeromagnetic anomalies; (4) the tectonic stress field; and (5) crustal structure as revealed by deep <span class="hlt">seismic</span>-reflection profiles. We find that: (1) Archean-age (3.8-2.5 Ga) North American crust is essentially aseismic, whereas post-Archean (less than 2.5 Ga) crust shows no clear correlation of crustal age and earthquake frequency or moment <span class="hlt">release</span>; (2) <span class="hlt">seismicity</span> is correlated with continental paleorifts; and (3) <span class="hlt">seismicity</span> is correlated with the NE-SW structural grain of the crust of eastern North America, which in turn reflects the opening and closing of the proto- and modern Atlantic Ocean. This structural grain can be discerned as clear NE-SW lineaments in the Bouguer gravity and aeromagnetic anomaly maps. Stable continental region <span class="hlt">seismicity</span> either: (1) follows the NE-SW lineaments; (2) is aligned at right angles to these lineaments; or (3) forms clusters at what have been termed stress concentrators (e.g., igneous intrusions and intersecting faults). <span class="hlt">Seismicity</span> levels are very low to the west of the Grenville Front (i.e., in the Archean Superior craton). The correlation of <span class="hlt">seismicity</span> with NE-SW-oriented lineaments implies that some stable continental region <span class="hlt">seismicity</span> is related to the accretion and rifting processes that have formed the North American continental crust during the past 2 b.y. We further evaluate this hypothesis by correlating stable continental region <span class="hlt">seismicity</span> with recently obtained deep <span class="hlt">seismic</span>-reflection images of the Appalachian and Grenville crust of southern Canada. These images show numerous faults that penetrate deep (40 km) into the crust. An analysis of hypocentral depths for stable continental region earthquakes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMDI21A0391S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMDI21A0391S"><span>Small aperture <span class="hlt">seismic</span> arrays for studying planetary interiors and <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmerr, N. C.; Lekic, V.; Fouch, M. J.; Panning, M. P.; Siegler, M.; Weber, R. C.</p> <p>2017-12-01</p> <p><span class="hlt">Seismic</span> arrays are a powerful tool for understanding the interior structure and <span class="hlt">seismicity</span> across objects in the Solar System. Given the operational constraints of ground-based lander investigations, a small aperture <span class="hlt">seismic</span> array can provide many of the benefits of a larger-scale network, but does not necessitate a global deployment of instrumentation. Here we define a small aperture array as a deployment of multiple seismometers, with a separation between instruments of 1-1000 meters. For example, small aperture <span class="hlt">seismic</span> arrays have been deployed on the Moon during the Apollo program, the Active <span class="hlt">Seismic</span> Experiments of Apollo 14 and 16, and the Lunar <span class="hlt">Seismic</span> Profiling Experiment deployed by the Apollo 17 astronauts. Both were high frequency geophone arrays with spacing of 50 meters that provided information on the layering and velocity structure of the uppermost kilometer of the lunar crust. Ideally such arrays would consist of instruments that are 3-axis short period or broadband seismometers. The instruments must have a sampling rate and frequency range sensitivity capable of distinguishing between waves arriving at each station in the array. Both terrestrial analogs and the data retrieved from the Apollo arrays demonstrate the efficacy of this approach. Future opportunities exist for deployment of <span class="hlt">seismic</span> arrays on Europa, asteroids, and other objects throughout the Solar System. Here we will present both observational data and 3-D synthetic modeling results that reveal the sensing requirements and the primary advantages of a small aperture <span class="hlt">seismic</span> array over single station approach. For example, at the smallest apertures of < 1 m, we constrain that sampling rates must exceed 500 Hz and instrument sensitivity must extend to 100 Hz or greater. Such advantages include the improved ability to resolve the location of the sources near the array through detection of backazimuth and differential timing between stations, determination of the small-scale structure</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70188674','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70188674"><span>The use of vertical <span class="hlt">seismic</span> profiles in <span class="hlt">seismic</span> investigations of the earth</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Balch, Alfred H.; Lee, M.W.; Miller, J.J.; Ryder, Robert T.</p> <p>1982-01-01</p> <p>During the past 8 years, the U.S. Geological Survey has conducted an extensive investigation on the use of vertical <span class="hlt">seismic</span> profiles (VSP) in a variety of <span class="hlt">seismic</span> exploration applications. <span class="hlt">Seismic</span> sources used were surface air guns, vibrators, explosives, marine air guns, and downhole air guns. Source offsets have ranged from 100 to 7800 ft. Well depths have been from 1200 to over 10,000 ft. We have found three specific ways in which VSPs can be applied to <span class="hlt">seismic</span> exploration. First, <span class="hlt">seismic</span> events observed at the surface of the ground can be traced, level by level, to their point of origin within the earth. Thus, one can tie a surface profile to a well log with an extraordinarily high degree of confidence. Second, one can establish the detectability of a target horizon, such as a porous zone. One can determine (either before or after surface profiling) whether or not a given horizon or layered sequence returns a detectable reflection to the surface. The amplitude and character of the reflection can also be observed. Third, acoustic properties of a stratigraphic sequence can be measured and sometimes correlated to important exploration parameters. For example, sometimes a relationship between apparent attenuation and sand percentage can be established. The technique shows additional promise of aiding surface exploration indirectly through studies of the evolution of the <span class="hlt">seismic</span> pulse, studies of ghosts and multiples, and studies of <span class="hlt">seismic</span> trace inversion techniques. Nearly all current <span class="hlt">seismic</span> data‐processing techniques are adaptable to the processing of VSP data, such as normal moveout (NMO) corrections, stacking, single‐and multiple‐channel filtering, deconvolution, and wavelet shaping.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29203901','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29203901"><span>Seismogenesis of dual subduction beneath Kanto, central Japan controlled by fluid <span class="hlt">release</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ji, Yingfeng; Yoshioka, Shoichi; Manea, Vlad C; Manea, Marina</p> <p>2017-12-04</p> <p>Dual subduction represents an unusual case of subduction where one oceanic plate subducts on top of another, creating a highly complex tectonic setting. Because of the complex interaction between the two subducted plates, the origin of <span class="hlt">seismicity</span> in such region is still not fully understood. Here we investigate the thermal structure of dual subduction beneath Kanto, central Japan formed as a consequence of a unique case of triple trench junction. Using high-resolution three-dimensional thermo-mechanical models tailored for the specific dual subduction settings beneath Kanto, we show that, compared with single-plate subduction systems, subduction of double slabs produces a strong variation of mantle flow, thermal and fluid <span class="hlt">release</span> pattern that strongly controls the regional <span class="hlt">seismicity</span> distribution. Here the deepening of <span class="hlt">seismicity</span> in the Pacific slab located under the Philippine Sea slab is explained by delaying at greater depths (~150 km depth) of the eclogitization front in this region. On the other hand, the shallower <span class="hlt">seismicity</span> observed in the Philippine Sea slab is related to a young and warm plate subduction and probably to the presence of a hot mantle flow traveling underneath the slab and then moving upward on top of the slab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S12C..02V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S12C..02V"><span>Non-linear and plastic soil response from strong ground motion detected using the ambient <span class="hlt">seismic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Viens, L.; Denolle, M.; Hirata, N.