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Sample records for system seismic boundary

  1. Regional variations in seismic boundaries

    NASA Astrophysics Data System (ADS)

    Shumlyanska, Ludmila

    2010-05-01

    Dividing of the Earth into zones in the frame one-dimensional velocity model was proposed Jeffreys and Gutenberg is the first half of XX century. They recovered the following zones: A - the crust; B - zone in the depth interval 33-413 km, C - zone 413-984 km, D - zone 984-2898 km, E - 2898-4982 km, F - 4982-5121 km, G - 5121-6371 km (centre of the Earth). These zones differ in their seismic properties. Later, zone D was divided to the areas D' (984-2700 km) and D" (2700-2900 km). At present, this scheme is significantly modified and only the layer D" is in wide use. The more seismological studies are carried out, the more seismic boundaries appear. Boundaries at 410, 520, 670, and 2900 km, at which increase in the velocity of the seismic waves is particularly noticeable are considered as having global significance. Moreover, there are indications of the existence of geophysical boundaries at 800, 1200-1300, 1700, 1900-2000 km. Using 3D P-velocity model of the mantle based on Taylor approximation method for solving of the inverse kinematics multi-dimensional seismic task we have obtained seismic boundaries for the area covering 20-55° E × 40-55° N. Data on the time of first arrivals of P waves from earthquakes and nuclear explosions recorded at ISC stations during 1964-2002 were used as input to construct a 3-D model. The model has two a priori limits: 1) the velocity is a continuous function of spatial coordinates, 2) the function v(r)/r where r is a radius in the spherical coordinate system r, φ, λ decreases with depth. The first limitation is forced since velocity leaps can not be sustainably restored from the times of first arrival; the second one follows from the nature of the observed data. Results presented as horizontal sections of the actual velocity every 25 km in the depth interval 850-2850 km, and as the longitudinal and latitudinal sections of the discrepancy on the 1-D reference model, obtained as a result of solving of the inversion task at 1

  2. Seismic link at plate boundary

    NASA Astrophysics Data System (ADS)

    Ramdani, Faical; Kettani, Omar; Tadili, Benaissa

    2015-06-01

    Seismic triggering at plate boundaries has a very complex nature that includes seismic events at varying distances. The spatial orientation of triggering cannot be reduced to sequences from the main shocks. Seismic waves propagate at all times in all directions, particularly in highly active zones. No direct evidence can be obtained regarding which earthquakes trigger the shocks. The first approach is to determine the potential linked zones where triggering may occur. The second step is to determine the causality between the events and their triggered shocks. The spatial orientation of the links between events is established from pre-ordered networks and the adapted dependence of the spatio-temporal occurrence of earthquakes. Based on a coefficient of synchronous seismic activity to grid couples, we derive a network link by each threshold. The links of high thresholds are tested using the coherence of time series to determine the causality and related orientation. The resulting link orientations at the plate boundary conditions indicate that causal triggering seems to be localized along a major fault, as a stress transfer between two major faults, and parallel to the geothermal area extension.

  3. Imaging a Fault Boundary System Using Controlled-Source Data Recorded on a Large-N Seismic Array

    NASA Astrophysics Data System (ADS)

    Paschall, O. C.; Chen, T.; Snelson, C. M.; Ralston, M. D.; Rowe, C. A.

    2016-12-01

    The Source Physics Experiment (SPE) is a series of chemical explosions conducted in southern Nevada with an objective of improving nuclear explosion monitoring. Five chemical explosions have occurred thus far in granite, the most recent being SPE-5 on April 26, 2016. The SPE series will improve our understanding of seismic wave propagation (primarily S-waves) due to explosions, and allow better discrimination of background seismicity such as earthquakes and explosions. The Large-N portion of the project consists of 996 receiver stations. Half of the stations were vertical component and the other half were three-component geophones. All receivers were deployed for 30 days and recorded the SPE-5 shot, earthquakes, noise, and an additional controlled-source: a large weight-drop, which is a 13,000 kg modified industrial pile driver. In this study, we undertake reflection processing of waveforms from the weight-drop, as recorded by a line of sensors extracted from the Large-N array. The profile is 1.2 km in length with 25 m station spacing and 100 m shot point spacing. This profile crosses the Boundary Fault that separates granite body and an alluvium basin, a strong acoustic impedance boundary that scatters seismic energy into S-waves and coda. The data were processed with traditional seismic reflection processing methods that include filtering, deconvolution, and stacking. The stack will be used to extract the location of the splays of the Boundary Fault and provide geologic constraints to the modeling and simulation teams within the SPE project.

  4. Seismic intrusion detector system

    DOEpatents

    Hawk, Hervey L.; Hawley, James G.; Portlock, John M.; Scheibner, James E.

    1976-01-01

    A system for monitoring man-associated seismic movements within a control area including a geophone for generating an electrical signal in response to seismic movement, a bandpass amplifier and threshold detector for eliminating unwanted signals, pulse counting system for counting and storing the number of seismic 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 seismic movements.

  5. Seismic waveform sensitivity to global boundary topography

    NASA Astrophysics Data System (ADS)

    Colombi, Andrea; Nissen-Meyer, Tarje; Boschi, Lapo; Giardini, Domenico

    2012-09-01

    We investigate the implications of lateral variations in the topography of global seismic discontinuities, in the framework of high-resolution forward modelling and seismic imaging. We run 3-D wave-propagation simulations accurate at periods of 10 s and longer, with Earth models including core-mantle boundary topography anomalies of ˜1000 km spatial wavelength and up to 10 km height. We obtain very different waveform signatures for PcP (reflected) and Pdiff (diffracted) phases, supporting the theoretical expectation that the latter are sensitive primarily to large-scale structure, whereas the former only to small scale, where large and small are relative to the frequency. PcP at 10 s seems to be well suited to map such a small-scale perturbation, whereas Pdiff at the same frequency carries faint signatures that do not allow any tomographic reconstruction. Only at higher frequency, the signature becomes stronger. We present a new algorithm to compute sensitivity kernels relating seismic traveltimes (measured by cross-correlation of observed and theoretical seismograms) to the topography of seismic discontinuities at any depth in the Earth using full 3-D wave propagation. Calculation of accurate finite-frequency sensitivity kernels is notoriously expensive, but we reduce computational costs drastically by limiting ourselves to spherically symmetric reference models, and exploiting the axial symmetry of the resulting propagating wavefield that collapses to a 2-D numerical domain. We compute and analyse a suite of kernels for upper and lower mantle discontinuities that can be used for finite-frequency waveform inversion. The PcP and Pdiff sensitivity footprints are in good agreement with the result obtained cross-correlating perturbed and unperturbed seismogram, validating our approach against full 3-D modelling to invert for such structures.

  6. Seismic images of a Grenvillian terrane boundary

    USGS Publications Warehouse

    Milkereit, B.; Forsyth, D. A.; Green, A.G.; Davidson, A.; Hanmer, S.; Hutchinson, Deborah R.; Hinze, W. J.; Mereu, R.F.

    1992-01-01

    A series of gently dipping reflection zones extending to mid-crustal depths is recorded by seismic data from Lakes Ontario and Erie. These prominent reflection zones define a broad complex of southeast-dipping ductile thrust faults in the interior of the Grenville orogen. One major reflection zone provides the first image of a proposed Grenvillian suture—the listric boundary zone between allochthonous terranes of the Central Gneiss and Central Metasedimentary belts. Curvilinear bands of reflections that may represent "ramp folds" and "ramp anticlines" that originally formed in a deep crustal-scale duplex abut several faults. Vertical stacking of some curvilinear features suggests coeval or later out-of-sequence faulting of imbricated and folded thrust sheets. Grenvillian structure reflections are overlain by a thin, wedge-shaped package of shallow-dipping reflections that probably originates from sediments deposited in a local half graben developed during a period of post-Grenville extension. This is the first seismic evidence for such extension in this region, which could have occurred during terminal collapse of the Grenville orogen, or could have marked the beginning of pre-Appalachian continental rifting.

  7. Induced Seismicity Monitoring System

    NASA Astrophysics Data System (ADS)

    Taylor, S. R.; Jarpe, S.; Harben, P.

    2014-12-01

    There are many seismological aspects associated with monitoring of permanent storage of carbon dioxide (CO2) in geologic formations. Many of these include monitoring underground gas migration through detailed tomographic studies of rock properties, integrity of the cap rock and micro seismicity with time. These types of studies require expensive deployments of surface and borehole sensors in the vicinity of the CO2 injection wells. Another problem that may exist in CO2 sequestration fields is the potential for damaging induced seismicity associated with fluid injection into the geologic reservoir. Seismic hazard monitoring in CO2 sequestration fields requires a seismic network over a spatially larger region possibly having stations in remote settings. Expensive observatory-grade seismic systems are not necessary for seismic hazard deployments or small-scale tomographic studies. Hazard monitoring requires accurate location of induced seismicity to magnitude levels only slightly less than that which can be felt at the surface (e.g. magnitude 1), and the frequencies of interest for tomographic analysis are ~1 Hz and greater. We have developed a seismo/acoustic smart sensor system that can achieve the goals necessary for induced seismicity monitoring in CO2 sequestration fields. The unit is inexpensive, lightweight, easy to deploy, can operate remotely under harsh conditions and features 9 channels of recording (currently 3C 4.5 Hz geophone, MEMS accelerometer and microphone). An on-board processor allows for satellite transmission of parameter data to a processing center. Continuous or event-detected data is kept on two removable flash SD cards of up to 64+ Gbytes each. If available, data can be transmitted via cell phone modem or picked up via site visits. Low-power consumption allows for autonomous operation using only a 10 watt solar panel and a gel-cell battery. The system has been successfully tested for long-term (> 6 months) remote operations over a wide range

  8. Seismic Velocity and Elastic Properties of Plate Boundary Faults

    NASA Astrophysics Data System (ADS)

    Jeppson, Tamara N.

    The elastic properties of fault zone rock at depth play a key role in rupture nucleation, propagation, and the magnitude of fault slip. Materials that lie within major plate boundary fault zones often have very different material properties than standard crustal rock values. In order to understand the mechanics of faulting at plate boundaries, we need to both measure these properties and understand how they govern the behavior of different types of faults. Mature fault zones tend to be identified in large-scale geophysical field studies as zones with low seismic velocity and/or electrical resistivity. These anomalous properties are related to two important mechanisms: (1) mechanical or diagenetic alteration of the rock materials and/or (2) pore fluid pressure and stress effects. However, in remotely-sensed and large-length-scale data it is difficult to determine which of these mechanisms are affecting the measured properties. The objective of this dissertation research is to characterize the seismic velocity and elastic properties of fault zone rocks at a range of scales, with a focus on understanding why the fault zone properties are different from those of the surrounding rock and the potential effects on earthquake rupture and fault slip. To do this I performed ultrasonic velocity experiments under elevated pressure conditions on drill core and outcrops samples from three plate boundary fault zones: the San Andreas Fault, California, USA; the Alpine Fault, South Island, New Zealand; and the Japan Trench megathrust, Japan. Additionally, I compared laboratory measurements to sonic log and large-scale seismic data to examine the scale-dependence of the measured properties. The results of this study provide the most comprehensive characterization of the seismic velocities and elastic properties of fault zone rocks currently available. My work shows that fault zone rocks at mature plate boundary faults tend to be significantly more compliant than surrounding crustal

  9. Interferometric Seismic Sources on the Core Mantle Boundary Revealed by Seismic Coda Crosscorrelation

    NASA Astrophysics Data System (ADS)

    Pham, T. S.; Tkalcic, H.; Sambridge, M.

    2017-12-01

    The crosscorrelation of earthquake coda can be used to extract seismic body waves which are sensitive to deep Earth interior. The retrieved peaks in crosscorrelation of two seismic records are commonly interpreted as seismic phases that originate at a point source collocated with the first recorder (Huygens-Fresnel principle), reflected upward from prominent underground reflectors and reaching the second recorder. From the time shift of these peaks measured at different interstation distances, new travel time curves can be constructed. This study focuses on a previously unexplained interferometric phase (named temporarily a ghost or "G phase") observed in crosscorrelogram stack sections utilizing seismic coda. In particular, we deploy waveforms recorded by two regional seismic networks, one in Australia and another in Alaska. We show that the G phase cannot be explained by as a reflection. Moreover, we demonstrate that the G phase is explained through the principle of energy partitioning, and specifically, conversions from compressional to shear motions at the core-mantle boundary (CMB). This can be thought of in terms of a continuous distribution of Huygens sources across the CMB that are "activated" in long-range wavefield coda following significant earthquakes. The newly explained phase is renamed to cPS, to indicate a CMB origin and the P to S conversion. This mechanism explains a range of newly observed global interferometric phases that can be used in combination with existing phases to constrain Earth structure.

  10. Seismic event classification system

    DOEpatents

    Dowla, F.U.; Jarpe, S.P.; Maurer, W.

    1994-12-13

    In the computer interpretation of seismic data, the critical first step is to identify the general class of an unknown event. For example, the classification might be: teleseismic, regional, local, vehicular, or noise. Self-organizing neural networks (SONNs) can be used for classifying such events. Both Kohonen and Adaptive Resonance Theory (ART) SONNs are useful for this purpose. Given the detection of a seismic event and the corresponding signal, computation is made of: the time-frequency distribution, its binary representation, and finally a shift-invariant representation, which is the magnitude of the two-dimensional Fourier transform (2-D FFT) of the binary time-frequency distribution. This pre-processed input is fed into the SONNs. These neural networks are able to group events that look similar. The ART SONN has an advantage in classifying the event because the types of cluster groups do not need to be pre-defined. The results from the SONNs together with an expert seismologist's classification are then used to derive event classification probabilities. 21 figures.

  11. Seismic event classification system

    DOEpatents

    Dowla, Farid U.; Jarpe, Stephen P.; Maurer, William

    1994-01-01

    In the computer interpretation of seismic data, the critical first step is to identify the general class of an unknown event. For example, the classification might be: teleseismic, regional, local, vehicular, or noise. Self-organizing neural networks (SONNs) can be used for classifying such events. Both Kohonen and Adaptive Resonance Theory (ART) SONNs are useful for this purpose. Given the detection of a seismic event and the corresponding signal, computation is made of: the time-frequency distribution, its binary representation, and finally a shift-invariant representation, which is the magnitude of the two-dimensional Fourier transform (2-D FFT) of the binary time-frequency distribution. This pre-processed input is fed into the SONNs. These neural networks are able to group events that look similar. The ART SONN has an advantage in classifying the event because the types of cluster groups do not need to be pre-defined. The results from the SONNs together with an expert seismologist's classification are then used to derive event classification probabilities.

  12. Seismicity and Seismic Hazard along the Western part of the Eurasia-Nubia plate boundary

    NASA Astrophysics Data System (ADS)

    Bezzeghoud, Mourad; Fontiela, João; Ferrão, Celia; Borges, José Fernando; Caldeira, Bento; Dib, Assia; Ousadou, Farida

    2016-04-01

    The seismic phenomenon is the most damaging natural hazard known in the Mediterranean area. The western part of the Eurasia-Nubia plate boundary extends from the Azores to the Mediterranean region. The oceanic part of the plate boundary is well delimited from the Azores Islands, along the Azores-Gibraltar fault to approximately 12°W (west of the Strait of Gibraltar). From 12°W to 3.5°E, including the Iberia-Nubia region and extending to the western part of Algeria, the boundary is more diffuse and forms a wider area of deformation. The boundary between the Iberia and Nubia plates is the most complex part of the margin. This region corresponds to the transition from an oceanic boundary to a continental boundary, where Iberia and Nubia collide. Although most earthquakes along this plate boundary are shallow and generally have magnitudes less than 5.5, there have been several high-magnitude events. Many devastating earthquakes, some of them tsunami-triggering, inflicted heavy loss and considerable economic damage to the region. From 1920 to present, three earthquakes with magnitudes of about 8.0 (Mw 8.2, 25 November 1941; Ms 8.0, 25 February 1969; and Mw 7.9, 26 May 1975) occurred in the oceanic region, and four earthquakes with magnitudes of about 7.0 (Mw 7.1, 8 May 1939, Santa Maria Island and Mw 7.1, January 1980, Terceira and Graciosa Islands, both in the Azores; Ms 7.1, 20 May 1931, Azores-Gibraltar fracture zone; and Mw 7.3, 10 October 1980, El Asnam, Algeria) occurred along the western part of the Eurasia-Nubia plate boundary. In general, large earthquakes (M ≥7) occur within the oceanic region, with the exception of the El Asnam (Algeria) earthquakes. Some of these events caused extensive damage. The 1755 Lisbon earthquake (˜Mw 9) on the Portugal Atlantic margin, about 200 km W-SW of Cape St. Vincent, was followed by a tsunami and fires that caused the near-total destruction of Lisbon and adjacent areas. Estimates of the death toll in Lisbon alone (~70

  13. An economical educational seismic system

    USGS Publications Warehouse

    Lehman, J. D.

    1980-01-01

    There is a considerable interest in seismology from the nonprofessional or amateur standpoint. The operation of a seismic system can be satisfying and educational, especially when you have built and operated the system yourself. A long-period indoor-type sensor and recording system that works extremely well has been developed in the James Madison University Physics Deparment. The system can be built quite economically, and any educational institution that cannot commit themselves to a professional installation need not be without first-hand seismic information. The system design approach has been selected by college students working a project or senior thesis, several elementary and secondary science teachers, as well as the more ambitious tinkerer or hobbyist at home 

  14. Advanced Seismic While Drilling System

    SciTech Connect

    Robert Radtke; John Fontenot; David Glowka

    by TII. An APS Turbine Alternator powered the SeismicPULSER{trademark} to produce two Hz frequency peak signals repeated every 20 seconds. Since the ION Geophysical, Inc. (ION) seismic survey surface recording system was designed to detect a minimum downhole signal of three Hz, successful performance was confirmed with a 5.3 Hz recording with the pumps running. The two Hz signal generated by the sparker was modulated with the 3.3 Hz signal produced by the mud pumps to create an intense 5.3 Hz peak frequency signal. The low frequency sparker source is ultimately capable of generating selectable peak frequencies of 1 to 40 Hz with high-frequency spectra content to 10 kHz. The lower frequencies and, perhaps, low-frequency sweeps, are needed to achieve sufficient range and resolution for realtime imaging in deep (15,000 ft+), high-temperature (150 C) wells for (a) geosteering, (b) accurate seismic hole depth, (c) accurate pore pressure determinations ahead of the bit, (d) near wellbore diagnostics with a downhole receiver and wired drill pipe, and (e) reservoir model verification. Furthermore, the pressure of the sparker bubble will disintegrate rock resulting in an increased overall rates of penetration. Other applications for the SeismicPULSER{trademark} technology are to deploy a low-frequency source for greater range on a wireline for Reverse Vertical Seismic Profiling (RVSP) and Cross-Well Tomography. Commercialization of the technology is being undertaken by first contacting stakeholders to define the value proposition for rig site services utilizing SeismicPULSER{trademark} technologies. Stakeholders include national oil companies, independent oil companies, independents, service companies, and commercial investors. Service companies will introduce a new Drill Bit SWD service for deep HTHP wells. Collaboration will be encouraged between stakeholders in the form of joint industry projects to develop prototype tools and initial field trials. No barriers have been

  15. Seismic constraints on the lithosphere-asthenosphere boundary

    NASA Astrophysics Data System (ADS)

    Rychert, Catherine A.

    2014-05-01

    The basic tenet of plate tectonics is that a rigid plate, or lithosphere, moves over a weaker asthenospheric layer. However, the exact location and defining mechanism of the boundary at the base of the plate, the lithosphere-asthenosphere boundary (LAB) is debated. The oceans should represent a simple scenario since the lithosphere is predicted to thicken with seafloor age if it thermally defined, whereas a constant plate thickness might indicate a compositional definition. However, the oceans are remote and difficult to constrain, and studies with different sensitivities and resolutions have come to different conclusions. Hotspot regions lend additional insight, since they are relatively well instrumented with seismic stations, and also since the effect of a thermal plume on the LAB should depend on the defining mechanism of the plate. Here I present new results using S-to-P receiver functions to image upper mantle discontinuity structure beneath volcanically active regions including Hawaii, Iceland, Galapagos, and Afar. In particular I focus on the lithosphere-asthenosphere boundary and discontinuities related to the base of melting, which can be used to highlight plume locations. I image a lithosphere-asthenosphere boundary in the 50 - 95 km depth range beneath Hawaii, Galapagos, and Iceland. Although LAB depth variations exist within these regions, significant thinning is not observed in the locations of hypothesized plume impingement from receiver functions (see below). Since a purely thermally defined lithosphere is expected to thin significantly in the presence of a thermal plume anomaly, a compositional component in the definition of the LAB is implied. Beneath Afar, an LAB is imaged at 75 km depth on the flank of the rift, but no LAB is imaged beneath the rift itself. The transition from flank of rift is relatively abrupt, again suggesting something other than a purely thermally defined lithosphere. Melt may also exist in the asthenosphere in these regions

  16. Sensitivities Kernels of Seismic Traveltimes and Amplitudes for Quality Factor and Boundary Topography

    NASA Astrophysics Data System (ADS)

    Hsieh, M.; Zhao, L.; Ma, K.

    2010-12-01

    Finite-frequency approach enables seismic tomography to fully utilize the spatial and temporal distributions of the seismic wavefield to improve resolution. In achieving this goal, one of the most important tasks is to compute efficiently and accurately the (Fréchet) sensitivity kernels of finite-frequency seismic observables such as traveltime and amplitude to the perturbations of model parameters. In scattering-integral approach, the Fréchet kernels are expressed in terms of the strain Green tensors (SGTs), and a pre-established SGT database is necessary to achieve practical efficiency for a three-dimensional reference model in which the SGTs must be calculated numerically. Methods for computing Fréchet kernels for seismic velocities have long been established. In this study, we develop algorithms based on the finite-difference method for calculating Fréchet kernels for the quality factor Qμ and seismic boundary topography. Kernels for the quality factor can be obtained in a way similar to those for seismic velocities with the help of the Hilbert transform. The effects of seismic velocities and quality factor on either traveltime or amplitude are coupled. Kernels for boundary topography involve spatial gradient of the SGTs and they also exhibit interesting finite-frequency characteristics. Examples of quality factor and boundary topography kernels will be shown for a realistic model for the Taiwan region with three-dimensional velocity variation as well as surface and Moho discontinuity topography.

  17. Tritium glovebox stripper system seismic design evaluation

    SciTech Connect

    Grinnell, J. J.; Klein, J. E.

    2015-09-01

    The use of glovebox confinement at US Department of Energy (DOE) tritium facilities has been discussed in numerous publications. Glovebox confinement protects the workers from radioactive material (especially tritium oxide), provides an inert atmosphere for prevention of flammable gas mixtures and deflagrations, and allows recovery of tritium released from the process into the glovebox when a glovebox stripper system (GBSS) is part of the design. Tritium recovery from the glovebox atmosphere reduces emissions from the facility and the radiological dose to the public. Location of US DOE defense programs facilities away from public boundaries also aids in reducing radiological dosesmore » to the public. This is a study based upon design concepts to identify issues and considerations for design of a Seismic GBSS. Safety requirements and analysis should be considered preliminary. Safety requirements for design of GBSS should be developed and finalized as a part of the final design process.« less

  18. Estimation of coefficients and boundary parameters in hyperbolic systems

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Murphy, K. A.

    1984-01-01

    Semi-discrete Galerkin approximation schemes are considered in connection with inverse problems for the estimation of spatially varying coefficients and boundary condition parameters in second order hyperbolic systems typical of those arising in 1-D surface seismic problems. Spline based algorithms are proposed for which theoretical convergence results along with a representative sample of numerical findings are given.

  19. Academia vs Industry: vanishing boundaries between global earthquake seismology and exploration seismics.

    NASA Astrophysics Data System (ADS)

    van der Hilst, R. D.

    2011-12-01

    Global seismology and exploration seismics have long lived in parallel universes, with little cross-fertilization of methodologies and with interaction between the associated communities often limited to company recruitment of students. Fortunately, this traditional separation of technology and people has begun to disappear. This is driven not only by continuing demands for human and financial resources (for companies and academia, respectively) but increasingly also by overlapping intellectual interest. First, 'waves are waves' (that is, the fundamental physics - and math to describe/handle it - is scale invariant) and many artificial boundaries are being removed by use of better wave theory, faster computers, and new data acquisition paradigms. For example, the development of dense sensor arrays (in USA, Europe, Asia - mostly China and Japan) is increasing the attraction (and need) of industry-style interrogation of massive data sets. Examples include large scale seismic exploration of Earth's deep interior with inverse scattering of teleseismic wavefields (e.g., Van der Hilst et al., Science, 2007). On the other hand, reservoir exploration and production benefits from expertise in earthquake seismology, both for better characterization of reservoirs and their overburden and for (induced) micro-earthquake analysis. Passive source methods (including but not restricted to ambient noise tomography) are providing new, economic opportunities for velocity analysis and monitoring, and studies of (micro)seismicity (e.g., source location, parameters, and moment tensor) allow in situ stress determination, tomographic velocity analysis with natural sources in the reservoir, and 4D monitoring (e.g., for hydrocarbon production, carbon sequestration, enhanced geothermal systems, and unconventional gas production). Second, the gap between the frequency ranges traditionally considered by both communities is being bridged by better theory, new sensor technology, and through

  20. Seismic waveform inversion for core-mantle boundary topography

    NASA Astrophysics Data System (ADS)

    Colombi, Andrea; Nissen-Meyer, Tarje; Boschi, Lapo; Giardini, Domenico

    2014-07-01

    The topography of the core-mantle boundary (CMB) is directly linked to the dynamics of both the mantle and the outer core, although it is poorly constrained and understood. Recent studies have produced topography models with mutual agreement up to degree 2. A broad-band waveform inversion strategy is introduced and applied here, with relatively low computational cost and based on a first-order Born approximation. Its performance is validated using synthetic waveforms calculated in theoretical earth models that include different topography patterns with varying lateral wavelengths, from 600 to 2500 km, and magnitudes (˜10 km peak-to-peak). The source-receiver geometry focuses mainly on the Pdiff, PKP, PcP and ScS phases. The results show that PKP branches, PcP and ScS generally perform well and in a similar fashion, while Pdiff yields unsatisfactory results. We investigate also how 3-D mantle correction influences the output models, and find that despite the disturbance introduced, the models recovered do not appear to be biased, provided that the 3-D model is correct. Using cross-correlated traveltimes, we derive new topography models from both P and S waves. The static corrections used to remove the mantle effect are likely to affect the inversion, compromising the agreement between models derived from P and S data. By modelling traveltime residuals starting from sensitivity kernels, we show how the simultaneous use of volumetric and boundary kernels can reduce the bias coming from mantle structures. The joint inversion approach should be the only reliable method to invert for CMB topography using absolute cross-correlation traveltimes.

  1. A seismic gap along an accreting plate boundary : Example of the Djibouti Ridge, Afar, East Africa

    NASA Astrophysics Data System (ADS)

    Ruegg, Jean-Claude; Lépine, Jean-Claude

    1983-05-01

    A segment of the Gulf of Tadjoura (Djibouti, East-Africa) accreting plate boundary, shows a period of quiescence in the seismic activity since 1974. This segment corresponds to the extension area of the aftershock activity that has occured after a cluster of magnitude 5.5 earthquakes in April 1973. From this example we propose that the seismic gap concept can be extended to moderate earthquakes occuring at extensional plate boundaries. The magnitude of the largest earthquakes at the spreading axis is limited by the size of the rupture length and by the strength of the brittle lithosphere. In the case of the Djibouti ridge recurrence time of 10-20 years are found for earthquakes of about M =6.

  2. An effective absorbing layer for the boundary condition in acoustic seismic wave simulation

    NASA Astrophysics Data System (ADS)

    Yao, Gang; da Silva, Nuno V.; Wu, Di

    2018-04-01

    Efficient numerical simulation of seismic wavefields generally involves truncating the Earth model in order to keep computing time and memory requirements down. Absorbing boundary conditions, therefore, are applied to remove the boundary reflections caused by this truncation, thereby allowing for accurate modeling of wavefields. In this paper, we derive an effective absorbing boundary condition for both acoustic and elastic wave simulation, through the simplification of the damping term of the split perfectly matched layer (SPML) boundary condition. This new boundary condition is accurate, cost-effective, and easily implemented, especially for high-performance computing. Stability analysis shows that this boundary condition is effectively as stable as normal (non-absorbing) wave equations for explicit time-stepping finite differences. We found that for full-waveform inversion (FWI), the strengths of the effective absorbing layer—a reduction of the computational and memory cost coupled with a simplistic implementation—significantly outweighs the limitation of incomplete absorption of outgoing waves relative to the SPML. More importantly, we demonstrate that this limitation can easily be overcome through the use of two strategies in FWI, namely variable cell size and model extension thereby fully compensating for the imperfectness of the proposed absorbing boundary condition.

  3. Seismic Retrofit for Electric Power Systems

    DOE PAGES

    Romero, Natalia; Nozick, Linda K.; Dobson, Ian; ...

    2015-05-01

    Our paper develops a two-stage stochastic program and solution procedure to optimize the selection of seismic retrofit strategies to increase the resilience of electric power systems against earthquake hazards. The model explicitly considers the range of earthquake events that are possible and, for each, an approximation of the distribution of damage experienced. Furthermore, this is important because electric power systems are spatially distributed and so their performance is driven by the distribution of component damage. We also test this solution procedure against the nonlinear integer solver in LINGO 13 and apply the formulation and solution strategy to the Eastern Interconnection,more » where seismic hazard stems from the New Madrid seismic zone.« less

  4. Cell boundary fault detection system

    DOEpatents

    Archer, Charles Jens [Rochester, MN; Pinnow, Kurt Walter [Rochester, MN; Ratterman, Joseph D [Rochester, MN; Smith, Brian Edward [Rochester, MN

    2009-05-05

    A method determines a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

  5. Optical seismic sensor systems and methods

    DOEpatents

    Beal, A. Craig; Cummings, Malcolm E.; Zavriyev, Anton; Christensen, Caleb A.; Lee, Keun

    2015-12-08

    Disclosed is an optical seismic sensor system for measuring seismic events in a geological formation, including a surface unit for generating and processing an optical signal, and a sensor device optically connected to the surface unit for receiving the optical signal over an optical conduit. The sensor device includes at least one sensor head for sensing a seismic disturbance from at least one direction during a deployment of the sensor device within a borehole of the geological formation. The sensor head includes a frame and a reference mass attached to the frame via at least one flexure, such that movement of the reference mass relative to the frame is constrained to a single predetermined path.

  6. Seismic Characterization of Oceanic Water Masses, Water Mass Boundaries, and Mesoscale Eddies SE of New Zealand

    NASA Astrophysics Data System (ADS)

    Gorman, Andrew R.; Smillie, Matthew W.; Cooper, Joanna K.; Bowman, M. Hamish; Vennell, Ross; Holbrook, W. Steven; Frew, Russell

    2018-02-01

    The Subtropical and Subantarctic Fronts, which separate Subtropical, Subantarctic, and Antarctic Intermediate Waters, are diverted to the south of New Zealand by the submerged continental landmass of Zealandia. In the upper ocean of this region, large volumes of dissolved or suspended material are intermittently transported across the Subtropical Front; however, the mechanisms of such transport processes are enigmatic. Understanding these oceanic boundaries in three dimensions generally depends on measurements collected from stationary vessels and moorings. The details of these data sets, which are critical for understanding how water masses interact and mix at the fine-scale (<10 m) to mesoscale (10-100 km), are inadequately constrained due to resolution considerations. Southeast of New Zealand, high-resolution seismic reflection images of oceanic water masses have been produced using petroleum industry data. These seismic sections clearly show three main water masses, the boundary zones (fronts) between them, and associated thermohaline fine structure that may be related to the mixing of water masses in this region. Interpretations of the data suggest that the Subtropical Front in this region is a landward-dipping zone, with a width that can vary between 20 and 40 km. The boundary zone between Subantarctic Waters and the underlying Antarctic Intermediate Waters is also observed to dip landward. Several isolated lenses have been identified on the three data sets, ranging in size from 9 to 30 km in diameter. These lenses are interpreted to be mesoscale eddies that form at relatively shallow depths along the south side of the Subtropical Front.

  7. Tectonics of the Scotia-Antarctica plate boundary constrained from seismic and seismological data

    NASA Astrophysics Data System (ADS)

    Civile, D.; Lodolo, E.; Vuan, A.; Loreto, M. F.

    2012-07-01

    The plate boundary between the Scotia and Antarctic plates runs along the broadly E-W trending South Scotia Ridge. It is a mainly transcurrent margin that juxtaposes thinned continental and transitional crust elements with restricted oceanic basins and deep troughs. Seismic profiles and regional-scale seismological constraints are used to define the peculiarities of the crustal structures in and around the southern Scotia Sea, and focal solutions from recent earthquakes help to understand the present-day geodynamic setting. The northern edge of the western South Scotia Ridge is marked by a sub-vertical, left-lateral master fault. Locally, a narrow wedge of accreted sediments is present at the base of the slope. This segment represents the boundary between the Scotia plate and the independent South Shetland continental block. Along the northern margin of the South Orkney microcontinent, the largest fragment of the South Scotia Ridge, an accretionary prism is present at the base of the slope, which was possibly created by the eastward drift of the South Orkney microcontinent and the consequent subduction of the transitional crust present to the north. East of the South Orkney microcontinent, the physiography and structure of the plate boundary are less constrained. Here the tectonic regime exhibits mainly strike-slip behavior with some grade of extensional component, and the plate boundary is segmented by a series of NNW-SSE trending release zones which favored the fragmentation and dispersion of the crustal blocks. Seismic data have also identified, along the north-western edge of the South Scotia Ridge, an elevated region - the Ona Platform - which can be considered, along with the Terror Rise, as the conjugate margin of the Tierra del Fuego, before the Drake Passage opening. We propose here an evolutionary sketch for the plate boundary (from the Late Oligocene to the present) encompassing the segment from the Elephant Island platform to the Herdman Bank.

  8. Development of Vertical Cable Seismic System

    NASA Astrophysics Data System (ADS)

    Asakawa, E.; Murakami, F.; Sekino, Y.; Okamoto, T.; Ishikawa, K.; Tsukahara, H.; Shimura, T.

    2011-12-01

    In 2009, Ministry of Education, Culture, Sports, Science and Technology(MEXT) started the survey system development for Hydrothermal deposit. We proposed the Vertical Cable Seismic (VCS), the reflection seismic survey with vertical cable above seabottom. VCS has the following advantages for hydrothermal deposit survey. (1) VCS is an efficient high-resolution 3D seismic survey in limited area. (2) It achieves high-resolution image because the sensors are closely located to the target. (3) It avoids the coupling problems between sensor and seabottom that cause serious damage of seismic data quality. (4) Because of autonomous recording system on sea floor, various types of marine source are applicable with VCS such as sea-surface source (GI gun etc.) , deep-towed or ocean bottom source. Our first experiment of 2D/3D VCS surveys has been carried out in Lake Biwa, JAPAN, in November 2009. The 2D VCS data processing follows the walk-away VSP, including wave field separation and depth migration. Seismic Interferometry technique is also applied. The results give much clearer image than the conventional surface seismic. Prestack depth migration is applied to 3D data to obtain good quality 3D depth volume. Seismic Interferometry technique is applied to obtain the high resolution image in the very shallow zone. Based on the feasibility study, we have developed the autonomous recording VCS system and carried out the trial experiment in actual ocean at the water depth of about 400m to establish the procedures of deployment/recovery and to examine the VC position or fluctuation at seabottom. The result shows that the VC position is estimated with sufficient accuracy and very little fluctuation is observed. Institute of Industrial Science, the University of Tokyo took the research cruise NT11-02 on JAMSTEC R/V Natsushima in February, 2011. In the cruise NT11-02, JGI carried out the second VCS survey using the autonomous VCS recording system with the deep towed source provided by

  9. Cell boundary fault detection system

    DOEpatents

    Archer, Charles Jens [Rochester, MN; Pinnow, Kurt Walter [Rochester, MN; Ratterman, Joseph D [Rochester, MN; Smith, Brian Edward [Rochester, MN

    2011-04-19

    An apparatus and program product determine a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

  10. Unsuccessful initial search for a midmantle chemical boundary with seismic arrays

    USGS Publications Warehouse

    Vidale, J.E.; Schubert, G.; Earle, P.S.

    2001-01-01

    Compositional layering of the midmantle has been proposed to account for seismic and geochemical patterns [van der Hilst and Karason, 1999], and inferred radiogenic heat source concentrations [Kellogg et al., 1999]. Compositional layering would require thermal boundary layers both above and below an interface. We construct a minimal 1-D model of a mid-mantle boundary consistent with the observed nearly adiabatic compressional velocity structure [Dziewonksi and Anderson, 1981] and the proposed high heat flow from the lower mantle [Albarede and van der Hilst, 1999; Kellogg et al., 1999]. Ray tracing and reflectivity synthetic seismograms show that a distinct triplication is predicted for short-period P waves. Although topography on a boundary would cause uncertainty in the strength and the range of the triplication, many clear observations would be expected. We examine data from the US West Coast regional networks in the most likely distance range of 60?? to 70?? for a 1770-km-depth boundary, and find no evidence for P wave triplications.

  11. Reconciling deep seismic refraction and reflection data from the grenvillian-appalachian boundary in western New England

    USGS Publications Warehouse

    Hughes, S.; Luetgert, J.H.; Christensen, N.I.

    1993-01-01

    The Grenvillian-Appalachian boundary is characterized by pervasive mylonitic deformation and retrograde alteration of a suite of imbricated allochthonous and parautochthonous gneisses that were thrust upon the Grenvillian continental margin during the lower Paleozoic. Seismic reflection profiling across this structural boundary zone reveals prominent dipping reflectors interpreted as overthrust basement slices (parautochthons) of the Green Mountain Anticlinorium. In contrast, a seismic refraction study of the Grenvillian-Appalachian boundary reveals a sub-horizontally layered seismic velocity model that is difficult to reconcile with the pronounced sub-vertical structures observed in the Green mountains. A suite of rock samples was collected from the Green Mountain Anticlinorium and measured at high pressures in the laboratory to determine the seismic properties of these allochthonous and parautochthonous gneisses. The laboratory-measured seismic velocities agree favorably with the modelled velocity structure across the Grenvillian-Appalachian boundary suggesting that the rock samples are reliable indicators of the rock mass as whole. Samples of the parautochthonous Grenvillian basement exposed in the Green Mountains have lower velocities, by about 0.5 km/s, than lithologically equivalent units exposed in the eastern Adirondack Highlands. Velocity reduction in the Green Mountain parautochthons can be accounted for by retrograde metamorphic alteration (hydration) of the paragneisses. Seismic anisotropies, ranging from 2 to 12%, in the mylonitized Green Mountain paragneisses may also contribute to the observation of lower seismic velocities, where the direction of ray propagation is normal to the foliation. The velocity properties of the Green Mountain paragneisses are thus insufficiently different from the mantling Appalachian allochthons to permit their resolution by the Ontario-New York-New England seismic refraction profile. ?? 1993.

  12. Seismic attenuation system for a nuclear reactor

    SciTech Connect

    Liszkai, Tamas; Cadell, Seth

    A system for attenuating seismic forces includes a reactor pressure vessel containing nuclear fuel and a containment vessel that houses the reactor pressure vessel. Both the reactor pressure vessel and the containment vessel include a bottom head. Additionally, the system includes a base support to contact a support surface on which the containment vessel is positioned in a substantially vertical orientation. An attenuation device is located between the bottom head of the reactor pressure vessel and the bottom head of the containment vessel. Seismic forces that travel from the base support to the reactor pressure vessel via the containment vesselmore » are attenuated by the attenuation device in a direction that is substantially lateral to the vertical orientation of the containment vessel.« less

  13. Spatial organization of seismicity and fracture pattern at the boundary between Alps and Dinarides

    NASA Astrophysics Data System (ADS)

    Bressan, Gianni; Ponton, Maurizio; Rossi, Giuliana; Urban, Sandro

    2016-04-01

    The paper affords the study of the spatial organization of seismicity in the easternmost region of the Alps (Friuli, in NE Italy and W Slovenia), dominated by the interference between the Alpine and the Dinaric tectonic systems. Two non-conventional methods of spatial analysis are used: fractal analysis and principal component analysis (PCA). The fractal analysis helps to discriminate the cases in which hypocentres clearly define a plane, from the ones in which hypocenter distribution tends to the planarity, without reaching it. The PCA analysis is used to infer the orientation of planes fitting through earthquake foci, or the direction of propagation of the hypocentres. Furthermore, we study the spatial seismicity pattern at the shallow depths in the context of a general damage model, through the crack density distribution. The results of the three methods concur to a complex and composite model of fracturing in the region. The hypocentre pattern fills only partially a plane, i.e. has a fractal dimension close to 2. The three exceptions regard planes with Dinaric trend, without interference with Alpine lineaments. The shallowest depth range (0-10 km depth) is characterized by the activation of planes with variable orientations, reflecting the interference between the Dinaric and the Alpine tectonic structures, and closely bound to the variation of the mechanical properties of the crust. The seismicity occurs mostly in areas characterized by a variation from low to moderate crack density, indicating the sharp transition from zones of low damage to zones of moderate damage. Low crack density indicates the presence of more competent rocks capable of sustaining high strain energy while high crack density areas pertain to highly fractured rocks that cannot store high strain energy. Brittle failure, i.e. seismic activity, is favoured within the sharp transitions from low to moderate crack density zones. The orientation of the planes depicting the seismic activity

  14. Chaotic system detection of weak seismic signals

    NASA Astrophysics Data System (ADS)

    Li, Y.; Yang, B. J.; Badal, J.; Zhao, X. P.; Lin, H. B.; Li, R. L.

    2009-09-01

    When the signal-to-noise (S/N) ratio is less than -3 dB or even 0 dB, seismic events are generally difficult to identify from a common shot record. To overcome this type of problem we present a method to detect weak seismic signals based on the oscillations described by a chaotic dynamic system in phase space. The basic idea is that a non-linear chaotic oscillator is strongly immune to noise. Such a dynamic system is less influenced by noise, but it is more sensitive to periodic signals, changing from a chaotic state to a large-scale periodic phase state when excited by a weak signal. With the purpose of checking the possible contamination of the signal by noise, we have performed a numerical experiment with an oscillator controlled by the Duffing-Holmes equation, taking a distorted Ricker wavelet sequence as input signal. In doing so, we prove that the oscillator system is able to reach a large-scale periodic phase state in a strong noise environment. In the case of a common shot record with low S/N ratio, the onsets reflected from a same interface are similar to one other and can be put on a single trace with a common reference time and the periodicity of the so-generated signal follows as a consequence of moveout at a particular scanning velocity. This operation, which is called `horizontal dynamic correction' and leads to a nearly periodic signal, is implemented on synthetic wavelet sequences taking various sampling arrival times and scanning velocities. Thereafter, two tests, both in a noisy ambient of -3.7 dB, are done using a chaotic oscillator: the first demonstrates the capability of the method to really detect a weak seismic signal; the second takes care of the fundamental weakness of the dynamic correction coming from the use of a particular scanning velocity, which is investigated from the effect caused by near-surface lateral velocity variation on the periodicity of the reconstructed seismic signal. Finally, we have developed an application of the

  15. On Mario Bunge's Definition of System and System Boundary

    ERIC Educational Resources Information Center

    Cavallo, Andrew M.

    2012-01-01

    In this short paper we discuss Mario Bunge's definition of system boundary. It is quickly discovered that Bunge's definition of system and system boundary are both deficient. We thus propose new definitions, which (hopefully) improve the situation. Our definition of system boundary works off the same intuition behind Bunge's.

  16. Seismic evidence of the lithosphere-asthenosphere boundary beneath Izu-Bonin area

    NASA Astrophysics Data System (ADS)

    Cui, H.; Gao, Y.; Zhou, Y.

    2016-12-01

    The lithosphere-asthenosphere boundary (LAB), separating the rigid lithosphere and the ductile asthenosphere layers, is the seismic discontinuity with the negative velocity contrast of the Earth's interior [Fischer et al., 2010]. The LAB has been also termed the Gutenberg (G) discontinuity that defines the top of the low velocity zone in the upper mantle [Gutenberg, 1959; Revenaugh and Jordan, 1991]. The seismic velocity, viscosity, resistivity and other physical parameters change rapidly with the depths across the boundary [Eaton et al., 2009]. Seismic detections on the LAB in subduction zone regions are of great help to understand the interactions between the lithosphere and asthenosphere layers and the geodynamic processes related with the slab subductions. In this study, the vertical broadband waveforms are collected from three deep earthquake events occurring from 2000 to 2014 with the focal depths of 400 600 km beneath the Izu-Bonin area. The waveform data is processed with the linear slant stack method [Zang and Zhou, 2002] to obtain the vespagrams in the relative travel-time to slowness domain and the stacked waveforms. The sP precursors reflected on the LAB (sLABP), which have the negative polarities with the amplitude ratios of 0.17 0.21 relative to the sP phases, are successfully extracted. Based on the one-dimensional modified velocity model (IASP91-IB), we obtain the distributions for six reflected points of the sLABP phases near the source region. Our results reveal that the LAB depths range between 58 and 65 km beneath the Izu-Bonin Arc, with the average depth of 62 km and the small topography of 7 km. Compared with the results of the tectonic stable areas in Philippine Sea [Kawakatsu et al., 2009; Kumar and Kawakatsu, 2011], the oceanic lithosphere beneath the Izu-Bonin Arc shows the obvious thinning phenomena. We infer that the lithospheric thinning is closely related with the partial melting, which is caused by the volatiles continuously released

  17. The Indirect Boundary Element Method (IBEM) for Seismic Response of Topographical Irregularities in Layered Media

    NASA Astrophysics Data System (ADS)

    Contreras Zazueta, M. A.; Perton, M.; Sanchez-Sesma, F. J.; Sánchez-Alvaro, E.

    2013-12-01

    The seismic hazard assessment of extended developments, such as a dam, a bridge or a pipeline, needs the strong ground motion simulation taking into account the effects of surface geology. In many cases the incoming wave field can be obtained from attenuation relations or simulations for layered media using Discrete Wave Number (DWN). Sometimes there is a need to include in simulations the seismic source as well. A number of methods to solve these problems have been developed. Among them the Finite Element and Finite Difference Methods (FEM and FDM) are generally preferred because of the facility of use. Nevertheless, the analysis of realistic dynamic loading induced by earthquakes requires a thinner mesh of the entire domain to consider high frequencies. Consequently this may imply a high computational cost. The Indirect Boundary Element Method (IBEM) can also be employed. Here it is used to study the response of a site to historical seismic activity. This method is particularly suited to model wave propagation through wide areas as it requires only the meshing of boundaries. Moreover, it is well suited to represent finely the diffraction that can occur on a fault. However, the IBEM has been applied mainly to simple geometrical configurations. In this communication significant refinements of the formulation are presented. Using IBEM we can simulate wave propagation in complex geometrical configurations such as a stratified medium crossed by thin faults or having a complex topography. Two main developments are here described; one integrates the DWN method inside the IBEM in order to represent the Green's functions of stratified media with relatively low computational cost but assuming unbounded parallel flat layers, and the other is the extension of IBEM to deal with multi-regions in contact which allows more versatility with a higher computational cost compared to the first one but still minor to an equivalent FEM formulation. The two approaches are fully

  18. The Caribbean-South American plate boundary at 65°W: Results from wide-angle seismic data

    NASA Astrophysics Data System (ADS)

    Bezada, M. J.; Magnani, M. B.; Zelt, C. A.; Schmitz, M.; Levander, A.

    2010-08-01

    We present the results of the analysis of new wide-angle seismic data across the Caribbean-South American plate boundary in eastern Venezuela at about 65°W. The ˜500 km long profile crosses the boundary in one of the few regions dominated by extensional structures, as most of the southeastern Caribbean margin is characterized by the presence of fold and thrust belts. A combination of first-arrival traveltime inversion and simultaneous inversion of PmP and Pn arrivals was used to develop a P wave velocity model of the crust and the uppermost mantle. At the main strike-slip fault system, we image the Cariaco Trough, a major pull-apart basin along the plate boundary. The crust under the Southern Caribbean Deformed Belt exhibits a thickness of ˜15 km, suggesting that the Caribbean Large Igneous Province extends to this part of the Caribbean plate. The velocity structures of basement highs and offshore sedimentary basins imaged by the profile are comparable to those of features found in other parts of the margin, suggesting similarities in their tectonic history. We do not image an abrupt change in Moho depth or velocity structure across the main strike-slip system, as has been observed elsewhere along the margin. It is possible that a terrane of Caribbean island arc origin was accreted to South America at this site and was subsequently bisected by the strike-slip fault system. The crust under the continental portion of the profile is thinner than observed elsewhere along the margin, possibly as a result of thinning during Jurassic rifting.

  19. Boundary-layer mantle flow under the Dead Sea transform fault inferred from seismic anisotropy.

    PubMed

    Rümpker, Georg; Ryberg, Trond; Bock, Günter

    2003-10-02

    Lithospheric-scale transform faults play an important role in the dynamics of global plate motion. Near-surface deformation fields for such faults are relatively well documented by satellite geodesy, strain measurements and earthquake source studies, and deeper crustal structure has been imaged by seismic profiling. Relatively little is known, however, about deformation taking place in the subcrustal lithosphere--that is, the width and depth of the region associated with the deformation, the transition between deformed and undeformed lithosphere and the interaction between lithospheric and asthenospheric mantle flow at the plate boundary. Here we present evidence for a narrow, approximately 20-km-wide, subcrustal anisotropic zone of fault-parallel mineral alignment beneath the Dead Sea transform, obtained from an inversion of shear-wave splitting observations along a dense receiver profile. The geometry of this zone and the contrast between distinct anisotropic domains suggest subhorizontal mantle flow within a vertical boundary layer that extends through the entire lithosphere and accommodates the transform motion between the African and Arabian plates within this relatively narrow zone.

  20. Five-day recorder seismic system

    USGS Publications Warehouse

    Criley, Ed; Eaton, Jerry P.; Ellis, Jim

    1978-01-01

    The 10-day recorder seismic system used by the USGS since 1965 has been modified substantially to improve its dynamic range and frequency response, to decrease its power consumption and physical complexity, and to make its recordings more compatible with other NCER systems to facilitate data processing. The principal changes include: 1. increasing tape speed from 15/160 ips to 15/80 ips (reducing running time from 10 days to 5 days with a 14' reel of 1 mil tape), 2. increasing the FM center frequency by a factor of 4, from 84.4 Hz to 337.6 Hz, 3. replacing the original amplifiers and FM modulators with new low-power units, 4. replacing the chronometer with a higher quality time code generator (with IRIG-C) to permit automation of data retrieval, 5. eliminating the amplifier/WWVB radio field case by incorporating these elements, along with the new TCG, in the weatherproof tape-recorder box, 6. reducing the power consumption of the motor-drive circuit by removal of a redundant component. In the new system, the tape-recorder case houses all components except the seismometers, the WWVB antenna, the 70-amp-hour 12-VDC battery (which powers the system for 5 days), and the cables to connect these external elements to the recorder box. The objectives of this report are: 1. to describe the new 5-day-recorder seismic system in terms of its constituent parts and their functions, 2. to describe modifications to parts of the original system that were retained and to document new or replacement components with appropriate circuit diagrams and constructional details, 3. to provide detailed instructions for the correct adjustment or alignment of the system in the laboratory, and 4. to provide detailed instructions for installing and operating the system in the field.

  1. The Advanced National Seismic System; management and implementation

    USGS Publications Warehouse

    Benz, H.M.; Shedlock, K.M.; Buland, R.P.

    2001-01-01

    What is the Advanced National Seismic System? The Advanced National Seismic System (ANSS) is designed to organize, modernize, and standardize operations of seismic networks in the United States to improve the Nation’s ability to respond effectively to damaging earthquakes, volcanoes, and tsunamis. To achieve this, the ANSS will link more than 7,000 national, regional and urban monitoring stations in real time

  2. On the likelihood of post-perovskite near the core-mantle boundary: A statistical interpretation of seismic observations

    NASA Astrophysics Data System (ADS)

    Cobden, Laura; Mosca, Ilaria; Trampert, Jeannot; Ritsema, Jeroen

    2012-11-01

    Recent experimental studies indicate that perovskite, the dominant lower mantle mineral, undergoes a phase change to post-perovskite at high pressures. However, it has been unclear whether this transition occurs within the Earth's mantle, due to uncertainties in both the thermochemical state of the lowermost mantle and the pressure-temperature conditions of the phase boundary. In this study we compare the relative fit to global seismic data of mantle models which do and do not contain post-perovskite, following a statistical approach. Our data comprise more than 10,000 Pdiff and Sdiff travel-times, global in coverage, from which we extract the global distributions of dln VS and dln VP near the core-mantle boundary (CMB). These distributions are sensitive to the underlying lateral variations in mineralogy and temperature even after seismic uncertainties are taken into account, and are ideally suited for investigating the likelihood of the presence of post-perovskite. A post-perovskite-bearing CMB region provides a significantly closer fit to the seismic data than a post-perovskite-free CMB region on both a global and regional scale. These results complement previous local seismic reflection studies, which have shown a consistency between seismic observations and the physical properties of post-perovskite inside the deep Earth.

  3. Development of Vertical Cable Seismic System (2)

    NASA Astrophysics Data System (ADS)

    Asakawa, E.; Murakami, F.; Tsukahara, H.; Ishikawa, K.

    2012-12-01

    The vertical cable seismic is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by surface, deep-towed or ocean bottom sources. Analyzing the reflections from the sub-seabed, we could look into the subsurface structure. This type of survey is generally called VCS (Vertical Cable Seismic). Because VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed the method for the hydrothermal deposit survey tool development program that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) started in 2009. We are now developing a VCS system, including not only data acquisition hardware but data processing and analysis technique. Our first experiment of VCS surveys has been carried out in Lake Biwa, JAPAN in November 2009 for a feasibility study. Prestack depth migration is applied to the 3D VCS data to obtain a high quality 3D depth volume. Based on the results from the feasibility study, we have developed two autonomous recording VCS systems. After we carried out a trial experiment in the actual ocean at a water depth of about 400m and we carried out the second VCS survey at Iheya Knoll with a deep-towed source. In this survey, we could establish the procedures for the deployment/recovery of the system and could examine the locations and the fluctuations of the vertical cables at a water depth of around 1000m. The acquired VCS data clearly shows the reflections from the sub-seafloor. Through the experiment, we could confirm that our VCS system works well even in the severe circumstances around the locations of seafloor hydrothermal deposits. We have carried out two field surveys in 2011. One is a 3D survey with a boomer for a high-resolution surface source and the other one for an actual field survey in the Izena Cauldron an active hydrothermal area in the Okinawa Trough. Through these surveys, we have confirmed that the

  4. Implications of a localized zone of seismic activity near the Inner Piedmont-Blue Ridge boundary

    SciTech Connect

    Douglas, S.; Powell, C.

    1994-03-01

    A small but distinct cluster of earthquake activity is located in Henderson County, NC, near the boundary of the Inner Piedmont and Blue Ridge physiographic provinces. Over twenty events have occurred within the cluster since 1776 and four had body-wave magnitudes exceeding 3.0. Average focal depth for instrumentally recorded events is 7.7 km. Epicenters plot within the Inner Piedmont, roughly 13 km from the surface expression of the Brevard fault zone. The reason for sustained earthquake activity in Henderson County is not known but the close spatial association of the events with the Brevard fault suggests a causal relationship. Themore » Brevard zone dips steeply to the SE and the events could be associated with the fault at depth. An even more intriguing possibility is that the events are associated with the intersection of the Brevard zone and the decollemont; this possibility is compatible with available information concerning the depth to the decollemont and the dip on the Brevard zone. An association of seismic activity with the Brevard zone at depth is supported by the presence of another small cluster of activity located in Rutherford County, NC. This cluster is located in the Inner Piedmont, roughly 30 km NE of the Henderson cluster and 16 km from the Brevard fault zone. Association of seismic activity with known faults is very rare in the eastern US and has implications for tectonic models and hazard evaluation. Additional research must be conducted to determine the feasibility that activity is associated with the Brevard zone.« less

  5. Development of Vertical Cable Seismic System (3)

    NASA Astrophysics Data System (ADS)

    Asakawa, E.; Murakami, F.; Tsukahara, H.; Mizohata, S.; Ishikawa, K.

    2013-12-01

    The VCS (Vertical Cable Seismic) is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by surface, deep-towed or ocean bottom sources. Analyzing the reflections from the sub-seabed, we could look into the subsurface structure. Because VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed the method for the hydrothermal deposit survey tool development program that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) started in 2009. We are now developing a VCS system, including not only data acquisition hardware but data processing and analysis technique. We carried out several VCS surveys combining with surface towed source, deep towed source and ocean bottom source. The water depths of the survey are from 100m up to 2100m. The target of the survey includes not only hydrothermal deposit but oil and gas exploration. Through these experiments, our VCS data acquisition system has been completed. But the data processing techniques are still on the way. One of the most critical issues is the positioning in the water. The uncertainty in the positions of the source and of the hydrophones in water degraded the quality of subsurface image. GPS navigation system are available on sea surface, but in case of deep-towed source or ocean bottom source, the accuracy of shot position with SSBL/USBL is not sufficient for the very high-resolution imaging. We have developed another approach to determine the positions in water using the travel time data from the source to VCS hydrophones. In the data acquisition stage, we estimate the position of VCS location with slant ranging method from the sea surface. The deep-towed source or ocean bottom source is estimated by SSBL/USBL. The water velocity profile is measured by XCTD. After the data acquisition, we pick the first break times of the VCS recorded data. The estimated positions of

  6. The nature of crustal boundaries: combined interpretation of wide-angle and normal-incidence seismic data

    NASA Astrophysics Data System (ADS)

    Long, Roger E.; Matthews, Patricia A.; Graham, Daniel P.

    1994-04-01

    After a few seconds two-way traveltime, normal-incidence seismic reflection sections are composed mainly of assemblages of short reflections. Very rarely are seen continuous reflections that might correspond to the Moho or a mid-crustal discontinuity. The inferred continuity of these boundaries has traditionally come from refraction seismology. There is now a body of high quality, coincident wide-angle and normal-incidence seismic data that have been recorded with 50-100 m shot spacing and with high frequency sources (e.g. MOBIL, BABEL). The complexity and characteristics of the wide-angle arrivals seen on these data suggest that they do not originate from continuous boundaries. It is suggested that these arrivals are reflections from the same assemblage of short length reflectors that are responsible for normal-incidence reflections. Seismic velocities below the middle crust may (1) change corresponding to normal-incidence reflectivity, or (2) generally increase with depth with localised sills or lens structures of different velocity accounting for the observed reflections. Wide-angle arrivals that have traditionally been identified as reflections from crustal boundaries (e.g. the mid-crust and Moho) and which were considered indicative of a sharp velocity discontinuity from continuous boundaries, may instead result from a concentration of lamellae.

  7. An assessment of seismic monitoring in the United States; requirement for an Advanced National Seismic System

    USGS Publications Warehouse

    ,

    1999-01-01

    This report assesses the status, needs, and associated costs of seismic monitoring in the United States. It sets down the requirement for an effective, national seismic monitoring strategy and an advanced system linking national, regional, and urban monitoring networks. Modernized seismic monitoring can provide alerts of imminent strong earthquake shaking; rapid assessment of distribution and severity of earthquake shaking (for use in emergency response); warnings of a possible tsunami from an offshore earthquake; warnings of volcanic eruptions; information for correctly characterizing earthquake hazards and for improving building codes; and data on response of buildings and structures during earthquakes, for safe, cost-effective design, engineering, and construction practices in earthquake-prone regions.

  8. Seismic Tomography of the South Carpathian System

    NASA Astrophysics Data System (ADS)

    Stuart, G. W.; Ren, Y.; Dando, B. D.; Houseman, G.; Ionescu, C.; Hegedus, E.; Radovanovic, S.; South Carpathian Project Working Group

    2010-12-01

    The South Carpathian Mountain Range is an enigmatic system, which includes one of the most seismically active regions in Europe today. That region, Vrancea in the SE Carpathians, is well studied and its deep structure may be geologically unique, but the mantle structures beneath the western part of the South Carpathian Range are not well resolved by previous tomographic studies. The South Carpathian Project (SCP) is a major temporary deployment (2009-2011) of seismic broadband systems extending across the eastern Pannonian Basin and the South Carpathian Mountains. In this project we aim to map the upper mantle structure in central Europe with the objective of testing geodynamic models of the process that produced extension in the Pannonian, synchronous with convergence and uplift in the Carpathians. Here, we describe initial results of finite-frequency tomography using body waves to image the mantle of the region. We have selected teleseismic earthquakes with magnitude greater than 5.9, which occurred between 2005 and 2010. The data were recorded on 57 temporary stations deployed in the South Carpathian Project, 56 temporary stations deployed in the earlier Carpathian Basins Project (CBP), and 41 permanent broadband stations. The differential travel times are measured in high, intermediate and low frequencies (0.5-2.0 Hz, 0.1-0.5 Hz and 0.03-0.1 Hz for both P-wave, 0.1-0.5 Hz, 0.05-0.1 Hz and 0.02-0.05 Hz for S-wave), and are inverted to produce P and S-wave velocity maps at different depths in the mantle. An extensive zone of high seismic velocities is located in the Mantle Transition zone beneath the Pannonian Basin, and is related to down-welling associated with an earlier phase of continental convergence in the Pannonian region. These results will be used in conjunction with 3D geodynamical modelling to help understand the geological evolution of this region. SCP working group: G. Houseman, G. Stuart, Y. Ren, B. Dando, P. Lorinczi, School of Earth and

  9. Investigating the Effects Fracture Systems Have on Seismic Wave Velocities at the Lajitas, Texas Seismic Station

    DTIC Science & Technology

    1989-05-01

    Victoria L. Sandidge-Bodoh % S Southern Methodist University Department of Geological Sciences Dallas, TX 75275 1 May 1989 Final Report 3 March 1987 - 2...Projects Agency or the U.S. Government. This technical report has been reviewed and is approved for publicj ion. JAME F. LEWKOW(CZ J/ S F. LEWKOWiC...Effects Fracture Systems Have on Seismic Wave Velocities at the Lajitas, Texas Seismic Station 12. PERSONAL AUTHOR( S ) Victoria L. Sandidge-Bodoh 13a. TYPE

  10. Wireless boundary monitor system and method

    DOEpatents

    Haynes, H.D.; Ayers, C.W.

    1997-12-09

    A wireless boundary monitor system used to monitor the integrity of a boundary surrounding an area uses at least two housings having at least one transmitting means for emitting ultrasonic pressure waves to a medium. Each of the housings has a plurality of receiving means for sensing the pressure waves in the medium. The transmitting means and the receiving means of each housing are aimable and communicably linked. At least one of the housings is equipped with a local alarm means for emitting a first alarm indication whereby, when the pressure waves propagating from a transmitting means to a receiving means are sufficiently blocked by an object a local alarm means or a remote alarm means or a combination thereof emit respective alarm indications. The system may be reset either manually or automatically. This wireless boundary monitor system has useful applications in both indoor and outdoor environments. 4 figs.

  11. Wireless boundary monitor system and method

    DOEpatents

    Haynes, Howard D.; Ayers, Curtis W.

    1997-01-01

    A wireless boundary monitor system used to monitor the integrity of a boundary surrounding an area uses at least two housings having at least one transmitting means for emitting ultrasonic pressure waves to a medium. Each of the housings has a plurality of receiving means for sensing the pressure waves in the medium. The transmitting means and the receiving means of each housing are aimable and communicably linked. At least one of the housings is equipped with a local alarm means for emitting a first alarm indication whereby, when the pressure waves propagating from a transmitting means to a receiving means are sufficiently blocked by an object a local alarm means or a remote alarm means or a combination thereof emit respective alarm indications. The system may be reset either manually or automatically. This wireless boundary monitor system has useful applications in both indoor and outdoor environments.

  12. Stability boundaries for command augmentation systems

    NASA Technical Reports Server (NTRS)

    Shrivastava, P. C.

    1987-01-01

    The Stability Augmentation System (SAS) is a special case of the Command Augmentation System (CAS). Control saturation imposes bounds on achievable commands. The state equilibrium depends only on the open loop dynamics and control deflection. The control magnitude to achieve a desired command equilibrium is independent of the feedback gain. A feedback controller provides the desired response, maintains the system equilibrium under disturbances, but it does not affect the equilibrium values of states and control. The saturation boundaries change with commands, but the location of the equilibrium points in the saturated region remains unchanged. Nonzero command vectors yield saturation boundaries that are asymmetric with respect to the state equilibrium. Except for the saddle point case with MCE control law, the stability boundaries change with commands. For the cases of saddle point and unstable nodes, the region of stability decreases with increasing command magnitudes.

  13. Locating seismicity on the Arctic plate boundary using multiple-event techniques and empirical signal processing

    NASA Astrophysics Data System (ADS)

    Gibbons, S. J.; Harris, D. B.; Dahl-Jensen, T.; Kværna, T.; Larsen, T. B.; Paulsen, B.; Voss, P. H.

    2017-12-01

    The oceanic boundary separating the Eurasian and North American plates between 70° and 84° north hosts large earthquakes which are well recorded teleseismically, and many more seismic events at far lower magnitudes that are well recorded only at regional distances. Existing seismic bulletins have considerable spread and bias resulting from limited station coverage and deficiencies in the velocity models applied. This is particularly acute for the lower magnitude events which may only be constrained by a small number of Pn and Sn arrivals. Over the past two decades there has been a significant improvement in the seismic network in the Arctic: a difficult region to instrument due to the harsh climate, a sparsity of accessible sites (particularly at significant distances from the sea), and the expense and difficult logistics of deploying and maintaining stations. New deployments and upgrades to stations on Greenland, Svalbard, Jan Mayen, Hopen, and Bjørnøya have resulted in a sparse but stable regional seismic network which results in events down to magnitudes below 3 generating high-quality Pn and Sn signals on multiple stations. A catalogue of several hundred events in the region since 1998 has been generated using many new phase readings on stations on both sides of the spreading ridge in addition to teleseismic P phases. A Bayesian multiple event relocation has resulted in a significant reduction in the spread of hypocentre estimates for both large and small events. Whereas single event location algorithms minimize vectors of time residuals on an event-by-event basis, the Bayesloc program finds a joint probability distribution of origins, hypocentres, and corrections to traveltime predictions for large numbers of events. The solutions obtained favour those event hypotheses resulting in time residuals which are most consistent over a given source region. The relocations have been performed with different 1-D velocity models applicable to the Arctic region and

  14. The International Plate Boundary Observatory Chile (IPOC) in the northern Chile seismic gap

    NASA Astrophysics Data System (ADS)

    Schurr, B.; Asch, A.; Sodoudi, F.; Manzanares, A.; Ritter, O.; Klotz, J.; Chong-Diaz, G.; Barrientos, S.; Villotte, J.-P.; Oncken, O.

    2009-04-01

    Fast convergence between the oceanic Nazca and the continental South American plate is accommodated by recurrent rupture of large segments of the two plates' interface. The resulting earthquakes are among the largest and, for their sizes, most frequent on Earth. Along the Chilean and southern Peruvian margin, all segments have ruptured at least once in the past 150 years for which there exist historic and/or instrumental records. The one segment that is most mature for re-rupture stretches for more than 500 km along the northernmost Chilean coast between roughly -23° and -18° latitude. It last broke in 1877 in a magnitude ~8.8 earthquake, triggering a major Tsunami. From the historical record, it has been known to have a recurrence cycle of approximately 110 years. The adjoining segments to the north and south broke rather recently in 1995 and 2001 in M>8 earthquakes and an M 7.7 earthquake encroached the southern part of the gap in 2007. The IPOC project intends to investigate this segment of the Nazca-South American plate boundary, on which a strong to devastating earthquake is expected to occur within the next years, by monitoring at a variety of time-scales deformation, seismicity, and magnetotelluric fields in the subduction zone at the closing stages of the interseismic cycle before and possibly during occurrence of a big earthquake. For that purpose, installation of long-term observatories in Northern Chile started in 2006 in a close cooperation of the Universidad de Chile (Santiago, Chile), the Universidad Catolica del Norte (Antofagasta, Chile), the Institut de Physique du Globe de Paris (Paris, France), and the German Research Centre for Geosciences (GFZ, Potsdam, Germany). Currently we are operating 14 modern seismological stations equipped with STS-2 broadband seismometers and accelerometers (EPI sensor). At least two more stations will be installed in the near future. To cope with the high resolution and dynamic of the sensors and data acquisition

  15. The boundary of the solar system

    NASA Technical Reports Server (NTRS)

    Smoluchowski, R.; Torbett, M.

    1984-01-01

    The shape of the boundary of the solar system, defined as the surface within which the gravitational attraction of the sun rather than that of the rest of the Galaxy controls the orbital motion of planets and comets, has been determined. Outside of this surface, the dominant factors are the radial tides due to the galactic center and the vertical tides caused by the galactic disk. Orbits which are direct with respect to the galactic plane have a boundary which differs from that for retrograde orbits, both being 10-20 percent oblate and both larger than the present Oort cloud. The surface may have been the boundary of the early cloud of comets which was later reduced by the passages of stars and molecular clouds.

  16. Origins of a national seismic system in the United States

    USGS Publications Warehouse

    Filson, John R.; Arabasz, Walter J.

    2016-01-01

    This historical review traces the origins of the current national seismic system in the United States, a cooperative effort that unifies national, regional, and local‐scale seismic monitoring within the structure of the Advanced National Seismic System (ANSS). The review covers (1) the history and technological evolution of U.S. seismic networks leading up to the 1990s, (2) factors that made the 1960s and 1970s a watershed period for national attention to seismology, earthquake hazards, and seismic monitoring, (3) genesis of the vision of a national seismic system during 1980–1983, (4) obstacles and breakthroughs during 1984–1989, (5) consensus building and convergence during 1990–1992, and finally (6) the two‐step realization of a national system during 1993–2000. Particular importance is placed on developments during the period between 1980 and 1993 that culminated in the adoption of a charter for the Council of the National Seismic System (CNSS)—the foundation for the later ANSS. Central to this story is how many individuals worked together toward a common goal of a more rational and sustainable approach to national earthquake monitoring in the United States. The review ends with the emergence of ANSS during 1999 and 2000 and its statutory authorization by Congress in November 2000.

  17. Proxies of oceanic Lithosphere/Asthenosphere Boundary from Global Seismic Anisotropy Tomography

    NASA Astrophysics Data System (ADS)

    Burgos, Gael; Montagner, Jean-Paul; Beucler, Eric; Trampert, Jeannot; Capdeville, Yann

    2013-04-01

    Surface waves provide essential information on the knowledge of the upper mantle global structure despite their low lateral resolution. This study, based on surface waves data, presents the development of a new anisotropic tomographic model of the upper mantle, a simplified isotropic model and the consequences of these results for the Lithosphere/Asthenosphere Boundary (LAB). As a first step, a large number of data is collected, these data are merged and regionalized in order to derive maps of phase and group velocity for the fundamental mode of Rayleigh and Love waves and their azimuthal dependence (maps of phase velocity are also obtained for the first six overtones). As a second step, a crustal a posteriori model is developped from the Monte-Carlo inversion of the shorter periods of the dataset, in order to take into account the effect of the shallow layers on the upper mantle. With the crustal model, a first Monte-Carlo inversion for the upper mantle structure is realized in a simplified isotropic parameterization to highlight the influence of the LAB properties on the surface waves data. Still using the crustal model, a first order perturbation theory inversion is performed in a fully anisotropic parameterization to build a 3-D tomographic model of the upper mantle (an extended model until the transition zone is also obtained by using the overtone data). Estimates of the LAB depth are derived from the upper mantle models and compared with the predictions of oceanic lithosphere cooling models. Seismic events are simulated using the Spectral Element Method in order to validate the ability of the anisotropic tomographic model of the upper mantle to re- produce observed seismograms.

  18. Imaging the SE Caribbean Accretionary Boundary: Results from the BOLIVAR Seismic Reflection and Refraction data at 65W

    NASA Astrophysics Data System (ADS)

    Magnani, M.; Zelt, C. A.; Sawyer, D.; Levander, A.

    2005-12-01

    We describe a N-S, ~550 km long onshore-offshore profile at approximately 65oW., which is one of the principal seismic reflection and refraction transects acquired in 2004 as part of the Broadband Ocean and Land Investigation of Venezuela and the Antilles arc Region (BOLIVAR) experiment. Goals of BOLIVAR are to understand the complex history of the progressive oblique collision between the Leeward Antilles arc and South America that has taken place since the late Cretaceous, and to unravel the mechanisms responsible for continental growth of the South American continent through arc accretion. The transect starts ~330 km offshore northern Venezuela, in the Venezuela Basin, crosses the South America/Caribbean incipient subduction zone, the Los Roques canyon, the ABC ridge, the Tuy-Cariaco Trough (bounded by the El Pilar-Moron dextral strike-slip system), and crosses the coast east of Barcelona, Ve., continues south 175 km through the Espino Graben, and the Eastern Venezuela Basin. Multi-channel seismic reflection data were acquired by the R/V Ewing along the offshore portion of the profile, while 7 ocean bottoms seismometers (offshore) and 485 Reftek Texans (onland) recorded the Ewing airgun shots. In addition two large land shots (600 kg and 1000 kg of pentanol) were recorded by the land stations, providing reversed refraction coverage. The profile is located in a unique position along the South America/Caribbean plate boundary as it lies astride a transfer zone between the Southern Caribbean Deformed Belt, where the Caribbean plate is subducting beneath South America, and the eastern Venezuela strike-slip boundary and modern Antilles volcanic arc, where the South American plate subducts beneath the Caribbean. The structure and motion across this apparent transfer zone are unknown. The seismic data show that this area is characterized by a basement high, with little sediment coverage and velocities as high as 6.5-6.7 km/s at a depth of 8-10 km. North of the coast

  19. The INGV seismic monitoring system: activities during the first month of the 2016 Amatrice seismic sequence.

    NASA Astrophysics Data System (ADS)

    Scognamiglio, L.; Margheriti, L.; Moretti, M.; Pintore, S.

    2016-12-01

    At 01:36:32 UTC on August 24, 2016 an earthquake of ML=6.0 occurred in Central Italy, near Amatrice village; 21 s after the origin time, the first automatic location became available while the first magnitude estimate followed 47s after. The INGV seismologists on duty provided the alert to the Italian Civil Protection Department and thereby triggered the seismic emergency protocol In the hours after the earthquake, hundreds of events were recorded by the Italian Seismic Network of the INGV. SISMIKO, the coordinating body of the emergency seismic network, was activated few minutes after the mainshock. The main goal of this emergency group is to install temporary dense seismic network integrated with the existing permanent networks in the epicentral area to better constrain the aftershock hypocenters. From August the 24th to the 30th, SISMIKO deployed 18 seismic stations, generally six components (equipped with both seismometer and accelerometer), 13 of which were transmitting in real-time to the INGV seismic surveillance room in Rome. All data acquired are available at the European Integrated Data Archive (EIDA). The seismic sequence in the first month generated thousands of earthquakes which were processed and detected by the INGV automated localization system. We analyzed the performance of this system. Hundreds of those events were located by seismologists on shifts, the others were left to be analyzed by the Bollettino Sismico Italiano (BSI). The procedures of the BSI revise and integrate all available data. This allows for a better constrained location and for a more realistic hypocentral depth estimation. The first eight hours of August 24th were the most critical for the INGV surveillance room. Data recorded in these hours were carefully re-analyzed by BSI operators and the number of located events increased from 133 to 408, while the magnitude of completeness dropped significantly from about 3.5 to 2.7.

  20. Magnetopause Boundary Processes Throughout the Solar System

    NASA Astrophysics Data System (ADS)

    Masters, A.

    2014-12-01

    Earth is not the only planet in the Solar System with a natural magnetic shield. Mercury, Jupiter, Saturn, Uranus, and Neptune are similarly protected from the solar wind and cosmic rays. However, like our planet, the magnetic shielding of each of these magnetized planets can break down, driving energy flow through each planetary magnetosphere. Although studies of the magnetopause boundary of Earth's magnetosphere have shed considerable light on the processes that lead to this breakdown, the extent to which we can apply this understanding to the diverse space plasma environments surrounding other planets remains unclear. Here we review what we have learnt so far about the operation of magnetopause boundary processes at all the magnetized planets in the Solar System, and outline some of the relevant outstanding questions. We start by consolidating present understanding of terrestrial magnetopause processes, which is our reference when considering other boundaries. We focus on selected processes (magnetic reconnection, Kelvin-Helmholtz instability), compare how we expect them to operate at each planetary magnetopause, and assess whether or not this is consistent with in situ spacecraft observations. For each planetary magnetosphere we then discuss the nature of the total interaction with the solar wind, and whether this is expected to be dominant over internal drivers of magnetospheric dynamics. A combination of further spacecraft exploration and dedicated numerical modeling is required in order to address the many outstanding questions concerning this topic. Progress in this direction would have broad implications for other space plasma systems, in our solar system and beyond.

  1. Seismic Hazard Analysis as a Controlling Technique of Induced Seismicity in Geothermal Systems

    NASA Astrophysics Data System (ADS)

    Convertito, V.; Sharma, N.; Maercklin, N.; Emolo, A.; Zollo, A.

    2011-12-01

    The effect of induced seismicity of geothermal systems during stimulation and fluid circulation can cover a wide range of values from light and unfelt to severe and damaging. If the design of a modern geothermal system requires the largest efficiency to be obtained from the social point of view it is required that the system could be managed in order to reduce possible impact in advance. In this framework, automatic control of the seismic response of the stimulated reservoir is nowadays mandatory, particularly in proximity of densely populated areas. Recently, techniques have been proposed for this purpose mainly based on the concept of the traffic light. This system provides a tool to decide the level of stimulation rate based on the real-time analysis of the induced seismicity and the ongoing ground motion values. However, in some cases the induced effect can be delayed with respect to the time when the reservoir is stimulated. Thus, a controlling system technique able to estimate the ground motion levels for different time scales can help to better control the geothermal system. Here we present an adaptation of the classical probabilistic seismic hazard analysis to the case where the seismicity rate as well as the propagation medium properties are not constant with time. We use a non-homogeneous seismicity model for modeling purposes, in which the seismicity rate and b-value of the recurrence relationship change with time. Additionally, as a further controlling procedure, we propose a moving time window analysis of the recorded peak ground-motion values aimed at monitoring the changes in the propagation medium. In fact, for the same set of magnitude values recorded at the same stations, we expect that on average peak ground motion values attenuate in same way. As a consequence, the residual differences can be reasonably ascribed to changes in medium properties. These changes can be modeled and directly introduced in the hazard integral. We applied the proposed

  2. BOLIVAR: the Caribbean-South America plate boundary between 60W and 71W as imaged by seismic reflection data

    NASA Astrophysics Data System (ADS)

    Magnani, M.; Mann, P.; Clark, S. A.; Escalona, A.; Zelt, C. A.; Christeson, G. L.; Levander, A.

    2007-12-01

    We present the results of ~6000km of marine multi-channel seismic (MCS) reflection data collected offshore Venezuela as part of the Broadband Ocean Land Investigation of Venezuela and the Antilles arc Region project (BOLIVAR). The imaged area spans almost 12 degrees of longitude and 5 degrees of latitude and encompasses the diffuse plate boundary between South America (SA) and the SE Caribbean plate (CAR). This plate boundary has been evolving for at least the past 55My when the volcanic island arc that borders the CAR plate started colliding obliquely with the SA continent: the collision front has migrated from west to east. BOLIVAR MCS data show that the crustal architecture of the present plate boundary is dominated by the eastward motion of the Caribbean plate with respect to SA and is characterized by a complex combination of convergent and strike-slip tectonics. To the north, the reflection data image the South Caribbean Deformed Belt (SCDB) and the structures related to the thrusting of the CAR plate under the Leeward Antilles volcanic arc region. The data show that the CAR underthrusting continues as far east as the southern edge of the Aves ridge and detailed stratigraphic dating of the Venezuela basin and trench deposits suggests that the collision began in the Paleogene. The amount of shortening along the SCDB decreases toward the east, in part due to the geometry of plate motion vectors and in part as a result of the NNE escape of the Maracaibo block in western Venezuela. South of the SCDB the MCS profiles cross the Leeward Antilles island arc and Cenozoic sedimentary basins, revealing a complex history of Paleogene-Neogene multiphase extension, compression, and tectonic inversion, as well as the influence of the tectonic activity along the right-lateral El Pilar - San Sebastian fault system. East of the Bonaire basin the MCS data image the southern end of the Aves Ridge abandoned volcanic island arc and the southwestern termination of the Grenada basin

  3. Seismic depth imaging of sequence boundaries beneath the New Jersey shelf

    NASA Astrophysics Data System (ADS)

    Riedel, M.; Reiche, S.; Aßhoff, K.; Buske, S.

    2018-06-01

    Numerical modelling of fluid flow and transport processes relies on a well-constrained geological model, which is usually provided by seismic reflection surveys. In the New Jersey shelf area a large number of 2D seismic profiles provide an extensive database for constructing a reliable geological model. However, for the purpose of modelling groundwater flow, the seismic data need to be depth-converted which is usually accomplished using complementary data from borehole logs. Due to the limited availability of such data in the New Jersey shelf, we propose a two-stage processing strategy with particular emphasis on reflection tomography and pre-stack depth imaging. We apply this workflow to a seismic section crossing the entire New Jersey shelf. Due to the tomography-based velocity modelling, the processing flow does not depend on the availability of borehole logging data. Nonetheless, we validate our results by comparing the migrated depths of selected geological horizons to borehole core data from the IODP expedition 313 drill sites, located at three positions along our seismic line. The comparison yields that in the top 450 m of the migrated section, most of the selected reflectors were positioned with an accuracy close to the seismic resolution limit (≈ 4 m) for that data. For deeper layers the accuracy still remains within one seismic wavelength for the majority of the tested horizons. These results demonstrate that the processed seismic data provide a reliable basis for constructing a hydrogeological model. Furthermore, the proposed workflow can be applied to other seismic profiles in the New Jersey shelf, which will lead to an even better constrained model.

  4. Areal distribution of sedimentary facies determined from seismic facies analysis and models of modern depositional systems

    SciTech Connect

    Seramur, K.C.; Powell, R.D.; Carpenter, P.J.

    1988-02-01

    Seismic facies analysis was applied to 3.5-kHz single-channel analog reflection profiles of the sediment fill within Muir Inlet, Glacier Bay, southeast Alaska. Nine sedimentary facies have been interpreted from seven seismic facies identified on the profiles. The interpretations are based on reflection characteristics and structural features of the seismic facies. The following reflection characteristics and structural features are used: reflector spacing, amplitude and continuity of reflections, internal reflection configurations, attitude of reflection terminations at a facies boundary, body geometry of a facies, and the architectural associations of seismic facies within each basin. The depositional systems are reconstructed by determining themore » paleotopography, bedding patterns, sedimentary facies, and modes of deposition within the basin. Muir Inlet is a recently deglaciated fjord for which successive glacier terminus positions and consequent rates of glacial retreat are known. In this environment the depositional processes and sediment characteristics vary with distance from a glacier terminus, such that during a retreat a record of these variations is preserved in the aggrading sediment fill. Sedimentary facies within the basins of lower Muir Inlet are correlated with observed depositional processes near the present glacier terminus in the upper inlet. The areal distribution of sedimentary facies within the basins is interpreted using the seismic facies architecture and inferences from known sediment characteristics proximal to present glacier termini.« less

  5. Seismic Structure in the Vicinity of the Inner Core Boundary beneath northeastern Asia

    NASA Astrophysics Data System (ADS)

    Ibourichene, A. S.; Romanowicz, B. A.

    2016-12-01

    The inner core boundary (ICB) separates the solid inner core from the liquid outer core. The crystallization of iron occurring at this limit induces the expulsion of lighter elements such as H, O, S, Si into the outer core, generating chemically-driven convection, which provides power for the geodynamo. Both the F layer, right above the ICB, and the uppermost inner core, are affected by this process so that their properties provide important constraints for a better understanding of core dynamics and, ultimately, the generation and sustained character of the earth's magnetic field. In this study, we investigate the evolution of model parameters (P-velocity, density and quality factor) with depth in the vicinity of the ICB. For this purpose, we combine observations of two body wave phases sensitive to this region: the PKP(DF) phase refracted in the inner core and the PKiKP reflected on the ICB. Variations in the PKP(DF)/PKiKP amplitude ratio and PKP(DF)-PKiKP differential travel times can be related to structure around the ICB. We use waveform data from earthquakes located in Sumatra and recorded by the dense USArray seismic network, which allows us to sample ICB structure beneath northeastern Asia. Observed waveforms are compared to synthetics computed using the DSM method (e.g., Geller et Takeuchi, 1995) in model AK135 (e.g., Montagner & Kennett, 1996) in order to measure amplitude and travel time anomalies. Previous studies (e.g., Tanaka, 1997 ; Cao and Romanowicz, 2004, Yu and Wen, 2006; Waszek and Deuss, 2011) have observed an hemispherical pattern in the vicinity of the ICB exhibiting a faster and more attenuated eastern hemisphere compared to the western hemisphere. The region studied is located in the eastern hemisphere. We find that, on average, travel time anomalies are consistent with previous studies of the eastern hemisphere, however, amplitude ratios are not. We conduct a parameter search for the 1D model that best fits our data. We also consider

  6. Imaging the crustal structure of Haiti's transpressional fault system using seismicity and tomography

    NASA Astrophysics Data System (ADS)

    Possee, D.; Keir, D.; Harmon, N.; Rychert, C.; Rolandone, F.; Leroy, S. D.; Stuart, G. W.; Calais, E.; Boisson, D.; Ulysse, S. M. J.; Guerrier, K.; Momplaisir, R.; Prepetit, C.

    2017-12-01

    Oblique convergence of the Caribbean and North American plates has partitioned strain across an extensive transpressional fault system that bisects Haiti. Most recently the 2010, MW7.0 earthquake ruptured multiple thrust faults in southern Haiti. However, while the rupture mechanism has been well studied, how these faults are segmented and link to deformation across the plate boundary is still debated. Understanding the link between strain accumulation and faulting in Haiti is also key to future modelling of seismic hazards. To assess seismic activity and fault structures we used data from 31 broadband seismic stations deployed on Haiti for 16-months. Local earthquakes were recorded and hypocentre locations determined using a 1D velocity model. A high-quality subset of the data was then inverted using travel-time tomography for relocated hypocentres and 2D images of Vp and Vp/Vs crustal structure. Earthquake locations reveal two clusters of seismic activity, the first delineates faults associated with the 2010 earthquake and the second shows activity 100km further east along a thrust fault north of Lake Enriquillo (Dominican Republic). The velocity models show large variations in seismic properties across the plate boundary; shallow low-velocity zones with a 5-8% decrease in Vp and high Vp/Vs ratios of 1.85-1.95 correspond to sedimentary basins that form the low-lying terrain on Haiti. We also image a region with a 4-5% decrease in Vp and an increased Vp/Vs ratio of 1.80-1.85 dipping south to a depth of 20km beneath southern Haiti. This feature matches the location of a major thrust fault and suggests a substantial damage zone around this fault. Beneath northern Haiti a transition to lower Vp/Vs values of 1.70-1.75 reflects a compositional change from mafic facies such as the Caribbean large igneous province in the south, to arc magmatic facies associated with the Greater Antilles arc in the north. Our seismic images are consistent with the fault system across

  7. State of art of seismic design and seismic hazard analysis for oil and gas pipeline system

    NASA Astrophysics Data System (ADS)

    Liu, Aiwen; Chen, Kun; Wu, Jian

    2010-06-01

    The purpose of this paper is to adopt the uniform confidence method in both water pipeline design and oil-gas pipeline design. Based on the importance of pipeline and consequence of its failure, oil and gas pipeline can be classified into three pipe classes, with exceeding probabilities over 50 years of 2%, 5% and 10%, respectively. Performance-based design requires more information about ground motion, which should be obtained by evaluating seismic safety for pipeline engineering site. Different from a city’s water pipeline network, the long-distance oil and gas pipeline system is a spatially linearly distributed system. For the uniform confidence of seismic safety, a long-distance oil and pipeline formed with pump stations and different-class pipe segments should be considered as a whole system when analyzing seismic risk. Considering the uncertainty of earthquake magnitude, the design-basis fault displacements corresponding to the different pipeline classes are proposed to improve deterministic seismic hazard analysis (DSHA). A new empirical relationship between the maximum fault displacement and the surface-wave magnitude is obtained with the supplemented earthquake data in East Asia. The estimation of fault displacement for a refined oil pipeline in Wenchuan M S8.0 earthquake is introduced as an example in this paper.

  8. Transpressional Tectonics across the N. American-Caribbean Plate Boundary: Preliminary Results of a Multichannel Seismic Survey of Lake Azuei, Haiti.

    NASA Astrophysics Data System (ADS)

    Hearn, C. K.; Cormier, M. H.; Sloan, H.; Wattrus, N. J.; Boisson, D.; Brown, B.; Guerrier, K.; King, J. W.; Knotts, P.; Momplaisir, R.; Sorlien, C. C.; Stempel, R.; Symithe, S. J.; Ulysse, S. M. J.

    2017-12-01

    On January 12, 2010, a Mw 7.0 earthquake struck Haiti, killing over 200,000 people and devastating the Capital city of Port-au-Prince and the surrounding regions. It ruptured a previously unknown blind-thrust fault that abuts the Enriquillo Plantain Garden Fault (EPGF), one of two transform faults that define the North American-Caribbean plate boundary. That earthquake highlighted how transpression across this complex boundary is accommodated by slip partitioning into strike-slip and compressional structures. Because the seismic hazard is higher for a rupture on a reverse or oblique-slip fault than on a vertical strike-slip fault, the need to characterize the geometry of that fault system is clear. Lake Azuei overlies this plate boundary 60 km east of the 2010 epicenter. The lake's 23 km long axis trends NW-SE, parallel to the Haitian fold-and-thrust belt and oblique to the EPGF. This tectonic context makes it an ideal target for investigating the partitioning of plate motion between strike-slip and compressional structures. In January 2017, we acquired 222 km of multichannel seismic (MCS) profiles in the lake, largely concurrent with subbottom seismic (CHIRP) profiles. The MCS data were acquired using a high-frequency BubbleGun source and a 75 m-long, 24-channel streamer, achieving a 24 seismic fold with a penetration of 200 m below lakebed. With the goal of resolving tectonic structures in 3-D, survey lines were laid out in a grid with profiles spaced 1.2 km apart. Additional profiles were acquired at the SE end of the lake where most of the tectonic activity is presumably occurring. The co-located CHIRP and MCS profiles document the continuity of tectonic deformation between the surficial sediments and the deeper strata. Preliminary processing suggests that a SW-dipping blind thrust fault, expressed updip as a large monocline fold, may control the western edge of the lake. Gentle, young folds that protrude from the flat lakebed are also imaged with the CHIRP

  9. Sequence stratigraphy, seismic stratigraphy, and seismic structures of the lower intermediate confining unit and most of the Floridan aquifer system, Broward County, Florida

    USGS Publications Warehouse

    Cunningham, Kevin J.; Kluesner, Jared W.; Westcott, Richard L.; Robinson, Edward; Walker, Cameron; Khan, Shakira A.

    2017-12-08

    sequence stratigraphic cycles that compose the Eocene to Miocene Oldsmar, Avon Park, and Arcadia Formations. The mapping of these seismic-reflection and well data has produced a refined Cenozoic sequence stratigraphic, seismic stratigraphic, and hydrogeologic framework of southeastern Florida. The upward transition from the Oldsmar Formation to the Avon Park Formation and the Arcadia Formation embodies the evolution from (1) a tropical to subtropical, shallow-marine, carbonate platform, represented by the Oldsmar and Avon Park Formations, to (2) a broad, temperate, mixed carbonate-siliciclastic shallow marine shelf, represented by the lower part of the Arcadia Formation, and to (3) a temperate, distally steepened carbonate ramp represented by the upper part of the Arcadia Formation.In the study area, the depositional sequences and seismic sequences have a direct correlation with hydrogeologic units. The approximate upper boundary of four principal permeable units of the Floridan aquifer system (Upper Floridan aquifer, Avon Park permeable zone, uppermost major permeable zone of the Lower Floridan aquifer, and Boulder Zone) have sequence stratigraphic and seismic-reflection signatures that were identified on cross sections, mapped, or both, and therefore the sequence stratigraphy and seismic stratigraphy were used to guide the development of a refined spatial representation of these hydrogeologic units. In all cases, the permeability of the four permeable units is related to stratiform megaporosity generated by ancient dissolution of carbonate rock associated with subaerial exposure and unconformities at the upper surfaces of carbonate depositional cycles of several hierarchical scales ranging from high-frequency cycles to depositional sequences. Additionally, interparticle porosity also contributes substantially to the stratiform permeability in much of the Upper Floridan aquifer. Information from seismic stratigraphy allowed 3D geomodeling of hydrogeologic units

  10. Online monitoring of seismic damage in water distribution systems

    NASA Astrophysics Data System (ADS)

    Liang, Jianwen; Xiao, Di; Zhao, Xinhua; Zhang, Hongwei

    2004-07-01

    It is shown that water distribution systems can be damaged by earthquakes, and the seismic damages cannot easily be located, especially immediately after the events. Earthquake experiences show that accurate and quick location of seismic damage is critical to emergency response of water distribution systems. This paper develops a methodology to locate seismic damage -- multiple breaks in a water distribution system by monitoring water pressure online at limited positions in the water distribution system. For the purpose of online monitoring, supervisory control and data acquisition (SCADA) technology can well be used. A neural network-based inverse analysis method is constructed for locating the seismic damage based on the variation of water pressure. The neural network is trained by using analytically simulated data from the water distribution system, and validated by using a set of data that have never been used in the training. It is found that the methodology provides an effective and practical way in which seismic damage in a water distribution system can be accurately and quickly located.

  11. Modeling the Geometry of Plate Boundary and Seismic Structure in the Southern Ryukyu Trench Subduction Zone, Japan, Using Amphibious Seismic Observations

    NASA Astrophysics Data System (ADS)

    Yamamoto, Y.; Takahashi, T.; Ishihara, Y.; Kaiho, Y.; Arai, R.; Obana, K.; Nakanishi, A.; Miura, S.; Kodaira, S.; Kaneda, Y.

    2018-02-01

    Here we present the new model, the geometry of the subducted Philippine Sea Plate interface beneath the southern Ryukyu Trench subduction zone, estimated from seismic tomography and focal mechanism estimation by using passive and active data from a temporary amphibious seismic network and permanent land stations. Using relocated low-angle thrust-type earthquakes, repeating earthquakes, and structural information, we constrained the geometry of plate boundary from the trench axis to a 60 km depth with uncertainties of less than 5 km. The estimated plate geometry model exhibited large variation, including a pronounced convex structure that may be evidence of a subducted seamount in the eastern portion of study area, whereas the western part appeared smooth. We also found that the active earthquake region near the plate boundary, defined by the distance from our plate geometry model, was clearly separated from the area dominated by short-term slow-slip events (SSEs). The oceanic crust just beneath the SSE-dominant region, the western part of the study area, showed high Vp/Vs ratios (>1.8), whereas the eastern side showed moderate or low Vp/Vs (<1.75). We interpreted this as an indication that high fluid pressures near the surface of the slab are contributing to the SSE activities. Within the toe of the mantle wedge, P and S wave velocities (<7.5 and <4.2 km/s, respectively) lower than those observed through normal mantle peridotite might suggest that some portions of the mantle may be at least 40% serpentinized.

  12. The seismic signatures of the solar system

    NASA Astrophysics Data System (ADS)

    Stähler, Simon C.; Kedar, Sharon; van Driel, Martin; Vance, Steven D.; Panning, Mark P.

    2017-04-01

    Seismology is a powerful tool to image the interior of planetary bodies. At the same time, its results are often difficult to visualize. The spectral-element solver AxiSEM (Nissen-Meyer et al. 2014) enables calculations of the broadband seismic response of terrestrial bodies with solid crusts and mantles, as well as icy moons with solid ice crusts overlying liquid oceans. In its database mode, Instaseis (van Driel et al. 2015), AxiSEM can efficiently calculate the seismic response for earthquakes at arbitrary distances and depths. We use this method to present a set of global stacks of seismograms, similar to the iconic global stack that Astiz and Shearer (1996) created for IRIS from thousands of seismograms on Earth. We present these stacks for models of Europa, Enceladus, Ganymede, Mercury, Venus, Moon and - for comparison - Earth. The results are based on thermodynamical modeling for the icy moons and orbital observations for the terrestrial planets. The results visualize how each planet and moon has its own unique seismic wavefield and which observables exist to infer its detailed structure by future lander missions. Astiz, L., P. Earle and P. Shearer, Global stacking of broadband seismograms, Seis. Res. Lett., 67, 8-18, 1996. M. van Driel, L. Krischer, S.C. Stähler, K. Hosseini, and T. Nissen-Meyer (2015), "Instaseis: instant global seismograms based on a broadband waveform database," Solid Earth, 6, 701-717, doi:10.5194/se-6-701-2015. Nissen-Meyer, T., van Driel, M., Stähler, S. C., Hosseini, K., Hempel, S., Auer, L., … Fournier, A. (2014). AxiSEM: broadband 3-D seismic wavefields in axisymmetric media. Solid Earth, 5(1), 425-445. https://doi.org/10.5194/se-5-425-2014

  13. Seismic Constraints on the Lithosphere-Asthenosphere Boundary Beneath the Izu-Bonin Area: Implications for the Oceanic Lithospheric Thinning

    NASA Astrophysics Data System (ADS)

    Cui, Qinghui; Wei, Rongqiang; Zhou, Yuanze; Gao, Yajian; Li, Wenlan

    2018-01-01

    The lithosphere-asthenosphere boundary (LAB) is the seismic discontinuity with negative velocity contrasts in the upper mantle. Seismic detections on the LAB are of great significance in understanding the plate tectonics, mantle convection and lithospheric evolution. In this paper, we study the LAB in the Izu-Bonin subduction zone using four deep earthquakes recorded by the permanent and temporary seismic networks of the USArray. The LAB is clearly revealed with sP precursors (sdP) through the linear slant stacking. As illustrated by reflected points of the identified sdP phases, the depth of LAB beneath the Izu-Bonin Arc (IBA) is about 65 km with a range of 60-68 km. The identified sdP phases with opposite polarities relative to sP phases have the average relative amplitude of 0.21, which means a 3.7% velocity drop and implies partial melting in the asthenosphere. On the basis of the crustal age data, the lithosphere beneath the IBA is located at the 1100 °C isotherm calculated with the GDH1 model. Compared to tectonically stable areas, such as the West Philippine Basin (WPB) and Parece Vela Basin (PVB) in the Philippine Sea, the lithosphere beneath the Izu-Bonin area shows the obvious lithospheric thinning. According to the geodynamic and petrological studies, the oceanic lithospheric thinning phenomenon can be attributed to the strong erosion of the small-scale convection in the mantle wedge enriched in volatiles and melts.

  14. Fault geometries illuminated from seismicity in central Taiwan: Implications for crustal scale structural boundaries in the northern Central Range

    NASA Astrophysics Data System (ADS)

    Gourley, Jonathan R.; Byrne, Timothy; Chan, Yu-Chang; Wu, Francis; Rau, Ruey-Juin

    2007-12-01

    Data sets of collapsed earthquake locations, earthquake focal mechanisms, GPS velocities and geologic data are integrated to constrain the geometry and kinematics of a crustal block within the accreted continental margin rocks of Taiwan's northeastern Central Range. This block is laterally extruding and exhuming towards the north-northeast. The block is bound on the west-southwest by the previously recognized Sanyi-Puli seismic zone and on the east by a vertical seismic structure that projects to the eastern mountain front of the Central Range. Focal mechanisms from the Broadband Array of Taiwan Seismicity (BATS) catalog consistently show west-side-up reverse displacements for this fault zone. A second vertical structure is recognized beneath the Slate Belt-Metamorphic Belt boundary as a post-Chi-Chi relaxation oblique normal fault. BATS focal mechanisms show east-side-up, normal displacements with a minor left-lateral component. The vertical and lateral extrusion of this crustal block may be driven by the current collision between the Philippine Sea Plate and the Puli basement high indenter on the Eurasian Plate and/or trench rollback along the Ryukyu subduction zone. In addition, the vertical extent of the two shear zones suggests that a basal décollement below the eastern Central Range is deeper than previously proposed and may extend below the brittle-ductile transition.

  15. Time-dependent boundary conditions for hyperbolic systems. II

    NASA Astrophysics Data System (ADS)

    Thompson, Kevin W.

    1990-08-01

    A general boundary condition formalism is developed for all types of boundary conditions to which hyperbolic systems are subject; the formalism makes possible a 'cookbook' approach to boundary conditions, by means of which novel boundary 'recipes' may be derived and previously devised ones may be consulted as required. Numerous useful conditions are derived for such CFD problems as subsonic and supersonic inflows and outflows, nonreflecting boundaries, force-free boundaries, constant pressure boundaries, and constant mass flux. Attention is given to the computation and integration of time derivatives.

  16. Time-dependent boundary conditions for hyperbolic systems. II

    NASA Technical Reports Server (NTRS)

    Thompson, Kevin W.

    1990-01-01

    A general boundary condition formalism is developed for all types of boundary conditions to which hyperbolic systems are subject; the formalism makes possible a 'cookbook' approach to boundary conditions, by means of which novel boundary 'recipes' may be derived and previously devised ones may be consulted as required. Numerous useful conditions are derived for such CFD problems as subsonic and supersonic inflows and outflows, nonreflecting boundaries, force-free boundaries, constant pressure boundaries, and constant mass flux. Attention is given to the computation and integration of time derivatives.

  17. Marine Seismic System At-Sea-Test Deployment Operation

    DTIC Science & Technology

    1981-10-09

    ton crane can handle deck loads. An early version Deloo type ASK ( Automatic Stationkeeping) system is used to maintain position over a deployed short...b --- 00 - Ir RPT 006-007EV "A 126283 [ I iMIIE SEISMIC SYSTEM I AT-SEA-TEST DEP OYiN OFERATION I GLOBAL MARINE DEVELOPMENT INC 2302 Martin Street...Seismic System At-Sea-Test Deployment Operation 6. PERFORNING *o. REPORT NUMOER IPT 006-007 7. AUTNMORI) O. CONTRACT Ol GRANT NUMOERIa iR. Wallerstedt

  18. Optimization of seismic isolation systems via harmony search

    NASA Astrophysics Data System (ADS)

    Melih Nigdeli, Sinan; Bekdaş, Gebrail; Alhan, Cenk

    2014-11-01

    In this article, the optimization of isolation system parameters via the harmony search (HS) optimization method is proposed for seismically 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 acceleration response of a seismically 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 seismic 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 seismic 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.

  19. Seismicity of the Indo-Australian/Solomon Sea Plate boundary in the Southeast Papua region

    NASA Astrophysics Data System (ADS)

    Ripper, I. D.

    1982-08-01

    Seismicity and earthquake focal mechanism plots of the Southeast Papua and Woodlark Basin region for the period January 1960 to May 1979 show that: (a) the West Woodlark Basin spreading centre extends from the deep West Woodlark Basin, through Dawson Strait into Goodenough Bay, Southeast Papua; (b) a southeast seismic trend in the West Woodlark Basin is associated with a left-lateral transform fault, but a gap exists between this zone and the seismic East Woodlark Basin spreading centre; (c) Southeast Papua Seismicity divides into a shallow earthquake zone in which the earthquakes occur mainly in the northeast side of the Owen Stanley Range, and an intermediate depth southwest dipping Benioff zone which extends almost from Mt. Lamington to Goroka. The Benioff zone indicates the presence of a southwest dipping slab of Solomon Sea Plate beneath the Indo-Australian Plate in the Southeast Papua and Ramu-Markham Valley region. This subduction zone has collided with the New Britain subduction zone of the Solomon Sea Plate along the Ramu-Markham Valley. The Solomon Sea Plate is now hanging suspended in the form of an arch beneath Ramu-Markham Valley, inhibiting further subduction beneath Southeast Papua.

  20. Seismic Fracture Characterization Methodologies for Enhanced Geothermal Systems

    SciTech Connect

    Queen, John H.

    2016-05-09

    Executive Summary The overall objective of this work was the development of surface and borehole seismic methodologies using both compressional and shear waves for characterizing faults and fractures in Enhanced Geothermal Systems. We used both surface seismic and vertical seismic profile (VSP) methods. We adapted these methods to the unique conditions encountered in Enhanced Geothermal Systems (EGS) creation. These conditions include geological environments with volcanic cover, highly altered rocks, severe structure, extreme near surface velocity contrasts and lack of distinct velocity contrasts at depth. One of the objectives was the development of methods for identifying more appropriate seismic acquisition parametersmore » for overcoming problems associated with these geological factors. Because temperatures up to 300º C are often encountered in these systems, another objective was the testing of VSP borehole tools capable of operating at depths in excess of 1,000 m and at temperatures in excess of 200º C. A final objective was the development of new processing and interpretation techniques based on scattering and time-frequency analysis, as well as the application of modern seismic migration imaging algorithms to seismic data acquired over geothermal areas. The use of surface seismic reflection data at Brady's Hot Springs was found useful in building a geological model, but only when combined with other extensive geological and geophysical data. The use of fine source and geophone spacing was critical in producing useful images. The surface seismic reflection data gave no information about the internal structure (extent, thickness and filling) of faults and fractures, and modeling suggests that they are unlikely to do so. Time-frequency analysis was applied to these data, but was not found to be significantly useful in their interpretation. Modeling does indicate that VSP and other seismic methods with sensors located at depth in wells will be the most

  1. Improved Seismic Acquisition System and Data Processing for the Italian National Seismic Network

    NASA Astrophysics Data System (ADS)

    Badiali, L.; Marcocci, C.; Mele, F.; Piscini, A.

    2001-12-01

    A new system for acquiring and processing digital signals has been developed in the last few years at the Istituto Nazionale di Geofisica e Vulcanologia (INGV). The system makes extensive use of the internet communication protocol standards such as TCP and UDP which are used as the transport highway inside the Italian network, and possibly in a near future outside, to share or redirect data among processes. The Italian National Seismic Network has been working for about 18 years equipped with vertical short period seismometers and transmitting through analog lines, to the computer center in Rome. We are now concentrating our efforts on speeding the migration towards a fully digital network based on about 150 stations equipped with either broad band or 5 seconds sensors connected to the data center partly through wired digital communication and partly through satellite digital communication. The overall process is layered through intranet and/or internet. Every layer gathers data in a simple format and provides data in a processed format, ready to be distributed towards the next layer. The lowest level acquires seismic data (raw waveforms) coming from the remote stations. It handshakes, checks and sends data in LAN or WAN according to a distribution list where other machines with their programs are waiting for. At the next level there are the picking procedures, or "pickers", on a per instrument basis, looking for phases. A picker spreads phases, again through the LAN or WAN and according to a distribution list, to one or more waiting locating machines tuned to generate a seismic event. The event locating procedure itself, the higher level in this stack, can exchange information with other similar procedures. Such a layered and distributed structure with nearby targets allows other seismic networks to join the processing and data collection of the same ongoing event, creating a virtual network larger than the original one. At present we plan to cooperate with other

  2. Korea Integrated Seismic System tool(KISStool) for seismic monitoring and data sharing at the local data center

    NASA Astrophysics Data System (ADS)

    Park, J.; Chi, H. C.; Lim, I.; Jeong, B.

    2011-12-01

    The Korea Integrated Seismic System(KISS) is a back-bone seismic network which distributes seismic data to different organizations in near-real time at Korea. The association of earthquake monitoring institutes has shared their seismic data through the KISS from 2003. Local data centers operating remote several stations need to send their free field seismic data to NEMA(National Emergency Management Agency) by the law of countermeasure against earthquake hazard in Korea. It is very important the efficient tool for local data centers which want to rapidly detect local seismic intensity and to transfer seismic event information toward national wide data center including PGA, PGV, dominant frequency of P-wave, raw data, and etc. We developed the KISStool(Korea Integrated Seismic System tool) for easy and convenient operation seismic network in local data center. The KISStool has the function of monitoring real time waveforms by clicking station icon on the Google map and real time variation of PGA, PGV, and other data by opening the bar type monitoring section. If they use the KISStool, any local data center can transfer event information to NEMA(National Emergency Management Agency), KMA(Korea Meteorological Agency) or other institutes through the KISS using UDP or TCP/IP protocols. The KISStool is one of the most efficient methods to monitor and transfer earthquake event at local data center in Korea. KIGAM will support this KISStool not only to the member of the monitoring association but also local governments.

  3. New insights into the kinematics and seismotectonics of the Adria-Eurasia boundary in the eastern Alps from geodetic and seismic data

    NASA Astrophysics Data System (ADS)

    Serpelloni, Enrico; Vannucci, Gianfranco; Bennett, Richard A.; Anderlini, Letizia; Cavaliere, Adriano

    2015-04-01

    In this work we describe a new kinematic and seismotectonic model of the eastern Alps, at the boundary between Italy, Austria, Slovenia and Croatia, obtained from the analysis of geodetic (GPS) and seismological data. We use a dense GPS velocity field, obtained from integration of continuous, semi-continuous and survey-mode networks (~200 GPS stations between longitude 10°E and 17°E and latitude 44.5°N and 47.5°N) and an updated seismic and focal mechanisms catalogue, with uniformly calibrated moment magnitudes from ~1000 B.C.. Improved accuracies and precisions of GPS motion rates have been obtained by filtering displacement time-series for the spatially correlated common mode errors. The eastern Alps mark the boundary between the Adriatic microplate and the Eurasian plate through a wide zone of distributed deformation. Geodetic deformation and seismic release are more localized, and characterized by larger earthquakes, along the southeastern Alps fold-and-thrust belt, which accommodates the large part of the ~N-S Adria-Eurasia convergence, and in Slovenia, where a transition from ~N-S shortening to the eastward escape of the Pannonian Basin units occurs through a complex pattern of crustal deformation. GPS velocities well describe the overall kinematics, with a transition from NNW-ward to NE-ward motion trends (in a Eurasian frame) across Slovenia and Austria, but also show small but significant crustal deformation far from the major blocks boundaries. This may suggest internal continuous deformation or a more complex configuration of interacting tectonic blocks in the eastern Alps. This second hypothesis is taken into account and tested in this work. We use seismic moment release rate maps, active faults databases and inspections of GPS velocities in different local frames to define the geometry of a kinematic block model, constrained by GPS horizontal velocities, in order to estimate blocks rotations and elastic strain at blocks bounding faults. The

  4. Areal distribution of sedimentary facies determined from seismic facies analysis and models of modern depositional systems

    SciTech Connect

    Seramur, K.C.; Powell, R.D.; Carpenter, P.J.

    1988-01-01

    Seismic facies analysis was applied to 3.5-kHz single-channel analog reflection profiles of the sediment fill within Muir Inlet, Glacier Bay, southeast Alaska. Nine sedimentary facies have been interpreted from seven seismic facies identified on the profiles. The interpretations are based on reflection characteristics and structural features of the seismic facies. The following reflection characteristics and structural features are used: reflector spacing, amplitude and continuity of reflections, internal reflection configurations, attitude of reflection terminations at a facies boundary, body geometry of a facies, and the architectural associations of seismic facies within each basin. The depositional systems are reconstructed by determining themore » paleotopography, bedding patterns, sedimentary facies, and modes of deposition within the basin. Muir Inlet is a recently deglaciated fjord for which successive glacier terminus positions and consequent rates of glacial retreat are known. In this environment the depositional processes and sediment characteristics vary with distance from a glacier terminus, such that during a retreat a record of these variations is preserved in the aggrading sediment fill. Sedimentary facies within the basins of lower Muir Inlet are correlated with observed depositional processes near the present glacier terminus in the upper inlet.« less

  5. Structure of the Lithosphere-Asthenosphere Boundary Onshore and Offshore the California Continental Margin from Three-Dimensional Seismic Anisotropy

    NASA Astrophysics Data System (ADS)

    Gomez, C. D.; Escobar, L., Sr.; Rathnayaka, S.; Weeraratne, D. S.; Kohler, M. D.

    2016-12-01

    The California continental margin, a major transform plate boundary in continental North America, is the locus of complex tectonic stress fields that are important in interpreting both remnant and ongoing deformational strain. Ancient subduction of the East Pacific Rise spreading center, the rotation and translation of tectonic blocks and inception of the San Andreas fault all contribute to the dynamic stress fields located both onshore and offshore southern California. Data obtained by the ALBACORE (Asthenospheric and Lithospheric Broadband Architecture from the California Offshore Region Experiment) and the CISN (California Integrated Seismic Network) seismic array are analyzed for azimuthal anisotropy of Rayleigh waves from 80 teleseismic events at periods 16 - 78 s. Here we invert Rayleigh wave data for shear wave velocity structure and three-dimensional seismic anisotropy in the thee regions designated within the continental margin including the continent, seafloor and California Borderlands. Preliminary results show that seismic anisotropy is resolved in multiple layers and can be used to determine the lithosphere-asthenosphere boundary (LAB) in offshore and continental regions. The oldest seafloor in our study at age 25-35 Ma indicates that the anisotropic transition across the LAB occurs at 73 km +/- 25 km with the lithospheric fast direction oriented WNW-ESE, consistent with current Pacific plate motion direction. The continent region west of the San Andreas indicates similar WNW-ESE anisotropy and LAB depth. Regions east of the San Andreas fault indicate NW-SE anisotropy transitioning to a N-S alignment at 80 km depth north of the Garlock fault. The youngest seafloor (15 - 25 Ma) and outer Borderlands indicate a more complex three layer fabric where shallow lithospheric NE-SW fast directions are perpendicular with ancient Farallon subduction arc, a mid-layer with E-W fast directions are perpendicular to remnant fossil fabric, and the deepest layer

  6. The Seismic Alert System of Mexico (SASMEX): Performance and Evolution

    NASA Astrophysics Data System (ADS)

    Espinosa Aranda, J.

    2013-05-01

    Originally the Seismic Alert System of Mexico (SASMEX) was proposed to integrate the Seismic Alert System of Mexico City (SAS), operating since 1991, with the Seismic Alert System of Oaxaca City (SASO), in services since 2003. And today, after the intense big earthquake activity observed in our world during 2010 and 2011, local governments of Mexico City, Oaxaca Estate, and the Mexican Ministry of the Interior have been promoting the expansion of this technological EEW development. Until 2012 SASMEX better coverage includes 48 new field seismic sensors (FS) deployed over the seismic region of Jalisco, Colima, Michoacan and Puebla, with someone enhancements over Guerrero and Oaxaca, to reach 97 FS. During 2013, 35 new FS has been proposed to SASMEX enhancements covering the Chiapas and Veracruz seismic regions. The SASMEX, with the support of the Mexico Valley Broadcasters Association (ARVM) since 1993, automatically issue Public and Preventive earthquake early warning signals in the Cities of Mexico, Toluca, Acapulco, Chilpancingo, and Oaxaca. The seismic warning range in each case is seated in accordance with local Civil Protection Authorities: Public Alert, if they expect strong earthquake effects, and Preventive Alert one, the effect could be moderated. Now the SASMEX warning time opportunity could be different to the 60 sec. average typically generated when SAS warned earthquake effects coming from Guerrero to Mexico City valley. Mexican EEW issued today reach: 16 Public and 62 Preventive Alert in Mexico City; 25 Public and 19 Preventive Alerts in Oaxaca City; also 14 Public and 4 Preventive Alerts in Acapulco; 14 Public and 5 Preventive Alerts in Chilpancingo. The earthquakes events registered by SASMEX FS until now reach 3448. With the support of private and Federal telecommunications infrastructure like, TELMEX, Federal Electric Commission, and the Mexican Security Ministry, it was developed a redundant communication system with pads to link the different

  7. Noise analysis of the seismic system employed in the northern and southern California seismic nets

    USGS Publications Warehouse

    Eaton, J.P.

    1984-01-01

    The seismic networks have been designed and operated to support recording on Develocorders (less than 40db dynamic range) and analog magnetic tape (about 50 db dynamic range). The principal analysis of the records has been based on Develocorder films; and background earth noise levels have been adjusted to be about 1 to 2 mm p-p on the film readers. Since the traces are separated by only 10 to 12 mm on the reader screen, they become hopelessly tangled when signal amplitudes on several adjacent traces exceed 10 to 20 mm p-p. Thus, the background noise level is hardly more than 20 db below the level of largest readable signals. The situation is somewhat better on tape playbacks, but the high level of background noise set to accomodate processing from film records effectively limits the range of maximum-signal to background-earth-noise on high gain channels to a little more than 30 db. Introduction of the PDP 11/44 seismic data acquisition system has increased the potential dynamic range of recorded network signals to more than 60 db. To make use of this increased dynamic range we must evaluate the characteristics and performance of the seismic system. In particular, we must determine whether the electronic noise in the system is or can be made sufficiently low so that background earth noise levels can be lowered significantly to take advantage of the increased dynamic range of the digital recording system. To come to grips with the complex problem of system noise, we have carried out a number of measurements and experiments to evaluate critical components of the system as well as to determine the noise characteristics of the system as a whole.

  8. A seismicity boundary in the low-strain region of Alentejo, south Portugal

    NASA Astrophysics Data System (ADS)

    Matos, Catarina; Zahradník, Jirí; Arroucau, Pierre; Silveira, Graça; Custódio, Susana

    2017-04-01

    Mainland Portugal lays on a stable continental setting characterized by low strain rates (convergence velocities < 1 mm/yr). However, the region has been the source of documented moderate magnitude earthquakes. The Alentejo region (south Portugal) presents belts of high epicenter density, the two main ones being (1) the Viana do Alentejo cluster in the south and (2) the NW-SE oriented Arraiolos alignment in the north. The latter appears as a sharp transition between a nearly aseismic area to the north and a seismically active area to the south. Active fault studies based on geological observations have not identified tectonic features able to explain the observed seismicity patterns. Our objective is to contribute to the understanding of the deformation pattern in south Portugal. Several hypotheses need to be addressed: (1) Are those clusters the expression of a broad region of distributed deformation?; (2) Do they mark structures that might have the potential to generate moderate magnitude events? We use a high-quality dataset recorded by a temporary array deployed in the area to produce a robust image of earthquake locations and to compute focal mechanisms. Newly detected events match well the previously identified earthquake alignments. The local network provides good control of the focal depths. We observe a spatial variation in the depth distribution. The Arraiolos alignment seems to produce deeper earthquakes than the Viana do Alentejo cluster. Earthquake locations inferred using 1D and 3D velocity models show a persistent concentration of seismicity at middle to lower crust depths (15 - 30 km) in the SE section of that alignment. We also present relocation of instrumental seismicity for the period (1970-2016). Previous studies show that a strike-slip faulting regime dominates mainland Portugal. IPMA (Instituto Português do Mar e da Atmosfera) routinely computes focal mechanisms for earthquakes with reported local magnitudes of 3.5 or greater using the

  9. Significant earthquakes on the Enriquillo fault system, Hispaniola, 1500-2010: Implications for seismic hazard

    USGS Publications Warehouse

    Bakun, William H.; Flores, Claudia H.; ten Brink, Uri S.

    2012-01-01

    Historical records indicate frequent seismic activity along the north-east Caribbean plate boundary over the past 500 years, particularly on the island of Hispaniola. We use accounts of historical earthquakes to assign intensities and the intensity assignments for the 2010 Haiti earthquakes to derive an intensity attenuation relation for Hispaniola. The intensity assignments and the attenuation relation are used in a grid search to find source locations and magnitudes that best fit the intensity assignments. Here we describe a sequence of devastating earthquakes on the Enriquillo fault system in the eighteenth century. An intensity magnitude MI 6.6 earthquake in 1701 occurred near the location of the 2010 Haiti earthquake, and the accounts of the shaking in the 1701 earthquake are similar to those of the 2010 earthquake. A series of large earthquakes migrating from east to west started with the 18 October 1751 MI 7.4–7.5 earthquake, probably located near the eastern end of the fault in the Dominican Republic, followed by the 21 November 1751 MI 6.6 earthquake near Port-au-Prince, Haiti, and the 3 June 1770 MI 7.5 earthquake west of the 2010 earthquake rupture. The 2010 Haiti earthquake may mark the beginning of a new cycle of large earthquakes on the Enriquillo fault system after 240 years of seismic quiescence. The entire Enriquillo fault system appears to be seismically active; Haiti and the Dominican Republic should prepare for future devastating earthquakes.

  10. Seismic Design of ITER Component Cooling Water System-1 Piping

    NASA Astrophysics Data System (ADS)

    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.

    2017-04-01

    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 seismic accelerations; 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 Seismic 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 seismic event.

  11. Identifying Conventionally Sub-Seismic Faults in Polygonal Fault Systems

    NASA Astrophysics Data System (ADS)

    Fry, C.; Dix, J.

    2017-12-01

    Polygonal Fault Systems (PFS) are prevalent in hydrocarbon basins globally and represent potential fluid pathways. However the characterization of these pathways is subject to the limitations of conventional 3D seismic imaging; only capable of resolving features on a decametre scale horizontally and metres scale vertically. While outcrop and core examples can identify smaller features, they are limited by the extent of the exposures. The disparity between these scales can allow for smaller faults to be lost in a resolution gap which could mean potential pathways are left unseen. Here the focus is upon PFS from within the London Clay, a common bedrock that is tunnelled into and bears construction foundations for much of London. It is a continuation of the Ieper Clay where PFS were first identified and is found to approach the seafloor within the Outer Thames Estuary. This allows for the direct analysis of PFS surface expressions, via the use of high resolution 1m bathymetric imaging in combination with high resolution seismic imaging. Through use of these datasets surface expressions of over 1500 faults within the London Clay have been identified, with the smallest fault measuring 12m and the largest at 612m in length. The displacements over these faults established from both bathymetric and seismic imaging ranges from 30cm to a couple of metres, scales that would typically be sub-seismic for conventional basin seismic imaging. The orientations and dimensions of the faults within this network have been directly compared to 3D seismic data of the Ieper Clay from the offshore Dutch sector where it exists approximately 1km below the seafloor. These have typical PFS attributes with lengths of hundreds of metres to kilometres and throws of tens of metres, a magnitude larger than those identified in the Outer Thames Estuary. The similar orientations and polygonal patterns within both locations indicates that the smaller faults exist within typical PFS structure but are

  12. Seismic and infrasonic source processes in volcanic fluid systems

    NASA Astrophysics Data System (ADS)

    Matoza, Robin S.

    Volcanoes exhibit a spectacular diversity in fluid oscillation processes, which lead to distinct seismic and acoustic signals in the solid earth and atmosphere. Volcano seismic waveforms contain rich information on the geometry of fluid migration, resonance effects, and transient and sustained pressure oscillations resulting from unsteady flow through subsurface cracks, fissures and conduits. Volcanic sounds contain information on shallow fluid flow, resonance in near-surface cavities, and degassing dynamics into the atmosphere. Since volcanoes have large spatial scales, the vast majority of their radiated atmospheric acoustic energy is infrasonic (<20 Hz). This dissertation presents observations from joint broadband seismic and infrasound array deployments at Mount St. Helens (MSH, Washington State, USA), Tungurahua (Ecuador), and Kilauea Volcano (Hawaii, USA), each providing data for several years. These volcanoes represent a broad spectrum of eruption styles ranging from hawaiian to plinian in nature. The catalogue of recorded infrasonic signals includes continuous broadband and harmonic tremor from persistent degassing at basaltic lava vents and tubes at Pu'u O'o (Kilauea), thousands of repetitive impulsive signals associated with seismic longperiod (0.5-5 Hz) events and the dynamics of the shallow hydrothermal system at MSH, rockfall signals from the unstable dacite dome at MSH, energetic explosion blast waves and gliding infrasonic harmonic tremor at Tungurahua volcano, and large-amplitude and long-duration broadband signals associated with jetting during vulcanian, subplinian and plinian eruptions at MSH and Tungurahua. We develop models for a selection of these infrasonic signals. For infrasonic long-period (LP) events at MSH, we investigate seismic-acoustic coupling from various buried source configurations as a means to excite infrasound waves in the atmosphere. We find that linear elastic seismic-acoustic transmission from the ground to atmosphere is

  13. A Methodology for Assessing the Seismic Vulnerability of Highway Systems

    SciTech Connect

    Cirianni, Francis; Leonardi, Giovanni; Scopelliti, Francesco

    2008-07-08

    Modern society is totally dependent on a complex and articulated infrastructure network of vital importance for the existence of the urban settlements scattered on the territory. On these infrastructure systems, usually indicated with the term lifelines, are entrusted numerous services and indispensable functions of the normal urban and human activity.The systems of the lifelines represent an essential element in all the urbanised areas which are subject to seismic risk. It is important that, in these zones, they are planned according to opportune criteria based on two fundamental assumptions: a) determination of the best territorial localization, avoiding, within limits, the placesmore » of higher dangerousness; b) application of constructive technologies finalized to the reduction of the vulnerability.Therefore it is indispensable that in any modern process of seismic risk assessment the study of the networks is taken in the rightful consideration, to be integrated with the traditional analyses of the buildings.The present paper moves in this direction, dedicating particular attention to one kind of lifeline: the highway system, proposing a methodology of analysis finalized to the assessment of the seismic vulnerability of the system.« less

  14. Real-time Seismic Alert System of NIED

    NASA Astrophysics Data System (ADS)

    Horiuchi, S.; Fujinawa, Y.; Negishi, H.; Matsumoto, T.; Fujiwara, H.; Kunugi, T.; Hayashi, Y.

    2001-12-01

    An extensive seismic network has been constructed nationwide composed of hi-sensitivity seismographic network, broadband seismographic network and strong motion seismographic network. All these data from some 3,000 sites belonging to NIED, JMA and universities are to be accumulated and distributed through NIED to any scientists and engineering through INTERNET under the coordination of the National Seismic Research Committee of MEXT. As a practical application of those data we are now developing a real-time seismic alert information system for the purpose of providing short-term warning of imminent strong grounds motions from major earthquakes from several seconds to a few days. The contents of information are seismic focal parameters (several seconds), seismic fault plane solutions (some 10 seconds), after-shock activities (several minutes-a few days ). The fundamental fault parameters are used to build specific information at sites for particular users for use of triggering automated and /or half-automated responses. The most important application is an immediate estimate of expected shaking distribution and damages in a district using synthetic database and site effects for local governments to initial proper measures of hazard mitigation. Another application is estimation of arrival time and shaking strength at any individual site for human lives to be safeguarded. The system could also start an automatic electrical isolation and protection of computer systems, protection of hazardous chronic systems, transportation systems and so on. The information are corrected successively as seismic ground motion are received at a larger number of sites in time with the result that more accurate and more sophisticated earthquake information is transmitted to any user. Besides the rapid determination of seismic parameters, one of essential items in this alert system is the data transmission means. The data transmission is chosen to assure negligibly small delay of data

  15. Seismic isolation systems with distinct multiple frequencies

    DOEpatents

    Wu, Ting-shu; Seidensticker, Ralph W.

    1990-01-01

    A method and apparatus for isolating a building or other structure from smic vibratory motion which provides increased assurance that large horizontal motion of the structure will not occur than is provided by other isolation systems. Increased assurance that large horizontal motion will not occur is achieved by providing for change of the natural frequency of the support and structure system in response to displacement of the structure beyond a predetermined value. The natural frequency of the support and structure system may be achieved by providing for engaging and disengaging of the structure and some supporting members in response to motion of the supported structure.

  16. Bed load transport and boundary roughness changes as competing causes of hysteresis in the relationship between river discharge and seismic amplitude recorded near a steep mountain stream

    NASA Astrophysics Data System (ADS)

    Roth, Danica L.; Finnegan, Noah J.; Brodsky, Emily E.; Rickenmann, Dieter; Turowski, Jens M.; Badoux, Alexandre; Gimbert, Florent