</p> <p>2017-12-01</p> <p>Strong ground motion can induce dynamic strains large enough for the shallow subsurface to respond non-linearly and cause permanent velocity changes during earthquakes. We investigate the behavior of the near-surface in the Tokyo metropolitan area during the 2011 Mw 9.0 Tohoku-Oki earthquake using continuous records from 234 seismometers of the Metropolitan <span class="hlt">Seismic</span> Observation network (MeSO-net). This network, which was deployed in shallow 20-m depth boreholes, recorded horizontal <span class="hlt">accelerations</span> up to 236 cm/s2 during the mainshock. For each MeSO-net station, we compute the near-surface response using the single-station cross-correlation technique between vertical and horizontal components, every 6 hours for 2.5 months around the main event. Comparing each near-surface response against the pre-event reference, we find <span class="hlt">seismic</span> velocity drops up to 10% in the near-surface of the Tokyo metropolitan area during the mainshock. The amplitude of the coseismic velocity drop increases with increasing ground shaking and decreasing VS30, which is the S-wave velocity the first 30-m of the ground. Furthermore, the waveforms experience a loss of coherence that recovers exponentially over a time. This recovery rate also increases with the <span class="hlt">acceleration</span> levels. While most of the velocity changes and waveform coherence recover within a few days, we also find permanent changes at stations that experienced liquefaction and the strongest ground motions. The ambient <span class="hlt">seismic</span> field captures the coseismic velocity changes in the shallow structure and the following healing process, and may be used to detect permanent damage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S54B..08M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S54B..08M"><span>Ground motions from induced earthquakes in Oklahoma and Kansas and the implications for <span class="hlt">seismic</span> hazard</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moschetti, M. P.; Rennolet, S.; Thompson, E.; Yeck, W.; McNamara, D. E.; Herrmann, R. B.; Powers, P.; Hoover, S. M.</p> <p>2016-12-01</p> <p>Recent efforts to characterize the <span class="hlt">seismic</span> hazard resulting from increased <span class="hlt">seismicity</span> rates in Oklahoma and Kansas highlight the need for a regionalized ground motion characterization. To support these efforts, we measure and compile strong ground motions and compare these average ground motions intensity measures (IMs) with existing ground motion prediction equations (GMPEs). IMs are computed for available broadband and strong-motion records from M≥3 earthquakes occurring January 2009-April 2016, using standard strong motion processing guidelines. We verified our methods by comparing results from specific earthquakes to other standard procedures such as the USGS Shakemap system. The large number of records required an automated processing scheme, which was complicated by the extremely high rate of small-magnitude earthquakes 2014-2016. Orientation-independent IMs include peak ground motions (<span class="hlt">acceleration</span> and velocity) and pseudo-spectral <span class="hlt">accelerations</span> (5 percent damping, 0.1-10 s period). Metadata for the records included relocated event hypocenters. The database includes more than 160,000 records from about 3200 earthquakes. Estimates of the mean and standard deviation of the IMs are computed by distance binning at intervals of 2 km. Mean IMs exhibit a clear break in geometrical attenuation at epicentral distances of about 50-70 km, which is consistent with previous studies in the CEUS. Comparisons of these ground motions with modern GMPEs provide some insight into the relative IMs of induced earthquakes in Oklahoma and Kansas relative to the western U.S. and the central and eastern U.S. The site response for these stations is uncertain because very little is known about shallow <span class="hlt">seismic</span> velocity in the region, and we make no attempt to correct observed IMs to a reference site conditions. At close distances, the observed IMs are lower than the predictions of the seed GMPEs of the NGA-East project (and about consistent with NGA-West-2 ground motions). This ground</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930049041&hterms=tyrosine&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtyrosine','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930049041&hterms=tyrosine&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtyrosine"><span>Tyrosine - Effects on catecholamine <span class="hlt">release</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Acworth, Ian N.; During, Matthew J.; Wurtman, Richard J.</p> <p>1988-01-01</p> <p>Tyrosine administration elevates striatal levels of dopamine metabolites in animals given treatments that <span class="hlt">accelerate</span> nigrostriatal firing, but not in untreated rats. We examined the possibility that the amino acid might actually enhance dopamine <span class="hlt">release</span> in untreated animals, but that the technique of measuring striatal dopamine metabolism was too insensitive to demonstrate such an effect. Dopamine <span class="hlt">release</span> was assessed directly, using brain microdialysis of striatal extracellular fluid. Tyrosine administration (50-200 mg/kg IP) did indeed cause a dose related increase in extracellular fluid dopamine levels with minor elevations in levels of DOPAC and HVA, its major metabolites, which were not dose-related. The rise in dopamine was short-lived, suggesting that receptor-mediated feedback mechanisms responded to the increased dopamine <span class="hlt">release</span> by diminishing neuronal firing or sensitivity to tyrosine. These observations indicate that measurement of changes in striatal DOPAC and HVA, if negative, need not rule out increases in nigrostriatal dopamine <span class="hlt">release</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70013910','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70013910"><span><span class="hlt">Seismicity</span> at Old Faithful Geyser: an isolated source of geothermal noise and possible analogue of volcanic <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kieffer, S.W.</p> <p>1984-01-01</p> <p>Old Faithful Geyser in Yellowstone National Park, U.S.A., is a relatively isolated source of <span class="hlt">seismic</span> noise and exhibits <span class="hlt">seismic</span> behavior similar to that observed at many volcanoes, including "bubblequakes" that resemble B-type "earthquakes", harmonic tremor before and during eruptions, and periods of <span class="hlt">seismic</span> quiet prior to eruptions. Although Old Faithful differs from volcanoes in that the conduit is continuously open, that rock-fracturing is not a process responsible for <span class="hlt">seismicity</span>, and that the erupting fluid is inviscid H2O rather than viscous magma, there are also remarkable similarities in the problems of heat and mass recharge to the system, in the eruption dynamics, and in the <span class="hlt">seismicity</span>. Water rises irregularly into the immediate reservoir of Old Faithful as recharge occurs, a fact that suggests that there are two enlarged storage regions: one between 18 and 22 m (the base of the immediate reservoir) and one between about 10 and 12 m depth. Transport of heat from hot water or steam entering at the base of the recharging water column into cooler overlying water occurs by migration of steam bubbles upward and their collapse in the cooler water, and by episodes of convective overturn. An eruption occurs when the temperature of the near-surface water exceeds the boiling point if the entire water column is sufficiently close to the boiling curve that the propagation of pressure-<span class="hlt">release</span> waves (rarefactions) down the column can bring the liquid water onto the boiling curve. The process of conversion of the liquid water in the conduit at the onset of an eruption into a two-phase liquid-vapor mixture takes on the order of 30 s. The <span class="hlt">seismicity</span> is directly related to the sequence of filling and heating during the recharge cycle, and to the fluid mechanics of the eruption. Short (0.2-0.3 s), monochromatic, high-frequency events (20-60 Hz) resembling unsustained harmonic tremor and, in some instances, B-type volcanic earthquakes, occur when exploding or imploding</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70073949','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70073949"><span>Common features and peculiarities of the <span class="hlt">seismic</span> activity at Phlegraean Fields, Long Valley, and Vesuvius</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Marzocchi, W.; Vilardo, G.; Hill, D.P.; Ricciardi, G.P.; Ricco, C.</p> <p>2001-01-01</p> <p>We analyzed and compared the <span class="hlt">seismic</span> activity that has occurred in the last two to three decades in three distinct volcanic areas: Phlegraean Fields, Italy; Vesuvius, Italy; and Long Valley, California. Our main goal is to identify and discuss common features and peculiarities in the temporal evolution of earthquake sequences that may reflect similarities and differences in the generating processes between these volcanic systems. In particular, we tried to characterize the time series of the number of events and of the <span class="hlt">seismic</span> energy <span class="hlt">release</span> in terms of stochastic, deterministic, and chaotic components. The time sequences from each area consist of thousands of earthquakes that allow a detailed quantitative analysis and comparison. The results obtained showed no evidence for either deterministic or chaotic components in the earthquake sequences in Long Valley caldera, which appears to be dominated by stochastic behavior. In contrast, earthquake sequences at Phlegrean Fields and Mount Vesuvius show a deterministic signal mainly consisting of a 24-hour periodicity. Our analysis suggests that the modulation in <span class="hlt">seismicity</span> is in some way related to thermal diurnal processes, rather than luni-solar tidal effects. Independently from the process that generates these periodicities on the <span class="hlt">seismicity</span>., it is suggested that the lack (or presence) of diurnal cycles is <span class="hlt">seismic</span> swarms of volcanic areas could be closely linked to the presence (or lack) of magma motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70184226','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70184226"><span>Ground motion models used in the 2014 U.S. National <span class="hlt">Seismic</span> Hazard Maps</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Rezaeian, Sanaz; Petersen, Mark D.; Moschetti, Morgan P.</p> <p>2015-01-01</p> <p>The National <span class="hlt">Seismic</span> Hazard Maps (NSHMs) are an important component of <span class="hlt">seismic</span> design regulations in the United States. This paper compares hazard using the new suite of ground motion models (GMMs) relative to hazard using the suite of GMMs applied in the previous version of the maps. The new source characterization models are used for both cases. A previous paper (Rezaeian et al. 2014) discussed the five NGA-West2 GMMs used for shallow crustal earthquakes in the Western United States (WUS), which are also summarized here. Our focus in this paper is on GMMs for earthquakes in stable continental regions in the Central and Eastern United States (CEUS), as well as subduction interface and deep intraslab earthquakes. We consider building code hazard levels for peak ground <span class="hlt">acceleration</span> (PGA), 0.2-s, and 1.0-s spectral <span class="hlt">accelerations</span> (SAs) on uniform firm-rock site conditions. The GMM modifications in the updated version of the maps created changes in hazard within 5% to 20% in WUS; decreases within 5% to 20% in CEUS; changes within 5% to 15% for subduction interface earthquakes; and changes involving decreases of up to 50% and increases of up to 30% for deep intraslab earthquakes for most U.S. sites. These modifications were combined with changes resulting from modifications in the source characterization models to obtain the new hazard maps.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/10029','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/10029"><span>Environmental Impact From <span class="hlt">Accelerator</span> Operation at SLAC</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Liu, James C</p> <p>1999-03-22</p> <p>Environmental impacts from electron <span class="hlt">accelerator</span> operations at the Stanford Linear <span class="hlt">Accelerator</span> Center, which is located near populated areas, are illustrated by using examples of three different <span class="hlt">accelerator</span> facilities: the low power (a few watts) SSRL, the high power (a few kilowatts) PEP-II, and the 50-kW SLC. Three types of major impacts are discussed: (1) off-site doses from skyshine radiation, mainly neutrons, (2) off-site doses from radioactive air emission, mainly {sup 13}N, and (3) radioactivities, mainly {sup 3}H, produced in the groundwater. It was found that, from SSRL operation, the skyshine radiation result in a MEI (Maximum Exposed Individual) of 0.3more » {mu}Sv/y while a conservative calculation using CAP88 showed a MEI of 0.36 {mu}Sv/y from radioactive air <span class="hlt">releases</span>. The calculated MEI doses due to future PEP-II operation are 30 {mu}Sv/y from skyshine radiation and 2 {mu}Sv/y from air <span class="hlt">releases</span>. The population doses due to radioactive air emission are 0.5 person-mSv from SSRL and 12 person-mSv from PEP-II. Because of the stronger decrease of skyshine dose as the distance increases, the population dose from skyshine radiation are smaller than that from air <span class="hlt">release</span>. The third environmental impact, tritium activity produced in the groundwater, was also demonstrated to be acceptable from both the well water measurements and the FLUKA calculations for the worst case of the SLC high-power dump.