    2017-05-01

    Hysteresis in the relationship between bed load transport and river stage is a well-documented phenomenon with multiple known causes. Consequently, numerous studies have interpreted hysteresis in the relationship between seismic ground motion near rivers and some measure of flow strength (i.e., discharge or stage) as the signature of bed load transport. Here we test this hypothesis in the Erlenbach stream (Swiss Prealps) using a metric to quantitatively compare hysteresis in seismic data with hysteresis recorded by geophones attached beneath steel plates within the streambed, a well-calibrated proxy for direct sediment transport measurements. We find that while both the geophones and seismometers demonstrate hysteresis, the magnitude and direction of hysteresis are not significantly correlated between these data, indicating that the seismic signal at this site is primarily reflecting hysteresis in processes other than sediment transport. Seismic hysteresis also does not correlate significantly with the magnitude of sediment transport recorded by the geophones, contrary to previous studies' assumptions. We suggest that hydrologic sources and changes in water turbulence, for instance due to evolving boundary conditions at the bed, rather than changes in sediment transport rates, may sometimes contribute to or even dominate the hysteresis observed in seismic amplitudes near steep mountain rivers.Plain Language SummaryAn increasing number of studies have recently observed changes in the amount of <span class="hlt">seismic</span> shaking (hysteresis) recorded near a river at a given discharge during floods. Most studies have assumed that this hysteresis was caused by changes in the amount of sediment being transported in the river and have therefore used the hysteresis to assess sediment transport rates and patterns. We examine concurrent <span class="hlt">seismic</span> and sediment transport data from a steep mountain stream in the Swiss Prealps and find that changes in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.T43A2294V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.T43A2294V"><span>Electromagnetic, <span class="hlt">seismic</span> and petro-physical investigations of the lithosphere-asthenosphere <span class="hlt">boundary</span> in central Tibet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vozar, J.; Fullea, J.; Jones, A. G.; Agius, M. R.; Lebedev, S.</p> <p>2011-12-01</p> <p> beneath Central Lhasa terrane S-velocities are close to global-average values. We perform the integrated petro-physical modeling of MT and surface-wave data using the software package LitMod. The program facilitates definition of realistic temperature and pressure distributions within the upper mantle, and characterizes the mineral assemblages given bulk chemical compositions as well as water content. This allows us to firstly define a bulk geoelectric and <span class="hlt">seismic</span> model of the upper mantle based on laboratory and xenolith data for the most relevant mantle minerals, and secondly to compute synthetic geophysical observables that are compared with measured data (i.e., MT responses, surface-wave dispersion curves, topography, and surface heat flow). Our preliminary results suggest an 80-120 km-thick, dry lithosphere in the central part of the Qiangtang Terrane. In the central Lhasa Terrane the data can be explained by a relatively warm 100-120 km-thick Tibetian lithosphere underlain by an 80-120-km-thick Indian lithosphere. The mid-lower crust in Lhasa shows strong <span class="hlt">seismic</span> and electric anisotropy, with a predominant E-W oriented high velocity/conductivity axis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990008176','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990008176"><span>Global <span class="hlt">Seismicity</span>: Three New Maps Compiled with Geographic Information <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lowman, Paul D., Jr.; Montgomery, Brian C.</p> <p>1996-01-01</p> <p>This paper presents three new maps of global <span class="hlt">seismicity</span> compiled from NOAA digital data, covering the interval 1963-1998, with three different magnitude ranges (mb): greater than 3.5, less than 3.5, and all detectable magnitudes. A commercially available geographic information <span class="hlt">system</span> (GIS) was used as the database manager. Epicenter locations were acquired from a CD-ROM supplied by the National Geophysical Data Center. A methodology is presented that can be followed by general users. The implications of the maps are discussed, including the limitations of conventional plate models, and the different tectonic behavior of continental vs. oceanic lithosphere. Several little-known areas of intraplate or passive margin <span class="hlt">seismicity</span> are also discussed, possibly expressing horizontal compression generated by ridge push.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMDI13C..04C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMDI13C..04C"><span>Near-Melting Condition of the Inner Core <span class="hlt">Boundary</span> Revealed from Antipodal <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>Cormier, V. F.; Attanayake, J.; de Silva, S. M. S.; Miller, M. S.; Thomas, C.</p> <p>2014-12-01</p> <p>First-principles calculations1 have suggested that the inner core's low shear velocity (3.5 km/sec) is a consequence of its temperature being very close to its melting temperature throughout its volume. Near the inner core's freezing or melting <span class="hlt">boundary</span>, the shear modulus could possibly approach zero. A test of this is made from observations of the amplitude of PKIIKP waves at antipodal (>175o) ranges. These underside reflections are very sensitive to the S velocity beneath the inner core <span class="hlt">boundary</span> due to energy subtracted from PKIIKP by converted S energy. This sensitivity is exploited by modeling PKIIKP waveforms observed by a transportable array in Morocco, which recorded many high-quality antipodal waveforms from Tonga. Differences in the in the sampling of the upper inner core between PKIIKP arriving from the short (<180o) and long (>180o) distances make it feasible to investigate lateral differences in the elastic and anelastic states of uppermost inner core from the amplitude and frequency content of the waveforms. In computational experiments, we show that a zero or small shear modulus in the uppermost inner core is the most effective way of matching large amplitude PKIIKP's observed from antipodal paths from Tonga to Morocco. The correlation of this bright spot in the PKIIKP reflection with a thin zone of low P velocity identified from multi-pathed PKIKP waves sampling a portion of the equatorial eastern hemisphere2suggests that at least this region of the inner core is near its melting temperature. Waveform modeling of PKIKP and PKIIKP from the combined effects of viscoelasticity and forward scattering is performed to determine whether this region of low shear modulus is consistent with freezing or melting. 1Martorell, B., L. Vocadlo, J.P. Brodholt, and I.G.Wood, (2013) Science, 342 (6157), doi: 10.1126/science.1243651. 2Stroujkova, A., and V.F. Cormier (2004), J. Geophys. Res., 109(B10), doi:10.1029/2004JB002976.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PEPI..101..189S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PEPI..101..189S"><span><span class="hlt">Seismic</span> velocities at the core-mantle <span class="hlt">boundary</span> inferred from P waves diffracted around the core</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sylvander, Matthieu; Ponce, Bruno; Souriau, Annie</p> <p>1997-05-01</p> <p>The very base of the mantle is investigated with core-diffracted P-wave (P diff) travel times published by the International Seismological Centre (ISC) for the period 1964-1987. Apparent slownesses are computed for two-station profiles using a difference method. As the short-period P diff mostly sample a very thin layer above the core-mantle <span class="hlt">boundary</span> (CMB), a good approximation of the true velocity structure at the CMB can be derived from the apparent slownesses. More than 27000 profiles are built, and this provides an unprecedented P diff sampling of the CMB. The overall slowness distribution has an average value of 4.62 s/deg, which corresponds to a velocity more than 4% lower than that of most mean radial models. An analysis of the residuals of absolute ISC P and P diff travel times is independently carried out and confirms this result. It also shows that the degree of heterogeneities is significantly higher at the CMB than in the lower mantle. A search for lateral velocity variations is then undertaken; a first large-scale investigation reveals the presence of coherent slowness anomalies of very large dimensions of the order of 3000 km at the CMB. A tomographic inversion is then performed, which confirms the existence of pronounced (±8-10%) lateral velocity variations and provides a reliable map of the heterogeneities in the northern hemisphere. The influence of heterogeneity in the overlying mantle, of noise in the data and of CMB topography is evaluated; it seemingly proves minor compared with the contribution of heterogeneities at the CMB. Our results support the rising idea of a thin, low-velocity laterally varying <span class="hlt">boundary</span> layer at the base of the D″ layer. The two principal candidate interpretations are the occurrence of partial melting, or the presence of a chemically distinct layer, featuring infiltrated core material.</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('http://adsabs.harvard.edu/abs/2012AGUFM.T43F2756G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.T43F2756G"><span>Structural and Tectonic Map Along the Pacific-North America Plate <span class="hlt">Boundary</span> in Northern Gulf of California, Sonora Desert and Valle de Mexicali, Mexico, from <span class="hlt">Seismic</span> Reflection Evidence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gonzalez-Escobar, M.; Suarez-Vidal, F.; Mendoza-Borunda, R.; Martin Barajas, A.; Pacheco-Romero, M.; Arregui-Estrada, S.; Gallardo-Mata, C.; Sanchez-Garcia, C.; Chanes-Martinez, J.</p> <p>2012-12-01</p> <p>Between 1978 and 1983, Petróleos Mexicanos (PEMEX) carried on an intense exploration program in the northern Gulf of California, the Sonora Desert and the southern part of the Mexicali Valley. This program was supported by a <span class="hlt">seismic</span> reflection field operation. The collected <span class="hlt">seismic</span> data was 2D, with travel time of 6 s recording, in 48 channels, and the source energy was: dynamite, vibroseis and air guns. Since 2007 to present time, the existing <span class="hlt">seismic</span> data has been re-processing and ire-interpreting as part of a collaboration project between the PEMEX's Subdirección de Exploración (PEMEX) and CICESE. The study area is located along a large portion of the Pacific-North America plate <span class="hlt">boundary</span> in the northern Gulf of California and the Southern part of the Salton Trough tectonic province (Mexicali Valley). We present the result of the processes reflection <span class="hlt">seismic</span> lines. Many of the previous reported known faults were identify along with the first time described located within the study region. We identified regions with different degree of tectonic activity. In structural map it can see the location of many of these known active faults and their associated <span class="hlt">seismic</span> activity, as well as other structures with no associated <span class="hlt">seismicity</span>. Where some faults are mist placed they were deleted or relocated based on new information. We included historical <span class="hlt">seismicity</span> for the region. We present six reflection lines that cross the aftershocks zone of the El Mayor-Cucapah earthquake of April 4, 2010 (Mw7.2). The epicenter of this earthquake and most of the aftershocks are located in a region where pervious to this earthquake no major earthquakes are been reported. A major result of this study is to demonstrate that there are many buried faults that increase the <span class="hlt">seismic</span> hazard.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/871758','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/871758"><span>Compact chemical energy <span class="hlt">system</span> for <span class="hlt">seismic</span> applications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Engelke, Raymond P.; Hedges, Robert O.; Kammerman, Alan B.; Albright, James N.</p> <p>1998-01-01</p> <p>A chemical energy <span class="hlt">system</span> is formed for producing detonations in a confined environment. An explosive mixture is formed from nitromethane (NM) and diethylenetriamine (DETA). A slapper detonator is arranged adjacent to the explosive mixture to initiate detonation of the mixture. NM and DETA are not classified as explosives when handled separately and can be safely transported and handled by workers in the field. In one aspect of the present invention, the chemicals are mixed at a location where an explosion is to occur. For application in a confined environment, the chemicals are mixed in an inflatable container to minimize storage space until it is desired to initiate an explosion. To enable an inflatable container to be used, at least 2.5 wt % DETA is used in the explosive mixture. A barrier is utilized that is formed of a carbon composite material to provide the appropriate barrel geometry and energy transmission to the explosive mixture from the slapper detonator <span class="hlt">system</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4180896','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4180896"><span>Evaluation of <span class="hlt">Seismic</span> Performance and Effectiveness of Multiple Slim-Type Damper <span class="hlt">System</span> for <span class="hlt">Seismic</span> Response Control of Building Structures</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kim, David; Sung, Eun Hee; Park, Kwan-Soon; Park, Jaegyun</p> <p>2014-01-01</p> <p>This paper presents the evaluation of <span class="hlt">seismic</span> performance and cost-effectiveness of a multiple slim-type damper <span class="hlt">system</span> developed for the vibration control of earthquake excited buildings. The multiple slim-type damper (MSD) that consists of several small slim-type dampers and linkage units can control damping capacity easily by changing the number of small dampers. To evaluate the performance of the MSD, dynamic loading tests are performed with three slim-type dampers manufactured at a real scale. Numerical simulations are also carried out by nonlinear time history analysis with a ten-story earthquake excited building structure. The <span class="hlt">seismic</span> performance and cost-effectiveness of the MSD <span class="hlt">system</span> are investigated according to the various installation configurations of the MSD <span class="hlt">system</span>. From the results of numerical simulation and cost-effectiveness evaluation, it is shown that combinations of the MSD <span class="hlt">systems</span> can effectively improve the <span class="hlt">seismic</span> performance of earthquake excited building structures. PMID:25301387</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024428','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024428"><span>Global significance of a sub-Moho <span class="hlt">boundary</span> layer (SMBL) deduced from high-resolution <span class="hlt">seismic</span> observations</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fuchs, K.; Tittgemeyer, M.; Ryberg, T.; Wenzel, F.; Mooney, W.</p> <p>2002-01-01</p> <p>We infer the fine structure of a sub-Moho <span class="hlt">boundary</span> layer (SMBL) at the top of the lithospheric mantle from high-resolution <span class="hlt">seismic</span> observations of Peaceful Nuclear Explosions (PNE) on superlong-range profiles in Russia. Densely recorded seismograms permit recognition of previously unknown features of teleseismic propagation of the well known Pn and Sn phases, such as a band of incoherent, scattered, high-frequency <span class="hlt">seismic</span> energy, developing consistently from station to station, apparent velocities of sub-Moho material, and high-frequency energy to distances of more than 3000 km with a coda band, incoherent at 10 km spacing and yet consistently observed to the end of the profiles. Estimates of the other key elements of the SMBL were obtained by finite difference calculations of wave propagation in elastic 2D models from a systematic grid search through parameter space. The SMBL consists of randomly distributed, mild velocity fluctuations of 2% or schlieren of high aspect ratios (???40) with long horizontal extent (???20 km) and therefore as thin as 0.5 km only; SMBL thickness is 60-100 km. It is suggested that the SMBL is of global significance as the physical base of the platewide observed high-frequency phases Pn and Sn. It is shown that wave propagation in the SMBL waveguide is insensitive to the background velocity distribution on which its schlieren are superimposed. This explains why the Pn and Sn phases traverse geological provinces of various age, heat flow, crustal thickness, and tectonic regimes. Their propagation appears to be independent of age. temperature, pressure, and stress. Dynamic stretching of mantle material during subduction or flow, possibly combined with chemical differentiation have to be considered as scale-forming processes in the upper mantle. However, it is difficult to distinguish with the present sets of Pn/Sn array data whether (and also where) the <span class="hlt">boundary</span> layer is a frozen-in feature of paleo-processes or whether it is a response to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGP33B..06A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGP33B..06A"><span>Eastern <span class="hlt">boundary</span> of the Siletz terrane in the Puget Lowland from gravity and magnetic modeling with implications for <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>Anderson, M. L.; Blakely, R. J.; Wells, R. E.; Dragovich, J.</p> <p>2011-12-01</p> <p>The forearc of the Cascadia subduction zone in coastal Oregon and Washington is largely composed of a 15-30 km-thick stack of basalt flows comprising the Crescent Formation (WA) and Siletz River Volcanics (OR), and collectively termed the Siletz terrane. We are developing 3-D structural maps of the Puget Lowland to distinguish older and currently active structures for <span class="hlt">seismic</span> hazard analysis. The <span class="hlt">boundaries</span> of the Siletz terrane in particular may strongly influence crustal rheology and neotectonic structures of the region. Careful analysis of the areal extent of this terrane will also facilitate more accurate interpretation of <span class="hlt">seismic</span> data and gravity anomalies, which will help define the extent and shape of overlying basins. Absence of extensive outcrop in the Lowland and a widespread veneer of Quaternary deposits require extensive subsurface geophysical studies to establish Lowland-wide crustal structure. Previous studies have used active <span class="hlt">seismic</span> surveys and interpretation of existing industry <span class="hlt">seismic</span> data, with several studies using gravity and magnetic data or passive-source tomography support. However, steeply dipping <span class="hlt">boundaries</span> in the mid-crust are difficult targets for <span class="hlt">seismic</span> study. We need to independently discriminate between potential models established by <span class="hlt">seismic</span> data using gravity and magnetic datasets. In the Puget Lowland the Siletz is a region of high <span class="hlt">seismic</span> wave speed, density, and magnetic susceptibility, and therefore its mid-crustal <span class="hlt">boundaries</span> are good targets for definition by gravity and magnetic data. We present interpretations of gravity and magnetic anomalies for the Puget Lowland region that together establish the most likely position and structure of the Crescent Formation <span class="hlt">boundary</span> in the mid-upper crust. Well-constrained physical properties of Crescent basalts inform our aeromagnetic map interpretation and give us baseline values for constructing three two-dimensional models by simultaneous forward modeling of aeromagnetic and isostatic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/5900198','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/5900198"><span>A multilevel preconditioner for domain decomposition <span class="hlt">boundary</span> <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bramble, J.H.; Pasciak, J.E.; Xu, Jinchao.</p> <p>1991-12-11</p> <p>In this note, we consider multilevel preconditioning of the reduced <span class="hlt">boundary</span> <span class="hlt">systems</span> which arise in non-overlapping domain decomposition methods. It will be shown that the resulting preconditioned <span class="hlt">systems</span> have condition numbers which be bounded in the case of multilevel spaces on the whole domain and grow at most proportional to the number of levels in the case of multilevel <span class="hlt">boundary</span> spaces without multilevel extensions into the interior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/325844','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/325844"><span>Definition and means of maintaining the supply ventilation <span class="hlt">system</span> <span class="hlt">seismic</span> shutdown portion of the PFP safety envelope</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Keck, R.D.</p> <p>1997-01-21</p> <p>The purpose of this document is to record the technical evaluation of the Limiting Condition for Operation (LCO) described in the Plutonium Finishing Plant (PFP) Operational Safety Requirements, WHC-SD-CP-OSR- 010, Rev. 0. Kay 1994, Section 3.2.3, `Supply Ventilation <span class="hlt">System</span> <span class="hlt">Seismic</span> Shutdown.` This document, with its appendices, provides the following: 1. The <span class="hlt">system</span> functional requirements for determining <span class="hlt">system</span> operability (Section 3). 2. Evaluations of equipment to determine the safety <span class="hlt">boundary</span> for the <span class="hlt">system</span> (Section 4). 3. A list of annotated drawings which show the safety envelope <span class="hlt">boundaries</span> (Appendix C). 4. A list of the safety envelope equipment (Appendix B). 5. Functionalmore » requirements for the individual safety envelope equipment, including appropriate setpoints and process parameters (Section 4.1). 6. A list of the operational, maintenance and surveillance procedures necessary to operate and maintain the <span class="hlt">system</span> equipment within the safety envelope (Sections 5 and 6 and Appendix A).« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1183763','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1183763"><span>Development of <span class="hlt">Seismic</span> Isolation <span class="hlt">Systems</span> Using Periodic Materials</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yan, Yiqun; Mo, Yi-Lung; Menq, Farn-Yuh</p> <p></p> <p>Advanced fast nuclear power plants and small modular fast reactors are composed of thin-walled structures such as pipes; as a result, they do not have sufficient inherent strength to resist <span class="hlt">seismic</span> loads. <span class="hlt">Seismic</span> isolation, therefore, is an effective solution for mitigating earthquake hazards for these types of structures. Base isolation, on which numerous studies have been conducted, is a well-defined structure protection <span class="hlt">system</span> against earthquakes. In conventional isolators, such as high-damping rubber bearings, lead-rubber bearings, and friction pendulum bearings, large relative displacements occur between upper structures and foundations. Only isolation in a horizontal direction is provided; these features are notmore » desirable for the piping <span class="hlt">systems</span>. The concept of periodic materials, based on the theory of solid-state physics, can be applied to earthquake engineering. The periodic material is a material that possesses distinct characteristics that prevent waves with certain frequencies from being transmitted through it; therefore, this material can be used in structural foundations to block unwanted <span class="hlt">seismic</span> waves with certain frequencies. The frequency band of periodic material that can filter out waves is called the band gap, and the structural foundation made of periodic material is referred to as the periodic foundation. The design of a nuclear power plant, therefore, can be unified around the desirable feature of a periodic foundation, while the continuous maintenance of the structure is not needed. In this research project, three different types of periodic foundations were studied: one-dimensional, two-dimensional, and three-dimensional. The basic theories of periodic foundations are introduced first to find the band gaps; then the finite element methods are used, to perform parametric analysis, and obtain attenuation zones; finally, experimental programs are conducted, and the test data are analyzed to verify the theory. This procedure shows that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816121N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816121N"><span>Stress interaction at the Lazufre volcanic region, as constrained by InSAR, <span class="hlt">seismic</span> tomography and <span class="hlt">boundary</span> element modelling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nikkhoo, Mehdi; Walter, Thomas R.; Lundgren, Paul; Spica, Zack; Legrand, Denis</p> <p>2016-04-01</p> <p>The Azufre-Lastarria volcanic complex in the central Andes has been recognized as a major region of magma intrusion. Both deep and shallow inflating reservoirs inferred through InSAR time series inversions, are the main sources of a multi-scale deformation accompanied by pronounced fumarolic activity. The possible interactions between these reservoirs, as well as the path of propagating fluids and the development of their pathways, however, have not been investigated. Results from recent <span class="hlt">seismic</span> noise tomography in the area show localized zones of shear wave velocity anomalies, with a low shear wave velocity region at 1 km depth and another one at 4 km depth beneath Lastarria. Although the inferred shallow zone is in a good agreement with the location of the shallow deformation source, the deep zone does not correspond to any deformation source in the area. Here, using the <span class="hlt">boundary</span> element method (BEM), we have performed an in-depth continuum mechanical investigation of the available ascending and descending InSAR data. We modelled the deep source, taking into account the effect of topography and complex source geometry on the inversion. After calculating the stress field induced by this source, we apply Paul's criterion (a variation on Mohr-Coulomb failure) to recognize locations that are liable for failure. We show that the locations of tensile and shear failure almost perfectly coincide with the shallow and deep anomalies as identified by shear wave velocity, respectively. Based on the stress-change models we conjecture that the deep reservoir controls the development of shallower hydrothermal fluids; a hypothesis that can be tested and applied to other volcanoes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2007/1047/srp/srp001/of2007-1047srp001_text.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2007/1047/srp/srp001/of2007-1047srp001_text.pdf"><span>Advances through collaboration: sharing <span class="hlt">seismic</span> reflection data via the Antarctic <span class="hlt">Seismic</span> Data Library <span class="hlt">System</span> for Cooperative Research (SDLS)</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wardell, N.; Childs, J. R.; Cooper, A. K.</p> <p>2007-01-01</p> <p>The Antarctic <span class="hlt">Seismic</span> Data Library <span class="hlt">System</span> for Cooperative Research (SDLS) has served for the past 16 years under the auspices of the Antarctic Treaty (ATCM Recommendation XVI-12) as a role model for collaboration and equitable sharing of Antarctic multichannel <span class="hlt">seismic</span> reflection (MCS) data for geoscience studies. During this period, collaboration in MCS studies has advanced deciphering the <span class="hlt">seismic</span> stratigraphy and structure of Antarctica’s continental margin more rapidly than previously. MCS data compilations provided the geologic framework for scientific drilling at several Antarctic locations and for high-resolution <span class="hlt">seismic</span> and sampling studies to decipher Cenozoic depositional paleoenvironments. The SDLS successes come from cooperation of National Antarctic Programs and individual investigators in “on-time” submissions of their MCS data. Most do, but some do not. The SDLS community has an International Polar Year (IPY) goal of all overdue MCS data being sent to the SDLS by end of IPY. The community science objective is to compile all Antarctic MCS data to derive a unified <span class="hlt">seismic</span> stratigraphy for the continental margin – a stratigraphy to be used with drilling data to derive Cenozoic circum-Antarctic paleobathymetry maps and local-to-regional scale paleoenvironmental histories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2008/1262/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2008/1262/"><span>Instrumentation Guidelines for the Advanced National <span class="hlt">Seismic</span> <span class="hlt">System</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>Working Group on Instrumentation, Siting</p> <p>2008-01-01</p> <p>This document provides guidelines for the <span class="hlt">seismic</span>-monitoring instrumentation used by long-term earthquake-monitoring stations that will sense ground motion, digitize and store the resulting signals in a local data acquisition unit, and optionally transmit these digital data. These guidelines are derived from specifications and requirements for data needed to address the nation's emergency response, engineering, and scientific needs as identified in U.S. Geological Survey Circular 1188 (1999). Data needs are discussed in terms of national, regional, and urban scales of monitoring in section 3. Functional performance specifications for instrumentation are introduced in section 4.3 and discussed in detail in section 6 in terms of instrument classes and definitions described in section 5. <span class="hlt">System</span> aspects and testing recommendations are discussed in sections 7 and 8, respectively. Although U.S. Geological Survey Circular 1188 (1999) recommends that the Advanced National <span class="hlt">Seismic</span> <span class="hlt">System</span> (ANSS) include portable instrumentation, performance specifications for this element are not specifically addressed in this document. Nevertheless, these guidelines are largely applicable to portable instrumentation. Volcano monitoring instrumentation is also beyond the scope of this document. Guidance for ANSS structural-response monitoring is discussed briefly herein but details are deferred to the ANSS document by the ANSS Structural Response Monitoring Committee (U.S. Geological Survey, 2005). Aspects of station planning, siting, and installation other than instrumentation are beyond the scope of this document.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T43E2702K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T43E2702K"><span>Along-strike variations in <span class="hlt">seismic</span> structure of the locked-sliding transition on the plate <span class="hlt">boundary</span> beneath the southern part of Kii Peninsula, southwestern Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurashimo, E.; Iidaka, T.; Iwasaki, T.; Saiga, A.; Umeyama, E.; Tsumura, N.; Sakai, S.; Hirata, N.</p> <p>2013-12-01</p> <p>The Nankai trough region, where the Philippine Sea Plate (PHS) subducts beneath the SW Japan arc, is a well-known seismogenic zone of interplate earthquakes. A narrow zone of nonvolcanic tremor has been found in the SW Japan fore-arc, along strike of the arc (Obara, 2002). The epicentral distribution of tremor corresponds to the locked-sliding transition estimated from thermal and deformation models (Hyndman et al., 1995). The spatial distribution of the tremor is not homogeneous in a narrow belt but is spatially clustered. Obara [2002] suggested fluids as a source for tremor because of the long duration and the mobility of the tremor activity. The behavior of fluids at the plate interface is a key factor in understanding fault slip processes. <span class="hlt">Seismic</span> reflection characteristics and <span class="hlt">seismic</span> velocity variations can provide important information on the fluid-related heterogeneity of structure around plate interface. However, little is known about the deeper part of the plate <span class="hlt">boundary</span>, especially the transition zone on the subducting plate. To reveal the <span class="hlt">seismic</span> structure of the transition zone, we conducted passive and active <span class="hlt">seismic</span> experiments in the southern part of Kii Peninsula, SW Japan. Sixty 3-component portable seismographs were installed on a 60-km-long line (SM-line) nearly perpendicular to the direction of the subduction of the PHS with approximately 1 km spacing. To improve accuracy of hypocenter locations, we additionally deployed six 3-component <span class="hlt">seismic</span> stations around the survey line. Waveforms were continuously recorded during a five-month period from December, 2009. In October of 2010, a deep <span class="hlt">seismic</span> profiling was also conducted. 290 seismometers were deployed on the SM-line with about 200 m spacing, on which five explosives shots were fired as controlled <span class="hlt">seismic</span> sources. Arrival times of local earthquakes and explosive shots were used in a joint inversion for earthquake locations and 3-D Vp and Vp/Vs structures, using the iterative damped least</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70026362','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70026362"><span>The Cottage Grove fault <span class="hlt">system</span> (Illinois Basin): Late Paleozoic transpression along a Precambrian crustal <span class="hlt">boundary</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>Duchek, A.B.; McBride, J.H.; Nelson, W.J.; Leetaru, H.E.</p> <p>2004-01-01</p> <p>The Cottage Grove fault <span class="hlt">system</span> in southern Illinois has long been interpreted as an intracratonic dextral strike-slip fault <span class="hlt">system</span>. We investigated its structural geometry and kinematics in detail using (1) outcrop data, (2) extensive exposures in underground coal mines, (3) abundant borehole data, and (4) a network of industry <span class="hlt">seismic</span> reflection profiles, including data reprocessed by us. Structural contour mapping delineates distinct monoclines, broad anticlines, and synclines that express Paleozoic-age deformation associated with strike slip along the fault <span class="hlt">system</span>. As shown on <span class="hlt">seismic</span> reflection profiles, prominent near-vertical faults that cut the entire Paleozoic section and basement-cover contact branch upward into outward-splaying, high-angle reverse faults. The master fault, sinuous along strike, is characterized along its length by an elongate anticline, ???3 km wide, that parallels the southern side of the master fault. These features signify that the overall kinematic regime was transpressional. Due to the absence of suitable piercing points, the amount of slip cannot be measured, but is constrained at less than 300 m near the ground surface. The Cottage Grove fault <span class="hlt">system</span> apparently follows a Precambrian terrane <span class="hlt">boundary</span>, as suggested by magnetic intensity data, the distribution of ultramafic igneous intrusions, and patterns of earthquake activity. The fault <span class="hlt">system</span> was primarily active during the Alleghanian orogeny of Late Pennsylvanian and Early Permian time, when ultramatic igneous magma intruded along en echelon tensional fractures. ?? 2004 Geological Society of America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5560K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5560K"><span><span class="hlt">Seismic</span> anisotropy and the state of stress in volcanic <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kendall, Michael</p> <p>2017-04-01</p> <p>The active magmatic and hydrothermal <span class="hlt">systems</span> of volcanoes can lead to complicated stress patterns that can vary over short spatial and temporal scales. An attractive approach to studying the state of stress in such <span class="hlt">systems</span> is to investigate <span class="hlt">seismic</span> anisotropy using shear-wave splitting in upper-crustal earthquakes. Anisotropy can be caused by a range of mechanisms, including crystal preferred orientation and fine scale layering, but the dominant mechanism in volcanic <span class="hlt">systems</span> is likely the preferred alignment of fluid-filled cracks and fractures. In general, cracks and fractures in the near surface tend to align parallel to the dominant direction of maximum horizontal stress. However, the observed patterns in volcanoes indicate more complicated stress patterns, which sometimes even change in time. A challenge is to untangle the magmatic versus hydrothermal control on stress. Here I summarise observations of <span class="hlt">seismic</span> anisotropy across several volcanoes in different settings. <span class="hlt">Seismic</span> anisotropy of the upper crust in the vicinity of the Soufrière Hills volcano - on the island of Montserrat in the Lesser Antilles - has been studied using shear wave splitting (SWS) analysis of shallow volcano-tectonic events. Clear spatial variations in anisotropy are observed, which are consistent with structurally controlled anisotropy resulting from a left-lateral transtensional array of faults that crosses the volcanic complex. Corbetti and Aluto are two volcanoes located roughly 100 km apart in the Main Ethiopian Rift. Their evolution is strongly controlled by pre-existing structural trends. In the case of Aluto, the anisotropy follows the Wonji fault belt in a rift parallel nearly N-S direction, but significantly oblique to the older border faults. In contrast, the shear-wave splitting at Corbetti is more complicated and supports ideas of the influence of a much-older pre-existing cross-rift structure known as the Goba-Bonga fault. Ontake volcano in Japan is another arc volcano. It</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3443G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3443G"><span><span class="hlt">Seismic</span> properties of fluid bearing formations in magmatic geothermal <span class="hlt">systems</span>: can we directly detect geothermal activity with <span class="hlt">seismic</span> methods?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grab, Melchior; Scott, Samuel; Quintal, Beatriz; Caspari, Eva; Maurer, Hansruedi; Greenhalgh, Stewart</p> <p>2016-04-01</p> <p><span class="hlt">Seismic</span> methods are amongst the most common techniques to explore the earth's subsurface. <span class="hlt">Seismic</span> properties such as velocities, impedance contrasts and attenuation enable the characterization of the rocks in a geothermal <span class="hlt">system</span>. The most important goal of geothermal exploration, however, is to describe the enthalpy state of the pore fluids, which act as the main transport medium for the geothermal heat, and to detect permeable structures such as fracture networks, which control the movement of these pore fluids in the subsurface. Since the quantities measured with <span class="hlt">seismic</span> methods are only indirectly related with the fluid state and the rock permeability, the interpretation of <span class="hlt">seismic</span> datasets is difficult and usually delivers ambiguous results. To help overcome this problem, we use a numerical modeling tool that quantifies the <span class="hlt">seismic</span> properties of fractured rock formations that are typically found in magmatic geothermal <span class="hlt">systems</span>. We incorporate the physics of the pore fluids, ranging from the liquid to the boiling and ultimately vapor state. Furthermore, we consider the hydromechanics of permeable structures at different scales from small cooling joints to large caldera faults as are known to be present in volcanic <span class="hlt">systems</span>. Our modeling techniques simulate oscillatory compressibility and shear tests and yield the P- and S-wave velocities and attenuation factors of fluid saturated fractured rock volumes. To apply this modeling technique to realistic scenarios, numerous input parameters need to be indentified. The properties of the rock matrix and individual fractures were derived from extensive literature research including a large number of laboratory-based studies. The geometries of fracture networks were provided by structural geologists from their published studies of outcrops. Finally, the physical properties of the pore fluid, ranging from those at ambient pressures and temperatures up to the supercritical conditions, were taken from the fluid physics</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S11F4406H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S11F4406H"><span>Development of real time monitor <span class="hlt">system</span> displaying <span class="hlt">seismic</span> waveform data observed at seafloor <span class="hlt">seismic</span> network, DONET, for disaster management information</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Horikawa, H.; Takaesu, M.; Sueki, K.; Takahashi, N.; Sonoda, A.; Miura, S.; Tsuboi, S.</p> <p>2014-12-01</p> <p>Mega-thrust earthquakes are anticipated to occur in the Nankai Trough in southwest Japan. In the source areas, we have deployed seafloor <span class="hlt">seismic</span> network, DONET (Dense Ocean-floor Network <span class="hlt">System</span> for Earthquake and Tsunamis), in 2010 in order to monitor <span class="hlt">seismicity</span>, crustal deformations, and tsunamis. DONET <span class="hlt">system</span> consists of totally 20 stations, which is composed of six kinds of sensors, including strong-motion seismometers and quartz pressure gauges. Those stations are densely distributed with an average spatial interval of 15-20 km and cover near the trench axis to coastal areas. Observed data are transferred to a land station through a fiber-optical cable and then to JAMSTEC (Japan Agency for Marine-Earth Science and Technology) data management center through a private network in real time. After 2011 off the Pacific coast of Tohoku Earthquake, each local government close to Nankai Trough try to plan disaster prevention scheme. JAMSTEC will disseminate DONET data combined with research accomplishment so that they will be widely recognized as important earthquake information. In order to open DONET data observed for research to local government, we have developed a web application <span class="hlt">system</span>, REIS (Real-time Earthquake Information <span class="hlt">System</span>). REIS is providing <span class="hlt">seismic</span> waveform data to some local governments close to Nankai Trough as a pilot study. As soon as operation of DONET is ready, REIS will start full-scale operation. REIS can display <span class="hlt">seismic</span> waveform data of DONET in real-time, users can select strong motion and pressure data, and configure the options of trace view arrangement, time scale, and amplitude. In addition to real-time monitoring, REIS can display past <span class="hlt">seismic</span> waveform data and show earthquake epicenters on the map. In this presentation, we briefly introduce DONET <span class="hlt">system</span> and then show our web application <span class="hlt">system</span>. We also discuss our future plans for further developments of REIS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950025817','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950025817"><span>A <span class="hlt">seismic</span> data compression <span class="hlt">system</span> using subband coding</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kiely, A. B.; Pollara, F.</p> <p>1995-01-01</p> <p>This article presents a study of <span class="hlt">seismic</span> data compression techniques and a compression algorithm based on subband coding. The algorithm includes three stages: a decorrelation stage, a quantization stage that introduces a controlled amount of distortion to allow for high compression ratios, and a lossless entropy coding stage based on a simple but efficient arithmetic coding method. Subband coding methods are particularly suited to the decorrelation of nonstationary processes such as <span class="hlt">seismic</span> events. Adaptivity to the nonstationary behavior of the waveform is achieved by dividing the data into separate blocks that are encoded separately with an adaptive arithmetic encoder. This is done with high efficiency due to the low overhead introduced by the arithmetic encoder in specifying its parameters. The technique could be used as a progressive transmission <span class="hlt">system</span>, where successive refinements of the data can be requested by the user. This allows seismologists to first examine a coarse version of waveforms with minimal usage of the channel and then decide where refinements are required. Rate-distortion performance results are presented and comparisons are made with two block transform methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70174838','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70174838"><span>Tracking changes in volcanic <span class="hlt">systems</span> with <span class="hlt">seismic</span> Interferometry</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Haney, Matt; Alicia J. Hotovec-Ellis,; Bennington, Ninfa L.; Silvio De Angelis,; Clifford Thurber,</p> <p>2014-01-01</p> <p>The detection and evaluation of time-dependent changes at volcanoes form the foundation upon which successful volcano monitoring is built. Temporal changes at volcanoes occur over all time scales and may be obvious (e.g., earthquake swarms) or subtle (e.g., a slow, steady increase in the level of tremor). Some of the most challenging types of time-dependent change to detect are subtle variations in material properties beneath active volcanoes. Although difficult to measure, such changes carry important information about stresses and fluids present within hydrothermal and magmatic <span class="hlt">systems</span>. These changes are imprinted on <span class="hlt">seismic</span> waves that propagate through volcanoes. In recent years, there has been a quantum leap in the ability to detect subtle structural changes systematically at volcanoes with <span class="hlt">seismic</span> waves. The new methodology is based on the idea that useful <span class="hlt">seismic</span> signals can be generated “at will” from <span class="hlt">seismic</span> noise. This means signals can be measured any time, in contrast to the often irregular and unpredictable times of earthquakes. With <span class="hlt">seismic</span> noise in the frequency band 0.1–1 Hz arising from the interaction of the ocean with the solid Earth known as microseisms, researchers have demonstrated that cross-correlations of passive <span class="hlt">seismic</span> recordings between pairs of seismometers yield coherent signals (Campillo and Paul 2003; Shapiro and Campillo 2004). Based on this principle, coherent signals have been reconstructed from noise recordings in such diverse fields as helioseismology (Rickett and Claerbout 2000), ultrasound (Weaver and Lobkis 2001), ocean acoustic waves (Roux and Kuperman 2004), regional (Shapiro et al. 2005; Sabra et al. 2005; Bensen et al. 2007) and exploration (Draganov et al. 2007) seismology, atmospheric infrasound (Haney 2009), and studies of the cryosphere (Marsan et al. 2012). Initial applications of ambient <span class="hlt">seismic</span> noise were to regional surface wave tomography (Shapiro et al. 2005). Brenguier et al. (2007) were the first to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1955d0011T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1955d0011T"><span>Design and implementation of a unified certification management <span class="hlt">system</span> based on <span class="hlt">seismic</span> business</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, Hongliang</p> <p>2018-04-01</p> <p>Many business software for <span class="hlt">seismic</span> <span class="hlt">systems</span> are based on web pages, users can simply open a browser and enter their IP address. However, how to achieve unified management and security management of many IP addresses, this paper introduces the design concept based on <span class="hlt">seismic</span> business and builds a unified authentication management <span class="hlt">system</span> using ASP technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.G44A..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.G44A..02B"><span>The GNSS Component of the <span class="hlt">Seismic</span> Monitoring <span class="hlt">System</span> 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>Barrientos, S. E.</p> <p>2016-12-01</p> <p>Chile is amongst the most <span class="hlt">seismically</span> active countries in the world. Since mid-XVI Century, a magnitude 8 or more earthquake has taken place every dozen of years, as an average. In the last 100 years, more than ten events with magnitudes around 8 or larger have taken place in this part of world. Three events with M>8 have taken place only in the last six years. The largest earthquake ever recorded took place in May, 1960, in southern Chile. Such extreme <span class="hlt">seismic</span> activity is the result of the interaction of the Nazca, Antarctic, Scotia and South American plates in southwestern South America where Chile is located. These megathrust earthquakes exhibit long rupture regions reaching several hundreds of km with fault displacements of several tens of meters. At least eighteen of these earthquakes have generated local tsunamis with runups larger than 4 m -including events in 2010, 2014 and 2015- therefore it is mandatory to establish a <span class="hlt">system</span> with capabilities to rapidly evaluate the tsunamigenic potential of these events. In 2013, the newly created National Seismological Center (CSN) of the University of Chile was tasked to upgrade the countrýs <span class="hlt">seismic</span> network by increasing the numbers of real-time monitoring stations. The most important change to previous practices is the establishment of a GNSS network composed by 130 devices, in addition to the incorporation of 65 new collocated broadband and strong motion instruments. Additional 297 strong motion instruments for engineering purposes complement the <span class="hlt">system</span>. Forty units -of the 130 devices- present an optional RTX capability, where satellite orbits and clock corrections are sent to the field device producing a 1-Hz position stream at 4-cm level. First records of ground displacement -using this technology-were recorded at the time of the largest aftershock (Mw=7.6) of the sequence that affected northern Chile in 2014. The CSN is currently developing automatic detectors and amplitude estimators of displacement from the</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/2017AGUFM.V24A..03W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V24A..03W"><span>Anatomy of Old Faithful hydrothermal <span class="hlt">system</span> from subsurface <span class="hlt">seismic</span> imaging of the Yellowstone Upper Geyser Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, S. M.; Lin, F. C.; Farrell, J.; Ward, K. M.; Karplus, M. S.; Smith, R. B.</p> <p>2017-12-01</p> <p>The Upper Geyser Basin (UGB) in Yellowstone National Park contains one of the highest concentrations of hydrothermal features on Earth including the iconic Old Faithful Geyser (OFG). Although this <span class="hlt">system</span> has been the focus of many geological, geochemical, and geophysical studies, the shallow (<200 m) subsurface structure and the hydrothermal tremor behavior remain poorly characterized. To probe the detailed structure that relates to the hydrothermal plumbing of the UGB, we deployed dense arrays of 3-C 5-Hz geophones in both November of 2015 and 2016, composed of 133 stations with 50 m spacing, and 519 station locations, with an 20 m spacing, respectively. By applying <span class="hlt">seismic</span> interferometry techniques, we extracted Rayleigh-wave signals between 1-10 Hz via <span class="hlt">seismic</span> signals excited by nearby hydrothermal features (e.g. geysers and pools). We observe a clear lateral velocity <span class="hlt">boundary</span> at 3.3 Hz frequency that delineates a higher phase velocity of 1.6 km/sec in the NE and a lower phase velocity of 1.0 km/sec in the SW corresponding to the local geologic formation of rhyolitic and glacial deposits, respectively. We also image a relatively shallow (20-60 m deep) large reservoir with an estimated porosity 30% located 100 meters southwest of the OFG from the significant spatial-dependent waveform distortions and delays between 5-10 Hz frequency. This reservoir is likely controlled by the local geology with a rhyolitic deposit in the NE acting as a relatively impermeable barrier to vertical fluid ascent. To understand the pre-eruption tremor signals from OFG, we first study the <span class="hlt">seismic</span> waveforms recorded at the closest station to the OFG cone. Many highly repetitive <span class="hlt">seismic</span> pulses associated with bubble collapse, which compose the tremor signal, can be identified. Using a reference event template and the cross-correlation method, we can determine the onset of each individual bubbling event using a cross-correlation coefficient threshold of 0.8. Based on the detected timing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhyEs..24..518F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhyEs..24..518F"><span>Classical <span class="hlt">system</span> <span class="hlt">boundaries</span> cannot be determined within quantum Darwinism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fields, Chris</p> <p></p> <p>Multiple observers who interact with environmental encodings of the states of a macroscopic quantum <span class="hlt">system</span> S as required by quantum Darwinism cannot demonstrate that they are jointly observing S without a joint a priori assumption of a classical <span class="hlt">boundary</span> separating S from its environment E. Quantum Darwinism cannot, therefore, be regarded as providing a purely quantum-mechanical explanation of the "emergence" of classicality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=information+AND+technology+AND+outsourcing&pg=5&id=ED521343','ERIC'); return false;" href="https://eric.ed.gov/?q=information+AND+technology+AND+outsourcing&pg=5&id=ED521343"><span><span class="hlt">Boundary</span> Spanning in Offshored Information <span class="hlt">Systems</span> Development Projects</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>Krishnan, Poornima</p> <p>2010-01-01</p> <p>Recent growth in offshore outsourcing of information <span class="hlt">systems</span> (IS) services is accompanied by managing the offshore projects successfully. Much of the project failures can be attributed to geographic and organizational <span class="hlt">boundaries</span> which create differences in culture, language, work patterns, and decision making processes among the offshore project…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1333521','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1333521"><span>A Fiber-Optic Borehole <span class="hlt">Seismic</span> Vector Sensor <span class="hlt">System</span> for Geothermal Site Characterization and Monitoring</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Paulsson, Bjorn N.P.; Thornburg, Jon A.; He, Ruiqing</p> <p>2015-04-21</p> <p><span class="hlt">Seismic</span> techniques are the dominant geophysical techniques for the characterization of subsurface structures and stratigraphy. The <span class="hlt">seismic</span> techniques also dominate the monitoring and mapping of reservoir injection and production processes. Borehole seismology, of all the <span class="hlt">seismic</span> techniques, despite its current shortcomings, has been shown to provide the highest resolution characterization and most precise monitoring results because it generates higher signal to noise ratio and higher frequency data than surface <span class="hlt">seismic</span> techniques. The operational environments for borehole <span class="hlt">seismic</span> instruments are however much more demanding than for surface <span class="hlt">seismic</span> instruments making both the instruments and the installation much more expensive. The currentmore » state-of-the-art borehole <span class="hlt">seismic</span> instruments have not been robust enough for long term monitoring compounding the problems with expensive instruments and installations. Furthermore, they have also not been able to record the large bandwidth data available in boreholes or having the sensitivity allowing them to record small high frequency micro <span class="hlt">seismic</span> events with high vector fidelity. To reliably achieve high resolution characterization and long term monitoring of Enhanced Geothermal <span class="hlt">Systems</span> (EGS) sites a new generation of borehole <span class="hlt">seismic</span> instruments must therefore be developed and deployed. To address the critical site characterization and monitoring needs for EGS programs, US Department of Energy (DOE) funded Paulsson, Inc. in 2010 to develop a fiber optic based ultra-large bandwidth clamped borehole <span class="hlt">seismic</span> vector array capable of deploying up to one thousand 3C sensor pods suitable for deployment into ultra-high temperature and high pressure boreholes. Tests of the fiber optic <span class="hlt">seismic</span> vector sensors developed on the DOE funding have shown that the new borehole <span class="hlt">seismic</span> sensor technology is capable of generating outstanding high vector fidelity data with extremely large bandwidth: 0.01 – 6,000 Hz. Field tests have</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhyB..459..105C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhyB..459..105C"><span>Modulus spectroscopy of grain-grain <span class="hlt">boundary</span> binary <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, Peng-Fei; Song, Jiang; Li, Sheng-Tao; Wang, Hui</p> <p>2015-02-01</p> <p>Understanding various polarization mechanisms in complex dielectric <span class="hlt">systems</span> and specifying their physical origins are key issues in dielectric physics. In this paper, four different methods for representing dielectric properties were analyzed and compared. Depending on the details of the <span class="hlt">system</span> under study, i.e., uniform or non-uniform, it was suggested that different representing approaches should be used to obtain more valuable information. Especially, for the grain-grain <span class="hlt">boundary</span> binary non-uniform <span class="hlt">system</span>, its dielectric response was analyzed in detail in terms of modulus spectroscopy (MS). Furthermore, it was found that through MS, the dielectric responses between uniform and non-uniform <span class="hlt">systems</span>, grain and grain <span class="hlt">boundary</span>, Maxwell-Wagner polarization and intrinsic polarization can be distinguished. Finally, with the proposed model, the dielectric properties of CaCu3Ti4O12 (CCTO) ceramics were studied. The colossal dielectric constant of CCTO at low frequency was attributed to the pseudo relaxation process of grain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.T31C2195V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.T31C2195V"><span>Geometry of the Arabia-Somalia Plate <span class="hlt">Boundary</span> into Afar: Preliminary Results from the <span class="hlt">Seismic</span> Profile Across the Asal Rift (Djibouti)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vergne, J.; Doubre, C.; Mohamed, K.; Tiberi, C.; Leroy, S.; Maggi, A.</p> <p>2010-12-01</p> <p>In the Afar Depression, the Asal-Ghoubbet Rift in Djibouti is a young segment on land at the propagating tip of the Aden Ridge. This segment represents an ideal laboratory to observe the mechanisms of extension and the structural evolutions involved, from the continental break-up to the first stage of oceanic spreading. However, we lack first order information about the crustal and upper mantle structure in this region, which for example prevent detailed numerical modeling of the deformations observed at the surface from GPS or InSAR. Moreover the current permanent network is not well suited to precisely constrain the ratio of <span class="hlt">seismic</span>/aseismic deformation and to characterize the active deformation and the rifting dynamics. Since November 2009 we have maintained a temporary network of 25 <span class="hlt">seismic</span> stations deployed along a 150 km-long profile. Because we expect rapid variations of the lithospheric structure across the 10 km-wide central part of the rift, we gradually decreased the inter-stations spacing to less than 1 km in the middle section of the profile. In order to obtain a continuous image of the plate <span class="hlt">boundary</span>, from the topographic surface to the upper mantle, several techniques and methods will be applied: P and S wave receiver functions, tomographies based on body waves, surface waves and <span class="hlt">seismic</span> noise correlation, anisotropy, and finally a gravity-<span class="hlt">seismic</span> joint inversion. We present some preliminary results deduced from the receiver functions applied to the data acquired during the first months of the experiment. We migrate several sets of receiver functions computed in various frequency bands to resolve both mantle interfaces and fine scale structures within the thin crust in the center of the rift. These first images confirm a rapid variation of the Moho depth on both sides of the rift and a very complex lithospheric structure in the central section with several low velocity zones within the top 50km that might correspond to magma lenses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFM.V12B1419N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFM.V12B1419N"><span>Pressure changes of volcanic <span class="hlt">systems</span> derived from <span class="hlt">seismic</span> signals</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.; Sturton, S.</p> <p>2002-12-01</p> <p><span class="hlt">Seismic</span> low-frequency events from Soufriere Hills volcano in Montserrat are a superposition of single interface waves travelling along the conduit and leaking into teh volcanic edifice at the upper end of a conduit section where magma properties change rapidly. These low-frequency signals are largely characterised by the intermittency of the interface waves, as well as by the dispersion effects they encounter. Using finite difference modelling of the <span class="hlt">seismic</span> wavefield together with simultaneous modelling of magma properties in time and at depth, allows us to link the <span class="hlt">seismic</span> signature directly to magma and conduit parameters. We retrieve a relationship between frequency content of <span class="hlt">seismic</span> signals and governing pressure in the magma which enables us to determine the pressure changes in the magma from spectral characteristics and their temporal changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1219482','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1219482"><span>Protocol for Addressing Induced <span class="hlt">Seismicity</span> Associated with Enhanced Geothermal <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Majer, Ernie; Nelson, James; Robertson-Tait, Ann</p> <p>2012-01-01</p> <p>This Protocol is a living guidance document for geothermal developers, public officials, regulators and the general public that provides a set of general guidelines detailing useful steps to evaluate and manage the effects of induced <span class="hlt">seismicity</span> related to EGS projects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMGP21A0110G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMGP21A0110G"><span>Paleomagnetic Data Bearing on the Eastern and Southern <span class="hlt">Boundaries</span> of the Walker Lane Belt Transfer <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grow, J. S.; Geissman, J. W.; Oldow, J. S.</p> <p>2007-12-01</p> <p>In west-central Nevada, a transfer zone, which initiated in the mid-Miocene, presently links, via the Mina Deflection, right-lateral faults of the Eastern California Shear Zone to the south and the Central Nevada <span class="hlt">Seismic</span> Belt and Walker Lane to the north. This transfer zone, the early inception of which is characterized by moderate (20-30°) clockwise crustal rotations previously identified (e.g., Candelaria Hills and surrounding ranges), along with right-lateral structures to the south and north, are part of a diffuse zone of intracontinental deformation that accommodates some 25 percent of the motion between the Pacific and North American plates. Although the northern and western <span class="hlt">boundaries</span> of the transfer zone are relatively well defined by paleomagnetic data, the eastern and southeastern <span class="hlt">boundaries</span> remain poorly constrained. Additional paleomagnetic data are being obtained from mid-to-late Tertiary volcanic rocks, presumably lying within (e.g., Montezuma Range, Palmetto Mountains, Monte Cristo Range) and outside (e.g., Goldfield Hills, San Antonio Mountains, Slate Ridge) of the transfer zone. Areas outside of the transfer zone are inferred to have not undergone any appreciable rotation since its inception. Volcanic rocks as well as shallow intrusions ranging in age from Oligocene to mid-Pliocene have been sampled (N=187) from inside and outside of the inferred southern and eastern <span class="hlt">boundaries</span> of the transfer zone. Overall, the collection responds very favorably to progressive demagnetization; initial results are tentatively interpreted as suggesting the absence of appreciable rotation of the San Antonio Range (Tonopah, Nevada area and farther north). The extent to which areas near the eastern and southeastern <span class="hlt">boundaries</span> have been rotated is under investigation. These data will aid in a better understanding of differential block rotation and tilting throughout the development of the west-central Nevada transfer <span class="hlt">system</span> from the mid-Miocene to late Pliocene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S51B0606K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S51B0606K"><span>Development of 3-axis precise positioning <span class="hlt">seismic</span> physical modeling <span class="hlt">system</span> in the simulation of marine <span class="hlt">seismic</span> exploration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, D.; Shin, S.; Ha, J.; Lee, D.; Lim, Y.; Chung, W.</p> <p>2017-12-01</p> <p><span class="hlt">Seismic</span> physical modeling is a laboratory-scale experiment that deals with the actual and physical phenomena that may occur in the field. In <span class="hlt">seismic</span> physical modeling, field conditions are downscaled and used. For this reason, even a small error may lead to a big error in an actual field. Accordingly, the positions of the source and the receiver must be precisely controlled in scale modeling. In this study, we have developed a <span class="hlt">seismic</span> physical modeling <span class="hlt">system</span> capable of precisely controlling the 3-axis position. For automatic and precise position control of an ultrasonic transducer(source and receiver) in the directions of the three axes(x, y, and z), a motor was mounted on each of the three axes. The motor can automatically and precisely control the positions with positional precision of 2''; for the x and y axes and 0.05 mm for the z axis. As it can automatically and precisely control the positions in the directions of the three axes, it has an advantage in that simulations can be carried out using the latest exploration techniques, such as OBS and Broadband <span class="hlt">Seismic</span>. For the signal generation section, a waveform generator that can produce a maximum of two sources was used, and for the data acquisition section, which receives and stores reflected signals, an A/D converter that can receive a maximum of four signals was used. As multiple sources and receivers could be used at the same time, the <span class="hlt">system</span> was set up in such a way that diverse exploration methods, such as single channel, multichannel, and 3-D exploration, could be realized. A computer control program based on LabVIEW was created, so that it could control the position of the transducer, determine the data acquisition parameters, and check the exploration data and progress in real time. A marine environment was simulated using a water tank 1 m wide, 1 m long, and 0.9 m high. To evaluate the performance and applicability of the <span class="hlt">seismic</span> physical modeling <span class="hlt">system</span> developed in this study, single channel and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EEEV...16...23T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EEEV...16...23T"><span>The <span class="hlt">boundary</span> conditions for simulations of a shake-table experiment on the <span class="hlt">seismic</span> response of 3D slope</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, Liang; Cong, Shengyi; Ling, Xianzhang; Ju, Nengpan</p> <p>2017-01-01</p> <p><span class="hlt">Boundary</span> conditions can significantly affect a slope's behavior under strong earthquakes. To evaluate the importance of <span class="hlt">boundary</span> conditions for finite element (FE) simulations of a shake-table experiment on the slope response, a validated three-dimensional (3D) nonlinear FE model is presented, and the numerical and experimental results are compared. For that purpose, the robust graphical user-interface "SlopeSAR", based on the open-source computational platform OpenSees, is employed, which simplifies the effort-intensive pre- and post-processing phases. The mesh resolution effect is also addressed. A parametric study is performed to evaluate the influence of <span class="hlt">boundary</span> conditions on the FE model involving the <span class="hlt">boundary</span> extent and three types of <span class="hlt">boundary</span> conditions at the end faces. Generally, variations in the <span class="hlt">boundary</span> extent produce inconsistent slope deformations. For the two end faces, fixing the y-direction displacement is not appropriate to simulate the shake-table experiment, in which the end walls are rigid and rough. In addition, the influence of the length of the 3D slope's top face and the width of the slope play an important role in the difference between two types of <span class="hlt">boundary</span> conditions at the end faces (fixing the y-direction displacement and fixing the ( y, z) direction displacement). Overall, this study highlights that the assessment of a comparison between a simulation and an experimental result should be performed with due consideration to the effect of the <span class="hlt">boundary</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70016645','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70016645"><span><span class="hlt">Seismic</span> response of transamerica building. II. <span class="hlt">System</span> identification</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Safak, E.; Celebi, M.</p> <p>1991-01-01</p> <p>A detailed analysis of the recorded <span class="hlt">seismic</span> response of the Transamerica Building during the October 17, 1989 Loma Prieta earthquake is presented. The <span class="hlt">system</span> identification algorithm used for the analysis is based on the discrete-time linear filtering approach with least-squares approximation, and assumes a multi-input, single-output model for the building. Fifteen modes in the north-south direction, and 18 modes in the east-west direction are identified from the records. The analysis shows that the building's response to the earthquake was dominated by a coupled mode of vibration at 0.28 Hz in the southwest-northeast direction, which is almost parallel to one of the diagonals in the building's square cross section. The reason for this behavior is the symmetry of the building's structural characteristics, as well as the strong polarization of the S-waves of the earthquake. Several higher modes of the building were excited during the strong-motion part of the earthquake. The results also show a significant amount of rocking in the building at a frequency of 2.15 Hz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017009','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017009"><span>Recorded <span class="hlt">seismic</span> response of Pacific Park Plaza. II. <span class="hlt">System</span> identification</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Safak, F.; Celebi, M.</p> <p>1992-01-01</p> <p>This is the second of two companion papers on the recorded <span class="hlt">seismic</span> response of the Pacific Park Plaza building, in Emeryville, Calif., during the October 17, 1989, Ms = 7.1 (surface-wave magnitude) Loma Prieta earthquake. In this second part, the recorded data are analyzed in more detail by using <span class="hlt">system</span>-identification techniques. The three-dimensional behavior and the coupled modes of the building are determined, and the effects of soil-structure interaction are investigated. The study shows that the response of the building is nonlinear at the beginning, and becomes linear after 17 sec into the earthquake. The dominant motion of the building follows an elliptical path oriented in the southeast-northwest direction. Some of the modes are complex, with nonproportional damping, and there are phase differences among modal response components. The fundamental mode of the building is a translation in the southeast-northwest direction at 0.4 Hz, with 13% damping. The wing displacements relative to the center core are large, about 50% of the center core displacements, and indicate significant torsion in the center core. The soil-structure interaction is characterized by a vibration at 0.7 Hz. This is believed to be the fundamental frequency of the surrounding soil medium. The rocking motions of the building are negligible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S53A2821E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S53A2821E"><span>Populating the Advanced National <span class="hlt">Seismic</span> <span class="hlt">System</span> Comprehensive Earthquake Catalog</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Earle, P. S.; Perry, M. R.; Andrews, J. R.; Withers, M. M.; Hellweg, M.; Kim, W. Y.; Shiro, B.; West, M. E.; Storchak, D. A.; Pankow, K. L.; Huerfano Moreno, V. A.; Gee, L. S.; Wolfe, C. J.</p> <p>2016-12-01</p> <p>The U.S. Geological Survey maintains a repository of earthquake information produced by networks in the Advanced National <span class="hlt">Seismic</span> <span class="hlt">System</span> with additional data from the ISC-GEM catalog and many non-U.S. networks through their contributions to the National Earthquake Information Center PDE bulletin. This Comprehensive Catalog (ComCat) provides a unified earthquake product while preserving attribution and contributor information. ComCat contains hypocenter and magnitude information with supporting phase arrival-time and amplitude measurements (when available). Higher-level products such as focal mechanisms, earthquake slip models, "Did You Feel It?" reports, ShakeMaps, PAGER impact estimates, earthquake summary posters, and tectonic summaries are also included. ComCat is updated as new events are processed and the catalog can be accesed at http://earthquake.usgs.gov/earthquakes/search/. Throughout the past few years, a concentrated effort has been underway to expand ComCat by integrating global and regional historic catalogs. The number of earthquakes in ComCat has more than doubled in the past year and it presently contains over 1.6 million earthquake hypocenters. We will provide an overview of catalog contents and a detailed description of numerous tools and semi-automated quality-control procedures developed to uncover errors including systematic magnitude biases, missing time periods, duplicate postings for the same events, and incorrectly associated events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4961712','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4961712"><span><span class="hlt">System</span>, Subsystem, Hive: <span class="hlt">Boundary</span> Problems in Computational Theories of Consciousness</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fekete, Tomer; van Leeuwen, Cees; Edelman, Shimon</p> <p>2016-01-01</p> <p>A computational theory of consciousness should include a quantitative measure of consciousness, or MoC, that (i) would reveal to what extent a given <span class="hlt">system</span> is conscious, (ii) would make it possible to compare not only different <span class="hlt">systems</span>, but also the same <span class="hlt">system</span> at different times, and (iii) would be graded, because so is consciousness. However, unless its design is properly constrained, such an MoC gives rise to what we call the <span class="hlt">boundary</span> problem: an MoC that labels a <span class="hlt">system</span> as conscious will do so for some—perhaps most—of its subsystems, as well as for irrelevantly extended <span class="hlt">systems</span> (e.g., the original <span class="hlt">system</span> augmented with physical appendages that contribute nothing to the properties supposedly supporting consciousness), and for aggregates of individually conscious <span class="hlt">systems</span> (e.g., groups of people). This problem suggests that the properties that are being measured are epiphenomenal to consciousness, or else it implies a bizarre proliferation of minds. We propose that a solution to the <span class="hlt">boundary</span> problem can be found by identifying properties that are intrinsic or <span class="hlt">systemic</span>: properties that clearly differentiate between <span class="hlt">systems</span> whose existence is a matter of fact, as opposed to those whose existence is a matter of interpretation (in the eye of the beholder). We argue that if a putative MoC can be shown to be <span class="hlt">systemic</span>, this ipso facto resolves any associated <span class="hlt">boundary</span> issues. As test cases, we analyze two recent theories of consciousness in light of our definitions: the Integrated Information Theory and the Geometric Theory of consciousness. PMID:27512377</p> </li> <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 <span class="hlt">system</span> 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 acceleration 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 acceleration 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/2014AGUFM.T11C4565B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T11C4565B"><span>Tsujal Marine Survey: Crustal Characterization of the Rivera Plate-Jalisco Block <span class="hlt">Boundary</span> and its Implications for <span class="hlt">Seismic</span> and Tsunami Hazard Assessment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bartolome, R.; Danobeitia, J.; Barba, D. C., Sr.; Nunez-Cornu, F. J.; Cameselle, A. L.; Estrada, F.; Prada, M.; Bandy, W. L.</p> <p>2014-12-01</p> <p>During the spring of 2014, a team of Spanish and Mexican scientists explored the western margin of Mexico in the frame of the TSUJAL project. The two main objectives were to characterize the nature and structure of the lithosphere and to identify potential sources triggering earthquakes and tsunamis at the contact between Rivera plate-Jalisco block with the North American Plate. With these purposes a set of marine geophysical data were acquired aboard the RRS James Cook. This work is focus in the southern part of the TSUJAL survey, where we obtain <span class="hlt">seismic</span> images from the oceanic domain up to the continental shelf. Thus, more than 800 km of MCS data, divided in 7 profiles, have been acquired with a 6km long streamer and using an air-gun sources ranging from 5800 c.i. to 3540 c.i. Furthermore, a wide-angle <span class="hlt">seismic</span> profile of 190 km length was recorded in 16 OBS deployed perpendicular to the coast of Manzanillo. Gravity and magnetic, multibeam bathymetry and sub-bottom profiler data were recorded simultaneously with <span class="hlt">seismic</span> data in the offshore area. Preliminary stacked MCS <span class="hlt">seismic</span> sections reveal the crustal structure in the different domains of the Mexican margin. The contact between the Rivera and NA Plates is observed as a strong reflection at 6 s two way travel time (TWTT), in a parallel offshore profile (TS01), south of Manzanillo. This contact is also identified in a perpendicular profile, TS02, along a section of more than 100 km in length crossing the Rivera transform zone, and the plate <span class="hlt">boundary</span> between Cocos and Rivera Plates. Northwards, offshore Pto. Vallarta, the MCS data reveals high amplitude reflections at around 7-8.5 s TWTT, roughly 2.5-3.5 s TWTT below the seafloor, that conspicuously define the subduction plane (TS06b). These strong reflections which we interpret as the Moho discontinuity define the starting bending of subduction of Rivera Plate. Another clear pattern observed within the first second of the MCS data shows evidences of a bottom</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S23B0807D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S23B0807D"><span>Statistical Analysis and ETAS Modeling of <span class="hlt">Seismicity</span> Induced by Production of Geothermal Energy from Hydrothermal <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dinske, C.; Langenbruch, C.; Shapiro, S. A.</p> <p>2017-12-01</p> <p>We investigate <span class="hlt">seismicity</span> related to hydrothermal <span class="hlt">systems</span> in Germany and Italy, focussing on temporal changes of <span class="hlt">seismicity</span> rates. Our analysis was motivated by numerical simulations The modeling of stress changes caused by the injection and production of fluid revealed that <span class="hlt">seismicity</span> rates decrease on a long-term perspective which is not observed in the considered case studies. We analyze the waiting time distributions of the <span class="hlt">seismic</span> events in both time domain (inter event times) and fluid volume domain (inter event volume). We find clear indications that the observed <span class="hlt">seismicity</span> comprises two components: (1) <span class="hlt">seismicity</span> that is directly triggered by production and re-injection of fluid, i.e. induced events, and (2) <span class="hlt">seismicity</span> that is triggered by earthquake interactions, i.e. aftershock triggering. In order to better constrain our numerical simulations using the observed induced <span class="hlt">seismicity</span> we apply catalog declustering to seperate the two components. We use the magnitude-dependent space-time windowing approach introduced by Gardner and Knopoff (1974) and test several published algorithms to calculate the space-time windows. After declustering, we conclude that the different hydrothermal reservoirs show a comparable <span class="hlt">seismic</span> response to the circulation of fluid and additional triggering by earthquake interactions. The declustered catalogs contain approximately 50 per cent of the number of events in the original catalogs. We then perform ETAS (Epidemic Type Aftershock; Ogata, 1986, 1988) modeling for two reasons. First, we want to know whether the different reservoirs are also comparable regarding earthquake interaction patterns. Second, if we identify systematic patterns, ETAS modeling can contribute to forecast <span class="hlt">seismicity</span> during production of geothermal energy. We find that stationary ETAS models cannot accurately capture real <span class="hlt">seismicity</span> rate changes. One reason for this finding is given by the rate of observed induced events which is not constant over time. Hence</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.5930K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.5930K"><span>Integrating Social impacts on Health and Health-Care <span class="hlt">Systems</span> in <span class="hlt">Systemic</span> <span class="hlt">Seismic</span> Vulnerability Analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kunz-Plapp, T.; Khazai, B.; Daniell, J. E.</p> <p>2012-04-01</p> <p>This paper presents a new method for modeling health impacts caused by earthquake damage which allows for integrating key social impacts on individual health and health-care <span class="hlt">systems</span> and for implementing these impacts in quantitative <span class="hlt">systemic</span> <span class="hlt">seismic</span> vulnerability analysis. In current earthquake casualty estimation models, demand on health-care <span class="hlt">systems</span> is estimated by quantifying the number of fatalities and severity of injuries based on empirical data correlating building damage with casualties. The expected number of injured people (sorted by priorities of emergency treatment) is combined together with post-earthquake reduction of functionality of health-care facilities such as hospitals to estimate the impact on healthcare <span class="hlt">systems</span>. The aim here is to extend these models by developing a combined engineering and social science approach. Although social vulnerability is recognized as a key component for the consequences of disasters, social vulnerability as such, is seldom linked to common formal and quantitative <span class="hlt">seismic</span> loss estimates of injured people which provide direct impact on emergency health care services. Yet, there is a consensus that factors which affect vulnerability and post-earthquake health of at-risk populations include demographic characteristics such as age, education, occupation and employment and that these factors can aggravate health impacts further. Similarly, there are different social influences on the performance of health care <span class="hlt">systems</span> after an earthquake both on an individual as well as on an institutional level. To link social impacts of health and health-care services to a <span class="hlt">systemic</span> <span class="hlt">seismic</span> vulnerability analysis, a conceptual model of social impacts of earthquakes on health and the health care <span class="hlt">systems</span> has been developed. We identified and tested appropriate social indicators for individual health impacts and for health care impacts based on literature research, using available European statistical data. The results will be used to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T42D..02F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T42D..02F"><span><span class="hlt">Seismicity</span> and lithospheric structure of Central Mozambique: implications for the southward propagation of the East African Rift <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fonseca, J. F. B. D.; Domingues, A.</p> <p>2017-12-01</p> <p>South of latitude 5ºS, there is scarce support for a single preferred location of continental rifting in SE Africa. Building on the complexity already displayed further north around the Victoria microplate, the structures associated with rifting activity are now distributed over three branches: one directed towards the SW through Zambia and into the Okawango rift in Botswana; one running offshore along the Mozambique Channel; and a central rift <span class="hlt">system</span> through lake Malawi and Central Mozambique. Our investigation focuses on this central branch, whose tectonic relevance was highlighted by the M7 Machaze earthquake in 2006. Through the temporary deployment of 30 broadband stations in central Mozambique we were able to document that the Shire and Urema grabens linking the Malawi rift to the Machaze epicentral area are <span class="hlt">seismically</span> active, correlating with a 300 km long narrow band of <span class="hlt">seismicity</span> reaching the lower crust. No significant <span class="hlt">seismicity</span> was recorded along the Mazenga graben, south of the Machaze epicentral area. A tomographic model derived from ambient noise analysis showed a strong correlation between the <span class="hlt">seismicity</span> and a sharp NNE-SSW <span class="hlt">boundary</span> between the fast crust of the Zimbabwe and Kaapvaal cratons and slower crust underneath the Mozambique Coastal Plains. The <span class="hlt">seismicity</span> shuts down were this trend rotates to a more N-S direction as the Lebombo monocline is approached. 20th Century <span class="hlt">seismicity</span> of SE Africa shows a clear cluster in time, with five M>6 earthquakes concentrated in the 1950's, distributed along the edges of the Zimbabwe craton and spanning distances of 600 km. Spatial correlation with such range is hard to reconcile with stress transmission in the crust and may point to the interaction of the cratonic root with asthenospheric flow. Under this light, the M6.5 Central Botswana earthquake of April 2017 and the M7 Machaze earthquake of 2006, both located in the vicinity of the borders of the Kaapvaal craton, may bear a similar correlation. The</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/2015MarGR..36..343M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MarGR..36..343M"><span>Using <span class="hlt">seismic</span> reflection data to reveal high-resolution structure and pathway of the upper Western <span class="hlt">Boundary</span> Undercurrent core at Eirik Drift</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Müller-Michaelis, Antje; Uenzelmann-Neben, Gabriele</p> <p>2015-12-01</p> <p>The method of <span class="hlt">seismic</span> oceanography was applied to identify fine structure and pathways of the Western <span class="hlt">Boundary</span> Undercurrent (WBUC) at Eirik Drift, 200 km south of Greenland. Three high-velocity cores of the WBUC were distinguished: a deep core in depths >2600 m which carries Denmark Strait Overflow Water, an upper core in depths between ~1900 and 3000 m transporting Iceland-Scotland Overflow Water, and a split-off of this upper core, which crosses the main crest of Eirik Drift at depths between ~1900 and 2400 m. For the upper WBUC core a detailed analysis of the structure was conducted. The WBUC core has as a domed structure, which changes in style, width and height above seafloor along the lines of the changing topography. We proved not only the influence of the topography on pathway and structure of the WBUC core but also that this information cannot be gained by measuring the overflow waters with discrete CTD stations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/53605','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/53605"><span>Determination of <span class="hlt">seismic</span> performance factors for CLT shear wall <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>M. Omar Amini; John W. van de Lindt; Douglas Rammer; Shiling Pei; Philip Line; Marjan Popovski</p> <p>2016-01-01</p> <p>This paper presents selected results of connector testing and wall testing which were part of a Forest Products Lab-funded project undertaken at Colorado State University in an effort to determine <span class="hlt">seismic</span> performance factors for cross laminated timber (CLT) shear walls in the United States. Archetype development, which is required as part of the process, is also...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1918040M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1918040M"><span>Implementation of a <span class="hlt">Seismic</span> Early Warning <span class="hlt">System</span> in Portugal Mainland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Madureira, Guilherme; Carrilho, Fernando</p> <p>2017-04-01</p> <p>Portugal mainland is located near the border between the Eurasian and Nubian plates, whose interaction is the main responsible for a significant <span class="hlt">seismic</span> activity in the area, with historical occurrence of several catastrophic events (e.g. Lisbon 1755 earthquake [Mag 8.7]), most of which haviguilhng epicenter rise in submerged area, located in the Cadiz Gulf and Southwest of San Vincent Cape. Early Warning <span class="hlt">Systems</span> (EEWS) is presently a very effective concept to be applied in the mitigation of the effects caused by large earthquakes. For the mentioned area a feasibility study of a EEWS was made in the ALERT-ES project. It was found that the <span class="hlt">system</span> could be effective to protect cities and infrastructures located at larger distances (ex: Lisbon) from the areas, located south and southwest of PT mainland, where the larger earthquakes are expected to be originated. Considering the use of a new strong-motion network recently implemented in the south of PT mainland, we concluded that the lead-times could be improved. We opted by the implementation of the well known computational platform PRESTO. In the adaptation of the mentioned platform to the local reality one of the challenges was the computation of fast moment magnitude estimates, because regional attenuation must be properly considered, and a specific study was made on this issue. The several simulations that were performed showed a reasonably good performance of the <span class="hlt">system</span>, both on magnitude evaluation and epicentre location. However we also noted that the problems in the acquisition instruments are a very important source of disturbance in the performance of the EEWS, pointing to a need of a very accurate quality control of the strong-motion network. Considering end-users, we are also developing specific software for intensity estimation at the target places and to trigger visual and audio alerts in accordance to the expected level of shaking. This work is supported by the EU project TSUMAPS-NEAM, Agreement Number</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29350212','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29350212"><span>Defining <span class="hlt">System</span> <span class="hlt">Boundaries</span> of an Institution Nitrogen Footprint.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>de la Reguera, Elizabeth; Castner, Elizabeth A; Galloway, James N; Leach, Allison M; Leary, Neil; Tang, Jianwu</p> <p>2017-04-01</p> <p>A nitrogen (N) footprint quantifies the amount of reactive nitrogen released to the environment and can be measured at different scales. The N footprint of a university includes activities and consumption within its geographic <span class="hlt">boundaries</span> as well as activities that support the institution. Determining <span class="hlt">system</span> bounds of an N footprint depends on the institution's mission and provides a common baseline for comparison. A comparison of three scopes of the N footprint, which describe how emissions are directly related to an institution's activities, was conducted for seven institutions. Scopes follow the established definition for the carbon footprint. In this article, the authors propose a new <span class="hlt">system</span> bounds definition (core campus versus adjunct). Two case studies were explored: how the N footprint of Dickinson College changed with air travel, and how the N footprint of the Marine Biological Laboratory changed with scientific research. Of the three scopes, scope 3 was consistently the largest proportion of the N footprint for all seven institutions. The core campus activities of Dickinson College made up 99 percent of its N footprint, with air travel making up the remaining 1 percent. The Marine Biological Laboratory's core campus activities made up 51 percent of its N footprint and the scientific research made up the remaining 49 percent. Institutions should define <span class="hlt">system</span> bounds based on their mission and stay consistent with their <span class="hlt">boundaries</span> following the baseline year. The core campus footprint could be used to compare institution footprints using consistent <span class="hlt">system</span> bounds. How institutions define their <span class="hlt">boundaries</span> will impact the recorded amount of nitrogen as well as how the institution will set reduction strategies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5765841','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5765841"><span>Defining <span class="hlt">System</span> <span class="hlt">Boundaries</span> of an Institution Nitrogen Footprint</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Castner, Elizabeth A.; Galloway, James N.; Leach, Allison M.; Leary, Neil; Tang, Jianwu</p> <p>2017-01-01</p> <p>Abstract A nitrogen (N) footprint quantifies the amount of reactive nitrogen released to the environment and can be measured at different scales. The N footprint of a university includes activities and consumption within its geographic <span class="hlt">boundaries</span> as well as activities that support the institution. Determining <span class="hlt">system</span> bounds of an N footprint depends on the institution's mission and provides a common baseline for comparison. A comparison of three scopes of the N footprint, which describe how emissions are directly related to an institution's activities, was conducted for seven institutions. Scopes follow the established definition for the carbon footprint. In this article, the authors propose a new <span class="hlt">system</span> bounds definition (core campus versus adjunct). Two case studies were explored: how the N footprint of Dickinson College changed with air travel, and how the N footprint of the Marine Biological Laboratory changed with scientific research. Of the three scopes, scope 3 was consistently the largest proportion of the N footprint for all seven institutions. The core campus activities of Dickinson College made up 99 percent of its N footprint, with air travel making up the remaining 1 percent. The Marine Biological Laboratory's core campus activities made up 51 percent of its N footprint and the scientific research made up the remaining 49 percent. Institutions should define <span class="hlt">system</span> bounds based on their mission and stay consistent with their <span class="hlt">boundaries</span> following the baseline year. The core campus footprint could be used to compare institution footprints using consistent <span class="hlt">system</span> bounds. How institutions define their <span class="hlt">boundaries</span> will impact the recorded amount of nitrogen as well as how the institution will set reduction strategies. PMID:29350212</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997SPIE.3031..397P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997SPIE.3031..397P"><span>Multimedia <span class="hlt">systems</span> in ultrasound image <span class="hlt">boundary</span> detection and measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pathak, Sayan D.; Chalana, Vikram; Kim, Yongmin</p> <p>1997-05-01</p> <p>Ultrasound as a medical imaging modality offers the clinician a real-time of the anatomy of the internal organs/tissues, their movement, and flow noninvasively. One of the applications of ultrasound is to monitor fetal growth by measuring biparietal diameter (BPD) and head circumference (HC). We have been working on automatic detection of fetal head <span class="hlt">boundaries</span> in ultrasound images. These detected <span class="hlt">boundaries</span> are used to measure BPD and HC. The <span class="hlt">boundary</span> detection algorithm is based on active contour models and takes 32 seconds on an external high-end workstation, SUN SparcStation 20/71. Our goal has been to make this tool available within an ultrasound machine and at the same time significantly improve its performance utilizing multimedia technology. With the advent of high- performance programmable digital signal processors (DSP), the software solution within an ultrasound machine instead of the traditional hardwired approach or requiring an external computer is now possible. We have integrated our <span class="hlt">boundary</span> detection algorithm into a programmable ultrasound image processor (PUIP) that fits into a commercial ultrasound machine. The PUIP provides both the high computing power and flexibility needed to support computationally-intensive image processing algorithms within an ultrasound machine. According to our data analysis, BPD/HC measurements made on PUIP lie within the interobserver variability. Hence, the errors in the automated BPD/HC measurements using the algorithm are on the same order as the average interobserver differences. On PUIP, it takes 360 ms to measure the values of BPD/HC on one head image. When processing multiple head images in sequence, it takes 185 ms per image, thus enabling 5.4 BPD/HC measurements per second. Reduction in the overall execution time from 32 seconds to a fraction of a second and making this multimedia <span class="hlt">system</span> available within an ultrasound machine will help this image processing algorithm and other computer-intensive imaging</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1985/0288/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1985/0288/report.pdf"><span>Description and Preliminary Testing of the CDSN <span class="hlt">Seismic</span> Sensor <span class="hlt">Systems</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>Peterson, Jon; Tilgner, Edwin E.</p> <p>1985-01-01</p> <p>INTRODUCTION The China Digital Seismograph Network (CDSN) is being designed and installed to provide the People's Republic of China with the facilities needed to create a national digital database for earthquake research. The CDSN, which is being developed jointly by the PRC State Seismological Bureau and the U.S. Geological Survey, will consist initially of nine digitally-recording seismograph stations, a data management <span class="hlt">system</span> to be used for compiling network-day tapes, and a depot maintenance center. Data produced by the network will be shared with research scientists throughout the world. A national seismograph network must be designed to support a variety of research objectives. From this standpoint, the choices and tradeoffs involved in specifying signal bandwidth, resolution, and dynamic range are the most important decisions in <span class="hlt">system</span> design. As in the case of the CDSN, these decisions are made during the selection and design of the <span class="hlt">seismic</span> sensor <span class="hlt">system</span> and encoder components. The purpose of this report is to describe the CDSN sensor <span class="hlt">systems</span>, their important signal characteristics, and the results of preliminary tests that have been performed on the instruments. Four overlapping data bands will be recorded at each station: short period (SP), broadband (BB), long period (LP), and very long period (VLP). Amplitude response curves are illustrated in Figure I. Vertical and horizontal components will be recorded for each data band. The SP and LP channels will be recorded with sufficient sensitivities to resolve earth background noise at <span class="hlt">seismically</span> quiet sites. The BB channels will have a lower sensitivity and are intended for broadband recording of moderate-to-large body-wave signals and for increasing the effective amplitude range in the short- and long-period bands. The VLP channel does not provide additional spectral coverage at long periods; its purpose is to make use of on-site filtration and decimation to reduce post processing requirements for VLP</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70001345','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70001345"><span>Recurrence of <span class="hlt">seismic</span> migrations along the central California segment of the San Andreas fault <span class="hlt">system</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>Wood, M.D.; Allen, S.S.</p> <p>1973-01-01</p> <p>VERIFICATIONS of tectonic concepts1 concerning seafloor spreading are emerging in a manner that has direct bearing on earthquake prediction. Although the gross pattern of worldwide <span class="hlt">seismicity</span> contributed to the formulation of the plate tectonic hypothesis, it is the space-time characteristics of this <span class="hlt">seismicity</span> that may contribute more toward understanding the kinematics and dynamics of the driving mechanism long speculated to originate in the mantle. If the lithosphere is composed of plates that move essentially as rigid bodies, then there should be <span class="hlt">seismic</span> edge effects associated with this movement. It is these interplate effects, especially <span class="hlt">seismic</span> migration patterns, that we discuss here. The unidirectional propagation at constant velocity (80 km yr-1 east to west) for earthquakes (M???7.2) on the Antblian fault for the period 1939 to 1956 (ref. 2) is one of the earliest observations of such a phenomenon. Similar studies3,4 of the Alaska Aleutian <span class="hlt">seismic</span> zone and certain regions of the west coast of South America suggest unidirectional and recurring migrations of earthquakes (M???7.7) occur in these areas. Between these two regions along the great transform faults of the west coast of North America, there is some evidence 5 for unidirectional, constant velocity and recurrent migration of great earthquakes. The small population of earthquakes (M>7.2) in Savage's investigation5 indicates a large spatial gap along the San Andreas <span class="hlt">system</span> in central California from 1830 to 1970. Previous work on the <span class="hlt">seismicity</span> of this gap in central California indicates that the recurrence curves remain relatively constant, independent of large earthquakes, for periods up to a century6. Recurrence intervals for earthquakes along the San Andreas Fault have been calculated empirically by Wallace7 on the basis of geological evidence, surface measurements and assumptions restricted to the surficial <span class="hlt">seismic</span> layer. Here we examine the evidence for recurrence of <span class="hlt">seismic</span> migrations along</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.V53A3063L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.V53A3063L"><span>VLP <span class="hlt">seismicity</span> from resonant modes of acoustic-gravity waves in a conduit-crack <span class="hlt">system</span> filled with multiphase magma</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.; Prochnow, B. N.; OReilly, O. J.; Dunham, E. M.; Karlstrom, L.</p> <p>2016-12-01</p> <p>Oscillation of magma in volcanic conduits connected to cracks (dikes and sills) has been suggested as an explanation for very long period (VLP) <span class="hlt">seismic</span> signals recorded at active basaltic volcanoes such as. Kilauea, Hawaii, and Erebus, Antarctica. We investigate the VLP <span class="hlt">seismicity</span> using a linearized model for waves in and associated eigenmodes of a coupled conduit-crack <span class="hlt">system</span> filled with multiphase magma, an extension of the Karlstrom and Dunham (2016) model for acoustic-gravity waves in volcanic conduits. We find that the long period surface displacement (as recorded on broadband seismometers) is dominated by opening/closing of the crack rather than the deformation of the conduit conduit walls. While the fundamental eigenmode is sensitive to the fluid properties and the geometry of the magma plumbing <span class="hlt">system</span>, a closer scrutiny of various resonant modes reveals that the surface displacement is often more sensitive to higher modes. Here we present a systematic analysis of various long period acoustic-gravity wave resonant modes of a coupled conduit-crack <span class="hlt">system</span> that the surface displacement is most sensitive to. We extend our previous work on a quasi-one-dimensional conduit model with inviscid magma to a more general axisymmetric conduit model that properly accounts for viscous <span class="hlt">boundary</span> layers near the conduit walls, based on the numerical method developed by Prochnow et al. (submitted to Computers and Fluids, 2016). The surface displacement is dominated by either the fundamental or higher eigenmodes, depending on magma properties and the geometry of conduit and crack. An examination of the energetics of these modes reveals the complex interplay of different restoring forces (magma compressibility in the conduit, gravity, and elasticity of the crack) driving the VLP oscillations. Both nonequilibrium bubble growth and resorption and viscosity contribute to the damping of VLP signals. Our models thus provide a means to infer properties of open-vent basaltic volcanoes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA162539','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA162539"><span>Comprehensive Final Report for the Marine <span class="hlt">Seismic</span> <span class="hlt">System</span> Program</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1985-08-01</p> <p>Executive summary g ■ -■• < ".• v>:.* From 1981 through 1983, the Defense Advanced Research Projects Agency funded the National Science...S. Government. Per Mr. J. A. Ballard, NORDA/Code 360 Accesion For NTIS CRA&I DUG TAB Unannou.iCed Justification G D By Distib...n>r" Analysis of Ambient <span class="hlt">Seismic</span> Noise Recorded by Downhole and Ocean-Bottom Seismometers on Dee: Sea Drilling Project Leg 78B Richard G</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.T41C2610C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.T41C2610C"><span>Deep <span class="hlt">Seismic</span> Reflection Images across a Major Reactivated Fracture Zone in the Wharton Basin: Implications for the Location of the Plate <span class="hlt">Boundary</span> between India and Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carton, H. D.; Singh, S. C.; Hananto, N. D.; Martin, J.; Djajadihardja, Y. S.; Udrekh, U.; Franke, D.; Gaedicke, C.</p> <p>2012-12-01</p> <p>The equatorial Indian Ocean has long been recognized to be hosting extensive "intra-plate" deformation. To west of the Ninety-East Ridge (NER), The Central Indian Ocean Basin is characterized by N-S compression in a broad region with E-W trending folds and high-angle reverse faulting. To the east of NER in the Wharton Basin, deformation mainly occurs along reactivated N5°E-trending oceanic fracture zones with left-lateral strike-slip motion. Near longitude 93°E in the Wharton Basin runs a major reactivated fracture zone, along which the epicenters of the two recent Mw=8.6 and Mw=8.2 strike-slip earthquakes of April 11, 2012, and an Mw=7.2 foreshock that occurred in January 2012 are aligned. The April 11 events are the largest known oceanic events occurring away from the main plate <span class="hlt">boundaries</span>. They ruptured a 20-40 km thick section of the oceanic lithosphere, i.e. down to depths at which no direct images of fault zones have been obtained so far. Deep <span class="hlt">seismic</span> reflection data acquired in the Mw=8.6 earthquake rupture zone ~100 km north of the epicenter shows the presence of sub-Moho reflectivity down to 37 km depth in the oceanic mantle. We interpret these events as reflections off the earthquake-generating fault plane in the oceanic mantle, in accordance with results suggesting that brittle deformation of the oceanic lithosphere extends well into the mantle down to the 600°C isotherm. The fracture zone near 93°E separates lithospheres of contrasting crustal thicknesses (3.5-4.5 km versus 6 km) with a 10 Ma age difference, and therefore seems to act as a rheological <span class="hlt">boundary</span>. We find that the deep reflections could originate from either a plane trending approximately N105°E, at high angle to the fracture zone, or from the fracture zone itself if the dip of the fault surface decreases from nearly vertical in the sediments to about 45° in the oceanic mantle. We propose that this fracture zone is a major tectonic <span class="hlt">boundary</span> in the Wharton Basin, and that the three</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhA...51v5001P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhA...51v5001P"><span>Linking matrices in <span class="hlt">systems</span> with periodic <span class="hlt">boundary</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panagiotou, Eleni; Millett, Kenneth C.</p> <p>2018-06-01</p> <p>We study the linking matrix, a measure of entanglement for a collection of closed or open chains in 3-space based on the Gauss linking number. Periodic <span class="hlt">boundary</span> conditions (PBC) are often used in the simulation of physical <span class="hlt">systems</span> of filaments. To measure entanglement of closed or open chains in <span class="hlt">systems</span> employing PBC we use the periodic linking matrix, based on the periodic linking number, defined in Panagiotou (2015 J. Comput. Phys. 300 533–73). We study the properties of the periodic linking matrix as a function of cell size. We provide analytical results concerning the eigenvalues of the periodic linking matrix and show that some of them are invariant of cell-size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22308900-analysis-ancient-river-systems-seismic-time-slice-technique-case-study-northeast-malay-basin-offshore-terengganu-malaysia','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22308900-analysis-ancient-river-systems-seismic-time-slice-technique-case-study-northeast-malay-basin-offshore-terengganu-malaysia"><span>Analysis of ancient-river <span class="hlt">systems</span> by 3D <span class="hlt">seismic</span> time-slice technique: A case study in northeast Malay Basin, offshore Terengganu, Malaysia</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sulaiman, Noorzamzarina; Hamzah, Umar; Samsudin, Abdul Rahim</p> <p>2014-09-03</p> <p>Fluvial sandstones constitute one of the major clastic petroleum reservoir types in many sedimentary basins around the world. This study is based on the analysis of high-resolution, shallow (seabed to 500 m depth) 3D <span class="hlt">seismic</span> data which generated three-dimensional (3D) time slices that provide exceptional imaging of the geometry, dimension and temporal and spatial distribution of fluvial channels. The study area is in the northeast of Malay Basin about 280 km to the east of Terengganu offshore. The Malay Basin comprises a thick (> 8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The youngest (Miocene to Pliocene), post-rift successionmore » is dominated by a thick (1–5 km), cyclic succession of coastal plain and coastal deposits, which accumulated in a humid-tropical climatic setting. This study focuses on the Pleistocene to Recent (500 m thick) succession, which comprises a range of <span class="hlt">seismic</span> facies analysis of the two-dimensional (2D) <span class="hlt">seismic</span> sections, mainly reflecting changes in fluvial channel style and river architecture. The succession has been divided into four <span class="hlt">seismic</span> units (Unit S1-S4), bounded by basin-wide strata surfaces. Two types of <span class="hlt">boundaries</span> have been identified: 1) a <span class="hlt">boundary</span> that is defined by a regionally-extensive erosion surface at the base of a prominent incised valley (S3 and S4); 2) a sequence <span class="hlt">boundary</span> that is defined by more weakly-incised, straight and low-sinuosity channels which is interpreted as low-stand alluvial bypass channel <span class="hlt">systems</span> (S1 and S2). Each unit displays a predictable vertical change of the channel pattern and scale, with wide low-sinuosity channels at the base passing gradationally upwards into narrow high-sinuosity channels at the top. The wide variation in channel style and size is interpreted to be controlled mainly by the sea-level fluctuations on the widely flat Sunda land Platform.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AIPC.1614..629S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AIPC.1614..629S"><span>Analysis of ancient-river <span class="hlt">systems</span> by 3D <span class="hlt">seismic</span> time-slice technique: A case study in northeast Malay Basin, offshore Terengganu, Malaysia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sulaiman, Noorzamzarina; Hamzah, Umar; Samsudin, Abdul Rahim</p> <p>2014-09-01</p> <p>Fluvial sandstones constitute one of the major clastic petroleum reservoir types in many sedimentary basins around the world. This study is based on the analysis of high-resolution, shallow (seabed to 500 m depth) 3D <span class="hlt">seismic</span> data which generated three-dimensional (3D) time slices that provide exceptional imaging of the geometry, dimension and temporal and spatial distribution of fluvial channels. The study area is in the northeast of Malay Basin about 280 km to the east of Terengganu offshore. The Malay Basin comprises a thick (> 8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The youngest (Miocene to Pliocene), post-rift succession is dominated by a thick (1-5 km), cyclic succession of coastal plain and coastal deposits, which accumulated in a humid-tropical climatic setting. This study focuses on the Pleistocene to Recent (500 m thick) succession, which comprises a range of <span class="hlt">seismic</span> facies analysis of the two-dimensional (2D) <span class="hlt">seismic</span> sections, mainly reflecting changes in fluvial channel style and river architecture. The succession has been divided into four <span class="hlt">seismic</span> units (Unit S1-S4), bounded by basin-wide strata surfaces. Two types of <span class="hlt">boundaries</span> have been identified: 1) a <span class="hlt">boundary</span> that is defined by a regionally-extensive erosion surface at the base of a prominent incised valley (S3 and S4); 2) a sequence <span class="hlt">boundary</span> that is defined by more weakly-incised, straight and low-sinuosity channels which is interpreted as low-stand alluvial bypass channel <span class="hlt">systems</span> (S1 and S2). Each unit displays a predictable vertical change of the channel pattern and scale, with wide low-sinuosity channels at the base passing gradationally upwards into narrow high-sinuosity channels at the top. The wide variation in channel style and size is interpreted to be controlled mainly by the sea-level fluctuations on the widely flat Sunda land Platform.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E3SWC..2401008I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E3SWC..2401008I"><span>Wireless acquisition of multi-channel <span class="hlt">seismic</span> data using the Seismobile <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Isakow, Zbigniew</p> <p>2017-11-01</p> <p>This paper describes the wireless acquisition of multi-channel <span class="hlt">seismic</span> data using a specialized mobile <span class="hlt">system</span>, Seismobile, designed for subsoil diagnostics for transportation routes. The paper presents examples of multi-channel <span class="hlt">seismic</span> records obtained during <span class="hlt">system</span> tests in a configuration with 96 channels (4 landstreamers of 24-channel) and various <span class="hlt">seismic</span> sources. <span class="hlt">Seismic</span> waves were generated at the same point using different sources: a 5-kg hammer, a Gisco's source with a 90-kg pile-driver, and two other the pile-drivers of 45 and 70 kg. Particular attention is paid to the synchronization of source timing, the measurement of geometry by autonomous GPS <span class="hlt">systems</span>, and the repeatability of triggering measurements constrained by an accelerometer identifying the <span class="hlt">seismic</span> waveform. The tests were designed to the registration, reliability, and range of the wireless transmission of survey signals. The effectiveness of the automatic numbering of measuring modules was tested as the <span class="hlt">system</span> components were arranged and fixed to the streamers. After measurements were completed, the accuracy and speed of data downloading from the internal memory (SDHC 32GB WiFi) was determined. Additionally, the functionality of automatic battery recharging, the maximum survey duration, and the reliability of battery discharge signalling were assessed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S21A4392H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S21A4392H"><span>Open Source <span class="hlt">Seismic</span> Software in NOAA's Next Generation Tsunami Warning <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hellman, S. B.; Baker, B. I.; Hagerty, M. T.; Leifer, J. M.; Lisowski, S.; Thies, D. A.; Donnelly, B. K.; Griffith, F. P.</p> <p>2014-12-01</p> <p>The Tsunami Information technology Modernization (TIM) is a project spearheaded by National Oceanic and Atmospheric Administration to update the United States' Tsunami Warning <span class="hlt">System</span> software currently employed at the Pacific Tsunami Warning Center (Eva Beach, Hawaii) and the National Tsunami Warning Center (Palmer, Alaska). This entirely open source software project will integrate various <span class="hlt">seismic</span> processing utilities with the National Weather Service Weather Forecast Office's core software, AWIPS2. For the real-time and near real-time <span class="hlt">seismic</span> processing aspect of this project, NOAA has elected to integrate the open source portions of GFZ's SeisComP 3 (SC3) processing <span class="hlt">system</span> into AWIPS2. To provide for better tsunami threat assessments we are developing open source tools for magnitude estimations (e.g., moment magnitude, energy magnitude, surface wave magnitude), detection of slow earthquakes with the Theta discriminant, moment tensor inversions (e.g. W-phase and teleseismic body waves), finite fault inversions, and array processing. With our reliance on common data formats such as QuakeML and <span class="hlt">seismic</span> community standard messaging <span class="hlt">systems</span>, all new facilities introduced into AWIPS2 and SC3 will be available as stand-alone tools or could be easily integrated into other real time <span class="hlt">seismic</span> monitoring <span class="hlt">systems</span> such as Earthworm, Antelope, etc. Additionally, we have developed a template based design paradigm so that the developer or scientist can efficiently create upgrades, replacements, and/or new metrics to the <span class="hlt">seismic</span> data processing with only a cursory knowledge of the underlying SC3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.S53A1461H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.S53A1461H"><span>An Experimental <span class="hlt">Seismic</span> Data and Parameter Exchange <span class="hlt">System</span> for Tsunami Warning <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoffmann, T. L.; Hanka, W.; Saul, J.; Weber, B.; Becker, J.; Heinloo, A.; Hoffmann, M.</p> <p>2009-12-01</p> <p>For several years GFZ Potsdam is operating a global earthquake monitoring <span class="hlt">system</span>. Since the beginning of 2008, this <span class="hlt">system</span> is also used as an experimental <span class="hlt">seismic</span> background data center for two different regional Tsunami Warning <span class="hlt">Systems</span> (TWS), the IOTWS (Indian Ocean) and the interim NEAMTWS (NE Atlantic and Mediterranean). The SeisComP3 (SC3) software, developed within the GITEWS (German Indian Ocean Tsunami Early Warning <span class="hlt">System</span>) project, capable to acquire, archive and process real-time data feeds, was extended for export and import of individual processing results within the two clusters of connected SC3 <span class="hlt">systems</span>. Therefore not only real-time waveform data are routed to the attached warning centers through GFZ but also processing results. While the current experimental NEAMTWS cluster consists of SC3 <span class="hlt">systems</span> in six designated national warning centers in Europe, the IOTWS cluster presently includes seven centers, with another three likely to join in 2009/10. For NEAMTWS purposes, the GFZ virtual real-time <span class="hlt">seismic</span> network (GEOFON Extended Virtual Network -GEVN) in Europe was substantially extended by adding many stations from Western European countries optimizing the station distribution. In parallel to the data collection over the Internet, a GFZ VSAT hub for secured data collection of the EuroMED GEOFON and NEAMTWS backbone network stations became operational and first data links were established through this backbone. For the Southeast Asia region, a VSAT hub has been established in Jakarta already in 2006, with some other partner networks connecting to this backbone via the Internet. Since its establishment, the experimental <span class="hlt">system</span> has had the opportunity to prove its performance in a number of relevant earthquakes. Reliable solutions derived from a minimum of 25 stations were very promising in terms of speed. For important events, automatic alerts were released and disseminated by emails and SMS. Manually verified solutions are added as soon as they become</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996GeoRL..23.2413B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996GeoRL..23.2413B"><span>Strong scattering of short-period <span class="hlt">seismic</span> waves by the core-mantle <span class="hlt">boundary</span> and the P-diffracted wave</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bataille, Klaus; Lund, Fernando</p> <p></p> <p>We interpret the long-tail-in-time (up to 3 minutes) decay of short-period Pdiff as being due to multiple scattering within D″, which, for this purpose, is assumed to be an heterogeneous region with a low velocity zone just next to the core-mantle <span class="hlt">boundary</span>. A simple multiple scattering theory, generalized for a two-dimensional spherical geometry, provides good agreement with observations for values of the scattering and attenuation coefficients (η) of about 10-3 km-1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.U23B..01K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.U23B..01K"><span>Back-Projection Imaging of extended, diffuse <span class="hlt">seismic</span> sources in volcanic and hydrothermal <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kelly, C. L.; Lawrence, J. F.; Beroza, G. C.</p> <p>2017-12-01</p> <p>Volcanic and hydrothermal <span class="hlt">systems</span> exhibit a wide range of <span class="hlt">seismicity</span> that is directly linked to fluid and volatile activity in the subsurface and that can be indicative of imminent hazardous activity. Seismograms recorded near volcanic and hydrothermal <span class="hlt">systems</span> typically contain "noisy" records, but in fact, these complex signals are generated by many overlapping low-magnitude displacements and pressure changes at depth. Unfortunately, excluding times of high-magnitude eruptive activity that typically occur infrequently relative to the length of a <span class="hlt">system</span>'s entire eruption cycle, these signals often have very low signal-to-noise ratios and are difficult to identify and study using established <span class="hlt">seismic</span> analysis techniques (i.e. phase-picking, template matching). Arrays of short-period and broadband <span class="hlt">seismic</span> sensors are proven tools for monitoring short- and long-term changes in volcanic and hydrothermal <span class="hlt">systems</span>. Time-reversal techniques (i.e. back-projection) that are improved by additional <span class="hlt">seismic</span> observations have been successfully applied to locating volcano-<span class="hlt">seismic</span> sources recorded by dense sensor arrays. We present results from a new computationally efficient back-projection method that allows us to image the evolution of extended, diffuse sources of volcanic and hydrothermal <span class="hlt">seismicity</span>. We correlate short time-window seismograms from receiver-pairs to find coherent signals and propagate them back in time to potential source locations in a 3D subsurface model. The strength of coherent <span class="hlt">seismic</span> signal associated with any potential source-receiver-receiver geometry is equal to the correlation of the short time-windows of <span class="hlt">seismic</span> records at appropriate time lags as determined by the velocity structure and ray paths. We stack (sum) all short time-window correlations from all receiver-pairs to determine the cumulative coherence of signals at each potential source location. Through stacking, coherent signals from extended and/or repeating sources of short-period energy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900002914','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900002914"><span>Convergence results for pseudospectral approximations of hyperbolic <span class="hlt">systems</span> by a penalty type <span class="hlt">boundary</span> treatment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Funaro, Daniele; Gottlieb, David</p> <p>1989-01-01</p> <p>A new method of imposing <span class="hlt">boundary</span> conditions in the pseudospectral approximation of hyperbolic <span class="hlt">systems</span> of equations is proposed. It is suggested to collocate the equations, not only at the inner grid points, but also at the <span class="hlt">boundary</span> points and use the <span class="hlt">boundary</span> conditions as penalty terms. In the pseudo-spectral Legrendre method with the new <span class="hlt">boundary</span> treatment, a stability analysis for the case of a constant coefficient hyperbolic <span class="hlt">system</span> is presented and error estimates are derived.</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('https://ntrs.nasa.gov/search.jsp?R=19950054992&hterms=plate+tectonics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dplate%2Btectonics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950054992&hterms=plate+tectonics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dplate%2Btectonics"><span>Topography and tectonics of the central New Madrid <span class="hlt">seismic</span> zone: Results of numerical experiements using a three-dimensional <span class="hlt">boundary</span> element program</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gomberg, Joan; Ellis, Michael</p> <p>1994-01-01</p> <p>We present results of a series of numerical experiments designed to test hypothetical mechanisms that derive deformation in the New Madrid <span class="hlt">seismic</span> zone. Experiments are constrained by subtle topography and the distribution of <span class="hlt">seismicity</span> in the region. We use a new <span class="hlt">boundary</span> element algorithm that permits calcuation of the three-dimensional deformation field. Surface displacement fields are calculated for the New Madrid zone under both far-field (plate tectonics scale) and locally derived driving strains. Results demonstrate that surface displacement fields cannot distinguish between either a far-field simple or pure shear strain field or one that involves a deep shear zone beneath the upper crustal faults. Thus, neither geomorphic nor geodetic studies alone are expected to reveal the ultimate driving mechanism behind the present-day deformation. We have also tested hypotheses about strain accommodation within the New Madrid contractional step-over by including linking faults, two southwest dipping and one vertical, recently inferred from microearthquake data. Only those models with step-over faults are able to predict the observed topography. Surface displacement fields for long-term, relaxed deformation predict the distribution of uplift and subsidence in the contractional step-over remarkably well. Generation of these displacement fields appear to require slip on both the two northeast trending vertical faults and the two dipping faults in the step-over region, with very minor displacements occurring during the interseismic period when the northeast trending vertical faults are locked. These models suggest that the gently dippling central step-over fault is a reverse fault and that the steeper fault, extending to the southeast of the step-over, acts as a normal fault over the long term.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhDT.......358C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhDT.......358C"><span>Artificial neural <span class="hlt">systems</span> for interpretation and inversion of <span class="hlt">seismic</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Calderon-Macias, Carlos</p> <p></p> <p>The goal of this work is to investigate the feasibility of using neural network (NN) models for solving geophysical exploration problems. First, a feedforward neural network (FNN) is used to solve inverse problems. The operational characteristics of a FNN are primarily controlled by a set of weights and a nonlinear function that performs a mapping between two sets of data. In a process known as training, the FNN weights are iteratively adjusted to perform the mapping. After training, the computed weights encode important features of the data that enable one pattern to be distinguished from another. Synthetic data computed from an ensemble of earth models and the corresponding models provide the training data. Two training methods are studied: the backpropagation method which is a gradient scheme, and a global optimization method called very fast simulated annealing (VFSA). A trained network is then used to predict models from new data (e.g., data from a new location) in a one-step procedure. The application of this method to the problems of obtaining formation resistivities and layer thicknesses from resistivity sounding data and 1D velocity models from <span class="hlt">seismic</span> data shows that trained FNNs produce reasonably accurate earth models when observed data are input to the FNNs. In a second application, a FNN is used for automating the NMO correction process of <span class="hlt">seismic</span> reflection data. The task of the FNN is to map CMP data at control locations along a <span class="hlt">seismic</span> line into subsurface velocities. The network is trained while the velocity analyses are performed at the control locations. Once trained, the computed weights are used as an operator that acts on the remaining CMP data as a velocity interpolator, resulting in a fast method for NMO correction. The second part of this dissertation describes the application of a Hopfield neural network (HNN) to the problems of deconvolution and multiple attenuation. In these applications, the unknown parameters (reflection coefficients</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SMaS...25e5030G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SMaS...25e5030G"><span>An innovative <span class="hlt">seismic</span> bracing <span class="hlt">system</span> based on a superelastic shape memory alloy ring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Nan; Jeon, Jong-Su; Hodgson, Darel E.; DesRoches, Reginald</p> <p>2016-05-01</p> <p>Shape memory alloys (SMAs) have great potential in <span class="hlt">seismic</span> applications because of their remarkable superelasticity. <span class="hlt">Seismic</span> bracing <span class="hlt">systems</span> based on SMAs can mitigate the damage caused by earthquakes. The current study investigates a bracing <span class="hlt">system</span> based on an SMA ring which is capable of both re-centering and energy dissipation. This lateral force resisting <span class="hlt">system</span> is a cross-braced <span class="hlt">system</span> consisting of an SMA ring and four tension-only cable assemblies, which can be applied to both new construction and <span class="hlt">seismic</span> retrofit. The performance of this bracing <span class="hlt">system</span> is examined through a quasi-static cyclic loading test and finite element (FE) analysis. This paper describes the experimental design in detail, discusses the experimental results, compares the performance with other bracing <span class="hlt">systems</span> based on SMAs, and presents an Abaqus FE model calibrated on the basis of experimental results to simulate the superelastic behavior of the SMA ring. The experimental results indicate that the <span class="hlt">seismic</span> performance of this <span class="hlt">system</span> is promising in terms of damping and re-centering. The FE model can be used in the simulation of building structures using the proposed bracing <span class="hlt">system</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100040700','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100040700"><span><span class="hlt">Boundary</span>-layer-ingesting inlet flow control <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Owens, Lewis R. (Inventor); Allan, Brian G. (Inventor)</p> <p>2010-01-01</p> <p>A <span class="hlt">system</span> for reducing distortion at the aerodynamic interface plane of a <span class="hlt">boundary</span>-layer-ingesting inlet using a combination of active and passive flow control devices is disclosed. Active flow control jets and vortex generating vanes are used in combination to reduce distortion across a range of inlet operating conditions. Together, the vortex generating vanes can reduce most of the inlet distortion and the active flow control jets can be used at a significantly reduced control jet mass flow rate to make sure the inlet distortion stays low as the inlet mass flow rate varies. Overall inlet distortion, measured and described as average SAE circumferential distortion descriptor, was maintained at a value of 0.02 or less. Advantageous arrangements and orientations of the active flow control jets and the vortex generating vanes were developed using computational fluid dynamics simulations and wind tunnel experimentations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810043543&hterms=collection+evaluation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcollection%2Bevaluation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810043543&hterms=collection+evaluation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcollection%2Bevaluation"><span>A <span class="hlt">seismic</span> signal processor suitable for use with the NOAA/GOES satellite data collection <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Webster, W. J., Jr.; Miller, W. H.; Whitley, R.; Allenby, R. J.; Dennison, R. T.</p> <p>1981-01-01</p> <p>Because of the high data-rate requirements, a practical <span class="hlt">system</span> capable of collecting <span class="hlt">seismic</span> information in the field and relaying it, via satellite, to a central collection point is not yet available. A <span class="hlt">seismic</span> signal processor has been developed and tested for use with the NOAA/GOES satellite data collection <span class="hlt">system</span>. Performance tests on recorded, as well as real time, short period signals indicate that the event recognition technique used is nearly perfect in its rejection of environmental noise and other non-<span class="hlt">seismic</span> signals and that, with the use of solid state buffer memories, data can be acquired in many swarm situations. The design of a complete field data collection platform is discussed based on the prototype evaluation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.8478G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.8478G"><span>Protective <span class="hlt">system</span> for civil buildings and industrial structures subjected to the <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>Ghica, D.; Grigore, A.; Ionescu, C.</p> <p>2009-04-01</p> <p>Romania is a European country with significant <span class="hlt">seismicity</span>. The most active <span class="hlt">seismic</span> zone is represented by the Vrancea area, located within the arch of the Carpathians Mountains. Vrancea <span class="hlt">seismicity</span> is characterized by intermediate depth earthquakes which occur in a narrow epicentral and hypocentral region. During the last 70 years, Romania experienced four strong Vrancea earthquakes: 10 November 1940 (Mw =7.7, 160 km depth), 4 March 1977 (Mw =7.5, 100 km depth), 30 August 1986 (Mw =7.2, 140 km depth), 30 May 30 1990 (Mw =6.9, 80 km depth). The 1977 event was characterized by catastrophic consequences: 1500 casualties and collapsing of 35 high-risk buildings, mostly occurring in Bucharest. The purpose of this paper is to present a protective <span class="hlt">system</span> designed to be installed in the civil buildings and industrial structures placed in the high <span class="hlt">seismic</span> regions, and therefore to contribute to the mitigation of the strong earthquake effects on human society. This <span class="hlt">system</span> proposes an efficient antiseismic protection, respectively shutting down the installations and equipments mounted in the building's infrastructure, which can become extremely dangerous in case of a major earthquake by appearing the possibility of explosions, deflagration, fires, toxic and polluting fluids leakage. The damages are strongly amplified by the fact that, simultaneously, water and electric energy lines distributions are damaged too, making impossible an efficient firemen intervention, for localizing the fire sources. Moreover, the installations of the individual heating stations which operate with open flame increase the risk of explosions inside the buildings during an earthquake. The protective <span class="hlt">system</span> consists of a <span class="hlt">seismic</span> switch used for activating through weak-electric-currents of the building's safety <span class="hlt">systems</span> in case of strong earthquake, especially designed for building's elevators, as well as for moving parts of installations, which require positioning in safety place areas. The originality</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70037507','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70037507"><span><span class="hlt">Seismic</span> imaging of a fractured gas hydrate <span class="hlt">system</span> in the Krishna-Godavari Basin offshore India</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Riedel, M.; Collett, T.S.; Kumar, P.; Sathe, A.V.; Cook, A.</p> <p>2010-01-01</p> <p>Gas hydrate was discovered in the Krishna-Godavari (KG) Basin during the India National Gas Hydrate Program (NGHP) Expedition 1 at Site NGHP-01-10 within a fractured clay-dominated sedimentary <span class="hlt">system</span>. Logging-while-drilling (LWD), coring, and wire-line logging confirmed gas hydrate dominantly in fractures at four borehole sites spanning a 500m transect. Three-dimensional (3D) <span class="hlt">seismic</span> data were subsequently used to image the fractured <span class="hlt">system</span> and explain the occurrence of gas hydrate associated with the fractures. A <span class="hlt">system</span> of two fault-sets was identified, part of a typical passive margin tectonic setting. The LWD-derived fracture network at Hole NGHP-01-10A is to some extent seen in the <span class="hlt">seismic</span> data and was mapped using <span class="hlt">seismic</span> coherency attributes. The fractured <span class="hlt">system</span> around Site NGHP-01-10 extends over a triangular-shaped area of ~2.5 km2 defined using <span class="hlt">seismic</span> attributes of the seafloor reflection, as well as " <span class="hlt">seismic</span> sweetness" at the base of the gas hydrate occurrence zone. The triangular shaped area is also showing a polygonal (nearly hexagonal) fault pattern, distinct from other more rectangular fault patterns observed in the study area. The occurrence of gas hydrate at Site NGHP-01-10 is the result of a specific combination of tectonic fault orientations and the abundance of free gas migration from a deeper gas source. The triangular-shaped area of enriched gas hydrate occurrence is bound by two faults acting as migration conduits. Additionally, the fault-associated sediment deformation provides a possible migration pathway for the free gas from the deeper gas source into the gas hydrate stability zone. It is proposed that there are additional locations in the KG Basin with possible gas hydrate accumulation of similar tectonic conditions, and one such location was identified from the 3D <span class="hlt">seismic</span> data ~6 km NW of Site NGHP-01-10. ?? 2010.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1612541D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1612541D"><span>High-precision relocation of induced <span class="hlt">seismicity</span> in the geothermal <span class="hlt">system</span> below 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>Diehl, Tobias; Kraft, Toni; Eduard, Kissling; Nicholas, Deichmann; Clinton, John; Wiemer, Stefan</p> <p>2014-05-01</p> <p>From July to November 2013 a sequence of more than 850 events, of which more than 340 could be located, was triggered in a planned hydrothermal <span class="hlt">system</span> below the city of St. Gallen in eastern Switzerland. <span class="hlt">Seismicity</span> initiated on July 14 and the maximum Ml in the sequence was 3.5, comparable in size with the Ml 3.4 event induced by stimulation below Basel in 2006. To improve absolute locations of the sequence, more than 1000 P and S wave arrivals were inverted for hypocenters and 1D velocity structure. Vp of 5.6-5.8 km/s and a Vp/Vs ratio of 1.82-1.9 in the source region indicate a limestone or shale-type composition and a comparison with a lithological model from a 3D <span class="hlt">seismic</span> model suggests that the <span class="hlt">seismically</span> active streak (height up to 400 m) is within the Mesozoic layer. To resolve the fine structure of the induced <span class="hlt">seismicity</span>, we applied waveform cross-correlation and double-difference algorithms. The results image a NE-SW striking lineament, consistent with a left-lateral fault plane derived from first motion polarities and moment tensor inversions. A spatio-temporal analysis of the relocated <span class="hlt">seismicity</span> shows that, during first acid jobs on July 17, microseismicity propagated towards southwest over the entire future Ml 3.5 rupture plane. The almost vertical focal plane associated with the Ml 3.5 event of July 20 is well imaged by the <span class="hlt">seismicity</span>. The area of the ruptured fault is approximately 675x400 m. <span class="hlt">Seismicity</span> images a change in focal depths along strike, which correlates with a kink or bend in the mapped fault <span class="hlt">system</span> northeast of the Ml 3.5 event. This change might indicate structural differences or a segmentation of the fault. Following the Ml 3.5 event, <span class="hlt">seismicity</span> propagated along strike to the northeast, in a region without any mapped faults, indicating a continuation of the fault segment. <span class="hlt">Seismicity</span> on this segment occurred in September and October. A complete rupture of the NE segment would have the potential to produce a magnitude larger than 3</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1916541I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1916541I"><span><span class="hlt">Seismic</span> and structural characterization of the fluid bypass <span class="hlt">system</span> using 3D and partial stack <span class="hlt">seismic</span> from passive margin: inside the plumbing <span class="hlt">system</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iacopini, David; Maestrelli, Daniele; Jihad, Ali; Bond, Clare; Bonini, Marco</p> <p>2017-04-01</p> <p>In recent years enormous attention has been paid to the understanding of the process and mechanism controlling the gas seepage and more generally the fluid expulsion affecting the earth <span class="hlt">system</span> from onshore to offshore environment. This is because of their demonstrated impact to our environment, climate change and during subsea drilling operation. Several example from active and paleo <span class="hlt">system</span> has been so far characterized and proposed using subsurface exploration, geophysical and geochemical monitoring technology approaches with the aims to explore what trigger and drive the overpressure necessary maintain the fluid/gas/material expulsion and what are the structure that act as a gateway for gaseous fluid and unconsolidated rock. In this contribution we explore a series of fluid escape structure (ranging from seepage pipes to large blowout pipes structure of km length) using 3D and partial stack <span class="hlt">seismic</span> data from two distinctive passive margin from the north sea (Loyal field, West Shetland) and the Equatorial Brazil (Ceara' Basin). We will focuses on the characterization of the plumbing <span class="hlt">system</span> internal architecture and, for selected example, exploring the AVO response (using partial stack) of the internal fluid/unconsolidated rock. The detailed <span class="hlt">seismic</span> mapping and <span class="hlt">seismic</span> attributes analysis of the conduit <span class="hlt">system</span> helped us to recover some detail from the signal response of the chimney internal structures. We observed: (1) small to medium seeps and pipes following structural or sedimentary discontinuities (2) large pipes (probably incipient mud volcanoes) and blowup structures propagating upward irrespective of pre-existing fault by hydraulic fracturing and assisted by the buoyancy of a fluidised and mobilised mud-hydrocarbon mixture. The reflector termination observed inside the main conduits, the distribution of stacked bright reflectors and the AVO analysis suggests an evolution of mechanisms (involving mixture of gas, fluid and probably mud) during pipe birth and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMOS43A1599A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMOS43A1599A"><span>Development of Vertical Cable <span class="hlt">Seismic</span> <span class="hlt">System</span> for Hydrothermal Deposit Survey (2) - Feasibility Study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asakawa, E.; Murakami, F.; Sekino, Y.; Okamoto, T.; Mikada, H.; Takekawa, J.; Shimura, T.</p> <p>2010-12-01</p> <p>In 2009, Ministry of Education, Culture, Sports, Science and Technology(MEXT) started the survey <span class="hlt">system</span> development for Hydrothermal deposit. We proposed the Vertical Cable <span class="hlt">Seismic</span> (VCS), the reflection <span class="hlt">seismic</span> survey with vertical cable above seabottom. VCS has the following advantages for hydrothermal deposit survey. . (1) VCS is an effective high-resolution 3D <span class="hlt">seismic</span> survey within limited area. (2) It achieves high-resolution image because the sensors are closely located to the target. (3) It avoids the coupling problems between sensor and seabottom that cause serious damage of <span class="hlt">seismic</span> data quality. (4) Various types of marine source are applicable with VCS such as sea-surface source (air gun, water gun etc.) , deep-towed or ocean bottom sources. (5) Autonomous recording <span class="hlt">system</span>. Our first experiment of 2D/3D VCS surveys has been carried out in Lake Biwa, JAPAN. in November 2009. The 2D VCS data processing follows the walk-away VSP, including wave field separation and depth migration. The result gives clearer image than the conventional surface <span class="hlt">seismic</span>. Prestack depth migration is applied to 3D data to obtain good quality 3D depth volume. Uncertainty of the source/receiver poisons in water causes the serious problem of the imaging. We used several transducer/transponder to estimate these positions. The VCS <span class="hlt">seismic</span> records themselves can also provide sensor position using the first break of each trace and we calibrate the positions. We are currently developing the autonomous recording VCS <span class="hlt">system</span> and planning the trial experiment in actual ocean to establish the way of deployment/recovery and the examine the position through the current flow in November, 2010. The second VCS survey will planned over the actual hydrothermal deposit with deep-towed source in February, 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914761M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914761M"><span>Data Analysis of <span class="hlt">Seismic</span> Sequence in Central Italy in 2016 using CTBTO- International Monitoring <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mumladze, Tea; Wang, Haijun; Graham, Gerhard</p> <p>2017-04-01</p> <p>The <span class="hlt">seismic</span> network that forms the International Monitoring <span class="hlt">System</span> (IMS) of the Comprehensive Nuclear-test-ban Treaty Organization (CTBTO) will ultimately consist of 170 <span class="hlt">seismic</span> stations (50 primary and 120 auxiliary) in 76 countries around the world. The Network is still under the development, but currently more than 80% of the network is in operation. The objective of <span class="hlt">seismic</span> monitoring is to detect and locate underground nuclear explosions. However, the data from the IMS also can be widely used for scientific and civil purposes. In this study we present the results of data analysis of the <span class="hlt">seismic</span> sequence in 2016 in Central Italy. Several hundred earthquakes were recorded for this sequence by the <span class="hlt">seismic</span> stations of the IMS. All events were accurately located the analysts of the International Data Centre (IDC) of the CTBTO. In this study we will present the epicentral and magnitude distribution, station recordings and teleseismic phases as obtained from the Reviewed Event Bulletin (REB). We will also present a comparison of the database of the IDC with the databases of the European-Mediterranean Seismological Centre (EMSC) and U.S. Geological Survey (USGS). Present work shows that IMS data can be used for earthquake sequence analyses and can play an important role in seismological research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.3376H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.3376H"><span>Autonomous telemetry <span class="hlt">system</span> by using mobile networks for a long-term <span class="hlt">seismic</span> observation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirahara, S.; Uchida, N.; Nakajima, J.</p> <p>2012-04-01</p> <p>When a large earthquake occurs, it is important to know the detailed distribution of aftershocks immediately after the main shock for the estimation of the fault plane. The large amount of <span class="hlt">seismic</span> data is also required to determine the three-dimensional <span class="hlt">seismic</span> velocity structure around the focal area. We have developed an autonomous telemetry <span class="hlt">system</span> using mobile networks, which is specialized for aftershock observations. Because the newly developed <span class="hlt">system</span> enables a quick installation and real-time data transmission by using mobile networks, we can construct a dense online <span class="hlt">seismic</span> network even in mountain areas where conventional wired networks are not available. This <span class="hlt">system</span> is equipped with solar panels that charge lead-acid battery, and enables a long-term <span class="hlt">seismic</span> observation without maintenance. Furthermore, this <span class="hlt">system</span> enables a continuous observation at low costs with flat-rate or prepaid Internet access. We have tried to expand coverage areas of mobile communication and back up Internet access by configuring plural mobile carriers. A micro server embedded with Linux consists of automatic control programs of the Internet connection and data transmission. A status monitoring and remote maintenance are available via the Internet. In case of a communication failure, an internal storage can back up data for two years. The power consumption of communication device ranges from 2.5 to 4.0 W. With a 50 Ah lead-acid battery, this <span class="hlt">system</span> continues to record data for four days if the battery charging by solar panels is temporarily unavailable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770008052','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770008052"><span>NASA Ames three-dimensional potential flow analyses <span class="hlt">system</span> (POTFAN) <span class="hlt">boundary</span> condition code (BCDN), version 1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Davis, J. E.; Medan, R. T.</p> <p>1977-01-01</p> <p>This segment of the POTFAN <span class="hlt">system</span> is used to generate right hand sides (<span class="hlt">boundary</span> conditions) of the <span class="hlt">system</span> of equations associated with the flow field under consideration. These specified flow <span class="hlt">boundary</span> conditions are encountered in the oblique derivative <span class="hlt">boundary</span> value problem (<span class="hlt">boundary</span> value problem of the third kind) and contain the Neumann <span class="hlt">boundary</span> condition as a special case. Arbitrary angle of attack and/or sideslip and/or rotation rates may be specified, as well as an arbitrary, nonuniform external flow field and the influence of prescribed singularity distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17466254','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17466254"><span>Flight decks and free flight: where are the <span class="hlt">system</span> <span class="hlt">boundaries</span>?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hollnagel, Erik</p> <p>2007-07-01</p> <p>The change from managed to free flight is expected to have large effects, over and above the intended efficiency gains. Human factor concerns have understandably focused on how free flight may affect the pilots in the cockpit. Yet it is necessary to see the change from managed to free flight as more than just an increment to the pilots' work. Despite the best intentions the transition will not be a case of a smooth, carefully planned and therefore uneventful introduction of a new technology. It is more likely to be a substantial change to an already challenging working environment, in the air as well as on the ground. The significant effects will therefore not just happen within the existing structure or distribution of work and responsibilities, but affect the structure of work itself. This paper takes a look at free flight from a cognitive <span class="hlt">systems</span> engineering perspective and identifies two major concerns: first what effects free flight has on the <span class="hlt">boundaries</span> of the joint cognitive <span class="hlt">systems</span>, and second how this affects demands to control. The conclusion is that both will change considerably and that we need to understand the nature of these changes before focusing on the possible effects of free flight on pilots' performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5507029-integrated-study-seismic-anisotropy-natural-fracture-system-conoco-borehole-test-facility-kay-county-oklahoma','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5507029-integrated-study-seismic-anisotropy-natural-fracture-system-conoco-borehole-test-facility-kay-county-oklahoma"><span>An integrated study of <span class="hlt">seismic</span> anisotropy and the natural fracture <span class="hlt">system</span> at the Conoco Borehole Test Facility, Kay County, Oklahoma</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Queen, J.H.; Rizer, W.D.</p> <p>1990-07-10</p> <p>A significant body of published work has developed establishing fracture-related <span class="hlt">seismic</span> anisotropy as an observable effect. To further the understanding of <span class="hlt">seismic</span> birefringence techniques in characterizing natural fracture <span class="hlt">systems</span> at depth, an integrated program of <span class="hlt">seismic</span> and geologic measurements has been conducted at Conoco's Borehole Test Facility in Kay County, Oklahoma. Birefringence parameters inferred from the <span class="hlt">seismic</span> data are consistent with a vertical fracture model of density 0.04 striking east-northeast. That direction is subparallel to a fracture set mapped both on the surface and from subsurface data, to the in situ maximum horizontal stress, and to the inferred microfabric.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/2006/3050/fs2006-3050.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/2006/3050/fs2006-3050.pdf"><span>Earthquake information products and tools from the Advanced National <span class="hlt">Seismic</span> <span class="hlt">System</span> (ANSS)</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wald, Lisa</p> <p>2006-01-01</p> <p>This Fact Sheet provides a brief description of postearthquake tools and products provided by the Advanced National <span class="hlt">Seismic</span> <span class="hlt">System</span> (ANSS) through the U.S. Geological Survey Earthquake Hazards Program. The focus is on products specifically aimed at providing situational awareness in the period immediately following significant earthquake events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4101210','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4101210"><span>The Effect Analysis of Strain Rate on Power Transmission Tower-Line <span class="hlt">System</span> under <span class="hlt">Seismic</span> Excitation</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, Wenming</p> <p>2014-01-01</p> <p>The effect analysis of strain rate on power transmission tower-line <span class="hlt">system</span> under <span class="hlt">seismic</span> excitation is studied in this paper. A three-dimensional finite element model of a transmission tower-line <span class="hlt">system</span> is created based on a real project. Using theoretical analysis and numerical simulation, incremental dynamic analysis of the power transmission tower-line <span class="hlt">system</span> is conducted to investigate the effect of strain rate on the nonlinear responses of the transmission tower and line. The results show that the effect of strain rate on the transmission tower generally decreases the maximum top displacements, but it would increase the maximum base shear forces, and thus it is necessary to consider the effect of strain rate on the <span class="hlt">seismic</span> analysis of the transmission tower. The effect of strain rate could be ignored for the <span class="hlt">seismic</span> analysis of the conductors and ground lines, but the responses of the ground lines considering strain rate effect are larger than those of the conductors. The results could provide a reference for the <span class="hlt">seismic</span> design of the transmission tower-line <span class="hlt">system</span>. PMID:25105157</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.2302K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.2302K"><span>Geological and <span class="hlt">Seismic</span> Data Mining For The Development of An Interpretation <span class="hlt">System</span> Within The Alptransit Project</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klose, C. D.; Giese, R.; Löw, S.; Borm, G.</p> <p></p> <p>Especially for deep underground excavations, the prediction of the locations of small- scale hazardous geotechnical structures is nearly impossible when exploration is re- stricted to surface based methods. Hence, for the AlpTransit base tunnels, exploration ahead has become an essential component of the excavation plan. The project de- scribed in this talk aims at improving the technology for the geological interpretation of reflection <span class="hlt">seismic</span> data. The discovered geological-<span class="hlt">seismic</span> relations will be used to develop an interpretation <span class="hlt">system</span> based on artificial intelligence to predict hazardous geotechnical structures of the advancing tunnel face. This talk gives, at first, an overview about the data mining of geological and <span class="hlt">seismic</span> properties of metamorphic rocks within the Penninic gneiss zone in Southern Switzer- land. The data results from measurements of a specific geophysical prediction <span class="hlt">system</span> developed by the GFZ Potsdam, Germany, along the 2600 m long and 1400 m deep Faido access tunnel. The goal is to find those <span class="hlt">seismic</span> features (i.e. compression and shear wave velocities, velocity ratios and velocity gradients) which show a significant relation to geological properties (i.e. fracturing and fabric features). The <span class="hlt">seismic</span> properties were acquired from different tomograms, whereas the geolog- ical features derive from tunnel face maps. The features are statistically compared with the <span class="hlt">seismic</span> rock properties taking into account the different methods used for the tunnel excavation (TBM and Drill/Blast). Fracturing and the mica content stay in a positive relation to the velocity values. Both, P- and S-wave velocities near the tunnel surface describe the petrology better, whereas in the interior of the rock mass they correlate to natural micro- and macro-scopic fractures surrounding tectonites, i.e. cataclasites. The latter lie outside of the excavation damage zone and the tunnel loos- ening zone. The shear wave velocities are better indicators for rock</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S21A2669S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S21A2669S"><span>a Borehole <span class="hlt">Seismic</span> <span class="hlt">System</span> for Active and Passive Seimsic Studies to 3 KM at Ptrc's Aquistore Project</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmitt, D. R.; Nixon, C.; Kofman, R.; White, D. J.; Worth, K.</p> <p>2015-12-01</p> <p>We have constructed a downhole <span class="hlt">seismic</span> recording <span class="hlt">system</span> for application to depths of nearly 3 km and temperatures up to 135 °C at Aquistore, an independent research and monitoring project in which liquid CO2 is being stored in a brine and sandstone water formation. The key component to this <span class="hlt">system</span> is a set of commercially available slim-hole 3-C sondes carrying 15 Hz geophones deployable in open and cased boreholes with diameters as small as 57 mm. The <span class="hlt">system</span> is currently hosted on a 4-conductor wireline with digital information streamed to the surface recording unit. We have further incorporated these sondes into a mobile passive monitoring unit that includes a number of redundancies such as a multiple Tbyte network accessible RAID hard-drive <span class="hlt">system</span> (NAS) and a self-designed uninterruptible power supply. The <span class="hlt">system</span> can be remotely controlled via the internet. The <span class="hlt">system</span> is currently deployed covering a range of depths from 2850 m to 2910 m. Ambient temperatures at this depth are approximately 110 °C with onboard tool temperatures running at 115 °C. Data is continuously streamed to the NAS for archiving, approximately 11 GBytes of data is recorded per day at the sampling period of 0.5 ms. The lack of noise at this depth allows short data snippets to be flagged with a simple amplitude threshold criteria. The greatly reduced data volume of the snippets allows for ready access via the internet to the <span class="hlt">system</span> for ongoing quality control. Spurious events, mostly small amplitude tube waves originating at or near the surface, are readily discounted. Active <span class="hlt">seismic</span> measurements are carried out simultaneously but these require that an appropriately accurate independent GPS based time synchronization be used. Various experiences with event detection, orientation of sondes using both explosives and <span class="hlt">seismic</span> vibrator, potential overheating of the surface electronics, and issues related to loss of shore power provide for a detailed case study. Aquistore, managed by the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.9569H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.9569H"><span>An Experimental <span class="hlt">Seismic</span> Data and Parameter Exchange <span class="hlt">System</span> for Interim NEAMTWS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hanka, W.; Hoffmann, T.; Weber, B.; Heinloo, A.; Hoffmann, M.; Müller-Wrana, T.; Saul, J.</p> <p>2009-04-01</p> <p>In 2008 GFZ Potsdam has started to operate its global earthquake monitoring <span class="hlt">system</span> as an experimental <span class="hlt">seismic</span> background data centre for the interim NEAMTWS (NE Atlantic and Mediterranean Tsunami Warning <span class="hlt">System</span>). The SeisComP3 (SC3) software, developed within the GITEWS (German Indian Ocean Tsunami Early Warning <span class="hlt">System</span>) project was extended to test the export and import of individual processing results within a cluster of SC3 <span class="hlt">systems</span>. The initiated NEAMTWS SC3 cluster consists presently of the 24/7 <span class="hlt">seismic</span> services at IMP, IGN, LDG/EMSC and KOERI, whereas INGV and NOA are still pending. The GFZ virtual real-time <span class="hlt">seismic</span> network (GEOFON Extended Virtual Network - GEVN) was substantially extended by many stations from Western European countries optimizing the station distribution for NEAMTWS purposes. To amend the public <span class="hlt">seismic</span> network (VEBSN - Virtual European Broadband <span class="hlt">Seismic</span> Network) some attached centres provided additional private stations for NEAMTWS usage. In parallel to the data collection by Internet the GFZ VSAT hub for the secured data collection of the EuroMED GEOFON and NEAMTWS backbone network stations became operational and the first data links were established. In 2008 the experimental <span class="hlt">system</span> could already prove its performance since a number of relevant earthquakes have happened in NEAMTWS area. The results are very promising in terms of speed as the automatic alerts (reliable solutions based on a minimum of 25 stations and disseminated by emails and SMS) were issued between 2 1/2 and 4 minutes for Greece and 5 minutes for Iceland. They are also promising in terms of accuracy since epicenter coordinates, depth and magnitude estimates were sufficiently accurate from the very beginning, usually don't differ substantially from the final solutions and provide a good starting point for the operations of the interim NEAMTWS. However, although an automatic <span class="hlt">seismic</span> <span class="hlt">system</span> is a good first step, 24/7 manned RTWCs are mandatory for regular manual verification</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('http://adsabs.harvard.edu/abs/2017EGUGA..1916199B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1916199B"><span>Shallow <span class="hlt">seismicity</span> in volcanic <span class="hlt">system</span>: what role does the edifice play?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bean, Chris; Lokmer, Ivan</p> <p>2017-04-01</p> <p><span class="hlt">Seismicity</span> in the upper two kilometres in volcanic <span class="hlt">systems</span> is complex and very diverse in nature. The origins lie in the multi-physics nature of source processes and in the often extreme heterogeneity in near surface structure, which introduces strong <span class="hlt">seismic</span> wave propagation path effects that often 'hide' the source itself. Other complicating factors are that we are often in the <span class="hlt">seismic</span> near-field so waveforms can be intrinsically more complex than in far-field earthquake seismology. The traditional focus for an explanation of the diverse nature of shallow <span class="hlt">seismic</span> signals is to call on the direct action of fluids in the <span class="hlt">system</span>. Fits to model data are then used to elucidate properties of the plumbing <span class="hlt">system</span>. Here we show that solutions based on these conceptual models are not unique and that models based on a diverse range of quasi-brittle failure of low stiffness near surface structures are equally valid from a data fit perspective. These earthquake-like sources also explain aspects of edifice deformation that are as yet poorly quantified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..230a2006L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..230a2006L"><span>The Experimental Research on <span class="hlt">Seismic</span> Capacity of the Envelope <span class="hlt">Systems</span> with Steel Frame</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Jiuyang; Wang, Bingbing; Li, Hengxu</p> <p>2017-09-01</p> <p>In this paper, according to the present application situation of the external envelope <span class="hlt">systems</span> steel frame in the severe cold region, the stuffed composite wall panels are improved, the flexible connection with the steel frame is designed, the reduced scale specimens are made, the <span class="hlt">seismic</span> capacity test is made and some indexes of the envelope <span class="hlt">systems</span> such as bearing capacity, energy consumption and ductility, etc. are compared, which provide reference for the development and application of the steel frame envelope <span class="hlt">systems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Tectp.622...44G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Tectp.622...44G"><span>The 2012 Emilia <span class="hlt">seismic</span> sequence (Northern Italy): Imaging the thrust fault <span class="hlt">system</span> by accurate aftershock location</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Govoni, Aladino; Marchetti, Alessandro; De Gori, Pasquale; Di Bona, Massimo; Lucente, Francesco Pio; Improta, Luigi; Chiarabba, Claudio; Nardi, Anna; Margheriti, Lucia; Agostinetti, Nicola Piana; Di Giovambattista, Rita; Latorre, Diana; Anselmi, Mario; Ciaccio, Maria Grazia; Moretti, Milena; Castellano, Corrado; Piccinini, Davide</p> <p>2014-05-01</p> <p>Starting from late May 2012, the Emilia region (Northern Italy) was severely shaken by an intense <span class="hlt">seismic</span> sequence, originated from a ML 5.9 earthquake on May 20th, at a hypocentral depth of 6.3 km, with thrust-type focal mechanism. In the following days, the <span class="hlt">seismic</span> rate remained high, counting 50 ML ≥ 2.0 earthquakes a day, on average. <span class="hlt">Seismicity</span> spreads along a 30 km east-west elongated area, in the Po river alluvial plain, in the nearby of the cities Ferrara and Modena. Nine days after the first shock, another destructive thrust-type earthquake (ML 5.8) hit the area to the west, causing further damage and fatalities. Aftershocks following this second destructive event extended along the same east-westerly trend for further 20 km to the west, thus illuminating an area of about 50 km in length, on the whole. After the first shock struck, on May 20th, a dense network of temporary <span class="hlt">seismic</span> stations, in addition to the permanent ones, was deployed in the meizoseismal area, leading to a sensible improvement of the earthquake monitoring capability there. A combined dataset, including three-component <span class="hlt">seismic</span> waveforms recorded by both permanent and temporary stations, has been analyzed in order to obtain an appropriate 1-D velocity model for earthquake location in the study area. Here we describe the main seismological characteristics of this <span class="hlt">seismic</span> sequence and, relying on refined earthquakes location, we make inferences on the geometry of the thrust <span class="hlt">system</span> responsible for the two strongest shocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PEPI..123...77W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PEPI..123...77W"><span>Comments on ``<span class="hlt">seismic</span> properties of the Eltanin transform <span class="hlt">system</span>, south Pacific'' by Emile A. Okal and Amy R. Langenhorst</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wessel, Paul; Kroenke, Loren W.</p> <p>2001-03-01</p> <p><span class="hlt">Seismicity</span> in the Eltanin transform <span class="hlt">system</span> region reflects the current relative motion between the Pacific and Antarctica plates. As such, the <span class="hlt">seismicity</span> provides little or no constraints on models for late Neogene Pacific absolute plate motion changes that in turn forced a synchronous change in relative plate motions resulting in the current relative plate motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.G14A..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.G14A..02B"><span>Crustal strain accumulation on Southern Basin and Range Province faults modulated by distant plate <span class="hlt">boundary</span> earthquakes? Evidence from geodesy, <span class="hlt">seismic</span> imaging, and paleoseismology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bennett, R. A.; Shirzaei, M.; Broermann, J.; Spinler, J. C.; Holland, A. A.; Pearthree, P.</p> <p>2014-12-01</p> <p>GPS in Arizona reveals a change in the pattern of crustal strain accumulation in 2010 and based on viscoelastic modeling appears to be associated with the distant M7.2 El Mayor-Cucapah (EMC) earthquake in Baja California, Mexico. GPS data collected between 1999 and 2009 near the Santa Rita normal fault in SE Arizona reveal a narrow zone of crustal deformation coincident with the fault trace, delineated by W-NW facing Pleistocene fault scarps of heights 1 to 7 m. The apparent deformation zone is also seen in a preliminary InSAR interferogram. Total motion across the zone inferred using an elastic block model constrained by the pre-2010 GPS measurements is ~1 mm/yr in a sense consistent with normal fault motion. However, continuous GPS measurements throughout Arizona reveal pronounced changes in crustal velocity following the EMC earthquake, such that the relative motion across the Santa Rita fault post-2010 is negligible. Paleoseismic evidence indicates that mapped Santa Rita fault scarps were formed by two or more large magnitude (M6.7 to M7.6) surface rupturing normal-faulting earthquakes 60 to 100 kyrs ago. <span class="hlt">Seismic</span> refraction and reflection data constrained by deep (~800 m) well log data provide evidence of progressive, possibly intermittent, displacement on the fault through time. The rate of strain accumulation observed geodetically prior to 2010, if constant over the past 60 to 100 kyrs, would imply an untenable minimum slip rate deficit of 60 to 100 m since the most recent earthquake. One explanation for the available geodetic, <span class="hlt">seismic</span>, and paleoseismic evidence is that strain accumulation is modulated by viscoelastic relaxation associated with frequent large magnitude earthquakes in the Salton Trough region, episodically inhibiting the accumulation of elastic strain required to generate large earthquakes on the Santa Rita and possibly other faults in the Southern Basin and Range. An important question is thus for how long the postseismic velocity changes</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 <span class="hlt">systems</span></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 <span class="hlt">systems</span> including steel-framed gypsum partition walls, suspended ceilings and fire sprinkler <span class="hlt">systems</span>. The frame can be configured to perform as an elastic or inelastic <span class="hlt">system</span> to generate large floor accelerations 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 <span class="hlt">systems</span> 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 <span class="hlt">systems</span> are investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860012733','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860012733"><span>On the <span class="hlt">boundary</span> treatment in spectral methods for hyperbolic <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Canuto, C.; Quarteroni, A.</p> <p>1986-01-01</p> <p>Spectral methods were successfully applied to the simulation of slow transients in gas transportation networks. Implicit time advancing techniques are naturally suggested by the nature of the problem. The correct treatment of the <span class="hlt">boundary</span> conditions are clarified in order to avoid any stability restriction originated by the <span class="hlt">boundaries</span>. The Beam and Warming and the Lerat schemes are unconditionally linearly stable when used with a Chebyshev pseudospectral method. Engineering accuracy for a gas transportation problem is achieved at Courant numbers up to 100.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870057722&hterms=treatment+gas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtreatment%2Bgas','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870057722&hterms=treatment+gas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtreatment%2Bgas"><span>On the <span class="hlt">boundary</span> treatment in spectral methods for hyperbolic <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Canuto, Claudio; Quarteroni, Alfio</p> <p>1987-01-01</p> <p>Spectral methods were successfully applied to the simulation of slow transients in gas transportation networks. Implicit time advancing techniques are naturally suggested by the nature of the problem. The correct treatment of the <span class="hlt">boundary</span> conditions is clarified in order to avoid any stability restriction originated by the <span class="hlt">boundaries</span>. The Beam and Warming and the Lerat schemes are unconditionally linearly stable when used with a Chebyshev pseudospectral method. Engineering accuracy for a gas transportation problem is achieved at Courant numbers up to 100.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/962316','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/962316"><span><span class="hlt">Seismic</span> fragility formulations for segmented buried pipeline <span class="hlt">systems</span> including the impact of differential ground subsidence</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pineda Porras, Omar Andrey; Ordaz, Mario</p> <p>2009-01-01</p> <p>Though Differential Ground Subsidence (DGS) impacts the <span class="hlt">seismic</span> response of segmented buried pipelines augmenting their vulnerability, fragility formulations to estimate repair rates under such condition are not available in the literature. Physical models to estimate pipeline <span class="hlt">seismic</span> damage considering other cases of permanent ground subsidence (e.g. faulting, tectonic uplift, liquefaction, and landslides) have been extensively reported, not being the case of DGS. The refinement of the study of two important phenomena in Mexico City - the 1985 Michoacan earthquake scenario and the sinking of the city due to ground subsidence - has contributed to the analysis of the interrelation ofmore » pipeline damage, ground motion intensity, and DGS; from the analysis of the 48-inch pipeline network of the Mexico City's Water <span class="hlt">System</span>, fragility formulations for segmented buried pipeline <span class="hlt">systems</span> for two DGS levels are proposed. The novel parameter PGV{sup 2}/PGA, being PGV peak ground velocity and PGA peak ground acceleration, has been used as <span class="hlt">seismic</span> parameter in these formulations, since it has shown better correlation to pipeline damage than PGV alone according to previous studies. By comparing the proposed fragilities, it is concluded that a change in the DGS level (from Low-Medium to High) could increase the pipeline repair rates (number of repairs per kilometer) by factors ranging from 1.3 to 2.0; being the higher the <span class="hlt">seismic</span> intensity the lower the factor.