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatGe..10..960S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatGe..10..960S"><span>Fossil intermediate-depth earthquakes in subducting slabs linked to differential stress <span class="hlt">release</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scambelluri, Marco; Pennacchioni, Giorgio; Gilio, Mattia; Bestmann, Michel; Plümper, Oliver; Nestola, Fabrizio</p> <p>2017-12-01</p> <p>The cause of intermediate-depth (50-300 km) <span class="hlt">seismicity</span> in subduction zones is uncertain. It is typically attributed either to rock embrittlement associated with fluid pressurization, or to thermal runaway instabilities. Here we document glassy pseudotachylyte fault rocks—the products of frictional melting during coseismic faulting—in the Lanzo Massif ophiolite in the Italian Western Alps. These pseudotachylytes formed at subduction-zone depths of 60-70 km in poorly hydrated to dry oceanic gabbro and mantle peridotite. This rock suite is a fossil analogue to an oceanic lithospheric mantle that undergoes present-day subduction. The pseudotachylytes locally preserve high-pressure minerals that indicate an intermediate-depth <span class="hlt">seismic</span> environment. These pseudotachylytes are important because they are hosted in a near-anhydrous lithosphere free of coeval ductile deformation, which excludes an origin by dehydration embrittlement or thermal runaway processes. Instead, our observations indicate that <span class="hlt">seismicity</span> in cold subducting slabs can be explained by the <span class="hlt">release</span> of differential stresses accumulated in strong dry metastable rocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1411977M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1411977M"><span>Communication during an evolving <span class="hlt">seismic</span> sequence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mucciarelli, M.; Camassi, R.</p> <p>2012-04-01</p> <p>Since October 2011 a <span class="hlt">seismic</span> swarm is affecting the Pollino mountain range, southern Italy. At the abstract submission date the sequence is still ongoing, with more than 500 events with M>1, at least 40 well perceived by the population and a maximum magnitude at 3.6. The area was hit by a magnitude 5.7 event in 1998 that caused one dead, some injured and widespread damage in at least six municipalities. The population main fear is that a large event could follow the <span class="hlt">seismic</span> swarm as it occurred at L'Aquila in 2009. Among the initiatives taken by Civil Protection at national and regional level, it was decided to try to implement at local scale two communication projects that were thought for "peace time" and not for dissemination during a <span class="hlt">seismic</span> crisis: the "Terremoto-Io non rischio" project for general public and the "EDURISK" project for school children. The main lesson learned during the first months of the activity are: 1) it is possible to take advantage of the increased awareness and risk perception from the population to attract more citizen toward topics that could go unnoticed otherwise; 2) the Civil Protection volunteers could be a very effective mean to reach a large amount of the population, provided they are carefully trained especially when children are involved; 3) the expectations about earthquake prediction raised from media without any scientific support proved to be the most difficult to be tackled: to overcome this bias risk education in "peace time" is absolutely essential; 4) door-to-door communication is perceived much better than official press <span class="hlt">release</span> on newspapers; 5) training of volunteers must be limited to a few basic information, with special attention to the local context.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSeis.tmp...36J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSeis.tmp...36J"><span>Introduction of conditional mean spectrum and conditional spectrum in the practice of <span class="hlt">seismic</span> safety evaluation in China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ji, Kun; Bouaanani, Najib; Wen, Ruizhi; Ren, Yefei</p> <p>2018-05-01</p> <p>This paper aims at implementing and introducing the use of conditional mean spectrum (CMS) and conditional spectrum (CS) as the main input parameters in the practice of <span class="hlt">seismic</span> safety evaluation (SSE) in China, instead of the currently used uniform hazard spectrum (UHS). For this purpose, a procedure for M-R-epsilon <span class="hlt">seismic</span> hazard deaggregation in China was first developed. For illustration purposes, two different typical sites in China, with one to two dominant <span class="hlt">seismic</span> zones, were considered as examples to carry out <span class="hlt">seismic</span> hazard deaggregation and illustrate the construction of CMS/CS. Two types of correlation coefficients were used to generate CMS and the results were compared over a vibration period range of interest. Ground motion records were selected from the NSMONS (2007-2015) and PEER NGA-West2 databases to correspond to the target CMS and CS. Hazard consistency of the spectral <span class="hlt">accelerations</span> of the selected ground motion records was evaluated and validated by computing the annual exceedance probability rate of the response spectra and comparing the results to the hazard curve corresponding to each site of concern at different periods. The tools developed in this work and their illustrative application to specific case studies in China are a first step towards the adoption of CMS and CS into the practice of <span class="hlt">seismic</span> safety evaluation in this country.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.S41D..04Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.S41D..04Z"><span><span class="hlt">Seismic</span> imaging of the oil and geothermal reservoirs using the induced <span class="hlt">seismicity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, H.; Toksoz, M. N.; Fehler, M.</p> <p>2011-12-01</p> <p>It is known that microseismicity can be induced in the oil field due to the stress change caused by oil/gas production. Similarly, injection of high-pressure fluids into the reservoir can also induce microseismicity. Due to the proximity of induced <span class="hlt">seismicity</span> to the reservoir, in some cases, it may be advantageous to use induced <span class="hlt">seismicity</span> to image the reservoir. The <span class="hlt">seismic</span> stations for monitoring the induced <span class="hlt">seismicity</span> are usually sparse. Conventional travel time tomography using travel times from <span class="hlt">seismic</span> events to stations may not be applicable because of poor ray coverage outside the source region. In comparison, the double-difference tomography method of Zhang and Thurber (2003) that uses the differential travel times is able to image the reservoir by avoiding determining the velocity structure outside the source region. In this study, we present two case studies of applying double-difference tomography to induced <span class="hlt">seismicity</span> monitored by borehole stations. In the case of an oil field in Oman, five closely spaced monitoring wells are used to monitor microseismicity induced by gas production. In each well, multiple <span class="hlt">seismic</span> sensors are positioned from depths 750 m - 1250 m and about 2000 events are selected for tomography. Reservoir imaging shows encouraging results in identifying structures and velocity changes within reservoir layers. Clear velocity contrast was seen across the major northeast-southwest faults. Low Vp, low Vs and low Vp/Vs anomalies are mainly associated with the gas production layer. For the case of the Soultz Enhanced Geothermal System at Soultz-sous-Forets, France, we used travel time data from the September and October 1993 hydraulic stimulations, where only four borehole stations are available. The results showed that the S-wave velocity structure correlated well with <span class="hlt">seismicity</span> and showed low velocity zones at depths between 2900 and 3300 meters, where fluid was believed to have infiltrated the reservoir. We also attempt time</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EEEV...15...19S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EEEV...15...19S"><span>Response of a 2-story test-bed structure for the <span class="hlt">seismic</span> evaluation of nonstructural systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Soroushian, Siavash; Maragakis, E. "Manos"; Zaghi, Arash E.; Rahmanishamsi, Esmaeel; Itani, Ahmad M.; Pekcan, Gokhan</p> <p>2016-03-01</p> <p>A full-scale, two-story, two-by-one bay, steel braced-frame was subjected to a number of unidirectional ground motions using three shake tables at the UNR-NEES site. The test-bed frame was designed to study the <span class="hlt">seismic</span> performance of nonstructural systems including steel-framed gypsum partition walls, suspended ceilings and fire sprinkler systems. The frame can be configured to perform as an elastic or inelastic system to generate large floor <span class="hlt">accelerations</span> or large inter story drift, respectively. In this study, the dynamic performance of the linear and nonlinear test-beds was comprehensively studied. The <span class="hlt">seismic</span> performance of nonstructural systems installed in the linear and nonlinear test-beds were assessed during extreme excitations. In addition, the dynamic interactions of the test-bed and installed nonstructural systems are investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3019L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3019L"><span>Probabilistic properties of injection induced <span class="hlt">seismicity</span> - implications for the <span class="hlt">seismic</span> hazard analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lasocki, Stanislaw; Urban, Pawel; Kwiatek, Grzegorz; Martinez-Garzón, Particia</p> <p>2017-04-01</p> <p>Injection induced <span class="hlt">seismicity</span> (IIS) is an undesired dynamic rockmass response to massive fluid injections. This includes reactions, among others, to hydro-fracturing for shale gas exploitation. Complexity and changeability of technological factors that induce IIS, may result in significant deviations of the observed distributions of <span class="hlt">seismic</span> process parameters from the models, which perform well in natural, tectonic <span class="hlt">seismic</span> processes. Classic formulations of probabilistic <span class="hlt">seismic</span> hazard analysis in natural <span class="hlt">seismicity</span> assume the <span class="hlt">seismic</span> marked point process to be a stationary Poisson process, whose marks - magnitudes are governed by a Gutenberg-Richter born exponential distribution. It is well known that the use of an inappropriate earthquake occurrence model and/or an inappropriate of magnitude distribution model leads to significant systematic errors of hazard estimates. It is therefore of paramount importance to check whether the mentioned, commonly used in natural <span class="hlt">seismicity</span> assumptions on the <span class="hlt">seismic</span> process, can be safely used in IIS hazard problems or not. <span class="hlt">Seismicity</span> accompanying shale gas operations is widely studied in the framework of the project "Shale Gas Exploration and Exploitation Induced Risks" (SHEER). Here we present results of SHEER project investigations of such <span class="hlt">seismicity</span> from Oklahoma and of a proxy of such <span class="hlt">seismicity</span> - IIS data from The Geysers geothermal field. We attempt to answer to the following questions: • Do IIS earthquakes follow the Gutenberg-Richter distribution law, so that the magnitude distribution can be modelled by an exponential distribution? • Is the occurrence process of IIS earthquakes Poissonian? Is it segmentally Poissonian? If yes, how are these segments linked to cycles of technological operations? Statistical tests indicate that the Gutenberg-Richter relation born exponential distribution model for magnitude is, in general, inappropriate. The magnitude distribution can be complex, multimodal, with no ready</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511243E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511243E"><span>On the adaptive daily forecasting of <span class="hlt">seismic</span> aftershock hazard</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ebrahimian, Hossein; Jalayer, Fatemeh; Asprone, Domenico; Lombardi, Anna Maria; Marzocchi, Warner; Prota, Andrea; Manfredi, Gaetano</p> <p>2013-04-01</p> <p>Post-earthquake ground motion hazard assessment is a fundamental initial step towards time-dependent <span class="hlt">seismic</span> risk assessment for buildings in a post main-shock environment. Therefore, operative forecasting of <span class="hlt">seismic</span> aftershock hazard forms a viable support basis for decision-making regarding search and rescue, inspection, repair, and re-occupation in a post main-shock environment. Arguably, an adaptive procedure for integrating the aftershock occurrence rate together with suitable ground motion prediction relations is key to Probabilistic <span class="hlt">Seismic</span> Aftershock Hazard Assessment (PSAHA). In the short-term, the <span class="hlt">seismic</span> hazard may vary significantly (Jordan et al., 2011), particularly after the occurrence of a high magnitude earthquake. Hence, PSAHA requires a reliable model that is able to track the time evolution of the earthquake occurrence rates together with suitable ground motion prediction relations. This work focuses on providing adaptive daily forecasts of the mean daily rate of exceeding various spectral <span class="hlt">acceleration</span> values (the aftershock hazard). Two well-established earthquake occurrence models suitable for daily <span class="hlt">seismicity</span> forecasts associated with the evolution of an aftershock sequence, namely, the modified Omori's aftershock model and the Epidemic Type Aftershock Sequence (ETAS) are adopted. The parameters of the modified Omori model are updated on a daily basis using Bayesian updating and based on the data provided by the ongoing aftershock sequence based on the methodology originally proposed by Jalayer et al. (2011). The Bayesian updating is used also to provide sequence-based parameter estimates for a given ground motion prediction model, i.e. the aftershock events in an ongoing sequence are exploited in order to update in an adaptive manner the parameters of an existing ground motion prediction model. As a numerical example, the mean daily rates of exceeding specific spectral <span class="hlt">acceleration</span> values are estimated adaptively for the L'Aquila 2009</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21148952-seismic-vulnerability-performance-level-confined-brick-walls','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21148952-seismic-vulnerability-performance-level-confined-brick-walls"><span><span class="hlt">Seismic</span> Vulnerability and Performance Level of confined brick walls</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ghalehnovi, M.; Rahdar, H. A.</p> <p>2008-07-08</p> <p>There has been an increase on the interest of Engineers and designers to use designing methods based on displacement and behavior (designing based on performance) Regarding to the importance of resisting structure design against dynamic loads such as earthquake, and inability to design according to prediction of nonlinear behavior element caused by nonlinear properties of constructional material.Economically speaking, easy carrying out and accessibility of masonry material have caused an enormous increase in masonry structures in villages, towns and cities. On the other hand, there is a necessity to study behavior and <span class="hlt">Seismic</span> Vulnerability in these kinds of structures since Iranmore » is located on the earthquake belt of Alpide.Different reasons such as environmental, economic, social, cultural and accessible constructional material have caused different kinds of constructional structures.In this study, some tied walls have been modeled with software and with relevant <span class="hlt">accelerator</span> suitable with geology conditions under dynamic analysis to research on the <span class="hlt">Seismic</span> Vulnerability and performance level of confined brick walls. Results from this analysis seem to be satisfactory after comparison of them with the values in Code ATC40, FEMA and standard 2800 of Iran.