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S13C4463S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S13C4463S"><span>Development of Compact Seafloor Cabled <span class="hlt">Seismic</span> and Tsunami Observation <span class="hlt">System</span> Using ICT and Installation Plan to Off-Sanriku Region, Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shinohara, M.; Yamada, T.; Sakai, S.; Shiobara, H.; Kanazawa, T.</p> <p>2014-12-01</p> <p>A <span class="hlt">seismic</span> and tsunami observation <span class="hlt">system</span> using seafloor optical fiber had been installed off Sanriku, northeastern Japan in 1996. The objectives of the <span class="hlt">system</span> are to obtain exact <span class="hlt">seismic</span> activity related to plate subduction and to observe tsunami on seafloor. The continuous real-time observation has been carried out since the installation. In March 2011, the Tohoku earthquake occurred at the plate <span class="hlt">boundary</span> near the Japan Trench, and the <span class="hlt">system</span> recorded <span class="hlt">seismic</span> waves and tsunamis by the mainshock. These data are useful to obtain accurate position of the source faults and source region of tsunami generated by the event. However, the landing station of the <span class="hlt">system</span> was damaged by huge tsunami, and the observation was suspended. Because the real-time seafloor observation by cabled <span class="hlt">system</span> is important in this region, we decide to reconstruct a landing station and install newly developed Ocean Bottom Cabled <span class="hlt">Seismic</span> and Tsunami (OBCST) observation <span class="hlt">system</span> for additional observation and/or replacement of the existing <span class="hlt">system</span>. From 2005, we have been developed the new compact Ocean Bottom Cabled Seismometer (OBCS) <span class="hlt">system</span> using Information and Communication Technology (ICT). Our <span class="hlt">system</span> is characterized by securement of reliability by using TCP/IP technology and down-sizing of an observation node using up-to-date electronics technology. In 2010, the first OBCS was installed near Awashima-island in the Japan Sea, and is being operated continuously. The new OBCST <span class="hlt">system</span> is placed as the second generation of our <span class="hlt">system</span>, and has two types of observation nodes. Both types have accelerometers as <span class="hlt">seismic</span> sensors. One type of observation nodes equips a crystal oscillator type pressure gauge as tsunami sensor. Another type has an external port for additional observation sensor by using Power over Ethernet technology. Clocks in observation nodes can be synchronized through TCP/IP protocol with an accuracy of 300 ns (IEEE 1588). A simple canister for tele-communication seafloor cable is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.8998G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.8998G"><span><span class="hlt">Seismic</span> detection <span class="hlt">system</span> for blocking the dangerous installations in case of strong earthquake occurrence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghica, Daniela; Corneliu Rau, Dan; Ionescu, Constantin; Grigore, Adrian</p> <p>2010-05-01</p> <p>During the last 70 years, four major earthquakes occurred in the Vrancea <span class="hlt">seismic</span> area affected Romania territory: 10 November 1940 (Mw = 7.7, 160 km depth), 4 March 1977 (Mw = 7.5, 100 km depth), 30 August 1986 (Mw = 7.2, 140 km depth), 30 May 30 1990 (Mw = 6.9, 80 km depth). Romania is a European country with significant <span class="hlt">seismicity</span>. So far, the 1977 event had the most catastrophic consequences: about 33,000 residences were totally destroyed or partially deteriorated, 1,571 people dies and another 11,300 were injured. Moreover, 61 natural-gas pipelines were damaged, causing destructive fires. The total losses were estimated at 3 mld. U.S. dollars. Recent studies clearly pointed out that in case of a strong earthquake occurrence in Vrancea region (Ms above 7), the biggest danger regarding the major cities comes from explosions and fires started immediately after the earthquake, and the most important factor of risk are the natural gas distribution networks. The damages are strongly amplified by the fact that, simultaneously, water and electric energy lines distributions are damaged too, making impossible the efficient firemen intervention, for localizing the fire sources. Presently, in Romania safe and efficient accepted solutions for improving the buildings securing, using antiseismic protection of the dangerous installations as natural-gas pipelines are not available. Therefore, we propose a <span class="hlt">seismic</span> detection <span class="hlt">system</span> based on a <span class="hlt">seismically</span> actuated gas shut-off valve, which is automatically shut down in case of a <span class="hlt">seismic</span> shock. The device is intended to be installed in the natural-gas supply line outside of buildings, as well at each user (group of users), inside of the buildings. The <span class="hlt">seismic</span> detection <span class="hlt">system</span> for blocking the dangerous installations in case of a strong earthquake occurrence was designed on the basis of 12 criteria enforced by the US regulations for <span class="hlt">seismic</span> valves, aimed to eliminate the critical situations as fluids and under pressure gases leakage</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PEPI..245..103A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PEPI..245..103A"><span>Global scale observations of scattered energy near the inner-core <span class="hlt">boundary</span>: <span class="hlt">Seismic</span> constraints on the base of the outer-core</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adam, J. M.-C.; Romanowicz, B.</p> <p>2015-08-01</p> <p>We have collected a global dataset of several thousands of high quality records of PKPdf, PKPbc, PKPbc-diff and PKPab phase arrivals in the distance range [149-178°]. Within this collection, we have identified an energy packet that arrives 5-20 s after the PKPbc (or PKPbc-diff) and represents a phase that is not predicted by 1D reference <span class="hlt">seismic</span> models. We use array analysis techniques to enhance the signal of these scattered phases and show that they originate along the great-circle path in a consistent range of arrival times and narrow range of ray parameters. We therefore refer to this scattered energy the "M" phase. Using the cross-correlation technique to detect and measure the scattered energy arrival times, we compiled a dataset of 1116 records of this M phase. There are no obvious variations with source or station location, nor with the depth of the source. After exploration of possible location for this M phase, we show that its origin is most likely in the vicinity of the inner-core <span class="hlt">boundary</span>. A tentative model is found that predicts an M-like phase, and produces good fits to its travel times as well as those of the main core phases. In this model, the P velocity profile with depth exhibits an increased gradient from about 400 km to 50 km above the ICB (i.e. slightly faster velocities than in AK135 or PREM), and a ∼ 50 km thick lower velocity layer right above the ICB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70021490','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70021490"><span><span class="hlt">Seismic</span> slope-performance analysis: from hazard map to decision support <span class="hlt">system</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>Miles, Scott B.; Keefer, David K.; Ho, Carlton L.</p> <p>1999-01-01</p> <p>In response to the growing recognition of engineers and decision-makers of the regional effects of earthquake-induced landslides, this paper presents a general approach to conducting <span class="hlt">seismic</span> landslide zonation, based on the popular Newmark's sliding block analogy for modeling coherent landslides. Four existing models based on the sliding block analogy are compared. The comparison shows that the models forecast notably different levels of slope performance. Considering this discrepancy along with the limitations of static maps as a decision tool, a spatial decision support <span class="hlt">system</span> (SDSS) for <span class="hlt">seismic</span> landslide analysis is proposed, which will support investigations over multiple scales for any number of earthquake scenarios and input conditions. Most importantly, the SDSS will allow use of any <span class="hlt">seismic</span> landslide analysis model and zonation approach. Developments associated with the SDSS will produce an object-oriented model for encapsulating spatial data, an object-oriented specification to allow construction of models using modular objects, and a direct-manipulation, dynamic user-interface that adapts to the particular <span class="hlt">seismic</span> landslide model configuration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T13D3037A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T13D3037A"><span>J-SHIS - an integrated <span class="hlt">system</span> for knowing <span class="hlt">seismic</span> hazard information in Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Azuma, H.; Fujiwara, H.; Kawai, S.; Hao, K. X.; Morikawa, N.</p> <p>2015-12-01</p> <p>An integrated <span class="hlt">system</span> of Japan <span class="hlt">seismic</span> hazard information station (J-SHIS) was established in 2005 for issuing and exchanging information of the National <span class="hlt">Seismic</span> Hazard Maps for Japan that are based on <span class="hlt">seismic</span> hazard assessment (SHA). A simplified app, also named J-SHIS, for smartphones is popularly used in Japan based on the integrated <span class="hlt">system</span> of http://www.j-shis.bosai.go.jp/map/?lang=en. "Smartphone tells hazard" is realized on a cellphone, a tablet and/or a PC. At a given spot, the comprehensive information of SHA map can be easily obtained as below: 1) A SHA probability at given intensity (JMA=5-, 5+, 6-, 6+) within 30 years. 2) A site amplification factor varies within 0.5 ~ 3.0 and expectation is 1 based on surface geology map information. 3) A depth of <span class="hlt">seismic</span> basement down to ~3,000m based on deeper borehole and geological structure. 4) Scenario earthquake maps: By choosing an active fault, one got the average case for different parameters of the modeling. Then choose a case, you got the shaking map of intensity with color scale. "<span class="hlt">Seismic</span> Hazard Karte tells more hazard" is another app based on website of http://www.j-shis.bosai.go.jp/labs/karte/. (1) For every mesh of 250m x 250m, professional service SHA information is provided over national-world. (2) With five ranks for eight items, comprehensive SHA information could be delivered. (3) Site amplification factor with an average index is given. (4) Deeper geologic structure modeling is provided with borehole profiling. (5) A SHA probability is assessed within 30 and/or 50 years for the given site. (6) <span class="hlt">Seismic</span> Hazard curves are given for earthquake sources from inland active fault, subduction zone, undetermined and their summarization. (7) The JMA <span class="hlt">seismic</span> intensities are assessed in long-term averaged periods of 500-years to ~100,000 years. The app of J-SHIS can be downloaded freely from http://www.j-shis.bosai.go.jp/app-jshis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1977/0224/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1977/0224/"><span>Factors limiting the sensitivity and dynamic range of a <span class="hlt">seismic</span> <span class="hlt">system</span> employing analog magnetic tape recording and a <span class="hlt">seismic</span> amplifier with adjustable gain settings and several output levels</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Eaton, Jerry P.; Van Schaack, John R.</p> <p>1977-01-01</p> <p>In the course of modernizing the low-speed-tape-recorder portable <span class="hlt">seismic</span> <span class="hlt">systems</span> and considering the possibilities for the design of a cassette-tape-recorder <span class="hlt">seismic</span> refraction <span class="hlt">system</span>, the factors that limit the sensitivity and dynamic range of such <span class="hlt">systems</span> have been reviewed. These factors will first be stated briefly, and then their influence on <span class="hlt">systems</span> such as the new 5-day-tape <span class="hlt">seismic</span> <span class="hlt">system</span> will be examined in more detail. To fix ideas, we shall assume that the <span class="hlt">system</span> consists of the following elements: 1. A <span class="hlt">seismic</span> sensor: usually a moving coil inertial seismometer with a period of about 1 second, a coil resistance of about 5000 ohms, and an effective motor constant of 1.0 V/cm/sec (across a 10K load terminating the seismometer sensitivity-and-damping-adjustment resistive network). 2. A <span class="hlt">seismic</span> amplifier/voltage controlled oscillator unit made up of the following components: a) A fixed gain preamplifier with an input resistance of 10K and an internal noise level of 0.5 muVpp referred to the preamp input (0.1 Hz <= freq. <= 30 hz). b) An adjustable gain (0 to 42 db in 6 db steps) intermediate amplifier c) One or more fixed gain output amplifiers. d) Two sections of 6 db/octave bandpass filter serving to couple the 3 amplifier stages together. e) Voltage controlled oscillators for each output amplifier to produce modulated FM carriers for recording on separate tape tracks or modulated FM subcarriers for subsequent multiplexing and direct recording on tape in the California Network format. 3. An analog magnetic tape recorder: e.g. the PI 5100 (15/80 ips recording in the FM mode or in the direct mode with the 'broad-band' variant-of the Cal Net multiplex <span class="hlt">system</span>, or 15/16 ips recording in the direct mode with the standard Cal Net multiplex <span class="hlt">system</span>), or the Sony TC-126 cassette recorder operating in the direct record mode with the standard Cal Net multiplex <span class="hlt">system</span>. 4. Appropriate magnetic tape playback equipment: e.g., the Bell and Howell 3700-B for the PI-5100 or</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2000/0379/pdf/of00-379.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2000/0379/pdf/of00-379.pdf"><span>A filter circuit board for the Earthworm <span class="hlt">Seismic</span> Data Acquisition <span class="hlt">System</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>Jensen, Edward Gray</p> <p>2000-01-01</p> <p>The Earthworm <span class="hlt">system</span> is a <span class="hlt">seismic</span> network data acquisition and processing <span class="hlt">system</span> used by the Northern California <span class="hlt">Seismic</span> Network as well as many other <span class="hlt">seismic</span> networks. The input to the <span class="hlt">system</span> is comprised of many realtime electronic waveforms fed to a multi-channel digitizer on a PC platform. The digitizer consists of one or more National Instruments Corp. AMUX–64T multiplexer boards attached to an A/D converter board located in the computer. Originally, passive filters were installed on the multiplexers to eliminate electronic noise picked up in cabling. It was later discovered that a small amount of crosstalk occurred between successive channels in the digitizing sequence. Though small, this crosstalk will cause what appear to be small earthquake arrivals at the wrong time on some channels. This can result in erroneous calculation of earthquake arrival times, particularly by automated algorithms. To deal with this problem, an Earthworm filter board was developed to provide the needed filtering while eliminating crosstalk. This report describes the tests performed to find a suitable solution, and the design of the circuit board. Also included are all the details needed to build and install this board in an Earthworm <span class="hlt">system</span> or any other <span class="hlt">system</span> using the AMUX–64T board. Available below is the report in PDF format as well as an archive file containing the circuit board manufacturing information.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1870d0069S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1870d0069S"><span>The analytical solution for drug delivery <span class="hlt">system</span> with nonhomogeneous moving <span class="hlt">boundary</span> condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saudi, Muhamad Hakimi; Mahali, Shalela Mohd; Harun, Fatimah Noor</p> <p>2017-08-01</p> <p>This paper discusses the development and the analytical solution of a mathematical model based on drug release <span class="hlt">system</span> from a swelling delivery device. The mathematical model is represented by a one-dimensional advection-diffusion equation with nonhomogeneous moving <span class="hlt">boundary</span> condition. The solution procedures consist of three major steps. Firstly, the application of steady state solution method, which is used to transform the nonhomogeneous moving <span class="hlt">boundary</span> condition to homogeneous <span class="hlt">boundary</span> condition. Secondly, the application of the Landau transformation technique that gives a significant impact in removing the advection term in the <span class="hlt">system</span> of equation and transforming the moving <span class="hlt">boundary</span> condition to a fixed <span class="hlt">boundary</span> condition. Thirdly, the used of separation of variables method to find the analytical solution for the resulted initial <span class="hlt">boundary</span> value problem. The results show that the swelling rate of delivery device and drug release rate is influenced by value of growth factor r.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ERL....13c4004T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ERL....13c4004T"><span>Induced <span class="hlt">seismicity</span> hazard and risk by enhanced geothermal <span class="hlt">systems</span>: an expert elicitation approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trutnevyte, Evelina; Azevedo, Inês L.</p> <p>2018-03-01</p> <p>Induced <span class="hlt">seismicity</span> is a concern for multiple geoenergy applications, including low-carbon enhanced geothermal <span class="hlt">systems</span> (EGS). We present the results of an international expert elicitation (n = 14) on EGS induced <span class="hlt">seismicity</span> hazard and risk. Using a hypothetical scenario of an EGS plant and its geological context, we show that expert best-guess estimates of annualized exceedance probabilities of an M ≥ 3 event range from 0.2%-95% during reservoir stimulation and 0.2%-100% during operation. Best-guess annualized exceedance probabilities of M ≥ 5 event span from 0.002%-2% during stimulation and 0.003%-3% during operation. Assuming that tectonic M7 events could occur, some experts do not exclude induced (triggered) events of up to M7 too. If an induced M = 3 event happens at 5 km depth beneath a town with 10 000 inhabitants, most experts estimate a 50% probability that the loss is contained within 500 000 USD without any injuries or fatalities. In the case of an induced M = 5 event, there is 50% chance that the loss is below 50 million USD with the most-likely outcome of 50 injuries and one fatality or none. As we observe a vast diversity in quantitative expert judgements and underlying mental models, we conclude with implications for induced <span class="hlt">seismicity</span> risk governance. That is, we suggest documenting individual expert judgements in induced <span class="hlt">seismicity</span> elicitations before proceeding to consensual judgements, to convene larger expert panels in order not to cherry-pick the experts, and to aim for multi-organization multi-model assessments of EGS induced <span class="hlt">seismicity</span> hazard and risk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/pp/1801/downloads/pp1801_Chap2_Okubo.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/pp/1801/downloads/pp1801_Chap2_Okubo.pdf"><span>The evolution of <span class="hlt">seismic</span> monitoring <span class="hlt">systems</span> at the Hawaiian Volcano Observatory: Chapter 2 in Characteristics of Hawaiian volcanoes</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Okubo, Paul G.; Nakata, Jennifer S.; Koyanagi, Robert Y.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.</p> <p>2014-01-01</p> <p>In the century since the Hawaiian Volcano Observatory (HVO) put its first seismographs into operation at the edge of Kīlauea Volcano’s summit caldera, <span class="hlt">seismic</span> monitoring at HVO (now administered by the U.S. Geological Survey [USGS]) has evolved considerably. The HVO <span class="hlt">seismic</span> network extends across the entire Island of Hawai‘i and is complemented by stations installed and operated by monitoring partners in both the USGS and the National Oceanic and Atmospheric Administration. The <span class="hlt">seismic</span> data stream that is available to HVO for its monitoring of volcanic and <span class="hlt">seismic</span> activity in Hawai‘i, therefore, is built from hundreds of data channels from a diverse collection of instruments that can accurately record the ground motions of earthquakes ranging in magnitude from <1 to ≥8. In this chapter we describe the growth of HVO’s <span class="hlt">seismic</span> monitoring <span class="hlt">systems</span> throughout its first hundred years of operation. Although other references provide specific details of the changes in instrumentation and data handling over time, we recount here, in more general terms, the evolution of HVO’s <span class="hlt">seismic</span> network. We focus not only on equipment but also on interpretative products and results that were enabled by the new instrumentation and by improvements in HVO’s <span class="hlt">seismic</span> monitoring, analytical, and interpretative capabilities implemented during the past century. As HVO enters its next hundred years of seismological studies, it is well situated to further improve upon insights into <span class="hlt">seismic</span> and volcanic processes by using contemporary seismological tools.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JAESc..64..125Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JAESc..64..125Y"><span>Nonlinear dynamic failure process of tunnel-fault <span class="hlt">system</span> in response to strong <span class="hlt">seismic</span> event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Zhihua; Lan, Hengxing; Zhang, Yongshuang; Gao, Xing; Li, Langping</p> <p>2013-03-01</p> <p>Strong earthquakes and faults have significant effect on the stability capability of underground tunnel structures. This study used a 3-Dimensional Discrete Element model and the real records of ground motion in the Wenchuan earthquake to investigate the dynamic response of tunnel-fault <span class="hlt">system</span>. The typical tunnel-fault <span class="hlt">system</span> was composed of one planned railway tunnel and one <span class="hlt">seismically</span> active fault. The discrete numerical model was prudentially calibrated by means of the comparison between the field survey and numerical results of ground motion. It was then used to examine the detailed quantitative information on the dynamic response characteristics of tunnel-fault <span class="hlt">system</span>, including stress distribution, strain, vibration velocity and tunnel failure process. The intensive tunnel-fault interaction during <span class="hlt">seismic</span> loading induces the dramatic stress redistribution and stress concentration in the intersection of tunnel and fault. The tunnel-fault <span class="hlt">system</span> behavior is characterized by the complicated nonlinear dynamic failure process in response to a real strong <span class="hlt">seismic</span> event. It can be qualitatively divided into 5 main stages in terms of its stress, strain and rupturing behaviors: (1) strain localization, (2) rupture initiation, (3) rupture acceleration, (4) spontaneous rupture growth and (5) stabilization. This study provides the insight into the further stability estimation of underground tunnel structures under the combined effect of strong earthquakes and faults.</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://hdl.handle.net/2060/20140012999','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140012999"><span>Bayesian Statistics and Uncertainty Quantification for Safety <span class="hlt">Boundary</span> Analysis in Complex <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>He, Yuning; Davies, Misty Dawn</p> <p>2014-01-01</p> <p>The analysis of a safety-critical <span class="hlt">system</span> often requires detailed knowledge of safe regions and their highdimensional non-linear <span class="hlt">boundaries</span>. We present a statistical approach to iteratively detect and characterize the <span class="hlt">boundaries</span>, which are provided as parameterized shape candidates. Using methods from uncertainty quantification and active learning, we incrementally construct a statistical model from only few simulation runs and obtain statistically sound estimates of the shape parameters for safety <span class="hlt">boundaries</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998AcSSn..11..573C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998AcSSn..11..573C"><span>Fractal and chaotic laws on <span class="hlt">seismic</span> dissipated energy in an energy <span class="hlt">system</span> of engineering structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cui, Yu-Hong; Nie, Yong-An; Yan, Zong-Da; Wu, Guo-You</p> <p>1998-09-01</p> <p>Fractal and chaotic laws of engineering structures are discussed in this paper, it means that the intrinsic essences and laws on dynamic <span class="hlt">systems</span> which are made from <span class="hlt">seismic</span> dissipated energy intensity E d and intensity of <span class="hlt">seismic</span> dissipated energy moment I e are analyzed. Based on the intrinsic characters of chaotic and fractal dynamic <span class="hlt">system</span> of E d and I e, three kinds of approximate dynamic models are rebuilt one by one: index autoregressive model, threshold autoregressive model and local-approximate autoregressive model. The innate laws, essences and systematic error of evolutional behavior I e are explained over all, the short-term behavior predictability and long-term behavior probability of which are analyzed in the end. That may be valuable for earthquake-resistant theory and analysis method in practical engineering structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoJI.209..876J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoJI.209..876J"><span>Hydrostratigraphy characterization of the Floridan aquifer <span class="hlt">system</span> 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>James, Stephanie R.; Screaton, Elizabeth J.; Russo, Raymond M.; Panning, Mark P.; Bremner, Paul M.; Stanciu, A. Christian; Torpey, Megan E.; Hongsresawat, Sutatcha; Farrell, Matthew E.</p> <p>2017-05-01</p> <p>We investigated a new technique for aquifer characterization that uses cross-correlation of ambient <span class="hlt">seismic</span> noise to determine <span class="hlt">seismic</span> velocity structure of the Floridan aquifer <span class="hlt">system</span> (FAS). Accurate characterization of aquifer <span class="hlt">systems</span> is vital to hydrogeological research and groundwater management but is difficult due to limited subsurface data and heterogeneity. Previous research on the carbonate FAS found that confining units and high permeability flow zones have distinct <span class="hlt">seismic</span> velocities. We deployed an array of 9 short period seismometers from 11/2013 to 3/2014 in Indian Lake State Forest near Ocala, Florida, to image the hydrostratigraphy of the aquifer <span class="hlt">system</span> using ambient <span class="hlt">seismic</span> noise. We find that interstation distance strongly influences the upper and lower frequency limits of the data set. <span class="hlt">Seismic</span> waves propagating within 1.5 and 7 wavelengths between stations were optimal for reliable group velocity measurements and both an upper and lower wavelength threshold was used. A minimum of 100-250 hr of signal was needed to maximize signal-to-noise ratio and to allow cross-correlation convergence. We averaged measurements of group velocity between station pairs at each frequency band to create a network average dispersion curve. A family of 1-D shear-wave velocity profiles that best represents the network average dispersion was then generated using a Markov Chain Monte Carlo (MCMC) algorithm. The MCMC algorithm was implemented with either a fixed number of layers, or as transdimensional in which the number of layers was a free parameter. Results from both algorithms require a prominent velocity increase at ∼200 m depth. A shallower velocity increase at ∼60 m depth was also observed, but only in model ensembles created by collecting models with the lowest overall misfit to the observed data. A final round of modelling with additional prior constraints based on initial results and well logs produced a mean shear-wave velocity profile taken as the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.7525J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.7525J"><span>A <span class="hlt">seismic</span> network to investigate the sedimentary hosted hydrothermal Lusi <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Javad Fallahi, Mohammad; Mazzini, Adriano; Lupi, Matteo; Obermann, Anne; Karyono, Karyono</p> <p>2016-04-01</p> <p>The 29th of May 2006 marked the beginning of the sedimentary hosted hydrothermal Lusi <span class="hlt">system</span>. During the last 10 years we witnessed numerous alterations of the Lusi <span class="hlt">system</span> behavior that coincide with the frequent <span class="hlt">seismic</span> and volcanic activity occurring in the region. In order to monitor the effect that the <span class="hlt">seismicity</span> and the activity of the volcanic arc have on Lusi, we deployed a ad hoc <span class="hlt">seismic</span> network. This temporary network consist of 10 broadband and 21 short period stations and is currently operating around the Arjuno-Welirang volcanic complex, along the Watukosek fault <span class="hlt">system</span> and around Lusi, in the East Java basin since January 2015. We exploit this dataset to investigate surface wave and shear wave velocity structure of the upper-crust beneath the Arjuno-Welirang-Lusi complex in the framework of the Lusi Lab project (ERC grant n° 308126). Rayleigh and Love waves travelling between each station-pair are extracted by cross-correlating long time series of ambient noise data recorded at the stations. Group and phase velocity dispersion curves are obtained by time-frequency analysis of cross-correlation functions, and are tomographically inverted to provide 2D velocity maps corresponding to different sampling depths. 3D shear wave velocity structure is then acquired by inverting the group velocity maps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/27621','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/27621"><span>The race to <span class="hlt">seismic</span> safety : protecting California's transportation <span class="hlt">system</span>.</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>2003-12-01</p> <p>Will future California earthquakes again cause destruction of portions of Californias transportation <span class="hlt">system</span>, or will their impacts be controlled to limit the damage and disruption any large earthquake will cause? This is the key question addressed...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22382178-variance-reduction-through-robust-design-boundary-conditions-stochastic-hyperbolic-systems-equations','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22382178-variance-reduction-through-robust-design-boundary-conditions-stochastic-hyperbolic-systems-equations"><span>Variance reduction through robust design of <span class="hlt">boundary</span> conditions for stochastic hyperbolic <span class="hlt">systems</span> of equations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nordström, Jan, E-mail: jan.nordstrom@liu.se; Wahlsten, Markus, E-mail: markus.wahlsten@liu.se</p> <p></p> <p>We consider a hyperbolic <span class="hlt">system</span> with uncertainty in the <span class="hlt">boundary</span> and initial data. Our aim is to show that different <span class="hlt">boundary</span> conditions give different convergence rates of the variance of the solution. This means that we can with the same knowledge of data get a more or less accurate description of the uncertainty in the solution. A variety of <span class="hlt">boundary</span> conditions are compared and both analytical and numerical estimates of the variance of the solution are presented. As an application, we study the effect of this technique on Maxwell's equations as well as on a subsonic outflow <span class="hlt">boundary</span> for themore » Euler equations.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70197380','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70197380"><span><span class="hlt">Seismic</span> experiment ross ice shelf 1990/91: Characteristics of the <span class="hlt">seismic</span> reflection 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></p> <p>1993-01-01</p> <p>The Transantarctic Mountains, with a length of 3000-3500 km and elevations of up to 4500 m, are one of the major Cenozoic mountain ranges in the world and are by far the most striking example of rift-shoulder mountains. Over the 1990-1991 austral summer <span class="hlt">Seismic</span> Experiment Ross Ice Shelf (SERIS) was carried out across the Transantarctic Mountain front, between latitudes 82 degrees to 83 degrees S, in order to investigate the transition zone between the rifted area of the Ross Embayment and the uplifted Transantarctic Mountains. This experiment involved a 140 km long <span class="hlt">seismic</span> reflection profile together with a 96 km long coincident wide-angle reflection/refraction profile. Gravity and relative elevation (using barometric pressure) were also measured along the profile. The primary purpose was to examine the <span class="hlt">boundary</span> between the rift <span class="hlt">system</span> and the uplifted rift margin (represented by the Transantarctic Mountains) using modern multi-channel crustal reflection/refraction techniques. The results provide insight into crustal structure across the plate <span class="hlt">boundary</span>. SERIS also represented one of the first large-scale and modern multi-channel <span class="hlt">seismic</span> experiments in the remote interior of Antarctica. As such, the project was designed to test different <span class="hlt">seismic</span> acquisition techniques which will be involved in future <span class="hlt">seismic</span> exploration of the continent. This report describes the results from the analysis of the acquisition tests as well as detailing some of the characteristics of the reflection <span class="hlt">seismic</span> data. (auths.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002Geo....30...11L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002Geo....30...11L"><span>Oceanic broad multifault transform plate <span class="hlt">boundaries</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ligi, Marco; Bonatti, Enrico; Gasperini, Luca; Poliakov, Alexei N. B.</p> <p>2002-01-01</p> <p>Oceanic transform plate <span class="hlt">boundaries</span> consist of a single, narrow (a few kilometers wide) strike-slip <span class="hlt">seismic</span> zone offsetting two mid-ocean ridge segments. However, we define here a new class of oceanic transform <span class="hlt">boundaries</span>, with broad complex multifault zones of deformation, similar to some continental strike-slip <span class="hlt">systems</span>. Examples are the 750-km- long, 120-km-wide Andrew Bain transform on the Southwest Indian Ridge, and the Romanche transform, where the Mid-Atlantic Ridge is offset by a lens-shaped, ˜900-km- long, ˜100-km-wide sliver of deformed lithosphere bound by two major transform valleys. One of the valleys is <span class="hlt">seismically</span> highly active and constitutes the present-day principal transform <span class="hlt">boundary</span>. However, strike-slip <span class="hlt">seismic</span> events also occur in the second valley and elsewhere in the deformed zone. Some of these events may be triggered by earthquakes from the principal <span class="hlt">boundary</span>. Numerical modeling predicts the development of wide multiple transform <span class="hlt">boundaries</span> when the age offset is above a threshold value of ˜30 m.y., i.e., in extra-long (>500 km) slow-slip transforms. Multiple <span class="hlt">boundaries</span> develop so that strike-slip ruptures avoid very thick and strong lithosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/207554','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/207554"><span>Chemical energy <span class="hlt">system</span> for a borehole <span class="hlt">seismic</span> source. [Final report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Engelke, R.; Hedges, R.O.</p> <p>1996-03-01</p> <p>We describe a detonation <span class="hlt">system</span> that will be useful in the seismological examination of geological structures. The explosive component of this <span class="hlt">system</span> is produced by the mixing of two liquids; these liquids are classified as non-explosive materials by the Department of Transportation. This detonation <span class="hlt">system</span> could be employed in a borehole tool in which many explosions are made to occur at various points in the borehole. The explosive for each explosion would be mixed within the tool immediately prior to its being fired. Such an arrangement ensures that no humans are ever in proximity to explosives. Initiation of the explosivemore » mixture is achieved with an electrical slapper detonator whose specific parameters are described; this electrical initiation <span class="hlt">system</span> does not contain any explosive. The complete electrical/mechanical/explosive <span class="hlt">system</span> is shown to be able to perform correctly at temperatures {le}120{degrees}C and at depths in a water-filled borehole of {le} 4600 ft (i.e., at pressures of {le}2000 psig).« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1175842','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1175842"><span>Methods and <span class="hlt">systems</span> for low frequency <span class="hlt">seismic</span> and infrasound detection of geo-pressure transition zones</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Shook, G. Michael; LeRoy, Samuel D.; Benzing, William M.</p> <p>2006-07-18</p> <p>Methods for determining the existence and characteristics of a gradational pressurized zone within a subterranean formation are disclosed. One embodiment involves employing an attenuation relationship between a <span class="hlt">seismic</span> response signal and increasing wavelet wavelength, which relationship may be used to detect a gradational pressurized zone and/or determine characteristics thereof. In another embodiment, a method for analyzing data contained within a response signal for signal characteristics that may change in relation to the distance between an input signal source and the gradational pressurized zone is disclosed. In a further embodiment, the relationship between response signal wavelet frequency and comparative amplitude may be used to estimate an optimal wavelet wavelength or range of wavelengths used for data processing or input signal selection. <span class="hlt">Systems</span> for <span class="hlt">seismic</span> exploration and data analysis for practicing the above-mentioned method embodiments are also disclosed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/918544','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/918544"><span><span class="hlt">Systems</span> for low frequency <span class="hlt">seismic</span> and infrasound detection of geo-pressure transition zones</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Shook, G. Michael; LeRoy, Samuel D.; Benzing, William M.</p> <p>2007-10-16</p> <p>Methods for determining the existence and characteristics of a gradational pressurized zone within a subterranean formation are disclosed. One embodiment involves employing an attenuation relationship between a <span class="hlt">seismic</span> response signal and increasing wavelet wavelength, which relationship may be used to detect a gradational pressurized zone and/or determine characteristics thereof. In another embodiment, a method for analyzing data contained within a response signal for signal characteristics that may change in relation to the distance between an input signal source and the gradational pressurized zone is disclosed. In a further embodiment, the relationship between response signal wavelet frequency and comparative amplitude may be used to estimate an optimal wavelet wavelength or range of wavelengths used for data processing or input signal selection. <span class="hlt">Systems</span> for <span class="hlt">seismic</span> exploration and data analysis for practicing the above-mentioned method embodiments are also disclosed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1710641V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1710641V"><span>SEISVIZ3D: Stereoscopic <span class="hlt">system</span> for the representation of <span class="hlt">seismic</span> data - Interpretation and Immersion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>von Hartmann, Hartwig; Rilling, Stefan; Bogen, Manfred; Thomas, Rüdiger</p> <p>2015-04-01</p> <p>The <span class="hlt">seismic</span> method is a valuable tool for getting 3D-images from the subsurface. <span class="hlt">Seismic</span> data acquisition today is not only a topic for oil and gas exploration but is used also for geothermal exploration, inspections of nuclear waste sites and for scientific investigations. The <span class="hlt">system</span> presented in this contribution may also have an impact on the visualization of 3D-data of other geophysical methods. 3D-<span class="hlt">seismic</span> data can be displayed in different ways to give a spatial impression of the subsurface.They are a combination of individual vertical cuts, possibly linked to a cubical portion of the data volume, and the stereoscopic view of the <span class="hlt">seismic</span> data. By these methods, the spatial perception for the structures and thus of the processes in the subsurface should be increased. Stereoscopic techniques are e. g. implemented in the CAVE and the WALL, both of which require a lot of space and high technical effort. The aim of the interpretation <span class="hlt">system</span> shown here is stereoscopic visualization of <span class="hlt">seismic</span> data at the workplace, i.e. at the personal workstation and monitor. The <span class="hlt">system</span> was developed with following criteria in mind: • Fast rendering of large amounts of data so that a continuous view of the data when changing the viewing angle and the data section is possible, • defining areas in stereoscopic view to translate the spatial impression directly into an interpretation, • the development of an appropriate user interface, including head-tracking, for handling the increased degrees of freedom, • the possibility of collaboration, i.e. teamwork and idea exchange with the simultaneous viewing of a scene at remote locations. The possibilities offered by the use of a stereoscopic <span class="hlt">system</span> do not replace a conventional interpretation workflow. Rather they have to be implemented into it as an additional step. The amplitude distribution of the <span class="hlt">seismic</span> data is a challenge for the stereoscopic display because the opacity level and the scaling and selection of the data have to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/880010','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/880010"><span>Method Apparatus And <span class="hlt">System</span> For Detecting <span class="hlt">Seismic</span> Waves In A Borehole</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>West, Phillip B.; Sumstine, Roger L.</p> <p>2006-03-14</p> <p>A method, apparatus and <span class="hlt">system</span> for detecting <span class="hlt">seismic</span> waves. A sensing apparatus is deployed within a bore hole and may include a source magnet for inducing a magnetic field within a casing of the borehole. An electrical coil is disposed within the magnetic field to sense a change in the magnetic field due to a displacement of the casing. The electrical coil is configured to remain substantially stationary relative to the well bore and its casing along a specified axis such that displacement of the casing induces a change within the magnetic field which may then be sensed by the electrical coil. Additional electrical coils may be similarly utilized to detect changes in the same or other associated magnetic fields along other specified axes. The additional sensor coils may be oriented substantially orthogonally relative to one another so as to detect <span class="hlt">seismic</span> waves along multiple orthogonal axes in three dimensional space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830048402&hterms=Physical+Review&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPhysical%2BReview','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830048402&hterms=Physical+Review&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPhysical%2BReview"><span><span class="hlt">Boundary</span>-fitted coordinate <span class="hlt">systems</span> for numerical solution of partial differential equations - A review</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thompson, J. F.; Warsi, Z. U. A.; Mastin, C. W.</p> <p>1982-01-01</p> <p>A comprehensive review of methods of numerically generating curvilinear coordinate <span class="hlt">systems</span> with coordinate lines coincident with all <span class="hlt">boundary</span> segments is given. Some general mathematical framework and error analysis common to such coordinate <span class="hlt">systems</span> is also included. The general categories of generating <span class="hlt">systems</span> are those based on conformal mapping, orthogonal <span class="hlt">systems</span>, nearly orthogonal <span class="hlt">systems</span>, <span class="hlt">systems</span> produced as the solution of elliptic and hyperbolic partial differential equations, and <span class="hlt">systems</span> generated algebraically by interpolation among the <span class="hlt">boundaries</span>. Also covered are the control of coordinate line spacing by functions embedded in the partial differential operators of the generating <span class="hlt">system</span> and by subsequent stretching transformation. Dynamically adaptive coordinate <span class="hlt">systems</span>, coupled with the physical solution, and time-dependent <span class="hlt">systems</span> that follow moving <span class="hlt">boundaries</span> are treated. References reporting experience using such coordinate <span class="hlt">systems</span> are reviewed as well as those covering the <span class="hlt">system</span> development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860017517','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860017517"><span>Regularity estimates up to the <span class="hlt">boundary</span> for elliptic <span class="hlt">systems</span> of difference equations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Strikwerda, J. C.; Wade, B. A.; Bube, K. P.</p> <p>1986-01-01</p> <p>Regularity estimates up to the <span class="hlt">boundary</span> for solutions of elliptic <span class="hlt">systems</span> of finite difference equations were proved. The regularity estimates, obtained for <span class="hlt">boundary</span> fitted coordinate <span class="hlt">systems</span> on domains with smooth <span class="hlt">boundary</span>, involve discrete Sobolev norms and are proved using pseudo-difference operators to treat <span class="hlt">systems</span> with variable coefficients. The elliptic <span class="hlt">systems</span> of difference equations and the <span class="hlt">boundary</span> conditions which are considered are very general in form. The regularity of a regular elliptic <span class="hlt">system</span> of difference equations was proved equivalent to the nonexistence of eigensolutions. The regularity estimates obtained are analogous to those in the theory of elliptic <span class="hlt">systems</span> of partial differential equations, and to the results of Gustafsson, Kreiss, and Sundstrom (1972) and others for hyperbolic difference equations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1711588H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711588H"><span><span class="hlt">Seismic</span> stratigraphic architecture of the Disko Bay trough-mouth fan <span class="hlt">system</span>, West Greenland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hofmann, Julia C.; Knutz, Paul C.</p> <p>2015-04-01</p> <p>Spatial and temporal changes of the Greenland Ice Sheet on the continental shelf bordering Baffin Bay remain poorly constrained. Then as now, fast-flowing ice streams and outlet glaciers have played a key role for the mass balance and stability of polar ice sheets. Despite their significance for Greenland Ice Sheet dynamics and evolution, our understanding of their long-term behaviour is limited. The central West Greenland margin is characterized by a broad continental shelf where a series of troughs extend from fjords to the shelf margin, acting as focal points for trough-mouth fan (TMF) accummulations. The sea-ward bulging morphology and abrupt shelf-break of these major depositional <span class="hlt">systems</span> is generated by prograding depocentres that formed during glacial maxima when ice streams reached the shelf edge, delivering large amounts of subglacial sediment onto the continental slope (Ó Cofaigh et al., 2013). The aim of this study is to unravel the <span class="hlt">seismic</span> stratigraphic architecture and depositional processes of the Disko Bay TMF, aerially the largest single sedimentary <span class="hlt">system</span> in West Greenland, using 2D and 3D <span class="hlt">seismic</span> reflection data, seabed bathymetry and stratigraphic information from exploration well Hellefisk-1. The south-west Disko Bay is intersected by a deep, narrow trough, Egedesminde Dyb, which extends towards the southwest and links to the shallower and broader cross-shelf Disko Trough (maximum water depths of > 1000 m and a trough length of c. 370 km). Another trough-like depression (trough length of c. 120 km) in the northern part of the TMF, indicating a previous position of the ice stream, can be distinguished on the seabed topographic map and the <span class="hlt">seismic</span> images. The Disko Bay TMF itself extends from the shelf edge down to the abyssal plain (abyssal floor depths of 2000 m) of the southern Baffin Bay. Based on <span class="hlt">seismic</span> stratigraphic configurations relating to reflection terminations, erosive patterns and <span class="hlt">seismic</span> facies (Mitchum et al., 1977), the TMF</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.T53B1605D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.T53B1605D"><span>From Subduction to a Compressional transform <span class="hlt">system</span>: Diffuse Deformation Processes at the Southeastern <span class="hlt">Boundary</span> of the Caribbean Plate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deville, E.; Padron, C.; Huyghe, P.; Callec, Y.; Lallemant, S.; Lebrun, J.; Mascle, A.; Mascle, G.; Noble, M.</p> <p>2006-12-01</p> <p>Geophysical data acquired in the southeastern Caribbean marine area (CARAMBA survey of the French O/V Atalante) provide new information about the deformation processes occurring in this subduction-to-strike-slip transitions zone. The 65 000 km2 of multibeam data and 5600 km of <span class="hlt">seismic</span> reflection and 3.5 kHz profiles which have been collected evidence that the connection between the Barbados accretionary prism and the south Caribbean transform <span class="hlt">system</span> is partitioned between a wide variety of recently active tectonic superficial features (complex folding, diffuse faulting, and mud volcanism), which accommodate the relative displacement between the Caribbean and the South America plates. The active deformation within the sedimentary pile is mostly aseismic (creeping) and this deformation is relatively diffuse over a large diffuse plate <span class="hlt">boundary</span>. There is no direct fault connection between the front of the Barbados prism and the strike-slip <span class="hlt">system</span> of northern Venezuela. The toe thrust <span class="hlt">system</span> at the southern edge of the Barbados prism, exhibits clear en-echelon geometry. The geometry of the syntectonic deposits evidence the diachronism of the deformation processes. Notably, it is well evidenced that early folds have been sealed by the recent turbidite deposits, whereas, some of the fold and thrust structures were active recently. Within this active compressional region, extension growth faults develop on the platform and on the slope of the Orinoco delta along a WNW-ESE trending en-echelon fault <span class="hlt">system</span> that we called the Orinoco Delta Fault Zone (ODFZ). This fault <span class="hlt">system</span> is clearly oblique with respect to the present-day Orinoco delta slope. These faults are not simply related to a passive gravitary collapse of the sediments accumulated on the Orinoco platform. Though there a decoupling between the shallow deformation processes in the sediments and the deep deformation characterized by earthquake activity, the ODFZ is inferred to be partly controlled by deep structures</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6432837-pennsylvanian-tyler-stratigraphic-seismic-concepts','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6432837-pennsylvanian-tyler-stratigraphic-seismic-concepts"><span>Pennsylvanian Tyler stratigraphic <span class="hlt">seismic</span> concepts</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moore, C.E.; Archer, R.J.</p> <p></p> <p>Recent drilling in the Rattler Butte area of central Montana has renewed interest in the Pennsylvanian Tyler Formation as a drilling objective. New production in this area, coupled with the surrounding well density, provides an ideal situation for further development of Tyler stratigraphic-<span class="hlt">seismic</span> exploration concepts and methods. Both geologic and geophysical Tyler thickness maps have proven to be useful tools in delineating eroded Heath and subsequent lower Tyler deposition. <span class="hlt">Seismic</span> modeling has revealed a series of possible Tyler-Heath erosional edge characteristics, providing another tool for Tyler-Heath <span class="hlt">boundary</span> definition. In modeling specific <span class="hlt">seismic</span> sand signatures, it was found that <span class="hlt">seismic</span> charactermore » and amplitude are dependent upon both formation thickness and lithology. Detailed mapping of the study area also revealed a new environmental interpretation of the Tyler. Unlike the fluvial <span class="hlt">system</span> to the north, the Tyler regime in the Rattler Butte area appears to have fluctuated among fluvial, deltaic, and marine <span class="hlt">systems</span>. Two hydrocarbon occurrence patterns have been noted within the Tyler: (1) although reservoir quality sands are present throughout the Tyler, those within the lower Tyler are more likely to contain hydrocarbons, and (2) close proximity to the Tyler-Heath erosional edge increases the chances of discovering oil-filled Tyler sands. Combined use of these exploration tools should greatly enhance the chances for successful lower Tyler exploration.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.T11A4544W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T11A4544W"><span>Updated mapping and <span class="hlt">seismic</span> reflection data processing along the Queen Charlotte fault <span class="hlt">system</span>, southeast Alaska</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walton, M. A. L.; Gulick, S. P. S.; Haeussler, P. J.; Rohr, K.; Roland, E. C.; Trehu, A. M.</p> <p>2014-12-01</p> <p>The Queen Charlotte Fault (QCF) is an obliquely convergent strike-slip <span class="hlt">system</span> that accommodates offset between the Pacific and North America plates in southeast Alaska and western Canada. Two recent earthquakes, including a M7.8 thrust event near Haida Gwaii on 28 October 2012, have sparked renewed interest in the margin and led to further study of how convergent stress is accommodated along the fault. Recent studies have looked in detail at offshore structure, concluding that a change in strike of the QCF at ~53.2 degrees north has led to significant differences in stress and the style of strain accommodation along-strike. We provide updated fault mapping and <span class="hlt">seismic</span> images to supplement and support these results. One of the highest-quality <span class="hlt">seismic</span> reflection surveys along the Queen Charlotte <span class="hlt">system</span> to date, EW9412, was shot aboard the R/V Maurice Ewing in 1994. The survey was last processed to post-stack time migration for a 1999 publication. Due to heightened interest in high-quality imaging along the fault, we have completed updated processing of the EW9412 <span class="hlt">seismic</span> reflection data and provide prestack migrations with water-bottom multiple reduction. Our new imaging better resolves fault and basement surfaces at depth, as well as the highly deformed sediments within the Queen Charlotte Terrace. In addition to re-processing the EW9412 <span class="hlt">seismic</span> reflection data, we have compiled and re-analyzed a series of publicly available USGS <span class="hlt">seismic</span> reflection data that obliquely cross the QCF. Using these data, we are able to provide updated maps of the Queen Charlotte fault <span class="hlt">system</span>, adding considerable detail along the northernmost QCF where it links up with the Chatham Strait and Transition fault <span class="hlt">systems</span>. Our results support conclusions that the changing geometry of the QCF leads to fundamentally different convergent stress accommodation north and south of ~53.2 degrees; namely, reactivated splay faults to the north vs. thickening of sediments and the upper crust to the south</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMMR41D0432M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMMR41D0432M"><span>Grain <span class="hlt">Boundary</span> Sliding (GBS) as a Plastic Instability Leading to Coeval Pseudotachylyte Development in Mylonites: an EBSD Study of the <span class="hlt">Seismic</span> Cycle in Brittle-Ductile Transition Rocks of the South Mountains Core Complex, Arizona, USA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miranda, E.; Stewart, C.</p> <p>2017-12-01</p> <p>Exposures of coeval pseudotachylytes and mylonites are relatively rare, but are crucial for understanding the <span class="hlt">seismic</span> cycle in the vicinity of the brittle-ductile transition (BDT). We use both field observations and electron backscatter diffraction (EBSD) analysis to investigate the coeval pseudotachylytes and granodiorite mylonites exposed in the footwall of the South Mountains core complex, Arizona, to evaluate how strain is localized both prior to and during pseudotachylyte development at the BDT. In the field, we observe numerous pseudotachylyte veins oriented parallel to mylonitic foliation; the veins have synthetic shear sense with adjacent mylonites, and are < 2 cm thick, laterally discontinuous, and confined to a few m in structural thickness. EBSD analysis reveals that deformation is strongly partitioned into quartz in mylonites, where quartz shows subgrain rotation overprinted by bulging recrystallization microstructures and lattice preferred orientation (LPO) patterns indicative of dislocation creep. Foliation-parallel zones of finely recrystallized, (< 5 μm diameter) bulge-nucleated grains in the mylonites show four-grain junctions and randomized LPO patterns consistent with grain <span class="hlt">boundary</span> sliding (GBS). Pseudotachylyte veins have elongate polycrystalline quartz survivor clasts that also exhibit GBS traits, suggesting that pseudotachylytes form within GBS zones in mylonites. We interpret the onset of GBS as a triggering mechanism for coeval pseudotachylyte development, where the accompanying decrease in effective viscosity and increase in strain rate initiated <span class="hlt">seismic</span> slip and pseudotachylyte formation within GBS zones. Strain became localized within the pseudotachylyte until crystallization of melt impeded flow, inducing pseudotachylyte development in other GBS zones. We associate the pseudotachylyte veins and host mylonites with the coseismic and interseismic parts of the <span class="hlt">seismic</span> cycle, respectively, where the abundance and lateral discontinuity 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_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/2011APS..CAL.F3005L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..CAL.F3005L"><span><span class="hlt">Boundary</span> of Phase Co-existence in Docosahexaenoic Acid <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lor, Chai; Hirst, Linda S.</p> <p>2011-11-01</p> <p>Docosahexaenoic acid (DHA) is a highly polyunsaturated fatty acid (PUFA) that exhibits six double bonds in the hydrocarbon tail. It induces phase separation of the membrane into liquid order and liquid disorder in mixtures containing other lipids with more saturation and cholesterol. With the utilization of atomic force microscopy, phase co-existence is observed in lipid mixtures containing DHA on a single supported lipid bilayer. The <span class="hlt">boundary</span> of phase co-existence with decreasing DHA concentration is explored. The elastic force, thickness, and roughness of the different phases are investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002ASAJ..112.2296S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002ASAJ..112.2296S"><span>Long codas of coupled wave <span class="hlt">systems</span> in <span class="hlt">seismic</span> basins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seligman, Thomas H.</p> <p>2002-11-01</p> <p>Quite some time ago it was pointed out that the damage patterns and Fourier spectra of the 1985 earthquake in Mexico City are only compatible with a resonant effect of horizontal waves with the approximate speed of sound waves in water [see Flores et al., Nature 326, 783 (1987)]. In a more recent paper it was pointed out that this indeed will occur with a very specific frequency selection for a coupled <span class="hlt">system</span> of Raleigh waves at the interface of the bottom of the ancient lakebed with the more solid deposits, and an evanescent sound wave in the mud above [see J. Flores et al., Bull. Seismol. Soc. Am. 89, 14-21 (1999)]. In the present talk we shall go over these arguments again and show that strong reflection at the edges of the lake must occur to account for the strong magnification entailing necessarily a long coda, and that the mecanism can be understood in the same terms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013CG.....54..113D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013CG.....54..113D"><span>MAHA: A comprehensive <span class="hlt">system</span> for the storage and visualization of subsoil data for <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>Di Felice, P.; Spadoni, M.</p> <p>2013-04-01</p> <p>MAHA is a database-centred software <span class="hlt">system</span> for the storage and visualization of subsoil data used for the production of <span class="hlt">seismic</span> microzonation maps in Italy. The application was implemented using open source software in order to grant its maximum diffusion and customization. A conceptual model of the subsoil, jointly developed by the Italian National Research Council and the National Department of Civil Protection, inspired the structure of the underlying database, consisting of 15 tables, 3 of which of spatial nature to accommodate geo-referenced data associated to points, lines and polygons. A web-GIS interface acts as a bridge between the user and the database, drives the input of geo-referenced data and enables the users to formulate different types of spatial queries. A series of forms designed "ad hoc" and enriched with combo boxes provide guided procedures to maximize the fluency of data entry and to reduce the possibility of erroneous typing. One of these procedures helps to transform the descriptions of the geological units (granular materials), given in technical paper documents by using a conversational style, into standardized numeric codes. Summary reports, produced in the pdf format, can be generated through decoding and graphic display of the parameters previously entered in the database. MAHA was approved by the national commission for <span class="hlt">seismic</span> microzonation established by the Italian Prime Minister and, in the next years, it is expected to significantly support the entire process of map production in the urban areas more exposed to <span class="hlt">seismic</span> hazard.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S23D..01T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S23D..01T"><span>Expert agreements and disagreements on induced <span class="hlt">seismicity</span> by Enhanced Geothermal <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trutnevyte, E.; Azevedo, I. L.</p> <p>2016-12-01</p> <p>Enhanced or Engineered Geothermal <span class="hlt">Systems</span> (EGS) are at an early stage of development and only a handful of projects exist worldwide. In face of limited empirical evidence on EGS induced <span class="hlt">seismicity</span>, expert elicitation provides a complementary view to quantitative assessments and basic science. We present the results of an international expert elicitation exercise with 14 experts from 6 countries. The elicitation aimed at evaluating induced <span class="hlt">seismicity</span> hazard and risk for EGS and characterizing associated uncertainty. The state-of-the-art expert elicitation method was used: it combines technical analysis with behavioral science-informed elicitation of expert judgement in order to minimize subjectivity. The experts assessed a harmonized scenario of an EGS plant, its operational characteristics, geological context, and surrounding buildings and infrastructures. The experts provided quantitative estimates of exceedance probabilities of induced M>=3 and M>=5, maximum magnitudes that could be observed, and made judgements on economic loss, injuries, and fatalities in the case of M=3 and M=5. The experts also rated the importance of factors that influence induced <span class="hlt">seismicity</span> hazard and risk (e.g. reservoir depth, injected volumes, exposed building stock etc.) and the potential uncertainty reductions through future research. We present the findings of this elicitation and highlight the points of expert agreements and disagreements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24076511','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24076511"><span>A question of fit: reflections on <span class="hlt">boundaries</span>, organizations and social-ecological <span class="hlt">systems</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sternlieb, Faith; Bixler, R Patrick; Huber-Stearns, Heidi; Huayhuaca, Ch'aska</p> <p>2013-11-30</p> <p>Although there is acknowledgment that the complexity of social-ecological <span class="hlt">systems</span> governance demands representation from diverse perspectives, there is little agreement in the literature on how to cross both fiat (human-demarcated) and bona fide (physical) <span class="hlt">boundaries</span> to address such complexities. As a cohort of interdisciplinary scholars, we navigate the <span class="hlt">boundary</span> between science and practice to address the question of fit regarding the role of organizations in transcending <span class="hlt">boundaries</span>. We found there is a need to rectify discrepancies between theories about <span class="hlt">boundaries</span> and theories about organizations. To this end, we propose a conceptual framework to analyze transboundary organizations, an umbrella term to group the literature on <span class="hlt">boundary</span> organizations, intermediaries and bridging organizations; we introduce this term to illustrate they are not mutually exclusive and to facilitate interdisciplinary research. We first examine social-ecological <span class="hlt">systems</span> (SES), a framework intended to improve understandings of <span class="hlt">boundaries</span> and governance. We then continue to unpack the complexity of <span class="hlt">boundaries</span> and organizations, specifically through important transboundary concepts such as scale and organizational learning. This helps frame our examination of the literature on: 1) <span class="hlt">boundary</span> organizations; 2) bridging organizations (third-party entities); and 3) intermediaries (distinguished by their position between other actors). Our review identifies a number of discrepancies that pertain to the types of <span class="hlt">boundaries</span> discussed and the roles assigned to organizations governing SES. Important characteristics have emerged from our review of transboundary organizations including legitimacy, saliency, urgency, and credibility. In developing a conceptual framework, we argue that transboundary organizations: 1) expand upon the <span class="hlt">boundary</span> spectrum, 2) incorporate transboundary concepts, and 3) hybridize characteristics of <span class="hlt">boundary</span>, bridging, and intermediary organizations. We conclude with a number</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS21A1937M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS21A1937M"><span>High-resolution multi-channel <span class="hlt">seismic</span> images of the Queen Charlotte Fault <span class="hlt">system</span> offshore southeastern Alaska</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miller, N. C.; Brothers, D. S.; Kluesner, J.; Balster-Gee, A.; Ten Brink, U. S.; Andrews, B. D.; Haeussler, P. J.; Watt, J. T.; Dartnell, P.; East, A. E.</p> <p>2016-12-01</p> <p>We present high-resolution multi-channel <span class="hlt">seismic</span> (MCS) images of fault structure and sedimentary stratigraphy along the southeastern Alaska margin, where the northern Queen Charlotte Fault (QCF) cuts the shelf-edge and slope. The QCF is a dominantly strike slip <span class="hlt">system</span> that forms the <span class="hlt">boundary</span> between the Pacific (PA) and North American (NA) plates offshore western Canada and southeastern Alaska. The data were collected using a 64 channel, 200 m digital streamer and a 0.75-3 kJ sparker source aboard the R/V Norseman in August 2016. The survey was designed to cross a seafloor fault trace recently imaged by multibeam sonar (see adjacent poster by Brothers et al.) and to extend the subsurface information landward and seaward from the fault. Analysis of these MCS and multibeam data focus on addressing key questions that have significant implications for the kinematic and geodynamic history of the fault, including: Is the imaged surface fault in multibeam sonar the only recently-active fault trace? What is the shallow fault zone width and structure, is the internal structure of the recently-discovered pull-apart basin a dynamically developing structure? How does sediment thickness vary along the margin and how does this variation affect the fault expression? Can previous glacial sequences be identified in the stratigraphy?</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890046331&hterms=1041&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2526%25231041','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890046331&hterms=1041&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2526%25231041"><span>Time dependent inflow-outflow <span class="hlt">boundary</span> conditions for 2D acoustic <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Watson, Willie R.; Myers, Michael K.</p> <p>1989-01-01</p> <p>An analysis of the number and form of the required inflow-outflow <span class="hlt">boundary</span> conditions for the full two-dimensional time-dependent nonlinear acoustic <span class="hlt">system</span> in subsonic mean flow is performed. The explicit predictor-corrector method of MacCormack (1969) is used. The methodology is tested on both uniform and sheared mean flows with plane and nonplanar sources. Results show that the acoustic <span class="hlt">system</span> requires three physical <span class="hlt">boundary</span> conditions on the inflow and one on the outflow <span class="hlt">boundary</span>. The most natural choice for the inflow <span class="hlt">boundary</span> conditions is judged to be a specification of the vorticity, the normal acoustic impedance, and a pressure gradient-density gradient relationship normal to the <span class="hlt">boundary</span>. Specification of the acoustic pressure at the outflow <span class="hlt">boundary</span> along with these inflow <span class="hlt">boundary</span> conditions is found to give consistent reliable results. A set of <span class="hlt">boundary</span> conditions developed earlier, which were intended to be nonreflecting is tested using the current method and is shown to yield unstable results for nonplanar acoustic waves.</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 <span class="hlt">systems</span> (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 Acceleration (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('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=214946&keyword=chemical+AND+pollution+AND+boundary&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=214946&keyword=chemical+AND+pollution+AND+boundary&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Atmospheric <span class="hlt">Boundary</span> Layer Modeling for Combined Meteorology and Air Quality <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Atmospheric Eulerian grid models for mesoscale and larger applications require sub-grid models for turbulent vertical exchange processes, particularly within the Planetary <span class="hlt">Boundary</span> Layer (PSL). In combined meteorology and air quality modeling <span class="hlt">systems</span> consistent PSL modeling of wi...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S31A2716J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S31A2716J"><span>Navy's "Full Ship Shock Trials" as Opportunities for USGS/CTBTO <span class="hlt">Seismic</span> <span class="hlt">System</span> Evaluation and Calibration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jih, R. S.</p> <p>2016-12-01</p> <p>The U.S. Navy conducts "full ship shock trials" (FSST) on new construction ships to validate the ability the ship to carry out assigned missions in the combat shock environment. The shock trial attempts to simulate the effects of a near-miss underwater explosion by detonating 10,000 pound high explosive charges near the ship. On June 10, June 23, and July 16, 2016, respectively, the Navy carried out three FSSTs on the Littoral Combat Ship USS Jackson (LCS-6) off Florida coast. The three events were well recorded in eastern United States, and the U.S. Geological Survey (USGS) reported the events as "experimental explosions", with magnitudes in 3.7-3.8; and 78, 82, and 114 associated/picked phases, respectively. The CTBTO's <span class="hlt">seismic</span> bulletin has the first and third FSSTs reported, but not the second. CTBTO's International Monitoring <span class="hlt">Systems</span> (IMS) stations in the United States (Tuckaleechee of TN, Lajitas of TX, Mina of NV, Eilson of AK), Canada (Lac du Bonnet), Turkey (Belbashi), Finland (Lahti), and Australia (Warramunga, Alice Springs) saw some of these events. In addition, five hydrophone channels at Ascension Island hydroacoustic array detected two events. IDC did not "screen out" the detected FSSTs as earthquakes. Both USGS and IDC locations are fairly reasonable. In the case of USGS, the events are off shore, while most of the reporting <span class="hlt">seismic</span> stations are on land, on one side. The test area selected by the Navy for FSSTs is a narrow hexagon, bounded by two arcs: the 600-ft depth bathymetry on the west, and an arc of radius 120 nautical miles centered at Mayport Naval Station (Florida). The <span class="hlt">seismic</span> solutions determined by USGS and IDC lie inside the hexagon, using the standard single-event location algorithm. In the <span class="hlt">seismic</span> monitoring mission area, it has been well known that the best calibration data points are those well-recorded, controlled active-source experiments for which the Ground Truth (of the event size, origin time, and coordinates) are known - such</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMIN53A1550E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMIN53A1550E"><span>Information <span class="hlt">system</span> evolution at the French National Network of <span class="hlt">Seismic</span> Survey (BCSF-RENASS)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Engels, F.; Grunberg, M.</p> <p>2013-12-01</p> <p>The aging information <span class="hlt">system</span> of the French National Network of <span class="hlt">Seismic</span> Survey (BCSF-RENASS), located in Strasbourg (EOST), needed to be updated to satisfy new practices from Computer science world. The latter means to evolve our <span class="hlt">system</span> at different levels : development method, datamining solutions, <span class="hlt">system</span> administration. The new <span class="hlt">system</span> had to provide more agility for incoming projects. The main difficulty was to maintain old <span class="hlt">system</span> and the new one in parallel the time to validate new solutions with a restricted team. Solutions adopted here are coming from standards used by the seismological community and inspired by the state of the art of devops community. The new <span class="hlt">system</span> is easier to maintain and take advantage of large community to find support. This poster introduces the new <span class="hlt">system</span> and choosen solutions like Puppet, Fabric, MongoDB and FDSN Webservices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyD..338...42F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyD..338...42F"><span>Initial-<span class="hlt">boundary</span> layer associated with the nonlinear Darcy-Brinkman-Oberbeck-Boussinesq <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fei, Mingwen; Han, Daozhi; Wang, Xiaoming</p> <p>2017-01-01</p> <p>In this paper, we study the vanishing Darcy number limit of the nonlinear Darcy-Brinkman-Oberbeck-Boussinesq <span class="hlt">system</span> (DBOB). This singular perturbation problem involves singular structures both in time and in space giving rise to initial layers, <span class="hlt">boundary</span> layers and initial-<span class="hlt">boundary</span> layers. We construct an approximate solution to the DBOB <span class="hlt">system</span> by the method of multiple scale expansions. The convergence with optimal convergence rates in certain Sobolev norms is established rigorously via the energy method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ArRMA.224.1205G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ArRMA.224.1205G"><span><span class="hlt">Boundary</span> Korn Inequality and Neumann Problems in Homogenization of <span class="hlt">Systems</span> of Elasticity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geng, Jun; Shen, Zhongwei; Song, Liang</p> <p>2017-06-01</p> <p>This paper is concerned with a family of elliptic <span class="hlt">systems</span> of linear elasticity with rapidly oscillating periodic coefficients, arising in the theory of homogenization. We establish uniform optimal regularity estimates for solutions of Neumann problems in a bounded Lipschitz domain with L 2 <span class="hlt">boundary</span> data. The proof relies on a <span class="hlt">boundary</span> Korn inequality for solutions of <span class="hlt">systems</span> of linear elasticity and uses a large-scale Rellich estimate obtained in Shen (Anal PDE, arXiv:1505.00694v2).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........20V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........20V"><span>Tracking "Large" or "Smal": <span class="hlt">Boundaries</span> and their Consequences for Veterinary Students within the Tracking <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vermilya, Jenny R.</p> <p></p> <p>In this dissertation, I use 42 in-depth qualitative interviews with veterinary medical students to explore the experience of being in an educational program that tracks students based on the species of non-human animals that they wish to treat. Specifically, I examine how tracking produces multiple <span class="hlt">boundaries</span> for veterinary students. The <span class="hlt">boundaries</span> between different animal species produce consequences for the treatment of those animals; this has been well documented. Using a symbolic interactionist perspective, my research extends the body of knowledge on species <span class="hlt">boundaries</span> by revealing other consequences of this <span class="hlt">boundary</span> work. For example, I analyze the symbolic <span class="hlt">boundaries</span> involved in the gendering of animals, practitioners, and professions. I also examine how <span class="hlt">boundaries</span> influence the collective identity of students entering an occupation segmented into various specialties. The collective identity of veterinarian is one characterized by care, thus students have to construct different definitions of care to access and maintain the collective identity. The tracking <span class="hlt">system</span> additionally produces consequences for the knowledge created and reproduced in different areas of animal medicine, creating a <span class="hlt">system</span> of power and inequality based on whose knowledge is privileged, how, and why. Finally, socially constructed <span class="hlt">boundaries</span> generated from tracking inevitably lead to cases that do not fit. In particular, horses serve as a "border species" for veterinary students who struggle to place them into the tracking <span class="hlt">system</span>. I argue that border species, like other metaphorical borders, have the potential to challenge discourses and lead to social change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985RpESc.......71K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985RpESc.......71K"><span>Relationship between <span class="hlt">seismic</span> status of Earth and relative position of bodies in sun-earth-moon <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kulanin, N. V.</p> <p>1985-03-01</p> <p>The time spectrum of variations in <span class="hlt">seismicity</span> is quite broad. There are <span class="hlt">seismic</span> seasons, as well as multiannual variations. The range of characteristic times of variation from days to about one year is studied. <span class="hlt">Seismic</span> activity as a function of the position of the moon relative to the Earth and the direction toward the Sun is studied. The moments of strong earthquakes, over 5.8 on the Richter scale, between 1968 and June 1980 are plotted in time coordinates relating them to the relative positions of the three bodies in the sun-earth-moon <span class="hlt">system</span>. Methods of mathematical statistics are applied to the points produced, indicating at least 99% probability that the distribution was not random. a periodicity of the earth's <span class="hlt">seismic</span> state of 413 days is observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2009/1095/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2009/1095/"><span>Finding Trapped Miners by Using a Prototype <span class="hlt">Seismic</span> Recording <span class="hlt">System</span> Made from Music-Recording Hardware</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pratt, Thomas L.</p> <p>2009-01-01</p> <p>The goal of this project was to use off-the-shelf music recording equipment to build and test a prototype <span class="hlt">seismic</span> <span class="hlt">system</span> to listen for people trapped in underground chambers (mines, caves, collapsed buildings). Previous workers found that an array of geophones is effective in locating trapped miners; displaying the data graphically, as well as playing it back into an audio device (headphones) at high speeds, was found to be effective for locating underground tapping. The desired <span class="hlt">system</span> should record the data digitally to allow for further analysis, be capable of displaying the data graphically, allow for rudimentary analysis (bandpass filter, deconvolution), and allow the user to listen to the data at varying speeds. Although existing <span class="hlt">seismic</span> reflection <span class="hlt">systems</span> are adequate to record, display and analyze the data, they are relatively expensive and difficult to use and do not have an audio playback option. This makes it difficult for individual mines to have a <span class="hlt">system</span> waiting on the shelf for an emergency. In contrast, music recording <span class="hlt">systems</span>, like the one I used to construct the prototype <span class="hlt">system</span>, can be purchased for about 20 percent of the cost of a <span class="hlt">seismic</span> reflection <span class="hlt">system</span> and are designed to be much easier to use. The prototype <span class="hlt">system</span> makes use of an ~$3,000, 16-channel music recording <span class="hlt">system</span> made by Presonus, Inc., of Baton Rouge, Louisiana. Other manufacturers make competitive <span class="hlt">systems</span> that would serve equally well. Connecting the geophones to the recording <span class="hlt">system</span> required the only custom part of this <span class="hlt">system</span> - a connector that takes the output from the geophone cable and breaks it into 16 microphone inputs to be connected to the music recording <span class="hlt">system</span>. The connector took about 1 day of technician time to build, using about $300 in off-the-shelf parts. Comparisons of the music recording <span class="hlt">system</span> and a standard <span class="hlt">seismic</span> reflection <span class="hlt">system</span> (A 24-channel 'Geode' <span class="hlt">system</span> manufactured by Geometrics, Inc., of San Jose, California) were carried out at two locations. Initial</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 <span class="hlt">system</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, 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 <span class="hlt">system</span> (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 <span class="hlt">system</span> 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 <span class="hlt">system</span>. Data reported and statistically sorted include pile shear, wave height, impulsive acceleration, convective acceleration and outer tank acceleration. The results show that the isolation <span class="hlt">system</span> 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/2017CQGra..34f5002B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CQGra..34f5002B"><span>Passive-performance, analysis, and upgrades of a 1-ton <span class="hlt">seismic</span> attenuation <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bergmann, G.; Mow-Lowry, C. M.; Adya, V. B.; Bertolini, A.; Hanke, M. M.; Kirchhoff, R.; Köhlenbeck, S. M.; Kühn, G.; Oppermann, P.; Wanner, A.; Westphal, T.; Wöhler, J.; Wu, D. S.; Lück, H.; Strain, K. A.; Danzmann, K.</p> <p>2017-03-01</p> <p>The 10 m prototype facility at the Albert-Einstein-institute (AEI) in Hanover, Germany, employs three large <span class="hlt">seismic</span> attenuation <span class="hlt">systems</span> to reduce mechanical motion. The AEI <span class="hlt">seismic-attenuation-system</span> (AEI-SAS) uses mechanical anti-springs in order to achieve resonance frequencies below 0.5 Hz. This <span class="hlt">system</span> provides passive isolation from ground motion by a factor of about 400 in the horizontal direction at 4 Hz and in the vertical direction at 9 Hz. The presented isolation performance is measured under vacuum conditions using a combination of commercial and custom-made inertial sensors. Detailed analysis of this performance led to the design and implementation of tuned dampers to mitigate the effect of the unavoidable higher order modes of the <span class="hlt">system</span>. These dampers reduce RMS motion substantially in the frequency range between 10 and 100 Hz in 6 degrees of freedom. The results presented here demonstrate that the AEI-SAS provides substantial passive isolation at all the fundamental mirror-suspension resonances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S41A2406A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S41A2406A"><span>Real-time estimation <span class="hlt">system</span> for <span class="hlt">seismic</span>-intensity exposed-population</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aoi, S.; Nakamura, H.; Kunugi, T.; Suzuki, W.; Fujiwara, H.