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AIPC.1020.1738G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AIPC.1020.1738G"><span><span class="hlt">Seismic</span> Vulnerability and Performance Level of confined brick walls</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghalehnovi, M.; Rahdar, H. A.</p> <p>2008-07-01</p> <p>There has been an increase on the interest of Engineers and designers to use designing methods based on displacement and behavior (designing based on performance) Regarding to the importance of resisting structure design against dynamic loads such as earthquake, and inability to design according to prediction of nonlinear behavior element caused by nonlinear properties of constructional material. Economically speaking, easy carrying out and accessibility of masonry material have caused an enormous increase in masonry structures in villages, towns and cities. On the other hand, there is a necessity to study behavior and <span class="hlt">Seismic</span> Vulnerability in these kinds of structures since Iran is located on the earthquake belt of Alpide. Different reasons such as environmental, economic, social, cultural and accessible constructional material have caused different kinds of constructional structures. In this study, some tied walls have been modeled with software and with relevant <span class="hlt">accelerator</span> suitable with geology conditions under dynamic analysis to research on the <span class="hlt">Seismic</span> Vulnerability and performance level of confined brick walls. Results from this analysis seem to be satisfactory after comparison of them with the values in Code ATC40, FEMA and standard 2800 of Iran.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.5544G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.5544G"><span>Detection capability of the IMS <span class="hlt">seismic</span> network based on ambient <span class="hlt">seismic</span> noise measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gaebler, Peter J.; Ceranna, Lars</p> <p>2016-04-01</p> <p>All nuclear explosions - on the Earth's surface, underground, underwater or in the atmosphere - are banned by the Comprehensive Nuclear-Test-Ban Treaty (CTBT). As part of this treaty, a verification regime was put into place to detect, locate and characterize nuclear explosion testings at any time, by anyone and everywhere on the Earth. The International Monitoring System (IMS) plays a key role in the verification regime of the CTBT. Out of the different monitoring techniques used in the IMS, the <span class="hlt">seismic</span> waveform approach is the most effective technology for monitoring nuclear underground testing and to identify and characterize potential nuclear events. This study introduces a method of <span class="hlt">seismic</span> threshold monitoring to assess an upper magnitude limit of a potential <span class="hlt">seismic</span> event in a certain given geographical region. The method is based on ambient <span class="hlt">seismic</span> background noise measurements at the individual IMS <span class="hlt">seismic</span> stations as well as on global distance correction terms for body wave magnitudes, which are calculated using the <span class="hlt">seismic</span> reflectivity method. From our investigations we conclude that a global detection threshold of around mb 4.0 can be achieved using only stations from the primary <span class="hlt">seismic</span> network, a clear latitudinal dependence for the detection threshold can be observed between northern and southern hemisphere. Including the <span class="hlt">seismic</span> stations being part of the auxiliary <span class="hlt">seismic</span> IMS network results in a slight improvement of global detection capability. However, including wave arrivals from distances greater than 120 degrees, mainly PKP-wave arrivals, leads to a significant improvement in average global detection capability. In special this leads to an improvement of the detection threshold on the southern hemisphere. We further investigate the dependence of the detection capability on spatial (latitude and longitude) and temporal (time) parameters, as well as on parameters such as source type and percentage of operational IMS stations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29247158','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29247158"><span>Hydrologically-driven crustal stresses and <span class="hlt">seismicity</span> in the New Madrid <span class="hlt">Seismic</span> Zone.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Craig, Timothy J; Chanard, Kristel; Calais, Eric</p> <p>2017-12-15</p> <p>The degree to which short-term non-tectonic processes, either natural and anthropogenic, influence the occurrence of earthquakes in active tectonic settings or 'stable' plate interiors, remains a subject of debate. Recent work in plate-boundary regions demonstrates the capacity for long-wavelength changes in continental water storage to produce observable surface deformation, induce crustal stresses and modulate <span class="hlt">seismicity</span> rates. Here we show that a significant variation in the rate of microearthquakes in the intraplate New Madrid <span class="hlt">Seismic</span> Zone at annual and multi-annual timescales coincides with hydrological loading in the upper Mississippi embayment. We demonstrate that this loading, which results in geodetically observed surface deformation, induces stresses within the lithosphere that, although of small amplitude, modulate the ongoing <span class="hlt">seismicity</span> of the New Madrid region. Correspondence between surface deformation, hydrological loading and <span class="hlt">seismicity</span> rates at both annual and multi-annual timescales indicates that <span class="hlt">seismicity</span> variations are the direct result of elastic stresses induced by the water load.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26911518','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26911518"><span>Impacts of soil petroleum contamination on nutrient <span class="hlt">release</span> during litter decomposition of Hippophae rhamnoides.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Xiaoxi; Liu, Zengwen; Luc, Nhu Trung; Yu, Qi; Liu, Xiaobo; Liang, Xiao</p> <p>2016-03-01</p> <p>Petroleum exploitation causes contamination of shrub lands close to oil wells. Soil petroleum contamination affects nutrient <span class="hlt">release</span> during the litter decomposition of shrubs, which influences nutrient recycling and the maintenance of soil fertility. Hence, this contamination may reduce the long-term growth and stability of shrub communities and consequently, the effects of phytoremediation. Fresh foliar litter of Hippophae rhamnoides, a potential phytoremediating species, was collected for this study. The litter was placed in litterbags and then buried in different petroleum-polluted soil media (the petroleum concentrations were 15, 30, and 45 g kg(-1) dry soil, which were considered as slightly, moderately and seriously polluted soil, respectively) for a decomposition test. The impacts of petroleum contamination on the <span class="hlt">release</span> of nutrients (including N, P, K, Cu, Zn, Fe, Mn, Ca and Mg) were assessed. The results showed that (1) after one year of decomposition, the <span class="hlt">release</span> of all nutrients was <span class="hlt">accelerated</span> in the slightly polluted soil. In the moderately polluted soil, P <span class="hlt">release</span> was <span class="hlt">accelerated</span>, while Cu, Zn and Mn <span class="hlt">release</span> was inhibited. In the seriously polluted soil, Cu and Zn <span class="hlt">release</span> was <span class="hlt">accelerated</span>, while the <span class="hlt">release</span> of the other nutrients was inhibited. (2) The effect of petroleum on nutrient <span class="hlt">release</span> from litter differed in different periods during decomposition; this was mainly due to changes in soil microorganisms and enzymes under the stress of petroleum contamination. (3) To maintain the nutrient cycling and the soil fertility of shrub lands, H. rhamnoides is only suitable for phytoremediation of soils containing less than 30 g kg(-1) of petroleum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PApGe.174.3725B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PApGe.174.3725B"><span>Periodicity of Strong <span class="hlt">Seismicity</span> in Italy: Schuster Spectrum Analysis Extended to the Destructive Earthquakes of 2016</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bragato, P. L.