</p> <p>2013-12-01</p> <p>For an appropriate first-action to an earthquake, risk (damage) information evaluated in real-time are important as well as hazard (ground motion) information. To meet this need, we are developing real-time estimation <span class="hlt">system</span> (J-RISQ) for exposed population and earthquake damage on buildings. We plan to open the web page of estimated exposed population to the public from autumn. When an earthquake occurs, <span class="hlt">seismic</span> intensities are calculated at each observation station and sent to the DMC (Data Management Center) in different timing. For rapid estimation, the <span class="hlt">system</span> does not wait for the data from all the stations but begins the first estimation when the number of the stations observing the <span class="hlt">seismic</span> intensity of 2.5 or larger exceeds the threshold amount. Estimations are updated several times using all the available data at that moment. Spatial distribution of <span class="hlt">seismic</span> intensity in 250 m meshes is estimated by the site amplification factor of surface layers and the observed data. By using this intensity distribution, the exposed population is estimated using population data of each mesh. The exposed populations for municipalities and prefectures are estimated by summing-up the exposures of included meshes for the area and are appropriately rounded taking estimation precision into consideration. The estimated intensities for major cities are shown by the histograms, which indicate the variation of the estimated values in the city together with the observed maximum intensity. The variation is mainly caused by the difference of the site amplification factors. The intensities estimated for meshes with large amplification factor are sometimes larger than the maximum value observed in the city. The estimated results are seen on the web site just after the earthquake. The results of the past earthquakes can be easily searched by keywords such as date, magnitudes, <span class="hlt">seismic</span> intensities and source areas. The summary of the results in the one-page report of Portable Document Format</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAG...143...31P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAG...143...31P"><span>Capabilities of <span class="hlt">seismic</span> and georadar 2D/3D imaging of shallow subsurface of transport route using the Seismobile <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pilecki, Zenon; Isakow, Zbigniew; Czarny, Rafał; Pilecka, Elżbieta; Harba, Paulina; Barnaś, Maciej</p> <p>2017-08-01</p> <p>In this work, the capabilities of the Seismobile <span class="hlt">system</span> for shallow subsurface imaging of transport routes, such as roads, railways, and airport runways, in different geological conditions were presented. The Seismobile <span class="hlt">system</span> combines the advantages of <span class="hlt">seismic</span> profiling using landstreamer and georadar (GPR) profiling. It consists of up to four <span class="hlt">seismic</span> measuring lines and carriage with a suspended GPR antenna. Shallow subsurface recognition may be achieved to a maximum width of 10.5 m for a distance of 3.5 m between the measurement lines. GPR measurement is performed in the axis of the construction. Seismobile allows the measurement time, labour and costs to be reduced due to easy technique of its installation, remote data transmission from geophones to accompanying measuring modules, automated location of the <span class="hlt">system</span> based on GPS and a highly automated method of <span class="hlt">seismic</span> wave excitation. In this paper, the results of field tests carried out in different geological conditions were presented. The methodologies of acquisition, processing and interpretation of <span class="hlt">seismic</span> and GPR measurements were broadly described. Seismograms and its spectrum registered by Seismobile <span class="hlt">system</span> were compared to the ones registered by Geode seismograph of Geometrix. <span class="hlt">Seismic</span> data processing and interpretation software allows for the obtaining of 2D/3D models of P- and S-wave velocities. Combined <span class="hlt">seismic</span> and GPR results achieved sufficient imaging of shallow subsurface to a depth of over a dozen metres. The obtained geophysical information correlated with geological information from the boreholes with good quality. The results of performed tests proved the efficiency of the Seismobile <span class="hlt">system</span> in <span class="hlt">seismic</span> and GPR imaging of a shallow subsurface of transport routes under compound conditions.</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://ntrs.nasa.gov/search.jsp?R=20060029186&hterms=currents+Canary&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcurrents%2BCanary','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060029186&hterms=currents+Canary&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcurrents%2BCanary"><span>Production regimes in four eastern <span class="hlt">boundary</span> current <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Carr, M. E.; Kearns, E. J.</p> <p>2003-01-01</p> <p>High productivity (maxima 3 g C m(sup -2)day(sup -1)) of the Eastern <span class="hlt">Boundary</span> Currents (EBCs), i.e. the California, Peru-Humboldt, Canary and Benguela Currents, is driven by a combination of local forcing and large-scale circulation. The characteristics of the deep water brought to the surface by upwelling favorable winds depend on the large-scale circulation patterns. Here we use a new hydrographic and nutrient climatology together with satellite measurements ofthe wind vector, sea-surface temperature (SST), chlorophyll concentration, and primary production modeled from ocean color to quantify the meridional and seasonal patterns of upwelling dynamics and biological response. The unprecedented combination of data sets allows us to describe objectively the variability for small regions within each current and to characterize the governing factors for biological production. The temporal and spatial environmental variability was due in most regions to large-scale circulation, alone or in combination with offshore transport (local forcing). The observed meridional and seasonal patterns of biomass and primary production were most highlycorrelated to components representing large-scale circulation. The biomass sustained by a given nutrient concentration in the Atlantic EBCs was twice as large as that of the Pacific EBCs. This apparent greater efficiency may be due toavailability of iron, physical retention, or differences in planktonic community structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AIPC.1618..269M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AIPC.1618..269M"><span>Magnetic field effect on the liquidus <span class="hlt">boundary</span> of Bi-Mn binary <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mitsui, Yoshifuru; Koyama, Keiichi; Oikawa, Katsunari; Watanabe, Kazuo</p> <p>2014-10-01</p> <p>The magnetic field effect (MFE) on liquidus <span class="hlt">boundary</span> of Bi-Mn binary <span class="hlt">system</span> was investigated by differential thermal analysis (DTA) and the computer coupling of phase diagram method (CALPHAD). The liquidus <span class="hlt">boundary</span> for Bi-18at.%Mn and Bi-24at.%Mn rose clearly by the application of the magnetic fields. The MFE for liquidus <span class="hlt">boundary</span> temperature Tliq changed from ΔTliq∝B2 to ΔTliq∝B because of the large increase of the peritectic temperature from BiMn and BiMn1.08 by the application of magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGeo...82...98C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGeo...82...98C"><span>Frontal compression along the Apennines thrust <span class="hlt">system</span>: The Emilia 2012 example from <span class="hlt">seismicity</span> to crustal structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chiarabba, Claudio; De Gori, Pasquale; Improta, Luigi; Lucente, Francesco Pio; Moretti, Milena; Govoni, Aladino; Di Bona, Massimo; Margheriti, Lucia; Marchetti, Alessandro; Nardi, Anna</p> <p>2014-12-01</p> <p>The evolution of the Apennines thrust-and-fold belt is related to heterogeneous process of subduction and continental delamination that generates extension within the mountain range and compression on the outer front of the Adria lithosphere. While normal faulting earthquakes diffusely occur along the mountain chain, the sparse and poor <span class="hlt">seismicity</span> in the compressional front does not permit to resolve the ambiguity that still exists about which structure accommodates the few mm/yr of convergence observed by geodetic data. In this study, we illustrate the 2012 Emilia <span class="hlt">seismic</span> sequence that is the most significant series of moderate-to-large earthquakes developed during the past decades on the compressional front of the Apennines. Accurately located aftershocks, along with P-wave and Vp/Vs tomographic models, clearly reveal the geometry of the thrust <span class="hlt">system</span>, buried beneath the Quaternary sediments of the Po Valley. The <span class="hlt">seismic</span> sequence ruptured two distinct adjacent thrust faults, whose different dip, steep or flat, accounts for the development of the arc-like shape of the compressional front. The first shock of May 20 (Mw 6.0) developed on the middle Ferrara thrust that has a southward dip of about 30°. The second shock of May 29 (Mw 5.8) ruptured the Mirandola thrust that we define as a steep dipping (50-60°) pre-existing (Permo-Triassic) basement normal fault inverted during compression. The overall geometry of the fault <span class="hlt">system</span> is controlled by heterogeneity of the basement inherited from the older extension. We also observe that the rupture directivity during the two main-shocks and the aftershocks concentration correlate with low Poisson ratio volumes, probably indicating that portions of the fault have experienced intense micro-damage.</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 release in shallow and intermediate-depth subduction <span class="hlt">systems</span></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 <span class="hlt">systems</span>. Its application to the Ryukyu-Taiwan-Luzon <span class="hlt">system</span> 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 release 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 release. 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 release and surface volcanism. Visualization using slab coordinate projections is extended systematically to a global survey of the geometry of stress release 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> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/circ/1972/0672/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/circ/1972/0672/report.pdf"><span>Ground motion values for use in the <span class="hlt">seismic</span> design of the Trans-Alaska Pipeline <span class="hlt">system</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>Page, Robert A.; Boore, D.M.; Joyner, W.B.; Coulter, H.W.</p> <p>1972-01-01</p> <p>The proposed trans-Alaska oil pipeline, which would traverse the state north to south from Prudhoe Bay on the Arctic coast to Valdez on Prince William Sound, will be subject to serious earthquake hazards over much of its length. To be acceptable from an environmental standpoint, the pipeline <span class="hlt">system</span> is to be designed to minimize the potential of oil leakage resulting from <span class="hlt">seismic</span> shaking, faulting, and <span class="hlt">seismically</span> induced ground deformation. The design of the pipeline <span class="hlt">system</span> must accommodate the effects of earthquakes with magnitudes ranging from 5.5 to 8.5 as specified in the 'Stipulations for Proposed Trans-Alaskan Pipeline <span class="hlt">System</span>.' This report characterizes ground motions for the specified earthquakes in terms of peak levels of ground acceleration, velocity, and displacement and of duration of shaking. Published strong motion data from the Western United States are critically reviewed to determine the intensity and duration of shaking within several kilometers of the slipped fault. For magnitudes 5 and 6, for which sufficient near-fault records are available, the adopted ground motion values are based on data. For larger earthquakes the values are based on extrapolations from the data for smaller shocks, guided by simplified theoretical models of the faulting process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JSeis..16..291V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JSeis..16..291V"><span>Adaptive neuro-fuzzy inference <span class="hlt">systems</span> for semi-automatic discrimination between <span class="hlt">seismic</span> events: a study in Tehran region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vasheghani Farahani, Jamileh; Zare, Mehdi; Lucas, Caro</p> <p>2012-04-01</p> <p>Thisarticle presents an adaptive neuro-fuzzy inference <span class="hlt">system</span> (ANFIS) for classification of low magnitude <span class="hlt">seismic</span> events reported in Iran by the network of Tehran Disaster Mitigation and Management Organization (TDMMO). ANFIS classifiers were used to detect <span class="hlt">seismic</span> events using six inputs that defined the <span class="hlt">seismic</span> events. Neuro-fuzzy coding was applied using the six extracted features as ANFIS inputs. Two types of events were defined: weak earthquakes and mining blasts. The data comprised 748 events (6289 signals) ranging from magnitude 1.1 to 4.6 recorded at 13 <span class="hlt">seismic</span> stations between 2004 and 2009. We surveyed that there are almost 223 earthquakes with M ≤ 2.2 included in this database. Data sets from the south, east, and southeast of the city of Tehran were used to evaluate the best short period <span class="hlt">seismic</span> discriminants, and features as inputs such as origin time of event, distance (source to station), latitude of epicenter, longitude of epicenter, magnitude, and spectral analysis (fc of the Pg wave) were used, increasing the rate of correct classification and decreasing the confusion rate between weak earthquakes and quarry blasts. The performance of the ANFIS model was evaluated for training and classification accuracy. The results confirmed that the proposed ANFIS model has good potential for determining <span class="hlt">seismic</span> events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.S21B2505S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.S21B2505S"><span><span class="hlt">Seismic</span> tomography of the Canterbury Plains and the geometry and evolution of <span class="hlt">seismicity</span> of the Greendale fault <span class="hlt">system</span>, 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>Syracuse, E. M.; Thurber, C. H.; Savage, M. K.</p> <p>2012-12-01</p> <p>The previously unknown Greendale fault produced the September 4, 2010 M 7.1 Darfield earthquake and later triggered the destructive February 22, 2011 M 6.3 Christchurch earthquake, as well as later M>5 aftershocks east of Christchurch. Surface rupture from the Darfield earthquake indicates up to 5 m of strike-slip motion along the main portion of the Greendale fault, while various geodetic and <span class="hlt">seismic</span> models also indicate reverse faulting on surrounding smaller faults. We combine <span class="hlt">seismic</span> data from a variety of sources (permanent network seismometers and strong motion instruments, temporary intermediate to broadband seismometers) to understand the geometry of these various sections of faults and the evolution of <span class="hlt">seismicity</span> along them for the first four months of aftershocks from the Darfield earthquake. We identify 4 to 5 fault segments that were likely active in the Darfield earthquake and an additional 5 to 6 segments that were active during the study period, prior to the Christchurch earthquake. While relocating hypocenters, we also jointly invert for 3D Vp, Vs, and Vp/Vs in the Canterbury region using an extended version of the double-difference tomography code tomoDD (Zhang et al., 2009). In the area of the Greendale and associated faults, Vp, Vs, and Vp/Vs are generally reduced from the top 8 km of the average velocity model for the Canterbury region of New Zealand. from the surface to ~8 km depth, below which the resolution begins to decline. Beneath Christchurch and areas immediately to the south and west, Vp and Vs are elevated and Vp/Vs is reduced from the surface to ~8 km depth, corresponding to the location of a negative Bouguer gravity anomaly and an increase in depth to basement (Hicks, 1989). In the northwest portion of the model, Vp and Vs increase when approaching the foothills of the Southern Alps. There are no clearly defined features in the velocity model that cross or are offset by the Greendale fault and no apparent contrast in velocities</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5831...15S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5831...15S"><span>Generalization of the Ehrenfest theorem to quantum <span class="hlt">systems</span> with periodical <span class="hlt">boundary</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sanin, Andrey L.; Bagmanov, Andrey T.</p> <p>2005-04-01</p> <p>A generalization of Ehrenfest's theorem is discussed. For this purpose the quantum <span class="hlt">systems</span> with periodical <span class="hlt">boundary</span> conditions are being revised. The relations for time derivations of mean coordinate and momentum are derived once again. In comparison with Ehrenfest's theorem and its conventional quantities, the additional local terms occur which are caused <span class="hlt">boundaries</span>. Because of this, the obtained new relations can be named as generalized. An example for using these relations is given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9401S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9401S"><span><span class="hlt">Seismic</span> Symphonies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Strinna, Elisa; Ferrari, Graziano</p> <p>2015-04-01</p> <p>The project started in 2008 as a sound installation, a collaboration between an artist, a barrel organ builder and a seismologist. The work differs from other attempts of sound transposition of <span class="hlt">seismic</span> records. In this case <span class="hlt">seismic</span> frequencies are not converted automatically into the "sound of the earthquake." However, it has been studied a musical translation <span class="hlt">system</span> that, based on the organ tonal scale, generates a totally unexpected sequence of sounds which is intended to evoke the emotions aroused by the earthquake. The symphonies proposed in the project have somewhat peculiar origins: they in fact come to life from the translation of graphic tracks into a sound track. The graphic tracks in question are made up by copies of seismograms recorded during some earthquakes that have taken place around the world. Seismograms are translated into music by a sculpture-instrument, half a seismograph and half a barrel organ. The organ plays through holes practiced on paper. Adapting the documents to the instrument score, holes have been drilled on the waves' peaks. The organ covers about three tonal scales, starting from heavy and deep sounds it reaches up to high and jarring notes. The translation of the <span class="hlt">seismic</span> records is based on a criterion that does match the highest sounds to larger amplitudes with lower ones to minors. Translating the seismogram in the organ score, the larger the amplitude of recorded waves, the more the seismogram covers the full tonal scale played by the barrel organ and the notes arouse an intense emotional response in the listener. Elisa Strinna's <span class="hlt">Seismic</span> Symphonies installation becomes an unprecedented tool for emotional involvement, through which can be revived the memory of the greatest disasters of over a century of <span class="hlt">seismic</span> history of the Earth. A bridge between art and science. <span class="hlt">Seismic</span> Symphonies is also a symbolic inversion: the instrument of the organ is most commonly used in churches, and its sounds are derived from the heavens and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1802b0006G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1802b0006G"><span>Numerical solution of <span class="hlt">system</span> of <span class="hlt">boundary</span> value problems using B-spline with free parameter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gupta, Yogesh</p> <p>2017-01-01</p> <p>This paper deals with method of B-spline solution for a <span class="hlt">system</span> of <span class="hlt">boundary</span> value problems. The differential equations are useful in various fields of science and engineering. Some interesting real life problems involve more than one unknown function. These result in <span class="hlt">system</span> of simultaneous differential equations. Such <span class="hlt">systems</span> have been applied to many problems in mathematics, physics, engineering etc. In present paper, B-spline and B-spline with free parameter methods for the solution of a linear <span class="hlt">system</span> of second-order <span class="hlt">boundary</span> value problems are presented. The methods utilize the values of cubic B-spline and its derivatives at nodal points together with the equations of the given <span class="hlt">system</span> and <span class="hlt">boundary</span> conditions, ensuing into the linear matrix equation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820000009&hterms=industrial+Security&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dindustrial%2BSecurity','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820000009&hterms=industrial+Security&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dindustrial%2BSecurity"><span>Scanning <span class="hlt">Seismic</span> Intrusion Detector</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lee, R. D.</p> <p>1982-01-01</p> <p>Scanning <span class="hlt">seismic</span> intrusion detector employs array of automatically or manually scanned sensors to determine approximate location of intruder. Automatic-scanning feature enables one operator to tend <span class="hlt">system</span> of many sensors. Typical sensors used with new <span class="hlt">system</span> are moving-coil <span class="hlt">seismic</span> pickups. Detector finds uses in industrial security <span class="hlt">systems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......382B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......382B"><span>Drop interaction with solid <span class="hlt">boundaries</span> in liquid/liquid <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bordoloi, Ankur Deep</p> <p></p> <p> wettability. For d/D<0.8, the <span class="hlt">Boundary</span> between drop capture and release depended on a modified Bond number relating drop gravitational time scale to orifice surface tension time scale. For the sharp-edged case, contact was initiated at the orifice edge immediately upon impact, such that surface wettability influenced the drop outcome.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2002/ofr-02-0092/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2002/ofr-02-0092/"><span>Technical guidelines for the implementation of the Advanced National <span class="hlt">Seismic</span> <span class="hlt">System</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>Committee, ANSS Technical Integration</p> <p>2002-01-01</p> <p>The Advanced National <span class="hlt">Seismic</span> <span class="hlt">System</span> (ANSS) is a major national initiative led by the US Geological Survey that serves the needs of the earthquake monitoring, engineering, and research communities as well as national, state, and local governments, emergency response organizations, and the general public. Legislation authorizing the ANSS was passed in 2000, and low levels of funding for planning and initial purchases of new <span class="hlt">seismic</span> instrumentation have been appropriated beginning in FY2000. When fully operational, the ANSS will be an advanced monitoring <span class="hlt">system</span> (modern digital seismographs and accelerographs, communications networks, data collection and processing centers, and well-trained personnel) distributed across the United States that operates with high performance standards, gathers critical technical data, and effectively provides timely and reliable earthquake products, information, and services to meet the Nation’s needs. The ANSS will automatically broadcast timely and authoritative products describing the occurrence of earthquakes, earthquake source properties, the distribution of ground shaking, and, where feasible, broadcast early warnings and alerts for the onset of strong ground shaking. Most importantly, the ANSS will provide earthquake data, derived products, and information to the public, emergency responders, officials, engineers, educators, researchers, and other ANSS partners rapidly and in forms that are useful for their needs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5856.1003O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5856.1003O"><span><span class="hlt">Seismic</span> damage identification using multi-line distributed fiber optic sensor <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ou, Jinping; Hou, Shuang</p> <p>2005-06-01</p> <p>Determination of the actual nonlinear inelastic response mechanisms developed by civil structures such as buildings and bridges during strong earthquakes and post-earthquake damage assessment of these structures represent very difficult challenges for earthquake structural engineers. One of the main reasons is that the traditional sensor can't serve for such a long period to cover an earthquake and the <span class="hlt">seismic</span> damage location in the structure can't be predicted in advance definitely. It is thought that the <span class="hlt">seismic</span> damage of reinforced concrete (RC) structure can be related to the maximum response the structure, which can also be related to the cracks on the concrete. A distributed fiber optic sensor was developed to detect the cracks on the reinforced concrete structure under load. Fiber optic couples were used in the sensor <span class="hlt">system</span> to extend the sensor <span class="hlt">system</span>'s capacity from one random point detection to more. An optical time domain reflectometer (OTDR) is employed for interrogation of the sensor signal. Fiber optic sensors are attached on the surface of the concrete by the epoxy glue. By choosing the strength of epoxy, the damage state of the concrete can be responded to the occurrence of the Fresnel scattering in the fiber optic sensor. Experiments involved monotonic loading to failure. Finally, the experimental results in terms of crack detection capability are presented and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006NIMPA.556..616B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006NIMPA.556..616B"><span>Mechanical design of a single-axis monolithic accelerometer for advanced <span class="hlt">seismic</span> attenuation <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bertolini, Alessandro; DeSalvo, Riccardo; Fidecaro, Francesco; Francesconi, Mario; Marka, Szabolcs; Sannibale, Virginio; Simonetti, Duccio; Takamori, Akiteru; Tariq, Hareem</p> <p>2006-01-01</p> <p>The design and mechanics for a new very-low noise low frequency horizontal accelerometer is presented. The sensor has been designed to be integrated in an advanced <span class="hlt">seismic</span> isolation <span class="hlt">system</span> for interferometric gravitational wave detectors. The motion of a small monolithic folded-pendulum (FP) is monitored by a high resolution capacitance displacement sensor; a feedback force actuator keeps the mass at the equilibrium position. The feedback signal is proportional to the ground acceleration in the frequency range 0-150 Hz. The very high mechanical quality factor, Q≃3000 at a resonant frequency of 0.5 Hz, reduces the Brownian motion of the proof mass of the accelerometer below the resolution of the displacement sensor. This scheme enables the accelerometer to detect the inertial displacement of a platform with a root-mean-square noise less than 1 nm, integrated over the frequency band from 0.01 to 150 Hz. The FP geometry, combined with the monolithic design, allows the accelerometer to be extremely directional. A vertical-horizontal coupling ranging better than 10-3 has been achieved. A detailed account of the design and construction of the accelerometer is reported here. The instrument is fully ultra-high vacuum compatible and has been tested and approved for integration in <span class="hlt">seismic</span> attenuation <span class="hlt">system</span> of japanese TAMA 300 gravitational wave detector. The monolithic design also makes the accelerometer suitable for cryogenic operation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1617006A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1617006A"><span>Prioritization of information using decision support <span class="hlt">systems</span> for <span class="hlt">seismic</span> risk in Bucharest city</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Armas, Iuliana; Gheorghe, Diana</p> <p>2014-05-01</p> <p>Nowadays, because of the ever increasing volume of information, policymakers are faced with decision making problems. Achieving an objective and suitable decision making may become a challenge. In such situations decision support <span class="hlt">systems</span> (DSS) have been developed. DSS can assist in the decision making process, offering support on how a decision should be made, rather than what decision should be made (Simon, 1979). This in turn potentially involves a huge number of stakeholders and criteria. Regarding <span class="hlt">seismic</span> risk, Bucharest City is highly vulnerable (Mandrescu et al., 2007). The aim of this study is to implement a spatial decision support <span class="hlt">system</span> in order to secure a suitable shelter in case of an earthquake occurrence in the historical centre of Bucharest City. In case of a <span class="hlt">seismic</span> risk, a shelter is essential for sheltering people who lost their homes or whose homes are in danger of collapsing while people at risk receive first aid in the post-disaster phase. For the present study, the SMCE Module for ILWIS 3.4 was used. The methodology included structuring the problem by creating a decision tree, standardizing and weighting of the criteria. The results showed that the most suitable buildings are Tania Hotel, Hanul lui Manuc, The National Bank of Romania, The Romanian Commercial Bank and The National History Museum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT........54T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT........54T"><span>Performance-Based <span class="hlt">Seismic</span> Retrofit of Soft-Story Woodframe Buildings Using Energy-Dissipation <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tian, Jingjing</p> <p></p> <p>Low-rise woodframe buildings with disproportionately flexible ground stories represent a significant percentage of the building stock in <span class="hlt">seismically</span> vulnerable communities in the Western United States. These structures have a readily identifiable structural weakness at the ground level due to an asymmetric distribution of large openings in the perimeter wall lines and to a lack of interior partition walls, resulting in a soft story condition that makes the structure highly susceptible to severe damage or collapse under design-level earthquakes. The conventional approach to retrofitting such structures is to increase the ground story stiffness. An alternate approach is to increase the energy dissipation capacity of the structure via the incorporation of supplemental energy dissipation devices (dampers), thereby relieving the energy dissipation demands on the framing <span class="hlt">system</span>. Such a retrofit approach is consistent with a Performance-Based <span class="hlt">Seismic</span> Retrofit (PBSR) philosophy through which multiple performance levels may be targeted. The effectiveness of such a retrofit is presented via examination of the <span class="hlt">seismic</span> response of a full-scale four-story building that was tested on the outdoor shake table at NEES-UCSD and a full-scale three-story building that was tested using slow pseudo-dynamic hybrid testing at NEES-UB. In addition, a Direct Displacement Design (DDD) methodology was developed as an improvement over current DDD methods by considering torsion, with or without the implementation of damping devices, in an attempt to avoid the computational expense of nonlinear time-history analysis (NLTHA) and thus facilitating widespread application of PBSR in engineering practice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70022904','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70022904"><span>New Site Coefficients and Site Classification <span class="hlt">System</span> Used in Recent Building <span class="hlt">Seismic</span> Code Provisions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dobry, R.; Borcherdt, R.D.; Crouse, C.B.; Idriss, I.M.; Joyner, W.B.; Martin, G.R.; Power, M.S.; Rinne, E.E.; Seed, R.B.</p> <p>2000-01-01</p> <p>Recent code provisions for buildings and other structures (1994 and 1997 NEHRP Provisions, 1997 UBC) have adopted new site amplification factors and a new procedure for site classification. Two amplitude-dependent site amplification factors are specified: Fa for short periods and Fv for longer periods. Previous codes included only a long period factor S and did not provide for a short period amplification factor. The new site classification <span class="hlt">system</span> is based on definitions of five site classes in terms of a representative average shear wave velocity to a depth of 30 m (V?? s). This definition permits sites to be classified unambiguously. When the shear wave velocity is not available, other soil properties such as standard penetration resistance or undrained shear strength can be used. The new site classes denoted by letters A - E, replace site classes in previous codes denoted by S1 - S4. Site classes A and B correspond to hard rock and rock, Site Class C corresponds to soft rock and very stiff / very dense soil, and Site Classes D and E correspond to stiff soil and soft soil. A sixth site class, F, is defined for soils requiring site-specific evaluations. Both Fa and Fv are functions of the site class, and also of the level of <span class="hlt">seismic</span> hazard on rock, defined by parameters such as Aa and Av (1994 NEHRP Provisions), Ss and S1 (1997 NEHRP Provisions) or Z (1997 UBC). The values of Fa and Fv decrease as the <span class="hlt">seismic</span> hazard on rock increases due to soil nonlinearity. The greatest impact of the new factors Fa and Fv as compared with the old S factors occurs in areas of low-to-medium <span class="hlt">seismic</span> hazard. This paper summarizes the new site provisions, explains the basis for them, and discusses ongoing studies of site amplification in recent earthquakes that may influence future code developments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMSF41A0749H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMSF41A0749H"><span>VORBrouter: A dynamic data routing <span class="hlt">system</span> for Real-Time <span class="hlt">Seismic</span> networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hansen, T.; Vernon, F.; Lindquist, K.; Orcutt, J.</p> <p>2004-12-01</p> <p>For anyone who has managed a moderately complex buffered real-time data transport <span class="hlt">system</span>, the need for reliable adaptive data transport is clear. The ROADNet VORBrouter <span class="hlt">system</span>, an extension to the ROADNet data catalog <span class="hlt">system</span> [AGU-2003, Dynamic Dataflow Topology Monitoring for Real-time <span class="hlt">Seismic</span> Networks], allows dynamic routing of real-time <span class="hlt">seismic</span> data from sensor to end-user. Traditional networks consist of a series of data buffer computers with data transport interconnections configured by hand. This allows for arbitrarily complex data networks, which can often exceed full comprehension by network administrators, sometimes resulting in data loops or accidental data cutoff. In order to manage data transport <span class="hlt">systems</span> in the event of a network failure, a network administrator must be called upon to change the data transport paths and to recover the missing data. Using VORBrouter, administrators can sleep at night while still providing 7/24 uninterupted data streams at realistic cost. This software package uses information from the ROADNet data catalog <span class="hlt">system</span> to route packets around failed link outages and to new consumers in real-time. Dynamic data routing protocols operating on top of the Antelope Data buffering layer allow authorized users to request data sets from their local buffer and to have them delivered from anywhere within the network of buffers. The VORBrouter software also allows for dynamic routing around network outages, and the elimination of duplicate data paths within the network, while maintaining the nearly lossless data transport features exhibited by the underlying Antelope <span class="hlt">system</span>. We present the design of the VORBrouter <span class="hlt">system</span>, its features, limitations and some future research directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1916634D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1916634D"><span><span class="hlt">Seismic</span> hazard of the Kivu rift (western branch, East African Rift <span class="hlt">system</span>): new neotectonic map and seismotectonic zonation model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delvaux, Damien; Mulumba, Jean-Luc; Sebagenzi Mwene Ntabwoba, Stanislas; Fiama Bondo, Silvanos; Kervyn, François; Havenith, Hans-Balder</p> <p>2017-04-01</p> <p>The first detailed probabilistic <span class="hlt">seismic</span> hazard assessment has been performed for the Kivu and northern Tanganyika rift region in Central Africa. This region, which forms the central part of the Western Rift Branch, is one of the most <span class="hlt">seismically</span> active part of the East African rift <span class="hlt">system</span>. It was already integrated in large scale <span class="hlt">seismic</span> hazard assessments, but here we defined a finer zonation model with 7 different zones representing the lateral variation of the geological and geophysical setting across the region. In order to build the new zonation model, we compiled homogeneous cross-border geological, neotectonic and sismotectonic maps over the central part of East D.R. Congo, SW Uganda, Rwanda, Burundi and NW Tanzania and defined a new neotectonic sheme. The <span class="hlt">seismic</span> risk assessment is based on a new earthquake catalogue, compiled on the basis of various local and global earthquake catalogues. The use of macroseismic epicenters determined from felt earthquakes allowed to extend the time-range back to the beginning of the 20th century, spanning 126 years, with 1068 events. The magnitudes have been homogenized to Mw and aftershocks removed. From this initial catalogue, a catalogue of 359 events from 1956 to 2015 and with M > 4.4 has been extracted for the <span class="hlt">seismic</span> hazard assessment. The seismotectonic zonation includes 7 <span class="hlt">seismic</span> source areas that have been defined on the basis of the regional geological structure, neotectonic fault <span class="hlt">systems</span>, basin architecture and distribution of thermal springs and earthquake epicenters. The Gutenberg-Richter <span class="hlt">seismic</span> hazard parameters were determined using both the least square linear fit and the maximum likelihood method (Kijko & Smit aue program). <span class="hlt">Seismic</span> hazard maps have been computed with the Crisis 2012 software using 3 different attenuation laws. We obtained higher PGA values (475 years return period) for the Kivu rift region than the previous estimates (Delvaux et al., 2016). They vary laterally in function of the tectonic</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://adsabs.harvard.edu/abs/2017AGUFM.S33G2925E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S33G2925E"><span>The results of the <span class="hlt">Seismic</span> Alert <span class="hlt">System</span> of Mexico SASMEX, during the earthquakes of 7 and 19 of September 2017</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Espinosa Aranda, J. M., Sr.; Cuellar Martinez, A.</p> <p>2017-12-01</p> <p>The <span class="hlt">Seismic</span> Alert <span class="hlt">System</span> of Mexico, SASMEX began in 1991, is integrated by the <span class="hlt">seismic</span> alert <span class="hlt">system</span> of Mexico City and the <span class="hlt">seismic</span> alert <span class="hlt">system</span> of Oaxaca. SASMEX has 97 <span class="hlt">seismic</span> sensors which are distributed in the <span class="hlt">seismic</span> regions of the Pacific coast and the South of the Trans-Mexican Volcanic Belt of states of Jalisco, Colima, Michoacán, Guerrero, Oaxaca and Puebla. The alert dissemination covers the cities of: Acapulco, Chilpancingo, Morelia, Puebla, Oaxaca, Toluca and Mexico City, reaching the earthquake warnings to more than 25 millions of people. SASMEX has detected correctly more than 5600 earthquakes and warned 156. Mexico City has different alert dissemination <span class="hlt">systems</span> like several Radio and Tv commercial broadcasters, dedicated radio receivers, EAS-SAME-SARMEX radio receivers and more tha 6700 public loud speakers. The other cities have only some of those <span class="hlt">systems</span>. The Mw 8.2 Chiapas earthquake on September 7, despite the epicentral distance far of the first <span class="hlt">seismic</span> detections (more than 180 km) and the low amplitudes of the P waves, the earthquake warning time gave more than 90 seconds to Mexico City before the arrivals of S waves with minor damages to the city in contrast with high damages in towns in the coast. This earthquake offered an opportunity to show the developments and lacks to reduce the risk, such as the need to increase the <span class="hlt">seismic</span> detection coverage and the earthquake warning dissemination in towns with high <span class="hlt">seismic</span> vulnerability. The Mw 7.1 Morelos earthquake on September 19 caused thousands of damages and hundreds of deaths and injuries in Mexico City, this earthquake is the second with the most damages after the Mw 8.1 Michoacán earthquake of September 19 on 1985. The earthquake early warning gave 11 seconds after the arrivals of S waves, however the activation occurred few seconds after the P waves arrives to Mexico City, and due to the <span class="hlt">seismic</span> focus was near to the city, the P waves were felt for the people. The Accelerographic Network</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP13C3537S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP13C3537S"><span><span class="hlt">Seismic</span> features and evolution of a late Miocene submarine channel <span class="hlt">system</span> in the Yinggehai basin, northwestern South China Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, H.; Jiang, T.; Wang, Z.; Zhang, Y.</p> <p>2014-12-01</p> <p>Submarine channel is one of key conduits for coarse terrigenous clastic sediments to abyssal plain, which provides the possibility for deepwater hydrocarbon exploration. Recently, a new high-quality 3D <span class="hlt">seismic</span> data is acquired in south Yinggehai basin (YGHB) and the detailed interpretations on those <span class="hlt">seismic</span> profiles as well as RMS amplitude attributes and variance slices reveal a submarine channel <span class="hlt">system</span> developed in late Miocene, which could be supplied from Hainan Island via turbidity currents so that it would be filled with sand-rich turbidites as good hydrocarbon reservoir. Based on the integration between regional <span class="hlt">seismic</span> survey and some boreholes, the investigations on its infilling architectures and depositional processes are carried out. The results show that it composes two converged submarine channels with two channelized submarine fans to their west and the main submarine channel (MSC) is characterized by a downstream increasing width and is infilled by sediments with high amplitude <span class="hlt">seismic</span> facies, which could be originated from channelized submarine fans. Furthermore, the complicated depositional processes around the confluence region of these two channels are pointed out and the interactions between the submarine channel <span class="hlt">system</span> and nearby channelized submarine fans are discussed. The detailed illustration on the <span class="hlt">seismic</span> features and depositional processes of the subsurface submarine <span class="hlt">system</span> provides us better understanding deepwater sedimentary dynamics and would be more benefit for the hydrocarbon exploration in similar deepwater area around the world.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.7821S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.7821S"><span>Active faults <span class="hlt">system</span> and related potential <span class="hlt">seismic</span> events near Ulaanbaatar, capital of Mongolia.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schlupp, Antoine; Ferry, Matthieu; Munkhuu, Ulziibat; Sodnomsambuu, Demberel; Al-Ashkar, Abeer</p> <p>2013-04-01</p> <p>The region of Ulaanbaatar lies several hundred kilometers from large known active faults that produced magnitude 6 to 8+ earthquakes during the last century. Beside the Hustai fault, which displays a clear morphological expression, no active fault was previously described less than 100 km from the city. In addition, no large historical (i.e. more recent than the 16th c.) earthquakes are known in this region. However, since 2005 a very dense <span class="hlt">seismic</span> activity has developed over the Emeelt Township area, a mere 10 km from Ulaanbaatar. The activity is characterized by numerous low magnitude events (M<2.8), which are distributed linearly along several tens of kilometers where no active fault has been identified. This raises several questions: Is this <span class="hlt">seismicity</span> associated to a -yet- unknown active fault? If so, are there other unknown active faults near Ulaanbaatar? Hence, we deployed a multi-disciplinary approach including morpho-tectonic, near-surface geophysical and paleoseismological investigations. We describe four large active faults west and south of Ulaanbaatar, three of them are newly discovered (Emeelt, Sharai, Avdar), one was previously known (Hustai) but without precise study on its <span class="hlt">seismic</span> potential. The Emeelt <span class="hlt">seismicity</span> can be mapped over 35 km along N150 and corresponds in the field to a smoothed, but clear, active fault morphology that can be mapped along a 10-km-long section. The fault dips at ~30° NE (GPR and surface morphology observations) and uplifts the eastern block. The age of the last surface rupture observed in trenches is about 10 ka (preliminary OSL dating). Considering a rupture length of 35 km, a full segment rupture would be comparable to the 1967 Mogod earthquake with a magnitude as large as Mw 7. It has to be considered today as a possible scenario for the <span class="hlt">seismic</span> risk of Ulaanbaatar. The 90-km-long Hustai Range Fault <span class="hlt">System</span>, oriented WSW-ENE and located about 10 km west of Ulaanbaatar, displays continuous microseismicity with five</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020063483','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020063483"><span>New <span class="hlt">Boundary</span> Constraints for Elliptic <span class="hlt">Systems</span> used in Grid Generation Problems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kaul, Upender K.; Clancy, Daniel (Technical Monitor)</p> <p>2002-01-01</p> <p>This paper discusses new <span class="hlt">boundary</span> constraints for elliptic partial differential equations as used in grid generation problems in generalized curvilinear coordinate <span class="hlt">systems</span>. These constraints, based on the principle of local conservation of thermal energy in the vicinity of the <span class="hlt">boundaries</span>, are derived using the Green's Theorem. They uniquely determine the so called decay parameters in the source terms of these elliptic <span class="hlt">systems</span>. These constraints' are designed for <span class="hlt">boundary</span> clustered grids where large gradients in physical quantities need to be resolved adequately. It is observed that the present formulation also works satisfactorily for mild clustering. Therefore, a closure for the decay parameter specification for elliptic grid generation problems has been provided resulting in a fully automated elliptic grid generation technique. Thus, there is no need for a parametric study of these decay parameters since the new constraints fix them uniquely. It is also shown that for Neumann type <span class="hlt">boundary</span> conditions, these <span class="hlt">boundary</span> constraints uniquely determine the solution to the internal elliptic problem thus eliminating the non-uniqueness of the solution of an internal Neumann <span class="hlt">boundary</span> value grid generation problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1612262P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1612262P"><span>REWSET: A prototype <span class="hlt">seismic</span> and tsunami early warning <span class="hlt">system</span> in Rhodes island, Greece</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Papadopoulos, Gerasimos; Argyris, Ilias; Aggelou, Savvas; Karastathis, Vasilis</p> <p>2014-05-01</p> <p>Tsunami warning in near-field conditions is a critical issue in the Mediterranean Sea since the most important tsunami sources are situated within tsunami wave travel times starting from about five minutes. The project NEARTOWARN (2012-2013) supported by the EU-DG ECHO contributed substantially to the development of new tools for the near-field tsunami early warning in the Mediterranean. One of the main achievements is the development of a local warning <span class="hlt">system</span> in the test-site of Rhodes island (Rhodes Early Warning <span class="hlt">System</span> for Earthquakes and Tsunamis - REWSET). The <span class="hlt">system</span> is composed by three main subsystems: (1) a network of eight <span class="hlt">seismic</span> early warning devices installed in four different localities of the island, one in the civil protection, another in the Fire Brigade and another two in municipality buildings; (2) two radar-type (ultrasonic) tide-gauges installed in the eastern coastal zine of the island which was selected since research on the historical earthquake and tsunami activity has indicated that the most important, near-field tsunami sources are situated offshore to the east of Rhodes; (3) a crisis Geographic Management <span class="hlt">System</span> (GMS), which is a web-based and GIS-based application incorporating a variety of thematic maps and other information types. The <span class="hlt">seismic</span> early warning devices activate by strong (magnitude around 6 or more) earthquakes occurring at distances up to about 100 km from Rhodes, thus providing immediate mobilization of the civil protection. The tide-gauges transmit sea level data, while during the crisis the GMS supports decisions to be made by civil protection. In the near future it is planned the REWSET <span class="hlt">system</span> to be integrated with national and international <span class="hlt">systems</span>. REWSET is a prototype which certainly could be developed in other coastal areas of the Mediterranean and beyond.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70022361','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70022361"><span>Correlation of offshore <span class="hlt">seismic</span> profiles with onshore New Jersey Miocene sediments</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Monteverde, D.H.; Miller, K.G.; Mountain, Gregory S.</p> <p>2000-01-01</p> <p>The New Jersey passive continental margin records the interaction of sequences and sea-level, although previous studies linking <span class="hlt">seismically</span> defined sequences, borehole control, and global ??18O records were hindered by a <span class="hlt">seismic</span> data gap on the inner-shelf. We describe new <span class="hlt">seismic</span> data from the innermost New Jersey shelf that tie offshore <span class="hlt">seismic</span> stratigraphy directly to onshore boreholes. These data link the onshore boreholes to existing <span class="hlt">seismic</span> grids across the outer margin and to boreholes on the continental slope. Surfaces defined by age; facies, and log signature in the onshore boreholes at the base of sequences Kw2b, Kw2a, Kw1c, and Kw0 are now tied to <span class="hlt">seismic</span> sequence <span class="hlt">boundaries</span> m5s, m5.2s, m5.4s, and m6s, respectively, defined beneath the inner shelf. Sequence <span class="hlt">boundaries</span> recognized in onshore boreholes and inner shelf <span class="hlt">seismic</span> profiles apparently correlate with reflections m5, m5.2, m5.4, and m6, respectively, that were dated at slope boreholes during ODP Leg 150. We now recognize an additional sequence <span class="hlt">boundary</span> beneath the shelf that we name m5.5s and correlate to the base of the onshore sequence Kw1b. The new <span class="hlt">seismic</span> data image prograding Oligocene clinoforms beneath the inner shelf, consistent with the results from onshore boreholes. A land-based <span class="hlt">seismic</span> profile crossing the Island Beach borehole reveals reflector geometries that we tie to Lower Miocene litho- and bio-facies in this borehole. These land-based <span class="hlt">seismic</span> profiles image well-defined sequence <span class="hlt">boundaries</span>, onlap and downlap truncations that correlate to Transgressive <span class="hlt">Systems</span> Tracts (TST) and Highstand <span class="hlt">Systems</span> Tracts (HST) identified in boreholes. Preliminary analysis of CH0698 data continues these <span class="hlt">system</span> tract delineations across the inner shelf The CH0698 <span class="hlt">seismic</span> profiles tie <span class="hlt">seismically</span> defined sequence <span class="hlt">boundaries</span> with sequences identified by lithiologic and paleontologic criteria. Both can now be related to global ??18O increases and attendant glacioeustatic lowerings. This integration of core</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1110946M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1110946M"><span>The SISMA Project: A pre-operative <span class="hlt">seismic</span> hazard monitoring <span class="hlt">system</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Massimiliano Chersich, M. C.; Amodio, A. A. Angelo; Francia, A. F. Andrea; Sparpaglione, C. S. Claudio</p> <p>2009-04-01</p> <p>Galileian Plus is currently leading the development, in collaboration with several Italian Universities, of the SISMA (<span class="hlt">Seismic</span> Information <span class="hlt">System</span> for Monitoring and Alert) Pilot Project financed by the Italian Space Agency. The <span class="hlt">system</span> is devoted to the continuous monitoring of the <span class="hlt">seismic</span> risk and is addressed to support the Italian Civil Protection decisional process. Completion of the Pilot Project is planned at the beginning of 2010. Main scientific paradigm of SISMA is an innovative deterministic approach integrating geophysical models, geodesy and active tectonics. This paper will give a general overview of project along with its progress status and a particular focus will be put on the architectural design details and to the software implementation choices. SISMA is built on top of a software infrastructure developed by Galileian Plus to integrate the scientific programs devoted to the update of <span class="hlt">seismic</span> risk maps. The main characteristics of the <span class="hlt">system</span> may be resumed as follow: automatic download of input data; integration of scientific programs; definition and scheduling of chains of processes; monitoring and control of the <span class="hlt">system</span> through a graphical user interface (GUI); compatibility of the products with ESRI ArcGIS, by mean of post-processing conversion. a) automatic download of input data SISMA needs input data such as GNSS observations, updated <span class="hlt">seismic</span> catalogue, SAR satellites orbits, etc. that are periodically updated and made available from remote servers through FTP and HTTP. This task is accomplished by a dedicated user configurable component. b) integration of scientific programs SISMA integrates many scientific programs written in different languages (Fortran, C, C++, Perl and Bash) and running into different operating <span class="hlt">systems</span>. This design requirements lead to the development of a distributed <span class="hlt">system</span> which is platform independent and is able to run any terminal-based program following few simple predefined rules. c) definition and scheduling of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2010/1292/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2010/1292/"><span>PQLX: A <span class="hlt">seismic</span> data quality control <span class="hlt">system</span> description, applications, and users manual</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McNamara, Daniel E.; Boaz, Richard I.</p> <p>2011-01-01</p> <p>We present a detailed description and users manual for a new tool to evaluate <span class="hlt">seismic</span> station performance and characteristics by providing quick and easy transitions between visualizations of the frequency and time domains. The software is based on the probability density functions (PDF) of power spectral densities (PSD) (McNamara and Buland, 2004) and builds on the original development of the PDF stand-alone software <span class="hlt">system</span> (McNamara and Boaz, 2005) and the seismological data viewer application PQL (IRIS-PASSCAL Quick Look) and PQLII (available through the IRIS PASSCAL program: http://www.passcal.nmt.edu/content/pql-ii-program-viewing-data). With PQLX (PQL eXtended), computed PSDs are stored in a MySQL database, allowing a user to access specific time periods of PSDs (PDF subsets) and time series segments through a GUI-driven interface. The power of the method and software lies in the fact that there is no need to screen the data for <span class="hlt">system</span> transients, earthquakes, or general data artifacts, because they map into a background probability level. In fact, examination of artifacts related to station operation and episodic cultural noise allow us to estimate both the overall station quality and a baseline level of Earth noise at each site. The output of this analysis tool is useful for both operational and scientific applications. Operationally, it is useful for characterizing the current and past performance of existing broadband stations, for conducting tests on potential new <span class="hlt">seismic</span> station locations, for evaluating station baseline noise levels (McNamara and others, 2009), for detecting problems with the recording <span class="hlt">system</span> or sensors, and for evaluating the overall quality of data and metadata. Scientifically, the tool allows for mining of PSDs for investigations on the evolution of <span class="hlt">seismic</span> noise (for example, Aster and others, 2008; and Aster and others, 2010) and other phenomena. Currently, PQLX is operational at several organizations including the USGS National</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.6808S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.6808S"><span>A networks-based discrete dynamic <span class="hlt">systems</span> approach to volcanic <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>Suteanu, Mirela</p> <p>2013-04-01</p> <p>The detection and relevant description of pattern change concerning earthquake events is an important, but challenging task. In this paper, earthquake events related to volcanic activity are considered manifestations of a dynamic <span class="hlt">system</span> evolving over time. The <span class="hlt">system</span> dynamics is seen as a succession of events with point-like appearance both in time and in space. Each event is characterized by a position in three-dimensional space, a moment of occurrence, and an event size (magnitude). A weighted directed network is constructed to capture the effects of earthquakes on subsequent events. Each <span class="hlt">seismic</span> event represents a node. Relations among events represent edges. Edge directions are given by the temporal succession of the events. Edges are also characterized by weights reflecting the strengths of the relation between the nodes. Weights are calculated as a function of (i) the time interval separating the two events, (ii) the spatial distance between the events, (iii) the magnitude of the earliest event among the two. Different ways of addressing weight components are explored, and their implications for the properties of the produced networks are analyzed. The resulting networks are then characterized in terms of degree- and weight distributions. Subsequently, the distribution of <span class="hlt">system</span> transitions is determined for all the edges connecting related events in the network. Two- and three-dimensional diagrams are constructed to reflect transition distributions for each set of events. Networks are thus generated for successive temporal windows of different size, and the evolution of (a) network properties and (b) <span class="hlt">system</span> transition distributions are followed over time and compared to the timeline of documented geologic processes. Applications concerning volcanic <span class="hlt">seismicity</span> on the Big Island of Hawaii show that this approach is capable of revealing novel aspects of change occurring in the volcanic <span class="hlt">system</span> on different scales in time and in space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70019979','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70019979"><span><span class="hlt">Seismic</span> interpretation of the deep structure of the Wabash Valley Fault <span class="hlt">System</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>Bear, G.W.; Rupp, J.A.; Rudman, A.J.</p> <p>1997-01-01</p> <p>Interpretations of newly available <span class="hlt">seismic</span> reflection profiles near the center of the Illinois Basin indicate that the Wabash Valley Fault <span class="hlt">System</span> is rooted in a series of basement-penetrating faults. The fault <span class="hlt">system</span> is composed predominantly of north-northeast-trending high-angle normal faults. The largest faults in the <span class="hlt">system</span> bound the 22-km wide 40-km long Grayville Graben. Structure contour maps drawn on the base of the Mount Simon Sandstone (Cambrian <span class="hlt">System</span>) and a deeper pre-Mount Simon horizon show dip-slip displacements totaling at least 600 meters across the New Harmony fault. In contrast to previous interpretations, the N-S extent of significant fault offsets is restricted to a region north of 38?? latitude and south of 38.35?? latitude. This suggests that the graben is not a NE extension of the structural complex composed of the Rough Creek Fault <span class="hlt">System</span> and the Reelfoot Rift as previously interpreted. Structural complexity on the graben floor also decreases to the south. Structural trends north of 38?? latitude are offset laterally across several large faults, indicating strike-slip motions of 2 to 4 km. Some of the major faults are interpreted to penetrate to depths of 7 km or more. Correlation of these faults with steep potential field gradients suggests that the fault positions are controlled by major lithologic contacts within the basement and that the faults may extend into the depth range where earthquakes are generated, revealing a potential link between specific faults and recently observed low-level <span class="hlt">seismicity</span> in the area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=88581&keyword=e+AND+commerce&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=88581&keyword=e+AND+commerce&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>LINKING ETA MODEL WITH THE COMMUNITY MULTISCALE AIR QUALITY (CMAQ) MODELING <span class="hlt">SYSTEM</span>: OZONE <span class="hlt">BOUNDARY</span> CONDITIONS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A prototype surface ozone concentration forecasting model <span class="hlt">system</span> for the Eastern U.S. has been developed. The model <span class="hlt">system</span> is consisting of a regional meteorological and a regional air quality model. It demonstrated a strong prediction dependence on its ozone <span class="hlt">boundary</span> conditions....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080042408','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080042408"><span>Advanced IR <span class="hlt">System</span> For Supersonic <span class="hlt">Boundary</span> Layer Transition Flight Experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Banks, Daniel W.</p> <p>2008-01-01</p> <p>Infrared thermography is a preferred method investigating transition in flight: a) Global and non-intrusive; b) Can also be used to visualize and characterize other fluid mechanic phenomena such as shock impingement, separation etc. F-15 based <span class="hlt">system</span> was updated with new camera and digital video recorder to support high Reynolds number transition tests. Digital Recording improves image quality and analysis capability and allows for accurate quantitative (temperature) measurements and greater enhancement through image processing allows analysis of smaller scale phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JDE...257.2485T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JDE...257.2485T"><span>Heat kernel for the elliptic <span class="hlt">system</span> of linear elasticity with <span class="hlt">boundary</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taylor, Justin; Kim, Seick; Brown, Russell</p> <p>2014-10-01</p> <p>We consider the elliptic <span class="hlt">system</span> of linear elasticity with bounded measurable coefficients in a domain where the second Korn inequality holds. We construct heat kernel of the <span class="hlt">system</span> subject to Dirichlet, Neumann, or mixed <span class="hlt">boundary</span> condition under the assumption that weak solutions of the elliptic <span class="hlt">system</span> are Hölder continuous in the interior. Moreover, we show that if weak solutions of the mixed problem are Hölder continuous up to the <span class="hlt">boundary</span>, then the corresponding heat kernel has a Gaussian bound. In particular, if the domain is a two dimensional Lipschitz domain satisfying a corkscrew or non-tangential accessibility condition on the set where we specify Dirichlet <span class="hlt">boundary</span> condition, then we show that the heat kernel has a Gaussian bound. As an application, we construct Green's function for elliptic mixed problem in such a domain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUSMNS21A..07M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUSMNS21A..07M"><span>Tunnel Detection Using <span class="hlt">Seismic</span> Methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miller, R.; Park, C. B.; Xia, J.; Ivanov, J.; Steeples, D. W.; Ryden, N.; Ballard, R. F.; Llopis, J. L.; Anderson, T. S.; Moran, M. L.; Ketcham, S. A.</p> <p>2006-05-01</p> <p>Surface <span class="hlt">seismic</span> methods have shown great promise for use in detecting clandestine tunnels in areas where unauthorized movement beneath secure <span class="hlt">boundaries</span> have been or are a matter of concern for authorities. Unauthorized infiltration beneath national borders and into or out of secure facilities is possible at many sites by tunneling. Developments in acquisition, processing, and analysis techniques using multi-channel <span class="hlt">seismic</span> imaging have opened the door to a vast number of near-surface applications including anomaly detection and delineation, specifically tunnels. Body waves have great potential based on modeling and very preliminary empirical studies trying to capitalize on diffracted energy. A primary limitation of all <span class="hlt">seismic</span> energy is the natural attenuation of high-frequency energy by earth materials and the difficulty in transmitting a high- amplitude source pulse with a broad spectrum above 500 Hz into the earth. Surface waves have shown great potential since the development of multi-channel analysis methods (e.g., MASW). Both shear-wave velocity and backscatter energy from surface waves have been shown through modeling and empirical studies to have great promise in detecting the presence of anomalies, such as tunnels. Success in developing and evaluating various <span class="hlt">seismic</span> approaches for detecting tunnels relies on investigations at known tunnel locations, in a variety of geologic settings, employing a wide range of <span class="hlt">seismic</span> methods, and targeting a range of uniquely different tunnel geometries, characteristics, and host lithologies. Body-wave research at the Moffat tunnels in Winter Park, Colorado, provided well-defined diffraction-looking events that correlated with the subsurface location of the tunnel complex. Natural voids related to karst have been studied in Kansas, Oklahoma, Alabama, and Florida using shear-wave velocity imaging techniques based on the MASW approach. Manmade tunnels, culverts, and crawl spaces have been the target of multi-modal analysis</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1212508B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1212508B"><span>Study of pre-<span class="hlt">seismic</span> kHz EM emissions by means of complex <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balasis, Georgios; Papadimitriou, Constantinos; Eftaxias, Konstantinos</p> <p>2010-05-01</p> <p>The field of study of complex <span class="hlt">systems</span> holds that the dynamics of complex <span class="hlt">systems</span> are founded on universal principles that may used to describe disparate problems ranging from particle physics to economies of societies. A corollary is that transferring ideas and results from investigators in hitherto disparate areas will cross-fertilize and lead to important new results. It is well-known that the Boltzmann-Gibbs statistical mechanics works best in dealing with <span class="hlt">systems</span> composed of either independent subsystems or interacting via short-range forces, and whose subsystems can access all the available phase space. For <span class="hlt">systems</span> exhibiting long-range correlations, memory, or fractal properties, non-extensive Tsallis statistical mechanics becomes the most appropriate mathematical framework. As it was mentioned a central property of the magnetic storm, solar flare, and earthquake preparation process is the possible occurrence of coherent large-scale collective with a very rich structure, resulting from the repeated nonlinear interactions among collective with a very rich structure, resulting from the repeated nonlinear interactions among its constituents. Consequently, the non-extensive statistical mechanics is an appropriate regime to investigate universality, if any, in magnetic storm, solar flare, earthquake and pre-failure EM emission occurrence. A model for earthquake dynamics coming from a non-extensive Tsallis formulation, starting from first principles, has been recently introduced. This approach leads to a Gutenberg-Richter type law for the magnitude distribution of earthquakes which provides an excellent fit to <span class="hlt">seismicities</span> generated in various large geographic areas usually identified as "<span class="hlt">seismic</span> regions". We examine whether the Gutenberg-Richter law corresponding to a non-extensive Tsallis statistics is able to describe the distribution of amplitude of earthquakes, pre-<span class="hlt">seismic</span> kHz EM emissions (electromagnetic earthquakes), solar flares, and magnetic storms. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.3966D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.3966D"><span>Using estimated risk to develop stimulation strategies for induced <span class="hlt">seismicity</span> in enhanced geothermal <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Douglas, John; Aochi, Hideo</p> <p>2014-05-01</p> <p>Enhanced Geothermal <span class="hlt">Systems</span> (EGS) are an attractive source of low-carbon electricity and heating. Consequently, a number of tests of this technology have been made during the past couple of decades and various projects are being planned or under development. EGS work by the injection of fluid into deep boreholes to increase permeability and hence allow the circulation and heating of fluid through a geothermal reservoir. Permeability is irreversibly increased by the shearing of pre-existing factures or fault segments, and hence by the generation of microseismicity. One aspect of this technology that can cause public concern and consequently could limit the widespread adoption of EGS within populated areas is the risk of generating earthquakes that are sufficiently large to be felt (or even to cause building damage). Therefore, there is a need to balance stimulation and exploitation of the geothermal reservoir by injecting fluids against the pressing requirement to keep the earthquake risk below an acceptable level. Current strategies to balance these potentially conflicting requirements rely on a traffic light <span class="hlt">system</span> based on the observed magnitudes of the triggered earthquakes and the measured peak ground velocities from these events. Douglas and Aochi (Pageoph, 2014) propose an alternative <span class="hlt">system</span> that uses the actual risk of generating felt (or damaging) earthquake ground motions at a site of interest (e.g. a nearby town) to control the injection rate. This risk is computed by combining characteristics of the observed <span class="hlt">seismicity</span> rate of the previous six hours, with a (potentially site-specific) ground-motion prediction equation to obtain a real-time <span class="hlt">seismic</span> hazard curve, and then the convolution of this with the derivative of a (potentially site-specific) fragility curve. Based on the relation between computed risk and pre-defined acceptable risk thresholds the injection is: increased (if the risk is below the amber level), decreased (if the risk is between amber</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21380919','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21380919"><span>Determining the depositional pattern by resistivity-<span class="hlt">seismic</span> inversion for the aquifer <span class="hlt">system</span> of Maira area, Pakistan.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Akhter, Gulraiz; Farid, Asim; Ahmad, Zulfiqar</p> <p>2012-01-01</p> <p>Velocity and density measured in a well are crucial for synthetic <span class="hlt">seismic</span> generation which is, in turn, a key to interpreting real <span class="hlt">seismic</span> amplitude in terms of lithology, porosity and fluid content. Investigations made in the water wells usually consist of spontaneous potential, resistivity long and short normal, point resistivity and gamma ray logs. The sonic logs are not available because these are usually run in the wells drilled for hydrocarbons. To generate the synthetic seismograms, sonic and density logs are required, which are useful to precisely mark the lithology contacts and formation tops. An attempt has been made to interpret the subsurface soil of the aquifer <span class="hlt">system</span> by means of resistivity to <span class="hlt">seismic</span> inversion. For this purpose, resistivity logs and surface resistivity sounding were used and the resistivity logs were converted to sonic logs whereas surface resistivity sounding data transformed into <span class="hlt">seismic</span> curves. The converted sonic logs and the surface <span class="hlt">seismic</span> curves were then used to generate synthetic seismograms. With the utilization of these synthetic seismograms, pseudo-<span class="hlt">seismic</span> sections have been developed. Subsurface lithologies encountered in wells exhibit different velocities and densities. The reflection patterns were marked by using amplitude standout, character and coherence. These pseudo-<span class="hlt">seismic</span> sections were later tied to well synthetics and lithologs. In this way, a lithology section was created for the alluvial fill. The cross-section suggested that the eastern portion of the studied area mainly consisted of sandy fill and the western portion constituted clayey part. This can be attributed to the depositional environment by the Indus and the Kabul Rivers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JSCSE..68I.584U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JSCSE..68I.584U"><span>SHAKING TABLE TEST AND EFFECTIVE STRESS ANALYSIS ON <span class="hlt">SEISMIC</span> PERFORMANCE WITH <span class="hlt">SEISMIC</span> ISOLATION RUBBER TO THE INTERMEDIATE PART OF PILE FOUNDATION IN LIQUEFACTION</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Uno, Kunihiko; Otsuka, Hisanori; Mitou, Masaaki</p> <p></p> <p>The pile foundation is heavily damaged at the <span class="hlt">boundary</span> division of the ground types, liquefied ground and non-liquefied ground, during an earthquake and there is a possibility of the collapse of the piles. In this study, we conduct a shaking table test and effective stress analysis of the influence of soil liquefaction and the <span class="hlt">seismic</span> inertial force exerted on the pile foundation. When the intermediate part of the pile, there is at the <span class="hlt">boundary</span> division, is subjected to section force, this part increases in size as compared to the pile head in certain instances. Further, we develop a <span class="hlt">seismic</span> resistance method for a pile foundation in liquefaction using <span class="hlt">seismic</span> isolation rubber and it is shown the middle part <span class="hlt">seismic</span> isolation <span class="hlt">system</span> is very effective.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SolE....8..883W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SolE....8..883W"><span>EBSD analysis of subgrain <span class="hlt">boundaries</span> and dislocation slip <span class="hlt">systems</span> in Antarctic and Greenland ice</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weikusat, Ilka; Kuiper, Ernst-Jan N.; Pennock, Gill M.; Kipfstuhl, Sepp; Drury, Martyn R.</p> <p>2017-09-01</p> <p>Ice has a very high plastic anisotropy with easy dislocation glide on basal planes, while glide on non-basal planes is much harder. Basal glide involves dislocations with the Burgers vector b = 〈a〉, while glide on non-basal planes can involve dislocations with b = 〈a〉, b = [c], and b = 〈c + a〉. During the natural ductile flow of polar ice sheets, most of the deformation is expected to occur by basal slip accommodated by other processes, including non-basal slip and grain <span class="hlt">boundary</span> processes. However, the importance of different accommodating processes is controversial. The recent application of micro-diffraction analysis methods to ice, such as X-ray Laue diffraction and electron backscattered diffraction (EBSD), has demonstrated that subgrain <span class="hlt">boundaries</span> indicative of non-basal slip are present in naturally deformed ice, although so far the available data sets are limited. In this study we present an analysis of a large number of subgrain <span class="hlt">boundaries</span> in ice core samples from one depth level from two deep ice cores from Antarctica (EPICA-DML deep ice core at 656 m of depth) and Greenland (NEEM deep ice core at 719 m of depth). EBSD provides information for the characterization of subgrain <span class="hlt">boundary</span> types and on the dislocations that are likely to be present along the <span class="hlt">boundary</span>. EBSD analyses, in combination with light microscopy measurements, are presented and interpreted in terms of the dislocation slip <span class="hlt">systems</span>. The most common subgrain <span class="hlt">boundaries</span> are indicative of basal 〈a〉 slip with an almost equal occurrence of subgrain <span class="hlt">boundaries</span> indicative of prism [c] or 〈c + a〉 slip on prism and/or pyramidal planes. A few subgrain <span class="hlt">boundaries</span> are indicative of prism 〈a〉 slip or slip of 〈a〉 screw dislocations on the basal plane. In addition to these classical polygonization processes that involve the recovery of dislocations into <span class="hlt">boundaries</span>, alternative mechanisms are discussed for the formation of subgrain <span class="hlt">boundaries</span> that are not related to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26ES...18a2147K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26ES...18a2147K"><span>A study on the development of automatic economic profit and loss calculation <span class="hlt">system</span> for maritime <span class="hlt">boundary</span> delimitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kwak, G.; Kim, K.; Park, Y.</p> <p>2014-02-01</p> <p>As the maritime <span class="hlt">boundary</span> delimitation is important for the purpose of securing marine resources, in addition to the aspect of maritime security, interest in maritime <span class="hlt">boundary</span> delimitation to help national benefits are increasing over the world. In Korea, the importance of maritime <span class="hlt">boundary</span> delimitation with the neighbouring countries is also increasing in practice. The quantity of obtainable marine resources depending on maritime <span class="hlt">boundary</span> acts as an important factor for maritime <span class="hlt">boundary</span> delimitation. Accordingly, a study is required to calculate quantity of our obtainable marine resources depending on maritime <span class="hlt">boundary</span> delimitation. This study intends to calculate obtainable marine resources depending on various maritime <span class="hlt">boundary</span> scenarios insisted by several countries. It mainly aims at developing a GIS-based automation <span class="hlt">system</span> to be utilized for decision making of the maritime <span class="hlt">boundary</span> delimitation. For this target, it has designed a module using spatial analysis technique to automatically calculate profit and loss waters area of each country upon maritime <span class="hlt">boundary</span> and another module to estimate economic profits and losses obtained by each country using the calculated waters area and pricing information of the marine resources. By linking both the designed modules, it has implemented an automatic economic profit and loss calculation <span class="hlt">system</span> for the GIS-based maritime <span class="hlt">boundary</span> delimitation. The <span class="hlt">system</span> developed from this study automatically calculate quantity of the obtainable marine resources of a country for the maritime <span class="hlt">boundary</span> to be added and created in the future. Thus, it is expected to support decision making for the maritime <span class="hlt">boundary</span> negotiators.</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/2015AGUFM.S33D2816T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S33D2816T"><span>The ANSS Station Information <span class="hlt">System</span>: A Centralized Station Metadata Repository for Populating, Managing and Distributing <span class="hlt">Seismic</span> Station Metadata</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomas, V. I.; Yu, E.; Acharya, P.; Jaramillo, J.; Chowdhury, F.</p> <p>2015-12-01</p> <p>Maintaining and archiving accurate site metadata is critical for <span class="hlt">seismic</span> network operations. The Advanced National <span class="hlt">Seismic</span> <span class="hlt">System</span> (ANSS) Station Information <span class="hlt">System</span> (SIS) is a repository of <span class="hlt">seismic</span> network field equipment, equipment response, and other site information. Currently, there are 187 different sensor models and 114 data-logger models in SIS. SIS has a web-based user interface that allows network operators to enter information about <span class="hlt">seismic</span> equipment and assign response parameters to it. It allows users to log entries for sites, equipment, and data streams. Users can also track when equipment is installed, updated, and/or removed from sites. When <span class="hlt">seismic</span> equipment configurations change for a site, SIS computes the overall gain of a data channel by combining the response parameters of the underlying hardware components. Users can then distribute this metadata in standardized formats such as FDSN StationXML or dataless SEED. One powerful advantage of SIS is that existing data in the repository can be leveraged: e.g., new instruments can be assigned response parameters from the Incorporated Research Institutions for Seismology (IRIS) Nominal Response Library (NRL), or from a similar instrument already in the inventory, thereby reducing the amount of time needed to determine parameters when new equipment (or models) are introduced into a network. SIS is also useful for managing field equipment that does not produce <span class="hlt">seismic</span> data (eg power <span class="hlt">systems</span>, telemetry devices or GPS receivers) and gives the network operator a comprehensive view of site field work. SIS allows users to generate field logs to document activities and inventory at sites. Thus, operators can also use SIS reporting capabilities to improve planning and maintenance of the network. Queries such as how many sensors of a certain model are installed or what pieces of equipment have active problem reports are just a few examples of the type of information that is available to SIS users.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2013/1141/pdf/ofr2013-1141.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2013/1141/pdf/ofr2013-1141.pdf"><span>Preliminary stratigraphic and hydrogeologic cross sections and <span class="hlt">seismic</span> profile of the Floridan aquifer <span class="hlt">system</span> of Broward County, Florida</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Reese, Ronald S.; Cunningham, Kevin J.</p> <p>2013-01-01</p> <p>To help water-resource managers evaluate the Floridan aquifer <span class="hlt">system</span> (FAS) as an alternative water supply, the U.S. Geological Survey initiated a study, in cooperation with the Broward County Environmental Protection and Growth Management Department, to refine the hydrogeologic framework of the FAS in the eastern part of Broward County. This report presents three preliminary cross sections illustrating stratigraphy and hydrogeology in eastern Broward County as well as an interpreted <span class="hlt">seismic</span> profile along one of the cross sections. Marker horizons were identified using borehole geophysical data and were initially used to perform well-to-well correlation. Core sample data were integrated with the borehole geophysical data to support stratigraphic and hydrogeologic interpretations of marker horizons. Stratigraphic and hydrogeologic units were correlated across the county using borehole geophysical data from multiple wells. <span class="hlt">Seismic</span>-reflection data were collected along the Hillsboro Canal. Borehole geophysical data were used to identify and correlate hydrogeologic units in the <span class="hlt">seismic</span>-reflection profile. Faults and collapse structures that intersect hydrogeologic units were also identified in the <span class="hlt">seismic</span> profile. The information provided in the cross sections and the <span class="hlt">seismic</span> profile is preliminary and subject to revision.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T21C2829M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T21C2829M"><span>Coda Q and its Frequency Dependence in the Eastern Himalayan and Indo-Burman Plate <span class="hlt">Boundary</span> <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mitra, S.; Kumar, A.</p> <p>2015-12-01</p> <p>We use broadband waveform data for 305 local earthquakes from the Eastern Himalayan and Indo-Burman plate <span class="hlt">boundary</span> <span class="hlt">systems</span>, to model the <span class="hlt">seismic</span> attenuation in NE India. We measure the decay in amplitude of coda waves at discreet frequencies (between 1 and 12Hz) to evaluate the quality factor (Qc) as a function of frequency. We combine these measurements to evaluate the frequency dependence of Qc of the form Qc(f)=Qof η, where Qo is the quality factor at 1Hz and η is the frequency dependence. Computed Qo values range from 80-360 and η ranges from 0.85-1.45. To study the lateral variation in Qo and η, we regionalise the Qc by combining all source-receiver measurements using a back-projection algorithm. For a single back scatter model, the coda waves sample an elliptical area with the epicenter and receiver at the two foci. We parameterize the region using square grids. The algorithm calculates the overlap in area and distributes Qc in the sampled grids using the average Qc as the <span class="hlt">boundary</span> value. This is done in an iterative manner, by minimising the misfit between the observed and computed Qc within each grid. This process is repeated for all frequencies and η is computed for each grid by combining Qc for all frequencies. Our results reveal strong variation in Qo and η across NE India. The highest Qo are in the Bengal Basin (210-280) and the Indo-Burman subduction zone (300-360). The Shillong Plateau and Mikir Hills have intermediate Qo (~160) and the lowest Qo (~80) is observed in the Naga fold thrust belt. This variation in Qo demarcates the <span class="hlt">boundary</span> between the continental crust beneath the Shillong Plateau and Mikir Hills and the transitional to oceanic crust beneath the Bengal Basin and Indo-Burman subduction zone. Thick pile of sedimentary strata in the Naga fold thrust belt results in the low Qo. Frequency dependence (η) of Qc across NE India is observed to be very high, with regions of high Qo being associated with relatively higher η.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21315155','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21315155"><span>The <span class="hlt">boundary</span> structure in the analysis of reversibly interacting <span class="hlt">systems</span> by sedimentation velocity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, Huaying; Balbo, Andrea; Brown, Patrick H; Schuck, Peter</p> <p>2011-05-01</p> <p>Sedimentation velocity (SV) experiments of heterogeneous interacting <span class="hlt">systems</span> exhibit characteristic <span class="hlt">boundary</span> structures that can usually be very easily recognized and quantified. For slowly interacting <span class="hlt">systems</span>, the <span class="hlt">boundaries</span> represent concentrations of macromolecular species sedimenting at different rates, and they can be interpreted directly with population models based solely on the mass action law. For fast reactions, migration and chemical reactions are coupled, and different, but equally easily discernable <span class="hlt">boundary</span> structures appear. However, these features have not been commonly utilized for data analysis, for the lack of an intuitive and computationally simple model. The recently introduced effective particle theory (EPT) provides a suitable framework. Here, we review the motivation and theoretical basis of EPT, and explore practical aspects for its application. We introduce an EPT-based design tool for SV experiments of heterogeneous interactions in the software SEDPHAT. As a practical tool for the first step of data analysis, we describe how the <span class="hlt">boundary</span> resolution of the sedimentation coefficient distribution c(s) can be further improved with a Bayesian adjustment of maximum entropy regularization to the case of heterogeneous interactions between molecules that have been previously studied separately. This can facilitate extracting the characteristic <span class="hlt">boundary</span> features by integration of c(s). In a second step, these are assembled into isotherms as a function of total loading concentrations and fitted with EPT. Methods for addressing concentration errors in isotherms are discussed. Finally, in an experimental model <span class="hlt">system</span> of alpha-chymotrypsin interacting with soybean trypsin inhibitor, we show that EPT provides an excellent description of the experimental sedimentation <span class="hlt">boundary</span> structure of fast interacting <span class="hlt">systems</span>. Published by Elsevier Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJEaS.105.1681H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJEaS.105.1681H"><span><span class="hlt">Seismic</span> anisotropy of the lithosphere/asthenosphere <span class="hlt">system</span> beneath the Rwenzori region of the Albertine Rift</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Homuth, B.; Löbl, U.; Batte, A. G.; Link, K.; Kasereka, C. M.; Rümpker, G.</p> <p>2016-09-01</p> <p>Shear-wave splitting measurements from local and teleseismic earthquakes are used to investigate the <span class="hlt">seismic</span> anisotropy in the upper mantle beneath the Rwenzori region of the East African Rift <span class="hlt">system</span>. At most stations, shear-wave splitting parameters obtained from individual earthquakes exhibit only minor variations with backazimuth. We therefore employ a joint inversion of SKS waveforms to derive hypothetical one-layer parameters. The corresponding fast polarizations are generally rift parallel and the average delay time is about 1 s. Shear phases from local events within the crust are characterized by an average delay time of 0.04 s. Delay times from local mantle earthquakes are in the range of 0.2 s. This observation suggests that the dominant source region for <span class="hlt">seismic</span> anisotropy beneath the rift is located within the mantle. We use finite-frequency waveform modeling to test different models of anisotropy within the lithosphere/asthenosphere <span class="hlt">system</span> of the rift. The results show that the rift-parallel fast polarizations are consistent with horizontal transverse isotropy (HTI anisotropy) caused by rift-parallel magmatic intrusions or lenses located within the lithospheric mantle—as it would be expected during the early stages of continental rifting. Furthermore, the short-scale spatial variations in the fast polarizations observed in the southern part of the study area can be explained by effects due to sedimentary basins of low isotropic velocity in combination with a shift in the orientation of anisotropic fabrics in the upper mantle. A uniform anisotropic layer in relation to large-scale asthenospheric mantle flow is less consistent with the observed splitting parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/twri/twri3-b5/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/twri/twri3-b5/"><span>Definition of <span class="hlt">boundary</span> and initial conditions in the analysis of saturated ground-water flow <span class="hlt">systems</span> - An introduction</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Franke, O. Lehn; Reilly, Thomas E.; Bennett, Gordon D.</p> <p>1987-01-01</p> <p>Accurate definition of <span class="hlt">boundary</span> and initial conditions is an essential part of conceptualizing and modeling ground-water flow <span class="hlt">systems</span>. This report describes the properties of the seven most common <span class="hlt">boundary</span> conditions encountered in ground-water <span class="hlt">systems</span> and discusses major aspects of their application. It also discusses the significance and specification of initial conditions and evaluates some common errors in applying this concept to ground-water-<span class="hlt">system</span> models. An appendix is included that discusses what the solution of a differential equation represents and how the solution relates to the <span class="hlt">boundary</span> conditions defining the specific problem. This report considers only <span class="hlt">boundary</span> conditions that apply to saturated ground-water <span class="hlt">systems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhyD..364...27X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhyD..364...27X"><span>Initial-<span class="hlt">boundary</span> value problems associated with the Ablowitz-Ladik <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xia, Baoqiang; Fokas, A. S.</p> <p>2018-02-01</p> <p>We employ the Ablowitz-Ladik <span class="hlt">system</span> as an illustrative example in order to demonstrate how to analyze initial-<span class="hlt">boundary</span> value problems for integrable nonlinear differential-difference equations via the unified transform (Fokas method). In particular, we express the solutions of the integrable discrete nonlinear Schrödinger and integrable discrete modified Korteweg-de Vries equations in terms of the solutions of appropriate matrix Riemann-Hilbert problems. We also discuss in detail, for both the above discrete integrable equations, the associated global relations and the process of eliminating of the unknown <span class="hlt">boundary</span> values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoJI.198...25P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoJI.198...25P"><span>Deformation of the western Indian Plate <span class="hlt">boundary</span>: insights from differential and multi-aperture InSAR data inversion for the 2008 Baluchistan (Western Pakistan) <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>Pezzo, Giuseppe; Merryman Boncori, John Peter; Atzori, Simone; Antonioli, Andrea; Salvi, Stefano</p> <p>2014-07-01</p> <p>In this study, we use Differential Synthetic Aperture Radar Interferometry (DInSAR) and multi-aperture interferometry (MAI) to constrain the sources of the three largest events of the 2008 Baluchistan (western Pakistan) <span class="hlt">seismic</span> sequence, namely two Mw 6.4 events only 12 hr apart and an Mw 5.7 event that occurred 40 d later. The sequence took place in the Quetta Syntaxis, the most <span class="hlt">seismically</span> active region of Baluchistan, tectonically located between the colliding Indian Plate and the Afghan Block of the Eurasian Plate. Surface displacements estimated from ascending and descending ENVISAT ASAR acquisitions were used to derive elastic dislocation models for the sources of the two main events. The estimated slip distributions have peak values of 120 and 130 cm on a pair of almost parallel and near-vertical faults striking NW-SE, and of 50 cm and 60 cm on two high-angle faults striking NE-SW. Values up to 50 cm were found for the largest aftershock on an NE-SW fault located between the sources of the main shocks. The MAI measurements, with their high sensitivity to the north-south motion component, are crucial in this area to accurately describe the coseismic displacement field. Our results provide insight into the deformation style of the Quetta Syntaxis, suggesting that right-lateral slip released at shallow depths on large NW fault planes is compatible with left-lateral activation on smaller NE-SW faults.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29715983','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29715983"><span>Three-dimensional transformation optics for arbitrary coordinate <span class="hlt">systems</span>: transforming conductive materials and <span class="hlt">boundaries</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kazemzadeh, Mohammad-Rahim; Alighanbari, Abbas</p> <p>2018-04-16</p> <p>A three-dimensional transformation optics method, leading to homogeneous materials, applicable to any non-Cartesian coordinate <span class="hlt">systems</span> or waveguides/objects of arbitrary cross-sections is presented. Both the conductive <span class="hlt">boundary</span> and internal material of the desired device is determined by the proposed formulation. The method is applicable to a wide range of waveguide, radiation, and cloaking problems, and is demonstrated for circular waveguide couplers and an external cloak. An advantage of the present method is that the material properties are simplified by appropriately selecting the conductive <span class="hlt">boundaries</span>. For instance, a right-angle circular waveguide bend is presented which uses only one homogenous material. Also, transformation of conductive materials and <span class="hlt">boundaries</span> are studied. The conditions in which the transformed <span class="hlt">boundaries</span> remain conductive are discussed. In addition, it is demonstrated that negative infinite conductivity can be replaced with positive conductivity, without affecting the field outside the conductive <span class="hlt">boundary</span>. It is also observed that a negative finite conductivity can be replaced with a positive one, by accepting some small errors. The general mathematical procedure and formulation for calculating the parametric surface equations of the conductive peripheries are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.4327S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.4327S"><span>Installation of seafloor cabled <span class="hlt">seismic</span> and tsunami observation <span class="hlt">system</span> developed by using ICT</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shinohara, Masanao; Yamada, Tomoaki; Sakai, Shin'ichi; Shiobara, Hajime; Kanazawa, Toshihiko</p> <p>2017-04-01</p> <p>A seafloor cabled <span class="hlt">system</span> is useful for study of earth science and disaster mitigation, because real-time and long-term observation can be performed. Therefore seafloor cabled <span class="hlt">systems</span> with seismometers and tsunami-meters have been used over the past 25 years around Japan. Because increase of a number of sensors is needed, a new <span class="hlt">system</span> with low costs for production, deployment and operation is expected. In addition, the new <span class="hlt">system</span> should have sufficient for flexibility of measurements after installation. To achieve these demands, we started development of a new <span class="hlt">system</span> using Information and Communication Technologies (ICT) for data transmission and <span class="hlt">system</span> control. The new <span class="hlt">system</span> can be made compact since software processes various measurements. Reliability of the <span class="hlt">system</span> is kept by using redundant <span class="hlt">system</span> which is easily constructed using the ICT. The first <span class="hlt">system</span> based on this concept was developed as Ocean Bottom Cabled Seismometer (OBCS) <span class="hlt">system</span> and deployed in Japan Sea. Development of the second <span class="hlt">system</span> started from 2012. The Ocean Bottom Cabled Seismometer and Tsunami-meter (OBCST) <span class="hlt">system</span> has both seismometers and tsunami-meters. Each observation node has a CPU and FPGAs. The OBCST <span class="hlt">system</span> uses standard TCP/IP protocol with a speed of 1 Gbps for data transmission, <span class="hlt">system</span> control and monitoring. IEEE-1588 (PTP) is implemented to synchronize a real-time clock, and accuracy is less than 300 ns. We developed two types of observation node. One equips a pressure gauge as tsunami sensor, and another has an external port for additional observation sensor using PoE. Deployment of the OBCST <span class="hlt">system</span> was carried out in September 2015 by using a commercial telecommunication cable ship. The noise levels at the OBCST <span class="hlt">system</span> are comparable to those at the existing cabled <span class="hlt">system</span> off Sanriku. It is found that the noise levels at the OBCST <span class="hlt">system</span> are low at frequencies greater than 2 Hz and smaller than 0.1 Hz. This level of ambient <span class="hlt">seismic</span> noise is close to a typical <span class="hlt">system</span> noise. From</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JOptB...6.....B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JOptB...6.....B"><span>CALL FOR PAPERS: Topical issue on the nonstationary Casimir effect and quantum <span class="hlt">systems</span> with moving <span class="hlt">boundaries</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barton, Gabriel; Dodonov, Victor V.; Man'ko, Vladimir I.</p> <p>2004-05-01</p> <p>The past few years have seen a growing interest in quantum mechanical <span class="hlt">systems</span> with moving <span class="hlt">boundaries</span>. One of its manifestations was the First International Workshop on Problems with Moving <span class="hlt">Boundaries</span> organized by Professor J Dittrich in Prague in October 2003. Another event in this series will be the (first) International Workshop on the Dynamical Casimir Effect in Padua in June 2004, organized by Professor G Carugno (see webpage www.pd.infn.it/casimir/ for details). As Guest Editors we invite researchers working in any area related to moving <span class="hlt">boundaries</span> to contribute to a Topical Issue of Journal of Optics B: Quantum and Semiclassical Optics on the nonstationary Casimir effect and quantum <span class="hlt">systems</span> with moving <span class="hlt">boundaries</span>. Our intention is to cover a wide range of topics. In particular, we envisage possible contributions in the following areas: Theoretical and experimental studies on quantum fields in cavities with moving <span class="hlt">boundaries</span> and time-dependent media. This area includes, in particular, various manifestations of the nonstationary (dynamical) Casimir effect, such as creation of quanta and modifications of Casimir force due to the motion of <span class="hlt">boundaries</span>. Other relevant subjects are: generation and evolution of nonclassical states of fields and moving mirrors; interaction between quantized fields and atoms in cavities with moving <span class="hlt">boundaries</span>; decoherence and entanglement due to the motion of <span class="hlt">boundaries</span>; field quantization in nonideal cavities with moving <span class="hlt">boundaries</span> taking into account losses and dispersion; nano-devices with moving <span class="hlt">boundaries</span>. Quantum particles in domains confined with moving <span class="hlt">boundaries</span>. This area includes: new exact and approximate solutions of the evolution equations (Schrödinger, Klein-Gordon, Dirac, Fokker-Planck, etc); quantum carpets and revivals; escape and tunnelling through moving barriers; evolution of quantum packets in the presence of moving <span class="hlt">boundaries</span>; ultracold atoms (ions) in traps with moving <span class="hlt">boundaries</span>. The topical issue is scheduled</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036224','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036224"><span>The Augustine magmatic <span class="hlt">system</span> as revealed by <span class="hlt">seismic</span> tomography and relocated earthquake hypocenters from 1994 through 2009</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Syracuse, E.M.; Thurber, C.H.; Power, J.A.</p> <p>2011-01-01</p> <p>We incorporate 14 years of earthquake data from the Alaska Volcano Observatory with data from a 1975 controlled-source <span class="hlt">seismic</span> experiment to obtain the three-dimensional P and S wave velocity structure and the first high-precision earthquake locations at Augustine Volcano to be calculated in a fully three-dimensional velocity model. Velocity tomography shows two main features beneath Augustine: a narrow, high-velocity column beneath the summit, extending from ???2 km depth to the surface, and elevated velocities on the south flank. Our relocation results allow a thorough analysis of the spatio-temoral patterns of <span class="hlt">seismicity</span> and the relationship to the magmatic and eruptive activity. Background <span class="hlt">seismicity</span> is centered beneath the summit at an average depth of 0.6 km above sea level. In the weeks leading to the January 2006 eruption of Augustine, <span class="hlt">seismicity</span> focused on a NW-SE line along the trend of an inflating dike. A series of drumbeat earthquakes occurred in the early weeks of the eruption, indicating further magma transport through the same dike <span class="hlt">system</span>. During the six months following the onset of the eruption, the otherwise quiescent region 1 to 5 km below sea level centered beneath the summit became <span class="hlt">seismically</span> active with two groups of earthquakes, differentiated by frequency content. The deep longer-period earthquakes occurred during the eruption and are interpreted as resulting from the movement of magma toward the summit, and the post-eruptive shorter-period earthquakes may be due to the relaxation of an emptied magma tube. The <span class="hlt">seismicity</span> subsequently returned to its normal background rates and patterns. Copyright 2011 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSMG14A1891L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSMG14A1891L"><span><span class="hlt">Seismic</span> geomorphology of the Lobed-channel <span class="hlt">System</span> of Upper Miocene Huangliu Formation, Yinggehai Basin, Northwestern South China Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, H.</p> <p>2016-02-01</p> <p>Three-dimensional <span class="hlt">seismic</span> data have been widely used in interpreting ancient river <span class="hlt">systems</span> and their associated sediment deposits. Thin-bed reservoirs of lobed-channel <span class="hlt">system</span> in lithostratigraphic units of Dongfang (DF) area are one of the major study areas for reservoir growth in the Yinggehai basin of northwestern South China Sea. Although it is understood that the transport mechanics of parent substrate and alluvium determine the morphology of channel for lobed-channel <span class="hlt">system</span>, the transport mechanism and regional gradient are relatively poorly understood. This study is focused on the application of various techniques in <span class="hlt">seismic</span> geomorphology to the Yinggehai Basin at paleo-water-depth of 120m to assess influences of regional gradient and relative sea level change on lobed-channel palaeogeomorphology in shallow-water environments. The Vietnam paleo-Blue River, which located at south of modern Red River, flowed through DF area and transported turbidity deposit to DF area in the coastal environment. In 3-D <span class="hlt">seismic</span> survey area, four fifth-order sequences in first member of upper Miocene Huangliu formation were identified using well and <span class="hlt">seismic</span> data. <span class="hlt">Seismic</span> inversion and 90° phasing of <span class="hlt">seismic</span> data were used to convert <span class="hlt">seismic</span> traces to pseudolithologic logs. Stratal slicing made it possible to interpolate and extrapolate well-data-derived sequence and identify submarine fan, channel fill, lobes and overbank deposit. Strata slices suggested that sea-floor slopes exerted main influence on channel morphology. Specifically, DF13-1 block had high gradient, which mainly distributed mud-sand-rich lobes. However, DF13-2 block established low gradient, which mostly indicated sand-rich braided channels. The values of sinuosity, channel widths, meander-belt widths in DF13-2 block are all greater than these in DF13-1 block. In addition, results of carbon isotope measurements and foraminiferal research of two blocks suggest that paleo sea level in DF13-2 block (30m 150m) was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S11D2482S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S11D2482S"><span>Installation of seafloor cabled <span class="hlt">seismic</span> and tsunami observation <span class="hlt">system</span> developed by using ICT</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shinohara, M.</p> <p>2016-12-01</p> <p>A seafloor cabled <span class="hlt">system</span> is useful for study of earth science and disaster mitigation, because real-time and long-term observation can be performed. Therefore seafloor cabled <span class="hlt">systems</span> with seismometers and tsunami-meters have been used over the past 25 years around Japan. Because increase of a number of sensors is needed, a new <span class="hlt">system</span> with low costs for production, deployment and operation is expected. In addition, the new <span class="hlt">system</span> should have sufficient for flexibility of measurements after installation. To achieve these demands, we started development of a new <span class="hlt">system</span> using Information and Communication Technologies (ICT) for data transmission and <span class="hlt">system</span> control. The new <span class="hlt">system</span> can be made compact since software processes various measurements. Reliability of the <span class="hlt">system</span> is kept by using redundant <span class="hlt">system</span> which is easily constructed using the ICT. The first <span class="hlt">system</span> based on this concept was developed as Ocean Bottom Cabled Seismometer (OBCS) <span class="hlt">system</span> and deployed in Japan Sea. Development of the second <span class="hlt">system</span> started from 2012. The Ocean Bottom Cabled Seismometer and tsunami-meter (OBCST) <span class="hlt">system</span> has both seismometers and tsunami-meters. Each observation node has an CPU and FPGAs. The OBCST <span class="hlt">system</span> uses standard TCP/IP protocol with a speed of 1 Gbps for data transmission, <span class="hlt">system</span> control and monitoring. IEEE-1588 (PTP) is implemented to synchronize a real-time clock, and accuracy is less than 300 ns. We developed two types of observation node. One equips a pressure gauge as tsunami sensor, and another has an external port for additional observation sensor using PoE. Deployment of the OBCST <span class="hlt">system</span> was carried out in September 2015 by using a commercial telecommunication cable ship. The noise levels at the OBCST <span class="hlt">system</span> are comparable to those at the existing cabled <span class="hlt">system</span> off Sanriku. It is found that the noise levels at the OBCST <span class="hlt">system</span> are low at frequencies greater than 2 Hz and smaller than 0.1 Hz. This level of ambient <span class="hlt">seismic</span> noise is close to a typical <span class="hlt">system</span> noise</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1067878','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1067878"><span><span class="hlt">Seismic</span> Technology Adapted to Analyzing and Developing Geothermal <span class="hlt">Systems</span> Below Surface-Exposed High-Velocity Rocks Final Report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hardage, Bob A.; DeAngelo, Michael V.; Ermolaeva, Elena</p> <p></p> <p>The objective of our research was to develop and demonstrate <span class="hlt">seismic</span> data-acquisition and data-processing technologies that allow geothermal prospects below high-velocity rock outcrops to be evaluated. To do this, we acquired a 3-component <span class="hlt">seismic</span> test line across an area of exposed high-velocity rocks in Brewster County, Texas, where there is high heat flow and surface conditions mimic those found at numerous geothermal prospects. <span class="hlt">Seismic</span> contractors have not succeeded in creating good-quality <span class="hlt">seismic</span> data in this area for companies who have acquired data for oil and gas exploitation purposes. Our test profile traversed an area where high-velocity rocks and low-velocity sedimentmore » were exposed on the surface in alternating patterns that repeated along the test line. We verified that these surface conditions cause non-ending reverberations of Love waves, Rayleigh waves, and shallow critical refractions to travel across the earth surface between the <span class="hlt">boundaries</span> of the fast-velocity and slow-velocity material exposed on the surface. These reverberating surface waves form the high level of noise in this area that does not allow reflections from deep interfaces to be seen and utilized. Our data-acquisition method of deploying a box array of closely spaced geophones allowed us to recognize and evaluate these surface-wave noise modes regardless of the azimuth direction to the surface anomaly that backscattered the waves and caused them to return to the test-line profile. With this knowledge of the surface-wave noise, we were able to process these test-line data to create P-P and SH-SH images that were superior to those produced by a skilled <span class="hlt">seismic</span> data-processing contractor. Compared to the P-P data acquired along the test line, the SH-SH data provided a better detection of faults and could be used to trace these faults upward to the <span class="hlt">boundaries</span> of exposed surface rocks. We expanded our comparison of the relative value of S-wave and P-wave <span class="hlt">seismic</span> data for</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/2007AGUFM.T22E..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.T22E..06S"><span><span class="hlt">Seismic</span> Reflection Images of Deep Lithospheric Faults and Thin Crust at the Actively Deforming Indo-Australian Plate <span class="hlt">Boundary</span> in the Indian Ocean</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.; Carton, H.; Chauhan, A.; Dyment, J.; Cannat, M.; Hananto, N.; Hartoyo, D.; Tapponnier, P.; Davaille, A.</p> <p>2007-12-01</p> <p>Recently, we acquired deep <span class="hlt">seismic</span> reflection data using a state-of-the-art technology of Schlumberger having a powerful source (10,000 cubic inch) and a 12 km long streamer along a 250 km long trench parallel line offshore Sumatra in the Indian Ocean deformation zone that provides <span class="hlt">seismic</span> reflection image down to 40 km depth over the old oceanic lithosphere formed at Wharton spreading centre about 55-57 Ma ago. We observe deep penetrating faults that go down to 37 km depth (~24 km in the oceanic mantle), providing the first direct evidence for full lithospheric-scale deformation in an intra-plate oceanic domain. These faults dip NE and have dips between 25 and 40 degrees. The majority of faults are present in the mantle and are spaced at about 5 km, and do not seem cut through the Moho. We have also imaged active strike-slip fault zones that seem to be associated with the re-activation of ancient fracture zones, which is consistent with previous seismological and seafloor observations. The geometries of the deep penetrating faults neither seem to correspond to faulting associated with the plate bending at the subduction front nor with the re-activation of fracture zone that initiated about 7.5 Ma ago, and therefore, we suggest that these deep mantle faults were formed due to compressive stress at the beginning of the hard collision between India and Eurasia, soon after the cessation of seafloor spreading in the Wharton basin. We also find that the crust generated at the fast Wharton spreading centre 55-57 Ma ago is only 3.5-4.5 km thick, the thinnest crust ever observed in a fast spreading environment. We suggest that this extremely thin crust is due to 40-50°C lower than normal mantle temperature in this part of the Indian Ocean during its formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16..250P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16..250P"><span>Deformation along the western Indian plate <span class="hlt">boundary</span>: new constraints from differential and multi-aperture InSAR data inversion for the 2008, Baluchistan (Western Pakistan) <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>Pezzo, Giuseppe; Merryman Boncori, John Peter; Atzori, Simone; Antonioli, Andrea; Salvi, Stefano</p> <p>2014-05-01</p> <p>We use Synthetic Aperture Radar Differential Interferometry (DInSAR) and Multi-Aperture Interferometry (MAI) to constrain the sources of the three largest events of the 2008 Baluchistan (western Pakistan) <span class="hlt">seismic</span> sequence, namely two Mw 6.4 events only 12 hours apart and an Mw 5.7event occurred 40 days later. The sequence took place in the Quetta Syntaxis, the most <span class="hlt">seismically</span> active region of Baluchistan, tectonically located between the colliding Indian Plate and the Afghan block of the Eurasian Plate. Elastic dislocation modelling of the surface displacements, derived from ascending and descending ENVISAT ASAR acquisitions, yields slip distributions with peak values of 80 cm and 70 cm for the two main events on a pair of strike-slip near-vertical faults, and values up to 50 cm for the largest aftershock on a NE-SW strike-slip fault. The MAI measurements, with their high sensitivity to the north-south motion component, are crucial in this area to resolve the fault plane ambiguity of moment tensors. We also studied the relationships between the largest earthquakes of the sequence by means of the Coulomb Failure Function to verify the agreement of our source modelling with the stress variations induced by the October 28 earthquake on the October 29 fault plane, and the stress variations induced by the two mainshocks on the December 09 fault plane. Our results provide insight into the deformation style of the Quetta Syntaxis, suggesting that right-lateral slip released at intermediate depths on large NW fault planes is compatible with contemporaneous left-lateral activation on NE-SW minor faults at shallower depths, in agreement with a bookshelf deformation mechanism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.T13B1937P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.T13B1937P"><span>P- and S- wave velocity structure in and around the Itoigawa-Shizuoka Tectonic Line (ISTL) fault <span class="hlt">system</span> revealed by dense <span class="hlt">seismic</span> array observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panayotopoulos, Y.; Hirata, N.; Sato, H.; Iwasaki, T.; Kato, A.; Imanishi, K.; Kuwahara, Y.; Cho, I.</p> <p>2008-12-01</p> <p>The ISTL is a major tectonic structure that divides the Japanese Island arc into northeast and southwest parts. It was formed as a normal fault in the early Miocene and represents the southwestern <span class="hlt">boundary</span> of the northern Fossa Mangna rift basin to the north, and the <span class="hlt">boundary</span> between the Japanese arc accretionary prism units and the Izu-Bonin arc crust to the south. Previous studies have provided the sallow structure of the different ISTL fault segments, but the detailed crustal structure along the ISTL is yet to be revealed. The online permanent <span class="hlt">seismic</span> station network in the area is not sufficient to accurately locate the earthquakes occurring in the area and also not dense enough to provide a detailed structure of the earth's crust. Over the past 3 years we have installed temporary <span class="hlt">seismic</span> stations along the STL. We have deployed 60 stations in the southern, 58 stations in the central and 60 stations in the northern ISTL regions. We have combined the data retrieved from the temporary stations with the data available from the online permanent stations in the ISTL area and manually re-picked 63,275 P- and 68,847 S- wave arrival times from 1,945 events from the 5th August 2003 to 31st December 2006. The Double Difference tomography method (Zhang and Thurber, 2003) was used in order to accurately relocate the hypocenters and obtain a 3D P- and S- wave velocity (Vp and Vs) structure beneath the ISTL fault <span class="hlt">system</span>. The relocated hypocenters in the southern ISTL coincide with the deeper extension of the active faults in the area. The relocated hypocenters are deeper than those reported by the Japan Meteorological Agency (JMA) in the northern ISTL and shallower at the central and southern parts. The average depth of the hypocenters is shallower in the northern ISTL (3 - 8 km) and gets progressively deeper towards the central (8-15 km) and southern (15-25 km) ISTL. The tomographic analysis has provided a detailed Vp and Vs image of the crust in the area below the ISTL</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5621127','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5621127"><span>An Electrochemical, Low-Frequency <span class="hlt">Seismic</span> Micro-Sensor Based on MEMS with a Force-Balanced Feedback <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Guanglei; Wang, Junbo; Chen, Deyong; Chen, Lianhong; Xu, Chao</p> <p>2017-01-01</p> <p>Electrochemical <span class="hlt">seismic</span> sensors are key components in monitoring ground vibration, which are featured with high performances in the low-frequency domain. However, conventional electrochemical <span class="hlt">seismic</span> sensors suffer from low repeatability due to limitations in fabrication and limited bandwidth. This paper presents a micro-fabricated electrochemical <span class="hlt">seismic</span> sensor with a force-balanced negative feedback <span class="hlt">system</span>, mainly composed of a sensing unit including porous sensing micro electrodes immersed in an electrolyte solution and a feedback unit including a feedback circuit and a feedback magnet. In this study, devices were designed, fabricated, and characterized, producing comparable performances among individual devices. In addition, bandwidths and total harmonic distortions of the proposed devices with and without a negative feedback <span class="hlt">system</span> were quantified and compared as 0.005–20 (feedback) Hz vs. 0.3–7 Hz (without feedback), 4.34 ± 0.38% (without feedback) vs. 1.81 ± 0.31% (feedback)@1 Hz@1 mm/s and 3.21 ± 0.25% (without feedback) vs. 1.13 ± 0.19% (feedback)@5 Hz@1 mm/s (ndevice = 6, n represents the number of the tested devices), respectively. In addition, the performances of the proposed MEMS electrochemical seismometers with feedback were compared to a commercial electrochemical <span class="hlt">seismic</span> sensor (CME 6011), producing higher bandwidth (0.005–20 Hz vs. 0.016–30 Hz) and lower self-noise levels (−165.1 ± 6.1 dB vs. −137.7 dB at 0.1 Hz, −151.9 ± 7.5 dB vs. −117.8 dB at 0.02 Hz (ndevice = 6)) in the low-frequency domain. Thus, the proposed device may function as an enabling electrochemical seismometer in the fields requesting <span class="hlt">seismic</span> monitoring at the ultra-low frequency domain. PMID:28902150</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('https://pubs.er.usgs.gov/publication/70022569','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70022569"><span>A model for the magmatic-hydrothermal <span class="hlt">system</span> at Mount Rainier, Washington, from <span class="hlt">seismic</span> and geochemical observations</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Moran, S.C.; Zimbelman, D.R.; Malone, S.D.</p> <p>2000-01-01</p> <p>Mount Rainier is one of the most <span class="hlt">seismically</span> active volcanoes in the Cascade Range, with an average of one to two high-frequency volcano-tectonic (or VT) earthquakes occurring directly beneath the summit in a given month. Despite this level of <span class="hlt">seismicity</span>, little is known about its cause. The VT earthquakes occur at a steady rate in several clusters below the inferred base of the Quaternary volcanic edifice. More than half of 18 focal mechanisms determined for these events are normal, and most stress axes deviate significantly from the regional stress field. We argue that these characteristics are most consistent with earthquakes in response to processes associated with circulation of fluids and magmatic gases within and below the base of the edifice. Circulation of these fluids and gases has weakened rock and reduced effective stress to the point that gravity-induced brittle fracture, due to the weight of the overlying edifice, can occur. Results from <span class="hlt">seismic</span> tomography and rock, water, and gas geochemistry studies support this interpretation. We combine constraints from these studies into a model for the magmatic <span class="hlt">system</span> that includes a large volume of hot rock (temperatures greater than the brittle-ductile transition) with small pockets of melt and/or hot fluids at depths of 8-18 km below the summit. We infer that fluids and heat from this volume reach the edifice via a narrow conduit, resulting in fumarolic activity at the summit, hydrothermal alteration of the edifice, and <span class="hlt">seismicity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006CQGra..23S.111B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006CQGra..23S.111B"><span>Design and prototype tests of a <span class="hlt">seismic</span> attenuation <span class="hlt">system</span> for the advanced-LIGO output mode cleaner</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bertolini, A.; DeSalvo, R.; Galli, C.; Gennaro, G.; Mantovani, M.; Márka, S.; Sannibale, V.; Takamori, A.; Torrie, C.</p> <p>2006-04-01</p> <p>Both present LIGO and advanced LIGO (Ad-LIGO) will need an output mode cleaner (OMC) to reach the desired sensitivity. We designed a suitable OMC <span class="hlt">seismically</span> attenuated optical table fitting to the existing vacuum chambers (horizontal access module, HAM chambers). The most straightforward and cost-effective solution satisfying the Ad-LIGO <span class="hlt">seismic</span> attenuation specifications was to implement a single passive <span class="hlt">seismic</span> attenuation stage, derived from the '<span class="hlt">seismic</span> attenuation <span class="hlt">system</span>' (SAS) concept. We built and tested prototypes of all critical components. On the basis of these tests and past experience, we expect that the passive attenuation performance of this new design, called HAM-SAS, will match all requirements for the LIGO OMC, and all Ad-LIGO optical tables. Its performance can be improved, if necessary, by implementation of a simple active attenuation loop at marginal additional cost. The design can be easily modified to equip the LIGO basic symmetric chamber (BSC) chambers and leaves space for extensive performance upgrades for future evolutions of Ad-LIGO. Design parameters and prototype test results are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoJI.196.1544A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoJI.196.1544A"><span>Self-induced <span class="hlt">seismicity</span> due to fluid circulation along faults</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aochi, Hideo; Poisson, Blanche; Toussaint, Renaud; Rachez, Xavier; Schmittbuhl, Jean</p> <p>2014-03-01</p> <p>In this paper, we develop a <span class="hlt">system</span> of equations describing fluid migration, fault rheology, fault thickness evolution and shear rupture during a <span class="hlt">seismic</span> cycle, triggered either by tectonic loading or by fluid injection. Assuming that the phenomena predominantly take place on a single fault described as a finite permeable zone of variable width, we are able to project the equations within the volumetric fault core onto the 2-D fault interface. From the basis of this `fault lubrication approximation', we simulate the evolution of <span class="hlt">seismicity</span> when fluid is injected at one point along the fault to model-induced <span class="hlt">seismicity</span> during an injection test in a borehole that intercepts the fault. We perform several parametric studies to understand the basic behaviour of the <span class="hlt">system</span>. Fluid transmissivity and fault rheology are key elements. The simulated <span class="hlt">seismicity</span> generally tends to rapidly evolve after triggering, independently of the injection history and end when the stationary path of fluid flow is established at the outer <span class="hlt">boundary</span> of the model. This self-induced <span class="hlt">seismicity</span> takes place in the case where shear rupturing on a planar fault becomes dominant over the fluid migration process. On the contrary, if healing processes take place, so that the fluid mass is trapped along the fault, rupturing occurs continuously during the injection period. <span class="hlt">Seismicity</span> and fluid migration are strongly influenced by the injection rate and the heterogeneity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1977/0844/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1977/0844/"><span>Frequency response of the USGS short period telemetered <span class="hlt">seismic</span> <span class="hlt">system</span> and its suitability for network studies of local 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>Eaton, Jerry P.</p> <p>1977-01-01</p> <p>The USGS telemetered <span class="hlt">seismic</span> <span class="hlt">system</span> was intended primarily to record small to moderate earthquakes (magnitude 0 to 4) at distances of a few km to several hundred km. Its frequency response is such that the recorded background noise at a moderately quite Coast Range site has a relatively flat 'record' spectrum from about 1/3 Hz to about 20 Hz. With the <span class="hlt">system</span> magnification set so that the background noise is clearly recorded (about 1 mm peak-to-peak) one can anticipate that any <span class="hlt">seismic</span> signal that exceeds background noise appreciably in this spectral region will be large enough to be seen on the seismogram. This response represents the highest sensitivity and broadest bandwidth that we were able to attain with a 1-Hz seismometer, a simple amplifier VCO employing very low-power integrated circuits, and an 8-channel constant-bandwidth FM subcarrier multiplex <span class="hlt">system</span> for use with commercial voice-grade phone lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720025618','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720025618"><span>Numerical method for the solution of large <span class="hlt">systems</span> of differential equations of the <span class="hlt">boundary</span> layer type</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Green, M. J.; Nachtsheim, P. R.</p> <p>1972-01-01</p> <p>A numerical method for the solution of large <span class="hlt">systems</span> of nonlinear differential equations of the <span class="hlt">boundary</span>-layer type is described. The method is a modification of the technique for satisfying asymptotic <span class="hlt">boundary</span> conditions. The present method employs inverse interpolation instead of the Newton method to adjust the initial conditions of the related initial-value problem. This eliminates the so-called perturbation equations. The elimination of the perturbation equations not only reduces the user's preliminary work in the application of the method, but also reduces the number of time-consuming initial-value problems to be numerically solved at each iteration. For further ease of application, the solution of the overdetermined <span class="hlt">system</span> for the unknown initial conditions is obtained automatically by applying Golub's linear least-squares algorithm. The relative ease of application of the proposed numerical method increases directly as the order of the differential-equation <span class="hlt">system</span> increases. Hence, the method is especially attractive for the solution of large-order <span class="hlt">systems</span>. After the method is described, it is applied to a fifth-order problem from <span class="hlt">boundary</span>-layer theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6052G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6052G"><span>Effect of inherited structures on strike-slip plate <span class="hlt">boundaries</span>: insight from analogue modelling of the central Levant Fracture <span class="hlt">System</span>, Lebanon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghalayini, Ramadan; Daniel, Jean-Marc; Homberg, Catherine; Nader, Fadi</p> <p>2015-04-01</p> <p>Analogue sandbox modeling is a tool to simulate deformation style and structural evolution of sedimentary basins. The initial goal is to test what is the effect of inherited and crustal structures on the propagation, evolution, and final geometry of major strike-slip faults at the <span class="hlt">boundary</span> between two tectonic plates. For this purpose, we have undertaken a series of analogue models to validate and reproduce the structures of the Levant Fracture <span class="hlt">System</span>, a major NNE-SSW sinistral strike-slip fault forming the <span class="hlt">boundary</span> between the Arabian and African plates. Onshore observations and recent high quality 3D <span class="hlt">seismic</span> data in the Levant Basin offshore Lebanon demonstrated that Mesozoic ENE striking normal faults were reactivated into dextral strike-slip faults during the Late Miocene till present day activity of the plate <span class="hlt">boundary</span> which shows a major restraining bend in Lebanon with a ~ 30°clockwise rotation in its trend. Experimental parameters consisted of a silicone layer at the base simulating the ductile crust, overlain by intercalated quartz sand and glass sand layers. Pre-existing structures were simulated by creating a graben in the silicone below the sand at an oblique (>60°) angle to the main throughgoing strike-slip fault. The latter contains a small stepover at depth to create transpression during sinistral strike-slip movement and consequently result in mountain building similarly to modern day Lebanon. Strike-slip movement and compression were regulated by steady-speed computer-controlled engines and the model was scanned using a CT-scanner continuously while deforming to have a final 4D model of the <span class="hlt">system</span>. Results showed that existing normal faults were reactivated into dextral strike-slip faults as the sinistral movement between the two plates accumulated. Notably, the resulting restraining bend is asymmetric and segmented into two different compartments with differing geometries. One compartment shows a box fold anticline, while the second shows an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/6019099','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/6019099"><span>Analytical simulation of nonlinear response to <span class="hlt">seismic</span> test excitations of HDR-VKL (Heissdampfreaktor-Versuchskreislauf) piping <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Srinivasan, M.G.; Kot, C.A.; Mojtahed, M.</p> <p></p> <p>The paper describes the analytical modeling, calculations, and results of the posttest nonlinear simulation of high-level <span class="hlt">seismic</span> testing of the VKL piping <span class="hlt">system</span> at the HDR Test Facility in Germany. One of the objectives of the tests was to evaluate analytical methods for calculating the nonlinear response of realistic piping <span class="hlt">systems</span> subjected to high-level <span class="hlt">seismic</span> excitation that would induce significant plastic deformation. Two out of the six different pipe-support configurations, (ranging from a stiff <span class="hlt">system</span> with struts and snubbers to a very flexible <span class="hlt">system</span> with practically no <span class="hlt">seismic</span> supports), subjected to simulated earthquakes, were tested at very high levels. Themore » posttest nonlinear calculations cover the KWU configuration, a reasonably compliant <span class="hlt">system</span> with only rigid struts. Responses for 800% safe-shutdown-earthquake loading were calculated using the NONPIPE code. The responses calculated with NONPIPE were found generally to have the same time trends as the measurements but contained under-, over-, and correct estimates of peak values, almost in equal proportions. The only exceptions were the peak strut forces, which were underestimated as a group. The scatter in the peak value estimate of displacements and strut forces was smaller than that for the strains. The possible reasons for the differences and the effort on further analysis are discussed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23941951','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23941951"><span>Clinical simulation as a <span class="hlt">boundary</span> object in design of health IT-<span class="hlt">systems</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rasmussen, Stine Loft; Jensen, Sanne; Lyng, Karen Marie</p> <p>2013-01-01</p> <p>Healthcare organizations are very complex, holding numerous stakeholders with various approaches and goals towards the design of health IT-<span class="hlt">systems</span>. Some of these differences may be approached by applying the concept of <span class="hlt">boundary</span> objects in a participatory IT-design process. Traditionally clinical simulation provides the opportunity to evaluate the design and the usage of clinical IT-<span class="hlt">systems</span> without endangering the patients and interrupting clinical work. In this paper we present how clinical simulation additionally holds the potential to function as a <span class="hlt">boundary</span> object in the design process. The case points out that clinical simulation provides an opportunity for discussions and mutual learning among the various stakeholders involved in design of standardized electronic clinical documentation templates. The paper presents and discusses the use of clinical simulation in the translation, transfer and transformation of knowledge between various stakeholders in a large healthcare organization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870013012','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870013012"><span>Approximation of discrete-time LQG compensators for distributed <span class="hlt">systems</span> with <span class="hlt">boundary</span> input and unbounded measurement</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gibson, J. S.; Rosen, I. G.</p> <p>1987-01-01</p> <p>The approximation of optimal discrete-time linear quadratic Gaussian (LQG) compensators for distributed parameter control <span class="hlt">systems</span> with <span class="hlt">boundary</span> input and unbounded measurement is considered. The approach applies to a wide range of problems that can be formulated in a state space on which both the discrete-time input and output operators are continuous. Approximating compensators are obtained via application of the LQG theory and associated approximation results for infinite dimensional discrete-time control <span class="hlt">systems</span> with bounded input and output. Numerical results for spline and modal based approximation schemes used to compute optimal compensators for a one dimensional heat equation with either Neumann or Dirichlet <span class="hlt">boundary</span> control and pointwise measurement of temperature are presented and discussed.</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('http://adsabs.harvard.edu/abs/2015BGD....1220071F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGD....1220071F"><span>Determination of the carbon budget of a pasture: effect of <span class="hlt">system</span> <span class="hlt">boundaries</span> and flux uncertainties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Felber, R.; Bretscher, D.; Münger, A.; Neftel, A.; Ammann, C.</p> <p>2015-12-01</p> <p>Carbon (C) sequestration in the soil is considered as a potential important mechanism to mitigate greenhouse gas (GHG) emissions of the agricultural sector. It can be quantified by the net ecosystem carbon budget (NECB) describing the change of soil C as the sum of all relevant import and export fluxes. NECB was investigated here in detail for an intensively grazed dairy pasture in Switzerland. Two budget approaches with different <span class="hlt">system</span> <span class="hlt">boundaries</span> were applied: NECBtot for <span class="hlt">system</span> <span class="hlt">boundaries</span> including the grazing cows and NECBpast for <span class="hlt">system</span> <span class="hlt">boundaries</span> excluding the cows. CO2 and CH4 exchange induced by soil/vegetation processes as well as direct emissions by the animals were derived from eddy covariance measurements. Other C fluxes were either measured (milk yield, concentrate feeding) or derived based on animal performance data (intake, excreta). For the investigated year, both approaches resulted in a small non-significant C loss: NECBtot - 13 ± 61 g C m-2 yr-1 and NECBpast - 17 ± 81 g C m-2 yr-1. The considerable uncertainties, depending on the approach, were mainly due to errors in the CO2 exchange or in the animal related fluxes. The associated GHG budget revealed CH4 emissions from the cows to be the major contributor, but with much lower uncertainty compared to NECB. Although only one year of data limit the representativeness of the carbon budget results, they demonstrated the important contribution of the non-CO2 fluxes depending on the chosen <span class="hlt">system</span> <span class="hlt">boundaries</span> and the effect of their propagated uncertainty in an exemplary way. The simultaneous application and comparison of both NECB approaches provides a useful consistency check for the carbon budget determination and can help to identify and eliminate systematic errors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016BGeo...13.2959F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016BGeo...13.2959F"><span>Determination of the carbon budget of a pasture: effect of <span class="hlt">system</span> <span class="hlt">boundaries</span> and flux uncertainties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Felber, Raphael; Bretscher, Daniel; Münger, Andreas; Neftel, Albrecht; Ammann, Christof</p> <p>2016-05-01</p> <p>Carbon (C) sequestration in the soil is considered as a potential important mechanism to mitigate greenhouse gas (GHG) emissions of the agricultural sector. It can be quantified by the net ecosystem carbon budget (NECB) describing the change of soil C as the sum of all relevant import and export fluxes. NECB was investigated here in detail for an intensively grazed dairy pasture in Switzerland. Two budget approaches with different <span class="hlt">system</span> <span class="hlt">boundaries</span> were applied: NECBtot for <span class="hlt">system</span> <span class="hlt">boundaries</span> including the grazing cows and NECBpast for <span class="hlt">system</span> <span class="hlt">boundaries</span> excluding the cows. CO2 and CH4 exchange induced by soil/vegetation processes as well as direct emissions by the animals were derived from eddy covariance measurements. Other C fluxes were either measured (milk yield, concentrate feeding) or derived based on animal performance data (intake, excreta). For the investigated year, both approaches resulted in a small near-neutral C budget: NECBtot -27 ± 62 and NECBpast 23 ± 76 g C m-2 yr-1. The considerable uncertainties, depending on the approach, were mainly due to errors in the CO2 exchange or in the animal-related fluxes. The comparison of the NECB results with the annual exchange of other GHG revealed CH4 emissions from the cows to be the major contributor in terms of CO2 equivalents, but with much lower uncertainty compared to NECB. Although only 1 year of data limit the representativeness of the carbon budget results, they demonstrate the important contribution of the non-CO2 fluxes depending on the chosen <span class="hlt">system</span> <span class="hlt">boundaries</span> and the effect of their propagated uncertainty in an exemplary way. The simultaneous application and comparison of both NECB approaches provides a useful consistency check for the carbon budget determination and can help to identify and eliminate systematic errors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JDE...245.1386B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JDE...245.1386B"><span>Reaction-diffusion <span class="hlt">systems</span> coupled at the <span class="hlt">boundary</span> and the Morse-Smale property</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Broche, Rita de Cássia D. S.; de Oliveira, Luiz Augusto F.</p> <p></p> <p>We study an one-dimensional nonlinear reaction-diffusion <span class="hlt">system</span> coupled on the <span class="hlt">boundary</span>. Such <span class="hlt">system</span> comes from modeling problems of temperature distribution on two bars of same length, jointed together, with different diffusion coefficients. We prove the transversality property of unstable and stable manifolds assuming all equilibrium points are hyperbolic. To this end, we write the <span class="hlt">system</span> as an equation with noncontinuous diffusion coefficient. We then study the nonincreasing property of the number of zeros of a linearized nonautonomous equation as well as the Sturm-Liouville properties of the solutions of a linear elliptic problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPCM...30e5002X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPCM...30e5002X"><span><span class="hlt">Boundary</span> states in the chiral symmetric <span class="hlt">systems</span> with a spatial symmetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xiao, Jinpeng; An, Jin</p> <p>2018-02-01</p> <p>We study topological <span class="hlt">systems</span> with both a chiral and a spatial symmetry which result in an additional spatial chiral symmetry. We distinguish the topologically nontrivial states according to the chiral symmetries protecting them and study several models in 1D and 3D <span class="hlt">systems</span>. The perturbations breaking the spatial symmetry can break only one of the two chiral symmetries while the perturbations preserving the spatial symmetry always break or preserve both of them. In 3D <span class="hlt">systems</span>, besides the 3D symmetries, the topologically nontrivial <span class="hlt">boundary</span> modes may also be protected by the hidden lower dimensional symmetries. We then figure out the corresponding topological invariants and connect them with the 3D invariants.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhCS1005a2019D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhCS1005a2019D"><span>Prediction of Flutter <span class="hlt">Boundary</span> Using Flutter Margin for The Discrete-Time <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dwi Saputra, Angga; Wibawa Purabaya, R.</p> <p>2018-04-01</p> <p>Flutter testing in a wind tunnel is generally conducted at subcritical speeds to avoid damages. Hence, The flutter speed has to be predicted from the behavior some of its stability criteria estimated against the dynamic pressure or flight speed. Therefore, it is quite important for a reliable flutter prediction method to estimates flutter <span class="hlt">boundary</span>. This paper summarizes the flutter testing of a wing cantilever model in a wind tunnel. The model has two degree of freedom; they are bending and torsion modes. The flutter test was conducted in a subsonic wind tunnel. The dynamic data responses was measured by two accelerometers that were mounted on leading edge and center of wing tip. The measurement was repeated while the wind speed increased. The dynamic responses were used to determine the parameter flutter margin for the discrete-time <span class="hlt">system</span>. The flutter <span class="hlt">boundary</span> of the model was estimated using extrapolation of the parameter flutter margin against the dynamic pressure. The parameter flutter margin for the discrete-time <span class="hlt">system</span> has a better performance for flutter prediction than the modal parameters. A model with two degree freedom and experiencing classical flutter, the parameter flutter margin for the discrete-time <span class="hlt">system</span> gives a satisfying result in prediction of flutter <span class="hlt">boundary</span> on subsonic wind tunnel test.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812350G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812350G"><span>The <span class="hlt">Seismic</span> Aftershock Monitoring <span class="hlt">System</span> (SAMS) for OSI - Experiences from IFE14</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gestermann, Nicolai; Sick, Benjamin; Häge, Martin; Blake, Thomas; Labak, Peter; Joswig, Manfred</p> <p>2016-04-01</p> <p>An on-site inspection (OSI) is the third of four elements of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The sole purpose of an OSI is to confirm whether a nuclear weapon test explosion or any other nuclear explosion has been carried out in violation of the treaty and to gather any facts which might assist in identifying any possible violator. It thus constitutes the final verification measure under the CTBT if all other available measures are not able to confirm the nature of a suspicious event. The Provisional Technical Secretariat (PTS) carried out the Integrated Field Exercise 2014 (IFE14) in the Dead Sea Area of Jordan from 3 November to 9. December 2014. It was a fictitious OSI whose aim was to test the inspection capabilities in an integrated manner. The technologies allowed during an OSI are listed in the Treaty. The aim of the <span class="hlt">Seismic</span> Aftershock Monitoring <span class="hlt">System</span> (SAMS) is to detect and localize aftershocks of low magnitudes of the triggering event or collapses of underground cavities. The locations of these events are expected in the vicinity of a possible previous explosion and help to narrow down the search area within an inspection area (IA) of an OSI. The success of SAMS depends on the main elements, hardware, software, deployment strategy, the search logic and not least the effective use of personnel. All elements of SAMS were tested and improved during the Built-Up Exercises (BUE) which took place in Austria and Hungary. IFE14 provided more realistic climatic and hazardous terrain conditions with limited resources. Significant variations in topography of the IA of IFE14 in the mountainous Dead Sea Area of Jordan led to considerable challenges which were not expected from experiences encountered during BUE. The SAMS uses mini arrays with an aperture of about 100 meters and with a total of 4 elements. The station network deployed during IFE14 and results of the data analysis will be presented. Possible aftershocks of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26PSL.493...47F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26PSL.493...47F"><span>Progressive reactivation of the volcanic plumbing <span class="hlt">system</span> beneath Tolbachik volcano (Kamchatka, Russia) revealed by long-period <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>Frank, William B.; Shapiro, Nikolaï M.; Gusev, Alexander A.</p> <p>2018-07-01</p> <p>After lying dormant for 36 yr, the Tolbachik volcano of the Klyuchevskoy group started to erupt on 27 November 2012. We investigate the preparatory phase of this eruption via a statistical analysis of the temporal behavior of long-period (LP) earthquakes that occurred beneath this volcanic <span class="hlt">system</span>. The LP <span class="hlt">seismicity</span> occurs close to the surface beneath the main volcanic edifices and at 30 km depth in the vicinity of a deep magmatic reservoir. The deep LP earthquakes and those beneath the Klyuchevskoy volcano occur quasi-periodically, while the LP earthquakes beneath Tolbachik are clustered in time. As the <span class="hlt">seismicity</span> rate increased beneath Tolbachik days before the eruption, the level of the time clustering decreased. We interpret this as a manifestation of the evolution of the volcano plumbing <span class="hlt">system</span>. We suggest that when a plumbing <span class="hlt">system</span> awakes after quiescence, multiple cracks and channels are reactivated simultaneously and their interaction results in the strong time clustering of LP earthquakes. With time, this network of channels and cracks evolves into a more stable state with an overall increased permeability, where fluids flow uninhibited throughout the plumbing <span class="hlt">system</span> except for a few remaining impediments that continue to generate <span class="hlt">seismic</span> radiation. The inter-<span class="hlt">seismic</span> source interaction and the level of earthquake time clustering in this latter state is weak. This scenario suggests that the observed evolution of the statistical behavior of the shallow LP <span class="hlt">seismicity</span> beneath Tolbachik is an indicator of the reactivation and consolidation of the near-surface plumbing <span class="hlt">system</span> prior to the Tolbachik eruption. The parts of the plumbing <span class="hlt">system</span> above the deep magmatic reservoir and beneath the Klyuchevskoy volcano remain in nearly permanent activity, as demonstrated by the continuous occurrence of the deep LP earthquakes and very frequent Klyuchevskoy eruptions. This implies that these parts of the plumbing <span class="hlt">system</span> remain in a stable permeable state and contain a few</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CEER...25...11A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CEER...25...11A"><span>Shakedown Analysis of Composite Steel-Concrete Frame <span class="hlt">Systems</span> with Plastic and Brittle Elements Under <span class="hlt">Seismic</span> Action</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alawdin, Piotr; Bulanov, George</p> <p>2017-06-01</p> <p>In this paper the earthquake analysis of composite steel-concrete frames is performed by finding solution of the optimization problem of shakedown analysis, which takes into account the nonlinear properties of materials. The constructions are equipped with <span class="hlt">systems</span> bearing structures of various elastic-plastic and brittle elements absorbing energy of <span class="hlt">seismic</span> actions. A mathematical model of this problem is presented on the base of limit analysis theory with partial redistribution of self-stressed internal forces. It is assumed that the load varies randomly within the specified limits. These limits are determined by the possible direction and magnitude of <span class="hlt">seismic</span> loads. The illustrative example of such analysis of <span class="hlt">system</span> is introduced. Some attention has been paid to the practical application of the proposed mathematical model.</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 release 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 <span class="hlt">system</span> 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/2009SPIE.7288E..2AR','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7288E..2AR"><span>Genetic algorithm-based multi-objective optimal absorber <span class="hlt">system</span> for three-dimensional <span class="hlt">seismic</span> structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ren, Wenjie; Li, Hongnan; Song, Gangbing; Huo, Linsheng</p> <p>2009-03-01</p> <p>The problem of optimizing an absorber <span class="hlt">system</span> for three-dimensional <span class="hlt">seismic</span> structures is addressed. The objective is to determine the number and position of absorbers to minimize the coupling effects of translation-torsion of structures at minimum cost. A procedure for a multi-objective optimization problem is developed by integrating a dominance-based selection operator and a dominance-based penalty function method. Based on the two-branch tournament genetic algorithm, the selection operator is constructed by evaluating individuals according to their dominance in one run. The technique guarantees the better performing individual winning its competition, provides a slight selection pressure toward individuals and maintains diversity in the population. Moreover, due to the evaluation for individuals in each generation being finished in one run, less computational effort is taken. Penalty function methods are generally used to transform a constrained optimization problem into an unconstrained one. The dominance-based penalty function contains necessary information on non-dominated character and infeasible position of an individual, essential for success in seeking a Pareto optimal set. The proposed approach is used to obtain a set of non-dominated designs for a six-storey three-dimensional building with shape memory alloy dampers subjected to earthquake.</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('http://adsabs.harvard.edu/abs/2009ExA....24....9W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ExA....24....9W"><span>Interstellar heliospheric probe/heliospheric <span class="hlt">boundary</span> explorer mission—a mission to the outermost <span class="hlt">boundaries</span> of the solar <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wimmer-Schweingruber, Robert F.; McNutt, Ralph; Schwadron, Nathan A.; Frisch, Priscilla C.; Gruntman, Mike; Wurz, Peter; Valtonen, Eino</p> <p>2009-05-01</p> <p>The Sun, driving a supersonic solar wind, cuts out of the local interstellar medium a giant plasma bubble, the heliosphere. ESA, jointly with NASA, has had an important role in the development of our current understanding of the Suns immediate neighborhood. Ulysses is the only spacecraft exploring the third, out-of-ecliptic dimension, while SOHO has allowed us to better understand the influence of the Sun and to image the glow of interstellar matter in the heliosphere. Voyager 1 has recently encountered the innermost <span class="hlt">boundary</span> of this plasma bubble, the termination shock, and is returning exciting yet puzzling data of this remote region. The next logical step is to leave the heliosphere and to thereby map out in unprecedented detail the structure of the outer heliosphere and its <span class="hlt">boundaries</span>, the termination shock, the heliosheath, the heliopause, and, after leaving the heliosphere, to discover the true nature of the hydrogen wall, the bow shock, and the local interstellar medium beyond. This will greatly advance our understanding of the heliosphere that is the best-known example for astrospheres as found around other stars. Thus, IHP/HEX will allow us to discover, explore, and understand fundamental astrophysical processes in the largest accessible plasma laboratory, the heliosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050028442','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050028442"><span><span class="hlt">Boundary</span> Layer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Loitsianskii. L. G.</p> <p>1956-01-01</p> <p>The fundamental, practically the most important branch of the modern mechanics of a viscous fluid or a gas, is that branch which concerns itself with the study of the <span class="hlt">boundary</span> layer. The presence of a <span class="hlt">boundary</span> layer accounts for the origin of the resistance and lift force, the breakdown of the smooth flow about bodies, and other phenomena that are associated with the motion of a body in a real fluid. The concept of <span class="hlt">boundary</span> layer was clearly formulated by the founder of aerodynamics, N. E. Joukowsky, in his well-known work "On the Form of Ships" published as early as 1890. In his book "Theoretical Foundations of Air Navigation," Joukowsky gave an account of the most important properties of the <span class="hlt">boundary</span> layer and pointed out the part played by it in the production of the resistance of bodies to motion. The fundamental differential equations of the motion of a fluid in a laminar <span class="hlt">boundary</span> layer were given by Prandtl in 1904; the first solutions of these equations date from 1907 to 1910. As regards the turbulent <span class="hlt">boundary</span> layer, there does not exist even to this day any rigorous formulation of this problem because there is no closed <span class="hlt">system</span> of equations for the turbulent motion of a fluid. Soviet scientists have done much toward developing a general theory of the <span class="hlt">boundary</span> layer, and in that branch of the theory which is of greatest practical importance at the present time, namely the study of the <span class="hlt">boundary</span> layer at large velocities of the body in a compressed gas, the efforts of the scientists of our country have borne fruit in the creation of a new theory which leaves far behind all that has been done previously in this direction. We shall herein enumerate the most important results by Soviet scientists in the development of the theory of the <span class="hlt">boundary</span> layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19..845Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19..845Z"><span>The analysis of the Tectonics - SSS - <span class="hlt">Seismicity</span> <span class="hlt">System</span> in the 3D-model of the Rasvumchorr Mine - Central Open Pit Natural and Technical <span class="hlt">System</span> (Khibiny)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhirov, Dmitry; Klimov, Sergey; Zhirova, Anzhela; Panteleev, Alexey; Rybin, Vadim</p> <p>2017-04-01</p> <p>Main hazardous factors during the operation of deposits represent tectonics (structural dislocation), strain and stress state (SSS), and <span class="hlt">seismicity</span>. The cause and effect relationships in the Fault Tectonics - SSS - <span class="hlt">Seismicity</span> <span class="hlt">system</span> were analyzed using a 3D geological and structural Rasvumchorr Mine - Central Open Pit model. This natural and technical <span class="hlt">system</span> (NTS) has resulted from the development of the world-class apatite-nepheline deposits the Apatite Circus and Rasvumchorr Plateau. The 3D model integrates various spatial data on the earth's surface topography before and after mining, geometry of mines and dumps, SSS measurements and rock pressure, <span class="hlt">seismicity</span>, fault tectonics and etc. The analysis of the 3D model has clearly demonstrated the localization of three main <span class="hlt">seismic</span> emanation zones in the areas of maximum anthropogenic variation of the initial rock state, and namely: ore pass zone under the Southern edge of the Central open pit, collapse and joining zone of the Rasvumchorr Mine and NW edge of the open pit, and zone under the Apatite Circus plate - collapse console. And, on the contrary, in the area of a large dump under the underground mine, a perennial <span class="hlt">seismic</span> minimum zone was identified. The relation of the <span class="hlt">seismicity</span> and fault tectonics was revealed only in three local sectors near come certain echelon fissures of the Main Fault(MF). No confinement of increased <span class="hlt">seismicity</span> areas to the MF and other numerous echelon fissures is observed. The same picture occurs towards manifestations of rock pressure. Only an insignificant part of echelon fissures (including low rank of hierarchy) controls hazardous manifestations of rock pressure (dumps, strong deformations of the mine contour, etc.). It is shown that the anthropogenic factor (explosive, geometry and arrangement of mined spaces and collapse console), as well as the time factor significantly change orientation and structure (contrast and heterogeneity) of the stress fields. Time series of natural</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2916819','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2916819"><span>Attraction Basins as Gauges of Robustness against <span class="hlt">Boundary</span> Conditions in Biological Complex <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Demongeot, Jacques; Goles, Eric; Morvan, Michel; Noual, Mathilde; Sené, Sylvain</p> <p>2010-01-01</p> <p>One fundamental concept in the context of biological <span class="hlt">systems</span> on which researches have flourished in the past decade is that of the apparent robustness of these <span class="hlt">systems</span>, i.e., their ability to resist to perturbations or constraints induced by external or <span class="hlt">boundary</span> elements such as electromagnetic fields acting on neural networks, micro-RNAs acting on genetic networks and even hormone flows acting both on neural and genetic networks. Recent studies have shown the importance of addressing the question of the environmental robustness of biological networks such as neural and genetic networks. In some cases, external regulatory elements can be given a relevant formal representation by assimilating them to or modeling them by <span class="hlt">boundary</span> conditions. This article presents a generic mathematical approach to understand the influence of <span class="hlt">boundary</span> elements on the dynamics of regulation networks, considering their attraction basins as gauges of their robustness. The application of this method on a real genetic regulation network will point out a mathematical explanation of a biological phenomenon which has only been observed experimentally until now, namely the necessity of the presence of gibberellin for the flower of the plant Arabidopsis thaliana to develop normally. PMID:20700525</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29024002','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29024002"><span><span class="hlt">Boundary</span>-spanning actors in complex adaptive governance <span class="hlt">systems</span>: The case of multisectoral nutrition.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pelletier, David; Gervais, Suzanne; Hafeez-Ur-Rehman, Hajra; Sanou, Dia; Tumwine, Jackson</p> <p>2018-01-01</p> <p>A growing literature highlights complexity of policy implementation and governance in global health and argues that the processes and outcomes of policies could be improved by explicitly taking this complexity into account. Yet there is a paucity of studies exploring how this can be achieved in everyday practice. This study documents the strategies, tactics, and challenges of <span class="hlt">boundary</span>-spanning actors working in 4 Sub-Saharan Africa countries who supported the implementation of multisectoral nutrition as part of the African Nutrition Security Partnership in Burkina Faso, Mali, Ethiopia, and Uganda. Three action researchers were posted to these countries during the final 2 years of the project to help the government and its partners implement multisectoral nutrition and document the lessons. Prospective data were collected through participant observation, end-line semistructured interviews, and document analysis. All 4 countries made significant progress despite a wide range of challenges at the individual, organizational, and <span class="hlt">system</span> levels. The <span class="hlt">boundary</span>-spanning actors and their collaborators deployed a wide range of strategies but faced significant challenges in playing these unconventional roles. The study concludes that, under the right conditions, intentional <span class="hlt">boundary</span> spanning can be a feasible and acceptable practice within a multisectoral, complex adaptive <span class="hlt">system</span> in low- and middle-income countries. © 2017 The Authors. The International Journal of Health Planning and Management Published by John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860011765','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860011765"><span>Stability analysis of spectral methods for hyperbolic initial-<span class="hlt">boundary</span> value <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gottlieb, D.; Lustman, L.; Tadmor, E.</p> <p>1986-01-01</p> <p>A constant coefficient hyperbolic <span class="hlt">system</span> in one space variable, with zero initial data is discussed. Dissipative <span class="hlt">boundary</span> conditions are imposed at the two points x = + or - 1. This problem is discretized by a spectral approximation in space. Sufficient conditions under which the spectral numerical solution is stable are demonstrated - moreover, these conditions have to be checked only for scalar equations. The stability theorems take the form of explicit bounds for the norm of the solution in terms of the <span class="hlt">boundary</span> data. The dependence of these bounds on N, the number of points in the domain (or equivalently the degree of the polynomials involved), is investigated for a class of standard spectral methods, including Chebyshev and Legendre collocations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.G41A..02H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.G41A..02H"><span>GPS Imaging suggests links between climate, magmatism, <span class="hlt">seismicity</span>, and tectonics in the Sierra Nevada-Long Valley Caldera-Walker Lane <span class="hlt">system</span>, western United States</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hammond, W. C.; Blewitt, G.; Kreemer, C.; Smith, K.</p> <p>2017-12-01</p> <p>The Walker Lane is a region of complex active crustal transtension in the western Great Basin of the western United States, accommodating about 20% of the 50 mm/yr relative motion between the Pacific and North American plates. The Long Valley caldera lies in the central Walker Lane in eastern California, adjacent to the eastern <span class="hlt">boundary</span> of the Sierra Nevada/Great Valley microplate, and experiences intermittent inflation, uplift, and volcanic unrest from the magma chamber that resides at middle crustal depths. Normal and transform faults accommodating regional tectonic transtension pass by and through the caldera, complicating the interpretation of the GPS-measured strain rate field, estimates of fault slip rates, and <span class="hlt">seismic</span> hazard. Several dozen continuously recording GPS stations measure strain and uplift in the area with mm precision. They observe that the most recent episode of uplift at Long Valley began in mid-2011, continuing until late 2016, raising the surface by 100 mm in 6 years. The timing of the initiation of uplift coincides with the beginning of severe drought in California. Furthermore, the timing of a recent pause in uplift coincides with the very wet 2016-2017 winter, which saw approximately double normal snow pack. In prior studies, we showed that the timing of changes in geodetically measured uplift rate of the Sierra Nevada coincides with the timing of drought conditions in California, suggesting a link between hydrological loading and Sierra Nevada elevation. Here we take the analysis three steps further to show that changes in Sierra Nevada uplift rate coincide in time with 1) enhanced inflation at the Long Valley caldera, 2) shifts in the patterns and rates of horizontal tensor strain rate, and 3) <span class="hlt">seismicity</span> patterns in the central Walker Lane. We use GPS solutions from the Nevada Geodetic Laboratory and the new GPS Imaging technique to produce robust animations of the time variable strain and uplift fields. The goals of this work are to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S43A4535F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S43A4535F"><span>Recent advancements on the development of web-based applications for the implementation of <span class="hlt">seismic</span> analysis and surveillance <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Friberg, P. A.; Luis, R. S.; Quintiliani, M.; Lisowski, S.; Hunter, S.</p> <p>2014-12-01</p> <p>Recently, a novel set of modules has been included in the Open Source Earthworm <span class="hlt">seismic</span> data processing <span class="hlt">system</span>, supporting the use of web applications. These include the Mole sub-<span class="hlt">system</span>, for storing relevant event data in a MySQL database (see M. Quintiliani and S. Pintore, SRL, 2013), and an embedded webserver, Moleserv, for serving such data to web clients in QuakeML format. These modules have enabled, for the first time using Earthworm, the use of web applications for <span class="hlt">seismic</span> data processing. These can greatly simplify the operation and maintenance of <span class="hlt">seismic</span> data processing centers by having one or more servers providing the relevant data as well as the data processing applications themselves to client machines running arbitrary operating <span class="hlt">systems</span>.Web applications with secure online web access allow operators to work anywhere, without the often cumbersome and bandwidth hungry use of secure shell or virtual private networks. Furthermore, web applications can seamlessly access third party data repositories to acquire additional information, such as maps. Finally, the usage of HTML email brought the possibility of specialized web applications, to be used in email clients. This is the case of EWHTMLEmail, which produces event notification emails that are in fact simple web applications for plotting relevant <span class="hlt">seismic</span> data.Providing web services as part of Earthworm has enabled a number of other tools as well. One is ISTI's EZ Earthworm, a web based command and control <span class="hlt">system</span> for an otherwise command line driven <span class="hlt">system</span>; another is a waveform web service. The waveform web service serves Earthworm data to additional web clients for plotting, picking, and other web-based processing tools. The current Earthworm waveform web service hosts an advanced plotting capability for providing views of event-based waveforms from a Mole database served by Moleserve.The current trend towards the usage of cloud services supported by web applications is driving improvements in Java</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.tmp.1302L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.tmp.1302L"><span>Simulating <span class="hlt">Seismic</span> Wave Propagation in Viscoelastic Media with an Irregular Free Surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Xiaobo; Chen, Jingyi; Zhao, Zhencong; Lan, Haiqiang; Liu, Fuping</p> <p>2018-05-01</p> <p>In <span class="hlt">seismic</span> numerical simulations of wave propagation, it is very important for us to consider surface topography and attenuation, which both have large effects (e.g., wave diffractions, conversion, amplitude/phase change) on <span class="hlt">seismic</span> imaging and inversion. An irregular free surface provides significant information for interpreting the characteristics of <span class="hlt">seismic</span> wave propagation in areas with rugged or rapidly varying topography, and viscoelastic media are a better representation of the earth's properties than acoustic/elastic media. In this study, we develop an approach for <span class="hlt">seismic</span> wavefield simulation in 2D viscoelastic isotropic media with an irregular free surface. Based on the <span class="hlt">boundary</span>-conforming grid method, the 2D time-domain second-order viscoelastic isotropic equations and irregular free surface <span class="hlt">boundary</span> conditions are transferred from a Cartesian coordinate <span class="hlt">system</span> to a curvilinear coordinate <span class="hlt">system</span>. Finite difference operators with second-order accuracy are applied to discretize the viscoelastic wave equations and the irregular free surface in the curvilinear coordinate <span class="hlt">system</span>. In addition, we select the convolutional perfectly matched layer <span class="hlt">boundary</span> condition in order to effectively suppress artificial reflections from the edges of the model. The snapshot and seismogram results from numerical tests show that our algorithm successfully simulates <span class="hlt">seismic</span> wavefields (e.g., P-wave, Rayleigh wave and converted waves) in viscoelastic isotropic media with an irregular free surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMOS41B..02C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMOS41B..02C"><span><span class="hlt">Seismic</span> Reflection Imaging of the Heat Source of an Ultramafic-Hosted Hydrothermal <span class="hlt">System</span> (Rainbow, Mid-Atlantic Ridge 36° 10-17'N)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Canales, J. P.; Dunn, R. A.; Sohn, R. A.; Horning, G.; Arai, R.; Paulatto, M.</p> <p>2015-12-01</p> <p>Most of our understanding of hydrothermal <span class="hlt">systems</span> and the nature of their heat sources comes from models and observations at fast and intermediate spreading ridges. In these settings, hydrothermal <span class="hlt">systems</span> are mainly located within the axial zone of a spreading segment, hosted in basaltic rock, and primarily driven by heat extracted from crystallization of crustal melt sills. In contrast, hydrothermal <span class="hlt">systems</span> at slow-spreading ridges like the Mid-Atlantic Ridge (MAR) show a great variety of venting styles and host-rock lithology, and are located in diverse tectonic settings like axial volcanic ridges, non-transform discontinuities (NTDs), the foot of ridge valley walls, and off-axis inside corner highs. Among MAR <span class="hlt">systems</span>, the Rainbow hydrothermal field (RHF) stands out as an end-member of this diversity: an ultramafic-hosted <span class="hlt">system</span> emitting H2 and CH4-rich fluids at high temperatures and high flow rates, which suggests a magmatic heat source despite the lack of evidence for recent volcanism and its location within an NTD with presumably low magma budget. We present 2D multichannel <span class="hlt">seismic</span> reflection images across the Rainbow massif from the NSF-funded MARINER multidisciplinary geophysical study that reveal, for the first time, the magmatic <span class="hlt">system</span> driving hydrothermal circulation in an ultramafic setting. Data were acquired in 2013 onboard the RV M. Langseth with an 8-km-long hydrophone streamer. The images have been obtained from pre-stack depth migrations using a regional 3D P-wave velocity model from a coincident controlled-source <span class="hlt">seismic</span> tomography experiment using ocean bottom seismometers. Our images show a complex magmatic <span class="hlt">system</span> centered beneath the RHF occupying an areal extent of ~3.7x6 km2, with partially molten sills ranging in depth between ~3.4 km and ~6.9 km below the seafloor. Our data also image high-amplitude dipping reflections within the massif coincident with strong lateral velocity gradients that may arise from detachment fault planes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRB..120..326C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRB..120..326C"><span>Synthetic earthquake catalogs simulating <span class="hlt">seismic</span> activity in the Corinth Gulf, Greece, fault <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Console, Rodolfo; Carluccio, Roberto; Papadimitriou, Eleftheria; Karakostas, Vassilis</p> <p>2015-01-01</p> <p>The characteristic earthquake hypothesis is the basis of time-dependent modeling of earthquake recurrence on major faults. However, the characteristic earthquake hypothesis is not strongly supported by observational data. Few fault segments have long historical or paleoseismic records of individually dated ruptures, and when data and parameter uncertainties are allowed for, the form of the recurrence distribution is difficult to establish. This is the case, for instance, of the Corinth Gulf Fault <span class="hlt">System</span> (CGFS), for which documents about strong earthquakes exist for at least 2000 years, although they can be considered complete for M ≥ 6.0 only for the latest 300 years, during which only few characteristic earthquakes are reported for individual fault segments. The use of a physics-based earthquake simulator has allowed the production of catalogs lasting 100,000 years and containing more than 500,000 events of magnitudes ≥ 4.0. The main features of our simulation algorithm are (1) an average slip rate released by earthquakes for every single segment in the investigated fault <span class="hlt">system</span>, (2) heuristic procedures for rupture growth and stop, leading to a self-organized earthquake magnitude distribution, (3) the interaction between earthquake sources, and (4) the effect of minor earthquakes in redistributing stress. The application of our simulation algorithm to the CGFS has shown realistic features in time, space, and magnitude behavior of the <span class="hlt">seismicity</span>. These features include long-term periodicity of strong earthquakes, short-term clustering of both strong and smaller events, and a realistic earthquake magnitude distribution departing from the Gutenberg-Richter distribution in the higher-magnitude range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T51B0457X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T51B0457X"><span><span class="hlt">Seismic</span> imaging of Late Cretaceous magmatic <span class="hlt">system</span> in the northern margin of South China Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xia, S.; Xu, H.; Sun, J.; Zhao, F.; Fan, C.