</p> <p>2017-10-01</p> <p>The strong earthquakes that occurred in Italy between 2009 and 2016 represent an abrupt <span class="hlt">acceleration</span> of <span class="hlt">seismicity</span> in respect of the previous 30 years. Such behavior seems to agree with the periodic rate change I observed in a previous paper. The present work improves that study by extending the data set up to the end of 2016, adopting the latest version of the historical <span class="hlt">seismic</span> catalog of Italy, and introducing Schuster spectrum analysis for the detection of the oscillatory period and the assessment of its statistical significance. Applied to the declustered catalog of M w ≥ 6 earthquakes that occurred between 1600 and 2016, the analysis individuates a marked periodicity of 46 years, which is recognized above the 95% confidence level. Monte Carlo simulation shows that the oscillatory behavior is stable in respect of random errors on magnitude estimation. A parametric oscillatory model for the annual rate of <span class="hlt">seismicity</span> is estimated by likelihood maximization under the hypothesis of inhomogeneous Poisson point process. According to the Akaike Information Criterion, such model outperforms the simpler homogeneous one with constant annual rate. A further element emerges form the analysis: so far, despite recent earthquakes, the Italian <span class="hlt">seismicity</span> is still within a long-term decreasing trend established since the first half of the twentieth century.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.9739G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.9739G"><span>Considering the ranges of uncertainties in the New Probabilistic <span class="hlt">Seismic</span> Hazard Assessment of Germany - Version 2016</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grunthal, Gottfried; Stromeyer, Dietrich; Bosse, Christian; Cotton, Fabrice; Bindi, Dino</p> <p>2017-04-01</p> <p>The <span class="hlt">seismic</span> load parameters for the upcoming National Annex to the Eurocode 8 result from the reassessment of the <span class="hlt">seismic</span> hazard supported by the German Institution for Civil Engineering . This 2016 version of hazard assessment for Germany as target area was based on a comprehensive involvement of all accessible uncertainties in models and parameters into the approach and the provision of a rational framework for facilitating the uncertainties in a transparent way. The developed <span class="hlt">seismic</span> hazard model represents significant improvements; i.e. it is based on updated and extended databases, comprehensive ranges of models, robust methods and a selection of a set of ground motion prediction equations of their latest generation. The output specifications were designed according to the user oriented needs as suggested by two review teams supervising the entire project. In particular, <span class="hlt">seismic</span> load parameters were calculated for rock conditions with a vS30 of 800 ms-1 for three hazard levels (10%, 5% and 2% probability of occurrence or exceedance within 50 years) in form of, e.g., uniform hazard spectra (UHS) based on 19 sprectral periods in the range of 0.01 - 3s, <span class="hlt">seismic</span> hazard maps for spectral response <span class="hlt">accelerations</span> for different spectral periods or for macroseismic intensities. The developed hazard model consists of a logic tree with 4040 end branches and essential innovations employed to capture epistemic uncertainties and aleatory variabilities. The computation scheme enables the sound calculation of the mean and any quantile of required <span class="hlt">seismic</span> load parameters. Mean, median and 84th percentiles of load parameters were provided together with the full calculation model to clearly illustrate the uncertainties of such a probabilistic assessment for a region of a low-to-moderate level of <span class="hlt">seismicity</span>. The regional variations of these uncertainties (e.g. ratios between the mean and median hazard estimations) were analyzed and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH11A1711G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH11A1711G"><span>The assessment of <span class="hlt">seismic</span> hazard for Gori, (Georgia) and preliminary studies of <span class="hlt">seismic</span> microzonation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gogoladze, Z.; Moscatelli, M.; Giallini, S.; Avalle, A.; Gventsadze, A.; Kvavadze, N.; Tsereteli, N.</p> <p>2016-12-01</p> <p><span class="hlt">Seismic</span> risk is a crucial issue for South Caucasus, which is the main gateway between Asia and Europe. The goal of this work is to propose new methods and criteria for defining an overall approach aimed at assessing and mitigating <span class="hlt">seismic</span> risk in Georgia. In this reguard <span class="hlt">seismic</span> microzonation represents a highly useful tool for <span class="hlt">seismic</span> risk assessmentin land management, for design of buildings or structures and for emergency planning.<span class="hlt">Seismic</span> microzonation assessment of local <span class="hlt">seismic</span> hazard,which is a component of <span class="hlt">seismicity</span> resulting from specific local characteristics which cause local amplification and soil instability, through identification of zones with <span class="hlt">seismically</span> homogeneous behavior. This paper presents the results of preliminary study of <span class="hlt">seismic</span> microzonation of Gori, Georgia. Gori is and is located in the Shida Kartli region and on both sides of Liachvi and Mtkvari rivers, with area of about 135 km2around the Gori fortress. Gori is located in Achara-Trialeti fold-thrust belt, that is tectonically unstable. Half of all earthquakes in Gori area with magnitude M≥3.5 have happened along this fault zone and on basis of damage caused by previous earthquakes, this territory show the highest level of risk (the maximum value of direct losses) in central part of the town. The <span class="hlt">seismic</span> microzonation map of level 1 for Gori was carried out using: 1) Already available data (i.e., topographic map and boreholes data), 2) Results of new geological surveys and 3) Geophysical measurements (i.e., MASW and noise measurements processed with HVSR technique). Our preliminary results highlight the presence of both stable zones susceptible to local amplifications and unstable zones susceptible to geological instability. Our results are directed to establish set of actions aimed at risk mitigation before initial onset of emergency, and to management of the emergency once the <span class="hlt">seismic</span> event has occurred. The products obtained, will contain the basic elements of an integrated system</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.S41B2442G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.S41B2442G"><span>Georgia-Armenia Transboarder <span class="hlt">seismicity</span> studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Godoladze, T.; Tvaradze, N.; Javakishvili, Z.; Elashvili, M.; Durgaryan, R.; Arakelyan, A.; Gevorgyan, M.</p> <p>2012-12-01</p> <p>In the presented study we performed Comprehensive <span class="hlt">seismic</span> analyses for the Armenian-Georgian transboarder active <span class="hlt">seismic</span> fault starting on Armenian territory, cutting the state boarder and having possibly northern termination on Adjara-Triealeti frontal structure in Georgia. In the scope of International projects: ISTC A-1418 "Open network of scientific Centers for mitigation risk of natural hazards in the Southern Caucasus and Central Asia" and NATO SfP- 983284 Project "Caucasus <span class="hlt">Seismic</span> Emergency Response" in Akhalkalaki (Georgia) <span class="hlt">seismic</span> center, Regional Summer school trainings and intensive filed investigations were conducted. Main goal was multidisciplinary study of the Javakheti fault structure and better understanding <span class="hlt">seismicity</span> of the area. Young scientists from Turkey, Armenia, Azerbaijan and Georgia were participated in the deployment of temporal <span class="hlt">seismic</span> network in order to monitor seisimity on the Javakheti highland and particularly delineate fault scarf and identify active <span class="hlt">seismic</span> structures. In the scope of international collaboration the common <span class="hlt">seismic</span> database has been created in the southern Caucasus and collected data from the field works is available now online. Javakheti highland, which is located in the central part of the Caucasus, belongs to the structure of the lesser Caucasus and represents a history of neotectonic volcanism existed in the area. Jasvakheti highland is seismicalu active region devastating from several severe earthquakes(1088, 1283, 1899…). Hypocenters located during analogue network were highly scattered and did not describe real pattern of <span class="hlt">seismicity</span> of the highland. We relocated hypocenters of the region and improved local velocity model. The hypocenters derived from recently deployed local <span class="hlt">seismic</span> network in the Javakheti highland, clearly identified <span class="hlt">seismically</span> active structures. Fault plane solutions of analogue data of the Soviet times have been carefully analyzed and examined. Moment tensor inversion were preformed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/381479-high-resolution-seismic-reflection-profiling-aberdeen-proving-grounds-maryland','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/381479-high-resolution-seismic-reflection-profiling-aberdeen-proving-grounds-maryland"><span>High resolution <span class="hlt">seismic</span> reflection profiling at Aberdeen Proving Grounds, Maryland</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Miller, R.D.; Xia, Jianghai; Swartzel, S.</p> <p>1996-11-01</p> <p>The effectiveness of shallow high resolution <span class="hlt">seismic</span> reflection (i.e., resolution potential) to image geologic interfaces between about 70 and 750 ft at the Aberdeen Proving Grounds, Maryland (APG), appears to vary locally with the geometric complexity of the unconsolidated sediments that overlay crystalline bedrock. The bedrock surface (which represents the primary geologic target of this study) was imaged at each of three test areas on walkaway noise tests and CDP (common depth point) stacked data. Proven high resolution techniques were used to design and acquire data on this survey. Feasibility of the technique and minimum acquisition requirements were determined throughmore » evaluation and correlation of walkaway noise tests, CDP survey lines, and a downhole velocity check shot survey. Data processing and analysis revealed several critical attributes of shallow <span class="hlt">seismic</span> data from APG that need careful consideration and compensation on reflection data sets. This survey determined: (1) the feasibility of the technique, (2) the resolution potential (both horizontal and vertical) of the technique, (3) the optimum source for this site, (4) the optimum acquisition geometries, (5) general processing flow, and (6) a basic idea of the acoustic variability across this site. Source testing involved an <span class="hlt">accelerated</span> weight drop, land air gun, downhole black powder charge, sledge hammer/plate, and high frequency vibrator. Shallow <span class="hlt">seismic</span> reflection profiles provided for a more detailed picture of the geometric complexity and variability of the distinct clay sequences (aquatards), previously inferred from drilling to be present, based on sparse drill holes and basewide conceptual models. The <span class="hlt">seismic</span> data also reveal a clear explanation for the difficulties previously noted in correlating individual, borehole-identified sand or clay units over even short distances.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5298620','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5298620"><span>A Fiber-Optic Interferometric Tri-Component Geophone for Ocean Floor <span class="hlt">Seismic</span> Monitoring</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Jiandong; Chang, Tianying; Fu, Qunjian; Lang, Jinpeng; Gao, Wenzhi; Wang, Zhongmin; Yu, Miao; Zhang, Yanbo; Cui, Hong-Liang</p> <p>2016-01-01</p> <p>For the implementation of an all fiber observation network for submarine <span class="hlt">seismic</span> monitoring, a tri-component geophone based on Michelson interferometry is proposed and tested. A compliant cylinder-based sensor head is analyzed with finite element method and tested. The operation frequency ranges from 2 Hz to 150 Hz for <span class="hlt">acceleration</span> detection, employing a phase generated carrier demodulation scheme, with a responsivity above 50 dB re rad/g for the whole frequency range. The transverse suppression ratio is about 30 dB. The system noise at low frequency originated mainly from the 1/f fluctuation, with an average system noise level −123.55 dB re rad/Hz ranging from 0 Hz to 500 Hz. The minimum detectable <span class="hlt">acceleration</span> is about 2 ng/Hz, and the dynamic range is above 116 dB. PMID:28036011</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.823a2017S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.823a2017S"><span><span class="hlt">Seismic</span> Design of ITER Component Cooling Water System-1 Piping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Aditya P.; Jadhav, Mahesh; Sharma, Lalit K.; Gupta, Dinesh K.; Patel, Nirav; Ranjan, Rakesh; Gohil, Guman; Patel, Hiren; Dangi, Jinendra; Kumar, Mohit; Kumar, A. G. A.</p> <p>2017-04-01</p> <p>The successful performance of ITER machine very much depends upon the effective removal of heat from the in-vessel components and other auxiliary systems during Tokamak operation. This objective will be accomplished by the design of an effective Cooling Water System (CWS). The optimized piping layout design is an important element in CWS design and is one of the major design challenges owing to the factors of large thermal expansion and <span class="hlt">seismic</span> <span class="hlt">accelerations</span>; considering safety, accessibility and maintainability aspects. An important sub-system of ITER CWS, Component Cooling Water System-1 (CCWS-1) has very large diameter of pipes up to DN1600 with many intersections to fulfill the process flow requirements of clients for heat removal. Pipe intersection is the weakest link in the layout due to high stress intensification factor. CCWS-1 piping up to secondary confinement isolation valves as well as in-between these isolation valves need to survive a <span class="hlt">Seismic</span> Level-2 (SL-2) earthquake during the Tokamak operation period to ensure structural stability of the system in the Safe Shutdown Earthquake (SSE) event. This paper presents the design, qualification and optimization of layout of ITER CCWS-1 loop to withstand SSE event combined with sustained and thermal loads as per the load combinations defined by ITER and allowable limits as per ASME B31.3, This paper also highlights the Modal and Response Spectrum Analyses done to find out the natural frequency and system behavior during the <span class="hlt">seismic</span> event.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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