</p> <p>2017-12-01</p> <p>The origin and evolution of magmatism in the rifting margins are the fundamentally geological subjects, and remain the focus of intense study. Different from the classical volcanic or nonvolcanic rifting margins, the northern margin of South China Sea (SCS) experienced uniquely regional tectonic processes, and formed plentiful intraplate seamounts mainly at the postrift period. There is considerable controversy over what caused the intensively postrift intraplate volcanism. Here we combine a new crustal structure with previously systematic petrologic and <span class="hlt">seismic</span> tomographic results to first provide importantly new insights into a mantle plume origin and complex multilevel plumbing <span class="hlt">system</span> of intraplate seamounts in the northern margin of SCS. Large amounts of active melts from the lower mantle migrated upward and reached the base of the lithosphere. The volatile-rich and overheated magmas continued ascending along the weak zone through the lithosphere and intruded into the lower crust. The intrusion magmas then ascended forward along the faults formed during the rifting, and supplied the magma source for the formation of intraplate seamounts in the northern margin of SCS. It supplies an important implication for the volume and range of late Cenozoic basaltic magmatism deriving from the Hainan mantle plume. Keywords: South China Sea; Late Cretaceous; Magmatic <span class="hlt">System</span>; Hainan Plume AcknowledgementsThe field work of this study was assisted by the captain and crew of the R/V Shiyan 2. Prof. Xuelin Qiu supplied great helps for the successful implementation of the cruise. This work was partially supported by grants from the National Natural Science Foundation of China (Grant Nos. 91328206 and 41576041).</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/2017AGUFM.T41C0630S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T41C0630S"><span><span class="hlt">Seismic</span> imaging of the southern California plate-<span class="hlt">boundary</span> around the South-Central Transverse Ranges using double-difference tomography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Share, P. E.; Ben-Zion, Y.; Thurber, C. H.; Zhang, H.; Guo, H.</p> <p>2017-12-01</p> <p>We derive P and S <span class="hlt">seismic</span> velocities within and around the South-Central Transverse Ranges section of the San Andreas Fault (SAF), using a new double-difference tomography algorithm incorporating both event-pair and station-pair differential times. The event-pair data can determine high-resolution relative earthquake locations and resolve fine-scale structure in seismogenic zones, whereas station-pair data allow for better absolute locations and higher resolution of structure near the surface where stations are most dense. The tomographic results are based on arrival times of P and S waves generated by 17,753 M>1 local events from 1/1/2010 to 6/30/2015 recorded by 259 stations within a 222 km x 164 km region. The resulting P and S velocity models include low velocities along major fault segments and across-fault velocity contrasts. For example, at depths <7 km, low velocity anomalies delineate the SAF from Cajon Pass to Coachella Valley, with the exception around San Gorgonio Pass (SGP) where a relatively fast rock body cuts across the fault. Extensive faulting and Pelona schist manifest as low velocities throughout the San Bernardino Basin (SBB). High velocity granites abut the SBB to the SW and NE, forming prominent velocity contrasts across the northern San Jacinto Fault Zone (SJFZ) and the SAF, respectively. At depths of 9-11 km, the models also show a velocity contrast with an areal extent of >50 km parallel to the SAF around Coachella Valley but offset to the NE by 13 km. This is interpreted to mark a dipping section of the SAF that separates granites at depth in the SW from gneisses and schists in the NE. Analysis of fault zone head waves propagating along these sections of the SAF and SJFZ show that major bimaterial interfaces are associated with the observed velocity contrasts. Additional features within the models include elongated low velocity anomalies extending from the SJFZ trifurcation area, which itself has associated low velocity at great depth</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.S51A1737D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.S51A1737D"><span>Quantitative Estimation of <span class="hlt">Seismic</span> Velocity Changes Using Time-Lapse <span class="hlt">Seismic</span> Data and Elastic-Wave Sensitivity Approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Denli, H.; Huang, L.</p> <p>2008-12-01</p> <p>Quantitative monitoring of reservoir property changes is essential for safe geologic carbon sequestration. Time-lapse <span class="hlt">seismic</span> surveys have the potential to effectively monitor fluid migration in the reservoir that causes geophysical property changes such as density, and P- and S-wave velocities. We introduce a novel method for quantitative estimation of <span class="hlt">seismic</span> velocity changes using time-lapse <span class="hlt">seismic</span> data. The method employs elastic sensitivity wavefields, which are the derivatives of elastic wavefield with respect to density, P- and S-wave velocities of a target region. We derive the elastic sensitivity equations from analytical differentiations of the elastic-wave equations with respect to <span class="hlt">seismic</span>-wave velocities. The sensitivity equations are coupled with the wave equations in a way that elastic waves arriving in a target reservoir behave as a secondary source to sensitivity fields. We use a staggered-grid finite-difference scheme with perfectly-matched layers absorbing <span class="hlt">boundary</span> conditions to simultaneously solve the elastic-wave equations and the elastic sensitivity equations. By elastic-wave sensitivities, a linear relationship between relative <span class="hlt">seismic</span> velocity changes in the reservoir and time-lapse <span class="hlt">seismic</span> data at receiver locations can be derived, which leads to an over-determined <span class="hlt">system</span> of equations. We solve this <span class="hlt">system</span> of equations using a least- square method for each receiver to obtain P- and S-wave velocity changes. We validate the method using both surface and VSP synthetic time-lapse <span class="hlt">seismic</span> data for a multi-layered model and the elastic Marmousi model. Then we apply it to the time-lapse field VSP data acquired at the Aneth oil field in Utah. A total of 10.5K tons of CO2 was injected into the oil reservoir between the two VSP surveys for enhanced oil recovery. The synthetic and field data studies show that our new method can quantitatively estimate changes in <span class="hlt">seismic</span> velocities within a reservoir due to CO2 injection/migration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMGP11A0058H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMGP11A0058H"><span>Vertical-Axis Rotations Within Columbia River Basalt Flows Define a Sharp Eastern <span class="hlt">Boundary</span> of the Coast Range Block with Potentially Increased <span class="hlt">Seismic</span> Risk for Portland, Oregon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hagstrum, J. T.; Wells, R. E.; Evarts, R. C.; Blakely, R. J.; Beeson, M. H.</p> <p>2006-12-01</p> <p>Paleomagnetic analysis of the Miocene Columbia River Basalt Group (CRBG) in the northern Willamette Valley of Oregon was undertaken as part of a larger mapping and hydrogeologic investigation of the CRBG's internal stratigraphy and structure. Differences in paleomagnetic directions between flows due to geomagnetic reversals and paleosecular variation, in combination with geochemical data, provide the most reliable means of flow identification. In addition, vertical-axis rotations between CRBG sites in the Portland area and sampling localities within the same flow units on the relatively stable Columbia Plateau were calculated. Clockwise rotations for sites within the northern Willamette Valley are remarkably consistent and have a weighted mean of 29°±3° (N=94). Available paleomagnetic data from CRBG sites along the Oregon coast at Cape Lookout (19°±22°, N=4) and Cape Foulweather (29°±18°, N=4) show similar results. East of the Portland Hills fault zone along the Columbia River Gorge, however, clockwise rotations are much less averaging 12°±3° (N=15). North of Portland, the CRBG rotational values drop abruptly from ~29° to 6°±17° (N=3) across an unnamed fault near Woodland, WA, identified using aeromagnetic data; to the south, the values drop from ~29° to 18°±3° (N=6) across the Mt. Angel-Gales Creek fault zone east of Salem, OR. The eastern <span class="hlt">boundary</span> of the Oregon Coast Range block is thus defined by three offset NW-trending fault segments, with the offsets corresponding to the Portland and Willamette pull-apart basins. North of the Coast Range block's northern <span class="hlt">boundary</span>, which is roughly coincident with the Columbia River, CRBG rotations also are about half that (15°±3°, N=15) found within the block. Northward movement and clockwise rotation of the Oregon Coast Range block have previously been modeled as decreasing continuously eastward to the Columbia Plateau. Our new paleomagnetic data indicate an abrupt step down of rotational values by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT.......220C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT.......220C"><span>Experimental and Analytical <span class="hlt">Seismic</span> Studies of a Four-Span Bridge <span class="hlt">System</span> with Innovative Materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cruz Noguez, Carlos Alonso</p> <p></p> <p>As part of a multi-university project utilizing the NSF Network for Earthquake Engineering Simulation (NEES), a quarter-scale model of a four-span bridge incorporating plastic hinges with different advanced materials was tested to failure on the three shake table <span class="hlt">system</span> at the University of Nevada, Reno (UNR). The bridge was the second test model in a series of three 4-span bridges, with the first model being a conventional reinforced-concrete (RC) structure. The purpose of incorporating advanced materials was to improve the <span class="hlt">seismic</span> performance of the bridge with respect to two damage indicators: (1) column damage and (2) permanent deformations. The goals of the study presented in this document were to (1) evaluate the <span class="hlt">seismic</span> performance of a 4-span bridge <span class="hlt">system</span> incorporating SMA/ECC and built-in rubber pad plastic hinges as well as post-tensioned piers, (2) quantify the relative merit of these advanced materials and details compared to each other and to conventional reinforced concrete plastic hinges, (3) determine the influence of abutment-superstructure interaction on the response, (4) examine the ability of available elaborate analytical modeling techniques to model the performance of advanced materials and details, and (5) conduct an extensive parametric study of different variations of the bridge model to study several important issues in bridge earthquake engineering. The bridge model included six columns, each pair of which utilized a different advanced detail at bottom plastic hinges: shape memory alloys (SMA), special engineered cementitious composites (ECC), elastomeric pads embedded into columns, and post-tensioning tendons. The design of the columns, location of the bents, and selection of the loading protocol were based on pre-test analyses conducted using computer program OpenSees. The bridge model was subjected to two-horizontal components of simulated earthquake records of the 1994 Northridge earthquake. Over 340 channels of data were collected</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNS41A3829J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNS41A3829J"><span>Characterization of Carbonate Hydrostratigraphy Using Ambient <span class="hlt">Seismic</span> Noise: A Pilot Study in the Floridan Aquifer <span class="hlt">System</span>, Ocala, FL, USA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>James, S.; Screaton, E.; Russo, R. M.; Panning, M. P.; Bremner, P. M.; Stanciu, A. C.; Torpey, M. E.; Hongsresawat, S.; Farrell, M. E.</p> <p>2014-12-01</p> <p>Defining zones of high and low hydraulic conductivity within aquifers is vital to hydrogeologic research and groundwater management. Carbonate aquifers are particularly difficult to characterize due to dissolution and dolomitization. We investigated a new imaging technique for aquifer characterization that uses cross-correlation of ambient <span class="hlt">seismic</span> noise to determine <span class="hlt">seismic</span> velocity structure. Differences in densities between confining units and high permeability flow zones can produce distinct <span class="hlt">seismic</span> velocities in the correlated signals. We deployed an array of 9 short period geophones from 11/2013 to 3/2014 in Indian Lake State Forest, Florida, to determine if the high frequency diffusive <span class="hlt">seismic</span> wavefield can be used for imaging hydrostratigraphy. Here, a thin surficial layer of siliciclastic deposits overlie a ~ 0.6 km sequence of Cenozoic limestone and dolomite units that comprise the Floridan Aquifer <span class="hlt">System</span> (FAS). A low permeability dolomite unit vertically divides the FAS throughout most of Florida. Deep boreholes surrounding the site constrain hydrostratigraphy, however the horizontal continuity of the middle dolomite unit as well as its effectiveness as a confining unit in the study area are not well known. The stations were spaced at distances ranging from 0.18 to 2.6 km, and yielded 72 cross-correlation Green's functions for Rayleigh wave propagation at frequencies between 0.2 and 40 Hz, with dominant peaks around 0.8 Hz, 3 Hz and 13 Hz. Local vehicle traffic did interfere to a degree with the correlation of the diffuse waves, but was minimized by using only nighttime data. At the lowest frequencies (greatest depths) investigated, velocities increase with depth; however, correlations become less coherent at higher frequencies, perhaps due to shallow complex scattering. Comparison of cross-correlations for all station pairs also indicates spatial variations in velocity. Thus, the method shows promise for characterization of the heterogeneity of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.S41B2441C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.S41B2441C"><span>Local Technical Resources for Development of <span class="hlt">Seismic</span> Monitoring in Caucasus and Central Asia - GMSys2009 Data Acquisition <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chkhaidze, D.; Basilaia, G.; Elashvili, M.; Shishlov, D.; Bidzinashvili, G.</p> <p>2012-12-01</p> <p>Caucasus and Central Asia represents regions of high <span class="hlt">seismic</span> activity, composing a significant part of Alpine-Himalayan continental collision zone. Natural catastrophic events cause significant damage to the infrastructure worldwide, among these approximately ninety percent of the annual loss is due to earthquakes. Monitoring of <span class="hlt">Seismic</span> Activity in these regions and adequate assessment of <span class="hlt">Seismic</span> Hazards represents indispensible condition for safe and stable development. Existence of critical engineering constructions in the Caucasus and Central Asia such as oil and gas pipelines, high dams and nuclear power plants dramatically raises risks associated with natural hazards and eliminates necessity of proper monitoring <span class="hlt">systems</span>. Our initial efforts were focused on areas that we are most familiar; the geophysical community in the greater Caucuses and Central Asia experiencing many of the same problems with the monitoring equipment. As a result, during the past years GMSys2009 was develop at the Institute of Earth Sciences of Ilia State University. Equipment represents a cost-effective, multifunctional Geophysical Data Acquisition <span class="hlt">System</span> (DAS) to monitor <span class="hlt">seismic</span> waves propagating in the earth and related geophysical parameters. Equipment best fits local requirements concerning power management, environmental protection and functionality, the same time competing commercial units available on the market. During past several years more than 30 units were assembled and what is most important installed in Georgia, Armenia, Azerbaijan and Tajikistan. GMSys2009 utilizes standard MiniSEED data format and data transmission protocols, making it possible online waveform data sharing between the neighboring Countries in the region and international community. All the mentioned installations were technically supported by the group of engineers from the Institute of Earth Sciences, on site trainings for local personnel in Armenia, Azerbaijan and Tajikistan was provided creating a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070006754','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070006754"><span>Blended Wing Body (BWB) <span class="hlt">Boundary</span> Layer Ingestion (BLI) Inlet Configuration and <span class="hlt">System</span> Studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kawai, Ronald T.; Friedman, Douglas M.; Serrano, Leonel</p> <p>2006-01-01</p> <p>A study was conducted to determine the potential reduction in fuel burned for BLI (<span class="hlt">boundary</span> layer ingestion) inlets on a BWB (blended wing body) airplane employing AFC (active flow control). The BWB is a revolutionary type airplane configuration with engines on the aft upper surface where thick <span class="hlt">boundary</span> layer offers the greatest opportunity for ram drag reduction. AFC is an emerging technology for <span class="hlt">boundary</span> layer control. Several BLI inlet configurations were analyzed in the NASA-developed RANS Overflow CFD code. The study determined that, while large reductions in ram drag result from BLI, lower inlet pressure recovery produces engine performance penalties that largely offset this ram drag reduction. AFC could, however, enable a short BLI inlet that allows surface mounting of the engine which, when coupled with a short diffuser, would significantly reduce drag and weight for a potential 10% reduction in fuel burned. Continuing studies are therefore recommended to achieve this reduction in fuel burned considering the use of more modest amounts of BLI coupled with both AFC and PFC (Passive Flow Control) to produce a fail-operational <span class="hlt">system</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_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/2003JCli...16.2454R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JCli...16.2454R"><span>Simulation and Sensitivity in a Nested Modeling <span class="hlt">System</span> for South America. Part II: GCM <span class="hlt">Boundary</span> Forcing.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rojas, Maisa; Seth, Anji</p> <p>2003-08-01</p> <p></a> of this study, the RegCM's ability to simulate circulation and rainfall observed in the two extreme seasons was demonstrated when driven at the lateral <span class="hlt">boundaries</span> by reanalyzed forcing. Seasonal integrations with the RegCM driven by GCM ensemble-derived lateral <span class="hlt">boundary</span> forcing demonstrate that the nested model responds well to the SST forcing, by capturing the major features of the circulation and rainfall differences between the two years. The GCM-driven model also improves upon the monthly evolution of rainfall compared with that from the GCM. However, the nested model rainfall simulations for the two seasons are degraded compared with those from the reanalyses-driven RegCM integrations. The poor location of the Atlantic intertropical convergence zone (ITCZ) in the GCM leads to excess rainfall in Nordeste in the nested model.An expanded domain was tested, wherein the RegCM was permitted more internal freedom to respond to SST and regional orographic forcing. Results show that the RegCM is able to improve the location of the ITCZ, and the seasonal evolution of rainfall in Nordeste, the Amazon region, and the southeastern region of Brazil. However, it remains that the limiting factor in the skill of the nested modeling <span class="hlt">system</span> is the quality of the lateral <span class="hlt">boundary</span> forcing provided by the global model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130010733','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130010733"><span>An Examination of the Effect of <span class="hlt">Boundary</span> Layer Ingestion on Turboelectric Distributed Propulsion <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Felder, James L.; Kim, Huyn Dae; Brown, Gerald V.; Chu, Julio</p> <p>2011-01-01</p> <p>A Turboelectric Distributed Propulsion (TeDP) <span class="hlt">system</span> differs from other propulsion <span class="hlt">systems</span> by the use of electrical power to transmit power from the turbine to the fan. Electrical power can be efficiently transmitted over longer distances and with complex topologies. Also the use of power inverters allows the generator and motors speeds to be independent of one another. This decoupling allows the aircraft designer to place the core engines and the fans in locations most advantageous for each. The result can be very different installation environments for the different devices. Thus the installation effects on this <span class="hlt">system</span> can be quite different than conventional turbofans where the fan and core both see the same installed environments. This paper examines a propulsion <span class="hlt">system</span> consisting of two superconducting generators, each driven by a turboshaft engine located so that their inlets ingest freestream air, superconducting electrical transmission lines, and an array of superconducting motor driven fan positioned across the upper/rear fuselage area of a hybrid wing body aircraft in a continuous nacelle that ingests all of the upper fuselage <span class="hlt">boundary</span> layer. The effect of ingesting the <span class="hlt">boundary</span> layer on the design of the <span class="hlt">system</span> with a range of design pressure ratios is examined. Also the impact of ingesting the <span class="hlt">boundary</span> layer on off-design performance is examined. The results show that when examining different design fan pressure ratios it is important to recalculate of the <span class="hlt">boundary</span> layer mass-average Pt and MN up the height for each inlet height during convergence of the design point for each fan design pressure ratio examined. Correct estimation of off-design performance is dependent on the height of the column of air measured from the aircraft surface immediately prior to any external diffusion that will flow through the fan propulsors. The mass-averaged Pt and MN calculated for this column of air determine the Pt and MN seen by the propulsor inlet. Since the height</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSMNS21C..04E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSMNS21C..04E"><span>Coherent Waves in <span class="hlt">Seismic</span> Researches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Emanov, A.; Seleznev, V. S.</p> <p>2013-05-01</p> <p>Development of digital processing algorithms of <span class="hlt">seismic</span> wave fields for the purpose of useful event picking to study environment and other objects is the basis for the establishment of new <span class="hlt">seismic</span> techniques. In the submitted paper a fundamental property of <span class="hlt">seismic</span> wave field coherence is used. The authors extended conception of coherence types of observed wave fields and devised a technique of coherent component selection from observed wave field. Time coherence and space coherence are widely known. In this paper conception "parameter coherence" has been added. The parameter by which wave field is coherent can be the most manifold. The reason is that the wave field is a multivariate process described by a set of parameters. Coherence in the first place means independence of linear connection in wave field of parameter. In <span class="hlt">seismic</span> wave fields, recorded in confined space, in building-blocks and stratified mediums time coherent standing waves are formed. In prospecting seismology at observation <span class="hlt">systems</span> with multiple overlapping head waves are coherent by parallel correlation course or, in other words, by one measurement on generalized plane of observation <span class="hlt">system</span>. For detail prospecting seismology at observation <span class="hlt">systems</span> with multiple overlapping on basis of coherence property by one measurement of area algorithms have been developed, permitting <span class="hlt">seismic</span> records to be converted to head wave time sections which have neither reflected nor other types of waves. Conversion in time section is executed on any specified observation base. Energy storage of head waves relative to noise on basis of multiplicity of observation <span class="hlt">system</span> is realized within area of head wave recording. Conversion on base below the area of wave tracking is performed with lack of signal/noise ratio relative to maximum of this ratio, fit to observation <span class="hlt">system</span>. Construction of head wave time section and dynamic plots a basis of automatic processing have been developed, similar to CDP procedure in method of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2014/1229/pdf/ofr2014-1229.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2014/1229/pdf/ofr2014-1229.pdf"><span>Bull trout in the <span class="hlt">Boundary</span> <span class="hlt">System</span>: managing connectivity and the feasibility of a reintroduction in the lower Pend Oreille River, northeastern Washington</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dunham, Jason B.; Taylor, Eric B.; Allendorf, Fred W.</p> <p>2014-01-01</p> <p>Assess the role of passage over <span class="hlt">Boundary</span> Dam, in the context of other factors in the <span class="hlt">system</span> that may influence the feasibility of establishing a self-sustaining bull trout population in the <span class="hlt">Boundary</span> <span class="hlt">system</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 <span class="hlt">boundaries</span> 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 release 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 <span class="hlt">boundaries</span>, and investigate controls on fault behavior that might produce the variations in the coupling coefficient observed in natural <span class="hlt">systems</span>. 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 <span class="hlt">systems</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S11F4407T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S11F4407T"><span>Development of an event search and download <span class="hlt">system</span> for analyzing waveform data observed at seafloor <span class="hlt">seismic</span> network, DONET</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takaesu, M.; Horikawa, H.; Sueki, K.; Kamiya, S.; Nakamura, T.; Nakano, M.; Takahashi, N.; Sonoda, A.; Tsuboi, S.</p> <p>2014-12-01</p> <p>Mega-thrust earthquakes are anticipated to occur in the Nankai Trough in southwest Japan. In the source areas, we installed seafloor <span class="hlt">seismic</span> network, DONET (Dense Ocean-floor Network <span class="hlt">System</span> for Earthquake and Tsunamis), in 2010 in order to monitor <span class="hlt">seismicity</span>, crustal deformations, and tsunamis. DONET <span class="hlt">system</span> consists of totally 20 stations, which is composed of six kinds of sensors; strong-motion and broadband seismometers, quartz and differential pressure gauges, hydrophone, and thermometer. The stations are densely distributed with an average spatial interval of 15-20 km and cover near coastal areas to the trench axis. Observed data are transferred to a land station through a fiber-optical cable and then to JAMSTEC (Japan Agency for Marine-Earth Science and Technology) data management center through a private network in real time. The data are based on WIN32 format in the private network and finally archived in SEED format in the management center to combine waveform data with related metadata. We are developing a web-based application <span class="hlt">system</span> to easily download <span class="hlt">seismic</span> waveform data of DONET. In this <span class="hlt">system</span>, users can select 20 Hz broadband (BH type) and 200 Hz strong-motion (EH type) data and download them in SEED. Users can also search events from the options of time periods, magnitude, source area and depth in a GUI platform. Event data are produced referring to event catalogues from USGS and JMA (Japan Meteorological Agency). The thresholds of magnitudes for the production are M6 for far-field and M4 for local events using the USGS and JMA lists, respectively. Available data lengths depend on magnitudes and epicentral distances. In this presentation, we briefly introduce DONET stations and then show our developed application <span class="hlt">system</span>. We open DONET data through the <span class="hlt">system</span> and want them to be widely recognized so that many users analyze. We also discuss next plans for further developments of the <span class="hlt">system</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030036972','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030036972"><span>Atmospheric <span class="hlt">Boundary</span> Layer Sensors for Application in a Wake Vortex Advisory <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zak, J. Allen; Rutishauser, David (Technical Monitor)</p> <p>2003-01-01</p> <p>Remote sensing of the atmospheric <span class="hlt">boundary</span> layer has advanced in recent years with the development of commercial off-the-shelf (COTS) radar, sodar, and lidar wind profiling technology. Radio acoustic sounding <span class="hlt">systems</span> for vertical temperature profiles of high temporal scales (when compared to routine balloon soundings- (radiosondes) have also become increasingly available as COTS capabilities. Aircraft observations during landing and departures are another source of available <span class="hlt">boundary</span> layer data. This report provides an updated assessment of available sensors, their performance specifications and rough order of magnitude costs for a potential future aircraft Wake Vortex Avoidance <span class="hlt">System</span> (WakeVAS). Future capabilities are also discussed. Vertical profiles of wind, temperature, and turbulence are anticipated to be needed at airports in any dynamic wake avoidance <span class="hlt">system</span>. Temporal and spatial resolution are dependent on the selection of approach and departure corridors to be protected. Recommendations are made for potential configurations of near-term sensor technologies and for testing some of the sensor <span class="hlt">systems</span> in order to validate performance in field environments with adequate groundtruth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AIPC.1020.1272M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AIPC.1020.1272M"><span>State of the Art of the Development and Application of Anti-<span class="hlt">Seismic</span> <span class="hlt">Systems</span> in Europe and Other Countries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martelli, Alessandro; Forni, Massimo</p> <p>2008-07-01</p> <p>There are already approximately 5,000 structures in the world, located in over 30 countries, that have been protected by <span class="hlt">seismic</span> isolation (SI), energy dissipation (ED) and other modern <span class="hlt">seismic</span> vibration passive control (SVPC) <span class="hlt">systems</span>. The number of such applications is increasing everywhere more and more. It has been confirmed that, in each country, the extension of the use of the SVPC <span class="hlt">systems</span> is conclusively influenced by earthquake experience, the availability of specific design rules and the features of those adopted. With regard to application, Japan has consolidated its worldwide leadership, with over 3,000 <span class="hlt">seismically</span> isolated buildings, many others protected by ED <span class="hlt">systems</span> and several isolated bridges & viaducts. Second is now the P. R. China, with 610 isolated buildings and 45 with dampers, in addition to numerous isolated bridges & viaducts. The Russian Federation is third for the number of isolated buildings, which are approximately 600. In the USA, due to the very penalizing design code in force for SI of buildings, there are at present only a few new applications of this kind (an overall number of approximately 200 was reported), although the US isolated buildings are mostly quite important, half being retrofits; on the contrary, the use of SI for bridges & viaducts and that of ED for buildings are more popular in the USA. At present (April 2008), Italy (which remains the worldwide leader as regards the application of the SVPC <span class="hlt">systems</span> to cultural heritage and keeps a key role also as to the number and importance of bridges & viaducts protected by such <span class="hlt">systems</span>) is at the fifth place, at least for the number of isolated buildings already open to activity: they are 51, besides others protected by other SVPC <span class="hlt">systems</span>. There, thanks to the new national <span class="hlt">seismic</span> code (enforced in May 2003), there has been a significant recent increase of building application and design of the SVPC <span class="hlt">systems</span>. With regard to the use of such <span class="hlt">systems</span> in other countries, Italy is now</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28804707','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28804707"><span>Framework to Define Structure and <span class="hlt">Boundaries</span> of Complex Health Intervention <span class="hlt">Systems</span>: The ALERT Project.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boriani, Elena; Esposito, Roberto; Frazzoli, Chiara; Fantke, Peter; Hald, Tine; Rüegg, Simon R</p> <p>2017-01-01</p> <p>Health intervention <span class="hlt">systems</span> are complex and subject to multiple variables in different phases of implementation. This constitutes a concrete challenge for the application of translational science in real life. Complex <span class="hlt">systems</span> as health-oriented interventions call for interdisciplinary approaches with carefully defined <span class="hlt">system</span> <span class="hlt">boundaries</span>. Exploring individual components of such <span class="hlt">systems</span> from different viewpoints gives a wide overview and helps to understand the elements and the relationships that drive actions and consequences within the <span class="hlt">system</span>. In this study, we present an application and assessment of a framework with focus on <span class="hlt">systems</span> and <span class="hlt">system</span> <span class="hlt">boundaries</span> of interdisciplinary projects. As an example on how to apply our framework, we analyzed ALERT [an integrated sensors and biosensors' <span class="hlt">system</span> (BEST) aimed at monitoring the quality, health, and traceability of the chain of the bovine milk], a multidisciplinary and interdisciplinary project based on the application of measurable biomarkers at strategic points of the milk chain for improved food security (including safety), human, and ecosystem health (1). In fact, the European food safety framework calls for science-based support to the primary producers' mandate for legal, scientific, and ethical responsibility in food supply. Because of its multidisciplinary and interdisciplinary approach involving human, animal, and ecosystem health, ALERT can be considered as a One Health project. Within the ALERT context, we identified the need to take into account the main actors, interactions, and relationships of stakeholders to depict a simplified skeleton of the <span class="hlt">system</span>. The framework can provide elements to highlight how and where to improve the project development when project evaluations are required.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5532392','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5532392"><span>Framework to Define Structure and <span class="hlt">Boundaries</span> of Complex Health Intervention <span class="hlt">Systems</span>: The ALERT Project</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Boriani, Elena; Esposito, Roberto; Frazzoli, Chiara; Fantke, Peter; Hald, Tine; Rüegg, Simon R.</p> <p>2017-01-01</p> <p>Health intervention <span class="hlt">systems</span> are complex and subject to multiple variables in different phases of implementation. This constitutes a concrete challenge for the application of translational science in real life. Complex <span class="hlt">systems</span> as health-oriented interventions call for interdisciplinary approaches with carefully defined <span class="hlt">system</span> <span class="hlt">boundaries</span>. Exploring individual components of such <span class="hlt">systems</span> from different viewpoints gives a wide overview and helps to understand the elements and the relationships that drive actions and consequences within the <span class="hlt">system</span>. In this study, we present an application and assessment of a framework with focus on <span class="hlt">systems</span> and <span class="hlt">system</span> <span class="hlt">boundaries</span> of interdisciplinary projects. As an example on how to apply our framework, we analyzed ALERT [an integrated sensors and biosensors’ <span class="hlt">system</span> (BEST) aimed at monitoring the quality, health, and traceability of the chain of the bovine milk], a multidisciplinary and interdisciplinary project based on the application of measurable biomarkers at strategic points of the milk chain for improved food security (including safety), human, and ecosystem health (1). In fact, the European food safety framework calls for science-based support to the primary producers’ mandate for legal, scientific, and ethical responsibility in food supply. Because of its multidisciplinary and interdisciplinary approach involving human, animal, and ecosystem health, ALERT can be considered as a One Health project. Within the ALERT context, we identified the need to take into account the main actors, interactions, and relationships of stakeholders to depict a simplified skeleton of the <span class="hlt">system</span>. The framework can provide elements to highlight how and where to improve the project development when project evaluations are required. PMID:28804707</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.G43A0917W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.G43A0917W"><span>Dynamics of Kilauea's Magmatic <span class="hlt">System</span> Imaged Using a Joint Analysis of Geodetic and <span class="hlt">Seismic</span> Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wauthier, C.; Roman, D. C.; Poland, M. P.; Fukushima, Y.; Hooper, A. J.</p> <p>2012-12-01</p> <p>Nowadays, Interferometric Synthetic Aperture Radar (InSAR) is commonly used to study a wide range of active volcanic areas. InSAR provides high-spatial-resolution measurements of surface deformation with centimeter-scale accuracy. At Kilauea Volcano, Hawai'i, InSAR shows complex processes that are not well constrained by GPS data (which have relatively poor spatial resolution). However, GPS data have higher temporal resolution than InSAR data. Both datasets are thus complementary. To overcome some of the limitations of conventional InSAR, which are mainly induced by temporal decorrelation, topographic, orbital and atmospheric delays, a Multi-Temporal InSAR (MT-InSAR) approach can be used. MT-InSAR techniques involve the processing of multiple SAR acquisitions over the same area. Two classes of MT-InSAR algorithms are defined: the persistent scatterers (PS) and small baseline (SBAS) methods. Each method is designed for a specific type of scattering mechanism. A PS pixel is a pixel in which a single scatterer dominates, while the contributions from other scatterers are negligible. A SBAS pixel is a pixel that includes distributed scatterers, which have a phase with little decorrelation over short time periods. Here, we apply the "StaMPS" ("Stanford Method for Permanent Scatterers") technique, which incorporates both a PS and SBAS approach, on ENVISAT and ALOS datasets acquired from 2003 to 2010 at Kilauea. In particular, we focus our InSAR analysis on the time period before the June 2007 "Father's Day" dike intrusion and eruption, and also incorporate <span class="hlt">seismic</span> and GPS data in our models. Our goal is to identify any precursors to the Father's Day event within Kilauea's summit magma <span class="hlt">system</span>, east rift zone, and/or southwest rift zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5693243','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5693243"><span>Building the School Attendance <span class="hlt">Boundary</span> Information <span class="hlt">System</span> (SABINS): Collecting, Processing, and Modeling K to 12 Educational Geography</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Saporito, Salvatore; Van Riper, David; Wakchaure, Ashwini</p> <p>2017-01-01</p> <p>The School Attendance <span class="hlt">Boundary</span> Information <span class="hlt">System</span> is a social science data infrastructure project that assembles, processes, and distributes spatial data delineating K through 12th grade school attendance <span class="hlt">boundaries</span> for thousands of school districts in U.S. Although geography is a fundamental organizing feature of K to 12 education, until now school attendance <span class="hlt">boundary</span> data have not been made readily available on a massive basis and in an easy-to-use format. The School Attendance <span class="hlt">Boundary</span> Information <span class="hlt">System</span> removes these barriers by linking spatial data delineating school attendance <span class="hlt">boundaries</span> with tabular data describing the demographic characteristics of populations living within those <span class="hlt">boundaries</span>. This paper explains why a comprehensive GIS database of K through 12 school attendance <span class="hlt">boundaries</span> is valuable, how original spatial information delineating school attendance <span class="hlt">boundaries</span> is collected from local agencies, and techniques for modeling and storing the data so they provide maximum flexibility to the user community. An important goal of this paper is to share the techniques used to assemble the SABINS database so that local and state agencies apply a standard set of procedures and models as they gather data for their regions. PMID:29151773</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29151773','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29151773"><span>Building the School Attendance <span class="hlt">Boundary</span> Information <span class="hlt">System</span> (SABINS): Collecting, Processing, and Modeling K to 12 Educational Geography.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saporito, Salvatore; Van Riper, David; Wakchaure, Ashwini</p> <p>2013-01-01</p> <p>The School Attendance <span class="hlt">Boundary</span> Information <span class="hlt">System</span> is a social science data infrastructure project that assembles, processes, and distributes spatial data delineating K through 12 th grade school attendance <span class="hlt">boundaries</span> for thousands of school districts in U.S. Although geography is a fundamental organizing feature of K to 12 education, until now school attendance <span class="hlt">boundary</span> data have not been made readily available on a massive basis and in an easy-to-use format. The School Attendance <span class="hlt">Boundary</span> Information <span class="hlt">System</span> removes these barriers by linking spatial data delineating school attendance <span class="hlt">boundaries</span> with tabular data describing the demographic characteristics of populations living within those <span class="hlt">boundaries</span>. This paper explains why a comprehensive GIS database of K through 12 school attendance <span class="hlt">boundaries</span> is valuable, how original spatial information delineating school attendance <span class="hlt">boundaries</span> is collected from local agencies, and techniques for modeling and storing the data so they provide maximum flexibility to the user community. An important goal of this paper is to share the techniques used to assemble the SABINS database so that local and state agencies apply a standard set of procedures and models as they gather data for their regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8351D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8351D"><span>Analysis of volcano-related <span class="hlt">seismicity</span> to constrain the magmatic plumbing <span class="hlt">system</span> beneath Fogo, Cape Verde, by (multi-)array techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dietrich, Carola; Wölbern, Ingo; Faria, Bruno; Rümpker, Georg</p> <p>2017-04-01</p> <p>Fogo is the only island of the Cape Verde archipelago with regular occurring volcanic eruptions since its discovery in the 15th century. The volcanism of the archipelago originates from a mantle plume beneath an almost stationary tectonic plate. With an eruption interval of approximately 20 years, Fogo belongs to the most active oceanic volcanoes. The latest eruption started in November 2014 and ceased in February 2015. This study aims to characterize and investigate the <span class="hlt">seismic</span> activity and the magmatic plumbing <span class="hlt">system</span> of Fogo, which is believed to be related to a magmatic source close to the neighboring island of Brava. According to previous studies, using conventional <span class="hlt">seismic</span> network configurations, most of the <span class="hlt">seismic</span> activity occurs offshore. Therefore, seismological array techniques represent powerful tools in investigating earthquakes and other volcano-related events located outside of the networks. Another advantage in the use of <span class="hlt">seismic</span> arrays is their possibility to detect events of relatively small magnitude and to locate <span class="hlt">seismic</span> signals without a clear onset of phases, such as volcanic tremors. Since October 2015 we have been operating a test array on Fogo as part of a pilot study. This array consists of 10 <span class="hlt">seismic</span> stations, distributed in a circular shape with an aperture of 700 m. The stations are equipped with Omnirecs CUBE dataloggers, and either 4.5 Hz geophones (7 stations) or Trillium-Compact broad-band seismometers (3 stations). In January 2016 we installed three additional broad-band stations distributed across the island of Fogo to improve the capabilities for event localization. The data of the pilot study is dominated by <span class="hlt">seismic</span> activity around Brava, but also exhibit tremors and hybrid events of unknown origin within the caldera of Fogo volcano. The preliminary analysis of these events includes the characterization and localization of the different event types using <span class="hlt">seismic</span> array processing in combination with conventional localization</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 <span class="hlt">System</span> (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 <span class="hlt">system</span> 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 <span class="hlt">system</span> 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 released by the ATF-<span class="hlt">seismicity</span> accounts</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25162728','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25162728"><span>Relationship between the frequency magnitude distribution and the visibility graph in the synthetic <span class="hlt">seismicity</span> generated by a simple stick-slip <span class="hlt">system</span> with asperities.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Telesca, Luciano; Lovallo, Michele; Ramirez-Rojas, Alejandro; Flores-Marquez, Leticia</p> <p>2014-01-01</p> <p>By using the method of the visibility graph (VG) the synthetic <span class="hlt">seismicity</span> generated by a simple stick-slip <span class="hlt">system</span> with asperities is analysed. The stick-slip <span class="hlt">system</span> mimics the interaction between tectonic plates, whose asperities are given by sandpapers of different granularity degrees. The VG properties of the <span class="hlt">seismic</span> sequences have been put in relationship with the typical seismological parameter, the b-value of the Gutenberg-Richter law. Between the b-value of the synthetic <span class="hlt">seismicity</span> and the slope of the least square line fitting the k-M plot (relationship between the magnitude M of each synthetic event and its connectivity degree k) a close linear relationship is found, also verified by real <span class="hlt">seismicity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950014926','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950014926"><span>Experiments on the flow field physics of confluent <span class="hlt">boundary</span> layers for high-lift <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nelson, Robert C.; Thomas, F. O.; Chu, H. C.</p> <p>1994-01-01</p> <p>The use of sub-scale wind tunnel test data to predict the behavior of commercial transport high lift <span class="hlt">systems</span> at in-flight Reynolds number is limited by the so-called 'inverse Reynolds number effect'. This involves an actual deterioration in the performance of a high lift device with increasing Reynolds number. A lack of understanding of the relevant flow field physics associated with numerous complicated viscous flow interactions that characterize flow over high-lift devices prohibits computational fluid dynamics from addressing Reynolds number effects. Clearly there is a need for research that has as its objective the clarification of the fundamental flow field physics associated with viscous effects in high lift <span class="hlt">systems</span>. In this investigation, a detailed experimental investigation is being performed to study the interaction between the slat wake and the <span class="hlt">boundary</span> layer on the primary airfoil which is known as a confluent <span class="hlt">boundary</span> layer. This little-studied aspect of the multi-element airfoil problem deserves special attention due to its importance in the lift augmentation process. The goal of this research is is to provide an improved understanding of the flow physics associated with high lift generation. This process report will discuss the status of the research being conducted at the Hessert Center for Aerospace Research at the University of Notre Dame. The research is sponsored by NASA Ames Research Center under NASA grant NAG2-905. The report will include a discussion of the models that have been built or that are under construction, a description of the planned experiments, a description of a flow visualization apparatus that has been developed for generating colored smoke for confluent <span class="hlt">boundary</span> layer studies and some preliminary measurements made using our new 3-component fiber optic LDV <span class="hlt">system</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.923a2026C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.923a2026C"><span>An optimal control method for fluid structure interaction <span class="hlt">systems</span> via adjoint <span class="hlt">boundary</span> pressure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chirco, L.; Da Vià, R.; Manservisi, S.</p> <p>2017-11-01</p> <p>In recent year, in spite of the computational complexity, Fluid-structure interaction (FSI) problems have been widely studied due to their applicability in science and engineering. Fluid-structure interaction <span class="hlt">systems</span> consist of one or more solid structures that deform by interacting with a surrounding fluid flow. FSI simulations evaluate the tensional state of the mechanical component and take into account the effects of the solid deformations on the motion of the interior fluids. The inverse FSI problem can be described as the achievement of a certain objective by changing some design parameters such as forces, <span class="hlt">boundary</span> conditions and geometrical domain shapes. In this paper we would like to study the inverse FSI problem by using an optimal control approach. In particular we propose a pressure <span class="hlt">boundary</span> optimal control method based on Lagrangian multipliers and adjoint variables. The objective is the minimization of a solid domain displacement matching functional obtained by finding the optimal pressure on the inlet <span class="hlt">boundary</span>. The optimality <span class="hlt">system</span> is derived from the first order necessary conditions by taking the Fréchet derivatives of the Lagrangian with respect to all the variables involved. The optimal solution is then obtained through a standard steepest descent algorithm applied to the optimality <span class="hlt">system</span>. The approach presented in this work is general and could be used to assess other objective functionals and controls. In order to support the proposed approach we perform a few numerical tests where the fluid pressure on the domain inlet controls the displacement that occurs in a well defined region of the solid domain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MS%26E..290a2057S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MS%26E..290a2057S"><span>Determining <span class="hlt">system</span> <span class="hlt">boundaries</span> on commercial broiler chicken production <span class="hlt">system</span> using ISO 14040/14044 guideline: A case Study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sidek, ‘A. A.; Suffian, S. A.; Al-Hazza, M. H. F.; Yusof, H. M.</p> <p>2018-01-01</p> <p>The demand of poultry product in Malaysia market shows an escalation throughout the year and expected to increase in the future. The expansion of poultry production has led to environmental concern in relation to their operational impact to environmentAt present, assessment of waste management of poultry production in Malaysia is lacking. A case study research was conducted in a commercial broiler farm to identify and assess the <span class="hlt">system</span> <span class="hlt">boundaries</span> in the lifecycle supply chain of broiler chicken production using ISO 14040/44 guidelines. ISO 14040/44 standard includes Life Cycle Assessment (LCA) framework guidelines to evaluate environmental influence associated with a product/process throughout its life span. All attributes associated with broiler operation is defined and the <span class="hlt">system</span> <span class="hlt">boundaries</span> is determined to identify possible inputs and outputs in the case study. This paper discuss the initial stage in the LCA process, which set the context of the research and prepare for the stage of Life Cycle Inventory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70047248','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70047248"><span><span class="hlt">Seismic</span> observations of Redoubt Volcano, Alaska - 1989-2010 and a conceptual model of the Redoubt magmatic <span class="hlt">system</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>Power, John A.; Stihler, Scott D.; Chouet, Bernard A.; Haney, Matthew M.; Ketner, D.M.</p> <p>2013-01-01</p> <p><span class="hlt">Seismic</span> activity at Redoubt Volcano, Alaska, has been closely monitored since 1989 by a network of five to ten seismometers within 22 km of the volcano's summit. Major eruptions occurred in 1989-1990 and 2009 and were characterized by large volcanic explosions, episodes of lava dome growth and failure, pyroclastic flows, and lahars. <span class="hlt">Seismic</span> features of the 1989-1990 eruption were 1) weak precursory tremor and a short, 23-hour-long, intense swarm of repetitive shallow long-period (LP) events centered 1.4 km below the crater floor, 2) shallow volcano-tectonic (VT) and hybrid earthquakes that separated early episodes of dome growth, 3) 13 additional swarms of LP events at shallow depths precursory to many of the 25 explosions that occurred over the more than 128 day duration of eruptive activity, and 4) a persistent cluster of VT earthquakes at 6 to 9 km depth. In contrast the 2009 eruption was preceded by a pronounced increase in deep-LP (DLP) events at lower crustal depths (25 to 38 km) that began in mid-December 2008, two months of discontinuous shallow volcanic tremor that started on January 23, 2009, a strong phreatic explosion on March 15, and a 58-hour-long swarm of repetitive shallow LP events. The 2009 eruption consisted of at least 23 major explosions between March 23 and April 5, again accompanied by shallow VT earthquakes, several episodes of shallow repetitive LP events and dome growth continuing until mid July. Increased VT earthquakes at 4 to 9 km depth began slowly in early April, possibly defining a mid-crustal magma source zone. Magmatic processes associated with the 2009 eruption <span class="hlt">seismically</span> activated the same portions of the Redoubt magmatic <span class="hlt">system</span> as the 1989-1990 eruption, although the time scales and intensity vary considerably among the two eruptions. The occurrence of precursory DLP events suggests that the 2009 eruption may have involved the rise of magma from lower crustal depths. Based on the evolution of <span class="hlt">seismicity</span> during the 1989-1990 and</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('http://adsabs.harvard.edu/abs/2017AGUFM.G43B0948N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.G43B0948N"><span>An integrated geodetic and <span class="hlt">seismic</span> study of the Cusco Fault <span class="hlt">system</span> in the Cusco Region-Southern Peru</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Norabuena, E. O.; Tavera, H. J.</p> <p>2017-12-01</p> <p>The Cusco Fault <span class="hlt">system</span> is composed by six main faults (Zurite, Tamboray, Qoricocha, Tambomachay, Pachatusan, and Urcos) extending in a NW-SE direction over the Cusco Region in southeastern Peru. From these, the Tambomachay is a normal fault of 20 km length, strikes N120°E and bounds a basin filled with quaternary lacustrine and fluvial deposits. Given its 5 km distance to Cusco, an historical and Inca's archeological landmark, it represents a great <span class="hlt">seismic</span> hazard for its more than 350,000 inhabitants. The Tambomachay fault as well as the other secondary faults have been a source of significant <span class="hlt">seismic</span> activity since historical times being the more damaging ones the Cusco earthquakes of 1650, 1950 and more recently April 1986 (M 5.8). Previous geological studies indicate that at the beginning of the Quaternary the fault showed a transcurrent mechanism leading to the formation of the Cusco basin. However, nowadays its mechanism is normal fault and scarps up to 22m can be observed. We report the current dynamics of the Tambomachay fault and secondary faults based on <span class="hlt">seismic</span> activity imaged by a network of 29 broadband stations deployed in the Cusco Region as well as the deformation field inferred from GPS survey measurements carried out between 2014 and 2016.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRB..119.8267H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRB..119.8267H"><span><span class="hlt">Seismicity</span> and subsidence following the 2011 Nabro eruption, Eritrea: Insights into the plumbing <span class="hlt">system</span> of an off-rift volcano</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hamlyn, Joanna E.; Keir, Derek; Wright, Tim J.; Neuberg, Jürgen W.; Goitom, Berhe; Hammond, James O. S.; Pagli, Carolina; Oppenheimer, Clive; Kendall, J.-Michael; Grandin, Raphaël.</p> <p>2014-11-01</p> <p>Nabro volcano, situated to the east of the Afar Rift Zone, erupted on 12 June 2011. Eruptions at such off-rift volcanoes are infrequent, and consequently, the plumbing <span class="hlt">systems</span> are poorly understood. We present posteruption Synthetic Aperture Radar (SAR) images from the TerraSAR-X satellite and posteruption continuous <span class="hlt">seismic</span> activity from a local <span class="hlt">seismic</span> array. Interferometric analysis of SAR data, reveals a circular, 12 km wide, signal subsiding at ˜200 mm/yr. We inverted for the best fit Mogi source finding a 4 ± 1 × 107 m3/yr volume decrease at 7 ± 1 km depth. Between 31 August and 7 October 2011, we located 658 and relocated 456 earthquakes with local magnitudes between -0.4 and 4.5. <span class="hlt">Seismicity</span> beneath the SE edge of Nabro at 11 km depth is likely associated with high strain rates from deep magma flow into the modeled reservoir. This suggests that magma is supplied through a narrow conduit and then stored at ˜7 km depth. We interpret <span class="hlt">seismicity</span> at 4-6 km depth as brittle fracturing above the inferred magma reservoir. Focal mechanisms delineate a thrust fault striking NE-SW and dipping 45° to the SE across the caldera floor. We propose that the crustal response is to slip on this fault which crosscuts the caldera rather than to deform on ring faults. The NE-SW fault plane is not associated with measurable surface deformation, indicating that it does not contribute much to the caldera deformation. We show that subsidence of the caldera is controlled by magma chamber processes rather than fault slip.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJWC.11706015I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJWC.11706015I"><span>Coupled-rearrangement-channels calculation of the three-body <span class="hlt">system</span> under the absorbing <span class="hlt">boundary</span> condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iwasaki, M.; Otani, R.; Ito, M.; Kamimura, M.</p> <p>2016-05-01</p> <p>We formulate the method of the absorbing <span class="hlt">boundary</span> condition (ABC) in the coupled-rearrangement-channels variational method (CRCMV) for the three-body problem. In the present study, we handle the simple three-boson <span class="hlt">system</span>, and the absorbing potential is introduced in the Jacobi coordinate in the individual rearrangement channels. The resonance parameters and the strength of the monopole breakup are compared with the complex scaling method (CSM). We have found that the CRCVM + ABC method nicely works in the threebody problem with the rearrangement channels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70018264','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70018264"><span>Proterozoic crustal <span class="hlt">boundary</span> in the southern part of the Illinois Basin</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Heigold, P.C.; Kolata, Dennis R.</p> <p>1993-01-01</p> <p>Recently acquired COCORP and proprietary <span class="hlt">seismic</span> reflection data in the southern part of the Illinois Basin, combined with other geological and geophysical data, indicate that a WNW-trending Proterozoic terrane <span class="hlt">boundary</span> (40 km wide) lies within basement. The <span class="hlt">boundary</span> is characterized by the termination of subhorizontal Proterozoic reflectors and associated diffraction patterns along a line coinciding with the major magnetic lineament in this region (South Central Magnetic Lineament). North of the <span class="hlt">boundary</span>, where reflectors thought to represent a sequence of layered Proterozoic rocks in the upper crust are widespread and as much as 11 km thick, total magnetic intensity values are relatively high, suggesting layers of rock with high magnetic susceptibility. To the south, the Proterozoic rocks are acoustically transparent on <span class="hlt">seismic</span> reflection sections and total magnetic intensity values are relatively low. Moreover, relatively high Bouguer gravity anomaly values to the south may be caused by a dense, altered, lower crustal layer similar to that interpreted from deep <span class="hlt">seismic</span> refraction studies to underlie the northern Mississippi Embayment. The <span class="hlt">boundary</span> lies along the projected trend of the northern margin of the Early Proterozoic Central Plains orogen and we suggest that it marks the convergent margin of this orogen. Reactivation of the <span class="hlt">boundary</span> and the associated zone of weakness during late Paleozoic times apparently resulted in structural deformation in the southern part of the Illinois Basin, including movement along the Cottage Grove Fault <span class="hlt">System</span> and Ste. Genevieve Fault Zone and igneous activity at Hicks Dome. In addition to the role played by this crustal <span class="hlt">boundary</span> in the evolution of the Illinois Basin, its location between the Wabash Valley <span class="hlt">Seismic</span> Zone to the northeast and the New Madrid <span class="hlt">Seismic</span> Zone to the southwest may be a significant factor in present-day <span class="hlt">seismicity</span>. ?? 1993.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1212303D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1212303D"><span>The ancient harbour <span class="hlt">system</span> of Terracina (Latium, Italy) obtained by gravity and <span class="hlt">seismic</span> surveys.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>di Nezza, Maria; di Filippo, Michele</p> <p>2010-05-01</p> <p>Historical research has shown that Terracina (Latina, Latium) played a fundamental role in the maritime and land traffic since before the foundation of the colony. The settlement was established where the organized <span class="hlt">system</span> of maritime, land, coastal, and fluvial transport had the most ideal conditions to constitute an important commercial crossroads, apparently since the beginning of recorded history. In order to reconstruction the buried archaeological structures attributed to the ancient Roman port, traditionally attributed to Traiano, in the current area of the harbour of Terracina, it was carried out a gravity survey, more than 380 gravity stations. The gravity method enables to recognize the cavity and the structures of the buildings underground through the results of variations density in the subsoil. <span class="hlt">Seismic</span> tomography treats the problem of identifying a buried structure as a wave propagation process by inverting the linearized wave equation to compute the spatial distribution of the slowness of the velocity. The purpose of our tomographic study is to further test the method and to guide archaeologists in their future excavations by locating and identifying buried structures. In the residual gravity anomaly map a series of positive anomalies are visible which confirm the round structures and the pier of the buried foundations of the Imperial harbour. Unfortunately, little remains of the functioning facilities of the harbour's activities. The modern construction of the harbour, in fact, has to be developed around the new inhabitable commercial area, know today as Terracina Bassa or Borgo alla Marina. It had to be developed with a modern infrastructure of a harbor area, as in the construction of the rooms for storage of goods, warehouses, as well as for the thermal baths, hotels and amphitheatre. Furthermore, there are always the positive anomalies that characterize the area to the north-east of "Montone" hill where archaeological remains are easily visible</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/27610','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/27610"><span><span class="hlt">Seismic</span> testing of precast segmental bridges, Phase III : bridge <span class="hlt">system</span> test.</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>2005-06-01</p> <p>This report discusses the main findings of a test examining the <span class="hlt">seismic</span> behavior of a precast, post-tensioned, segmental bridge : superstructure with a cast-in-place, hollow, rectangular column. The half-scale specimen modeled a prototype bridge from...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S33D2461J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S33D2461J"><span>Micro-<span class="hlt">seismic</span> earthquakes characteristics at natural and exploited hydrothermal <span class="hlt">systems</span> in West Java, Indonesia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jousset, P. G.; Jaya, M. S.; Sule, R.; Diningrat, W.; Gassner, A.; Akbar, F.; Ryannugroho, R.; Hendryana, A.; Kusnadi, Y.; Syahbana, D.; Nugraha, A. D.; Umar, M.; Indrinanto, Y.; Erbas, K.</p> <p>2013-12-01</p> <p>The assessment of geothermal resources requires the understanding of the structure and the dynamics of geothermal reservoirs. We deployed a multidisciplinary geophysical network around geothermal areas in the south of Bandung, West Java, Indonesia. The first deployment included a network of 30 broadband and 4 short-period <span class="hlt">seismic</span> stations with Güralp and Trillium sensors (0.008 - 100 Hz) since October 2012. In a second step, we extended the network in June 2013 with 16 short-period (1 Hz) seismometers. We describe the set-up of the <span class="hlt">seismic</span> networks and discuss first observations and results. The co-existence of a large variety of intense surface manifestations like geysers, hot-steaming grounds, hot water pools, and active volcanoes suggest an intimate coupling between volcanic, tectonic and hydrothermal processes in this area. Preliminary location of earthquakes is performed using a non-linear algorithm, which allows us to define at least 3 <span class="hlt">seismic</span> clusters. We discuss this <span class="hlt">seismic</span> pattern within the geothermal fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17064141','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17064141"><span>Phase diagram and high-pressure <span class="hlt">boundary</span> of hydrate formation in the ethane-water <span class="hlt">system</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kurnosov, Alexander V; Ogienko, Andrey G; Goryainov, Sergei V; Larionov, Eduard G; Manakov, Andrey Y; Lihacheva, Anna Y; Aladko, Eugeny Y; Zhurko, Fridrikh V; Voronin, Vladimir I; Berger, Ivan F; Ancharov, Aleksei I</p> <p>2006-11-02</p> <p>Dissociation temperatures of gas hydrate formed in the ethane-water <span class="hlt">system</span> were studied at pressures up to 1500 MPa. In situ neutron diffraction analysis and X-ray diffraction analysis in a diamond anvil cell showed that the gas hydrate formed in the ethane-water <span class="hlt">system</span> at 340, 700, and 1840 MPa and room temperature belongs to the cubic structure I (CS-I). Raman spectra of C-C vibrations of ethane molecules in the hydrate phase, as well as the spectra of solid and liquid ethane under high-pressure conditions were studied at pressures up to 6900 MPa. Within 170-3600 MPa Raman shift of the C-C vibration mode of ethane in the hydrate phase did not show any discontinuities, which could be evidence of possible phase transformations. The upper pressure <span class="hlt">boundary</span> of high-pressure hydrate existence was discovered at the pressure of 3600 MPa. This <span class="hlt">boundary</span> corresponds to decomposition of the hydrate to solid ethane and ice VII. The type of phase diagram of ethane-water <span class="hlt">system</span> was proposed in the pressure range of hydrate formation (0-3600 MPa).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSG...104..159S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSG...104..159S"><span>The emergence of asymmetric normal fault <span class="hlt">systems</span> under symmetric <span class="hlt">boundary</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schöpfer, Martin P. J.; Childs, Conrad; Manzocchi, Tom; Walsh, John J.; Nicol, Andrew; Grasemann, Bernhard</p> <p>2017-11-01</p> <p>Many normal fault <span class="hlt">systems</span> and, on a smaller scale, fracture boudinage often exhibit asymmetry with one fault dip direction dominating. It is a common belief that the formation of domino and shear band boudinage with a monoclinic symmetry requires a component of layer parallel shearing. Moreover, domains of parallel faults are frequently used to infer the presence of a décollement. Using Distinct Element Method (DEM) modelling we show, that asymmetric fault <span class="hlt">systems</span> can emerge under symmetric <span class="hlt">boundary</span> conditions. A statistical analysis of DEM models suggests that the fault dip directions and <span class="hlt">system</span> polarities can be explained using a random process if the strength contrast between the brittle layer and the surrounding material is high. The models indicate that domino and shear band boudinage are unreliable shear-sense indicators. Moreover, the presence of a décollement should not be inferred on the basis of a domain of parallel faults alone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/392223-deepwater-seismic-acquisition-technology','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/392223-deepwater-seismic-acquisition-technology"><span>Deepwater <span class="hlt">seismic</span> acquisition technology</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Caldwell, J.</p> <p>1996-09-01</p> <p>Although truly new technology is not required for successful acquisition of <span class="hlt">seismic</span> data in deep Gulf of Mexico waters, it is helpful to review some basic aspects of these <span class="hlt">seismic</span> surveys. Additionally, such surveys are likely to see early use of some emerging new technology which can improve data quality. Because such items as depth imaging, borehole <span class="hlt">seismic</span>, 4-D and marine 3-component recording were mentioned in the May 1996 issue of World Oil, they are not discussed again here. However, these technologies will also play some role in the deepwater <span class="hlt">seismic</span> activities. What is covered in this paper are somemore » new considerations for: (1) longer data records needed in deeper water, (2) some pros and cons of very long steamer use, and (3) two new commercial <span class="hlt">systems</span> for quantifying data quality.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H41O..02Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H41O..02Z"><span>Modeling of time-lapse multi-scale <span class="hlt">seismic</span> monitoring of CO2 injected into a fault zone to enhance the characterization of permeability in enhanced geothermal <span class="hlt">systems</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, R.; Borgia, A.; Daley, T. M.; Oldenburg, C. M.; Jung, Y.; Lee, K. J.; Doughty, C.; Altundas, B.; Chugunov, N.; Ramakrishnan, T. S.</p> <p>2017-12-01</p> <p>Subsurface permeable faults and fracture networks play a critical role for enhanced geothermal <span class="hlt">systems</span> (EGS) by providing conduits for fluid flow. Characterization of the permeable flow paths before and after stimulation is necessary to evaluate and optimize energy extraction. To provide insight into the feasibility of using CO2 as a contrast agent to enhance fault characterization by <span class="hlt">seismic</span> methods, we model <span class="hlt">seismic</span> monitoring of supercritical CO2 (scCO2) injected into a fault. During the CO2 injection, the original brine is replaced by scCO2, which leads to variations in geophysical properties of the formation. To explore the technical feasibility of the approach, we present modeling results for different time-lapse <span class="hlt">seismic</span> methods including surface <span class="hlt">seismic</span>, vertical <span class="hlt">seismic</span> profiling (VSP), and a cross-well survey. We simulate the injection and production of CO2 into a normal fault in a <span class="hlt">system</span> based on the Brady's geothermal field and model pressure and saturation variations in the fault zone using TOUGH2-ECO2N. The simulation results provide changing fluid properties during the injection, such as saturation and salinity changes, which allow us to estimate corresponding changes in <span class="hlt">seismic</span> properties of the fault and the formation. We model the response of the <span class="hlt">system</span> to active <span class="hlt">seismic</span> monitoring in time-lapse mode using an anisotropic finite difference method with modifications for fracture compliance. Results to date show that even narrow fault and fracture zones filled with CO2 can be better detected using the VSP and cross-well survey geometry, while it would be difficult to image the CO2 plume by using surface <span class="hlt">seismic</span> methods.</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 <span class="hlt">System</span> CARINA. In 2012, the Spanish IGN together</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMMR43C0482D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMMR43C0482D"><span>Implications for the melting phase relations in the MgO-FeO <span class="hlt">system</span> at Core-Mantle <span class="hlt">Boundary</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deng, J.; Lee, K. K. M.</p> <p>2017-12-01</p> <p>At nearly 2900 km depth, the core-mantle <span class="hlt">boundary</span> (CMB) represents the largest density increase within the Earth going from a rocky mantle into an iron-alloy core. This compositional change sets up steep temperature gradients, which in turn influences mantle flow, structure and <span class="hlt">seismic</span> velocities. Here we compute the melting phase relations of (Mg,Fe)O ferropericlase, the second most abundant mineral in the Earth's mantle, at CMB conditions and find that ultralow-velocity zones (ULVZs) could be explained by solid ferropericlase with 35 < Mg# = 100×(Mg/(Mg+Fe) by mol%) < 65. For compositions outside of this range, a solid ferropericlase cannot explain ULVZs. Additionally, solid ferropericlase can also provide a matrix for iron infiltration at the CMB by morphological instability, providing a mechanism for a high electrical conductivity layer of appropriate length scale inferred from core nutations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS43C..07B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS43C..07B"><span>On the Past, Present, and Future of Eastern <span class="hlt">Boundary</span> Upwelling <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bograd, S. J.; Black, B.; Garcia-Reyes, M.; Rykaczewski, R. R.; Thompson, S. A.; Turley, B. D.; van der Sleen, P.; Sydeman, W. J.</p> <p>2016-12-01</p> <p>Coastal upwelling in Eastern <span class="hlt">Boundary</span> Upwelling <span class="hlt">Systems</span> (EBUS) drives high productivity and marine biodiversity and supports lucrative commercial fishing operations. Thus there is significant interest in understanding the mechanisms underlying variations in the upwelling process, its drivers, and potential changes relative to global warming. Here we review recent results from a combination of regional and global observations, reanalysis products, and climate model projections that describe variability in coastal upwelling in EBUS. Key findings include: (1) interannual variability in California Current upwelling occurs in two orthogonal seasonal modes: a winter/early spring mode dominated by interannual variability and a summer mode dominated by long-term increasing trend; (2) there is substantial coherence in year-to-year variability between this winter/spring upwelling mode and upper trophic level demographic processes, including fish growth rates (rockfish and salmon) and seabird phenology, breeding success and survival; (3) a meta-analysis of existing literature suggests consistency with the Bakun (1990) hypothesis that rising global greenhouse-gas concentrations would result in upwelling-favorable wind intensification; however, (4) an ensemble of coupled, global ocean-atmosphere models finds limited evidence for intensification of upwelling-favorable winds over the 21st century, although summertime winds near the poleward <span class="hlt">boundaries</span> of climatalogical upwelling zones are projected to intensify. We will also review a new comparative research program between the California and Benguela Upwelling <span class="hlt">Systems</span>, including efforts to understand patterns of change and variation between climate, upwelling, fish, and seabirds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1233..644T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1233..644T"><span>Development of the Patient-specific Cardiovascular Modeling <span class="hlt">System</span> Using Immersed <span class="hlt">Boundary</span> Technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tay, Wee-Beng; Lin, Liang-Yu; Tseng, Wen-Yih; Tseng, Yu-Heng</p> <p>2010-05-01</p> <p>A computational fluid dynamics (CFD) based, patient-specific cardiovascular modeling <span class="hlt">system</span> is under-developed. The <span class="hlt">system</span> can identify possible diseased conditions and facilitate physicians' diagnosis at early stage through the hybrid CFD simulation and time-resolved magnetic resonance imaging (MRI). The CFD simulation is initially based on the three-dimensional heart model developed by McQueen and Peskin, which can simultaneously compute fluid motions and elastic <span class="hlt">boundary</span> motions using the immersed <span class="hlt">boundary</span> method. We extend and improve the three-dimensional heart model for the clinical application by including the patient-specific hemodynamic information. The flow features in the ventricles and their responses are investigated under different inflow and outflow conditions during diastole and systole phases based on the quasi-realistic heart model, which takes advantage of the observed flow scenarios. Our results indicate distinct differences between the two groups of participants, including the vortex formation process in the left ventricle (LV), as well as the flow rate distributions at different identified sources such as the aorta, vena cava and pulmonary veins/artery. We further identify some key parameters which may affect the vortex formation in the LV. Thus it is hypothesized that disease-related dysfunctions in intervals before complete heart failure can be observed in the dynamics of transmitral blood flow during early LV diastole.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EP%26S...70...61A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EP%26S...70...61A"><span><span class="hlt">Seismic</span> evidence for arc segmentation, active magmatic intrusions and syn-rift fault <span class="hlt">system</span> in the northern Ryukyu volcanic arc</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arai, Ryuta; Kodaira, Shuichi; Takahashi, Tsutomu; Miura, Seiichi; Kaneda, Yoshiyuki</p> <p>2018-04-01</p> <p>Tectonic and volcanic structures of the northern Ryukyu arc are investigated on the basis of multichannel <span class="hlt">seismic</span> (MCS) reflection data. The study area forms an active volcanic front in parallel to the non-volcanic island chain in the eastern margin of the Eurasian plate and has been undergoing regional extension on its back-arc side. We carried out a MCS reflection experiment along two across-arc lines, and one of the profiles was laid out across the Tokara Channel, a linear bathymetric depression which demarcates the northern and central Ryukyu arcs. The reflection image reveals that beneath this topographic valley there exists a 3-km-deep sedimentary basin atop the arc crust, suggesting that the arc segment <span class="hlt">boundary</span> was formed by rapid and focused subsidence of the arc crust driven by the arc-parallel extension. Around the volcanic front, magmatic conduits represented by tubular transparent bodies in the reflection images are well developed within the shallow sediments and some of them are accompanied by small fragments of dipping <span class="hlt">seismic</span> reflectors indicating intruded sills at their bottoms. The spatial distribution of the conduits may suggest that the arc volcanism has multiple active outlets on the seafloor which bifurcate at crustal depths and/or that the location of the volcanic front has been migrating trenchward over time. Further distant from the volcanic front toward the back-arc (> 30 km away), these volcanic features vanish, and alternatively wide rift basins become predominant where rapid transitions from normal-fault-dominant regions to strike-slip-fault-dominant regions occur. This spatial variation in faulting patterns indicates complex stress regimes associated with arc/back-arc rifting in the northern Okinawa Trough.[Figure not available: see fulltext.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....5286C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....5286C"><span>GeoNetGIS: a Geodetic Network Geographical Information <span class="hlt">System</span> to manage GPS networks in <span class="hlt">seismic</span> and 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>Cristofoletti, P.; Esposito, A.; Anzidei, M.</p> <p>2003-04-01</p> <p>This paper presents the methodologies and issues involved in the use of GIS techniques to manage geodetic information derived from networks in <span class="hlt">seismic</span> and volcanic areas. Organization and manipulation of different geodetical, geological and <span class="hlt">seismic</span> database, give us a new challenge in interpretation of information that has several dimensions, including spatial and temporal variations, also the flexibility and brand range of tools available in GeoNetGIS, make it an attractive platform for earthquake risk assessment. During the last decade the use of geodetic networks based on the Global Positioning <span class="hlt">System</span>, devoted to geophysical applications, especially for crustal deformation monitoring in <span class="hlt">seismic</span> and volcanic areas, increased dramatically. The large amount of data provided by these networks, combined with different and independent observations, such as epicentre distribution of recent and historical earthquakes, geological and structural data, photo interpretation of aerial and satellite images, can aid for the detection and parameterization of seismogenic sources. In particular we applied our geodetic oriented GIS to a new GPS network recently set up and surveyed in the Central Apennine region: the CA-GeoNet. GeoNetGIS is designed to analyze in three and four dimensions GPS sources and to improve crustal deformation analysis and interpretation related with tectonic structures and <span class="hlt">seismicity</span>. It manages many database (DBMS) consisting of different classes, such as Geodesy, Topography, <span class="hlt">Seismicity</span>, Geology, Geography and Raster Images, administrated according to Thematic Layers. GeoNetGIS represents a powerful research tool allowing to join the analysis of all data layers to integrate the different data base which aid for the identification of the activity of known faults or structures and suggesting the new evidences of active tectonics. A new approach to data integration given by GeoNetGIS capabilities, allow us to create and deliver a wide range of maps, digital</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JAfES.140..134B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JAfES.140..134B"><span><span class="hlt">Seismic</span> reflection and structuring characterization of deep aquifer <span class="hlt">system</span> in the Dakhla syncline (Cap Bon, North-Eastern Tunisia)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bellali, Abir; Jarraya Horriche, Faten; Gabtni, Hakim; Bédir, Mourad</p> <p>2018-04-01</p> <p>The Dakhla syncline is located in the North-Eastern Tunisia. It is bounded by Abd El Rahmene anticline to the North-West, El Haouaria Graben to the North-East, Grombalia Graben to the South-West and the Mediterranean Sea to the East. The main aquifer reservoirs of Dakhla syncline are constituted by stacks of fluvial to deltaic Neogene sequences and carbonates. The interpretation of eight <span class="hlt">seismic</span> reflection profiles, calibrated by wire line logging data of three oil wells, hydraulic wells and geologic field sections highlighted the impact of tectonics on the structuring geometry of aquifers and their distribution in elevated structures and subsurface depressions. Lithostratigraphic correlations and <span class="hlt">seismic</span> profiles analysis through the syncline show that the principal aquifers are thickest within the central and northern part of the study area and thinnest to the southern part of the syncline. <span class="hlt">Seismic</span> sections shows that the fracture/fault pattern in this syncline is mainly concentrated along corridors with a major direction of NW-SE and secondary directions of N-S, E-W and NE-SW with different release. This is proved by the complexity structure of Eastern Tunisia, resulted from the interaction between the African and Eurasiatic plates. Isochron maps of aquifers <span class="hlt">systems</span> exhibited the structuring of this syncline in sub-surface characterized by important lateral and vertical geometric and thickness variations. <span class="hlt">Seismic</span> sections L1, L2, L3, L4, L5 and petroleum wells showed an heterogeneous multilayer aquifers of Miocene formed by the arrangement of ten sandstone bodies, separated by impermeable clay packages. Oligo-Miocene deposits correspond to the most great potential aquifers, with respectively an average transmissivity estimated: Somaa aquifer 6.5 10-4 m2/s, Sandstone level aquifer 2.6 10-3 m2/s, Beglia aquifer 1.1 10-3 m2/s, Ain Ghrab aquifer 1.3 10-4 m2/s and Oligocene aquifer 2 10-3 m2/s. The interpretation of spatial variations of <span class="hlt">seismic</span> units and the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770044370&hterms=balloon+tethered&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dballoon%2Btethered','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770044370&hterms=balloon+tethered&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dballoon%2Btethered"><span>A combined <span class="hlt">boundary</span>-profile and automated data-reduction and analysis <span class="hlt">system</span>. [meteorological balloon-calculator <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deloach, R.; Morris, A. L.; Mcbeth, R. B.</p> <p>1976-01-01</p> <p>A portable <span class="hlt">boundary</span>-layer meteorological data-acquisition and analysis <span class="hlt">system</span> is described which employs a small tethered balloon and a programmable calculator. The <span class="hlt">system</span> is capable of measuring pressure, wet- and dry-bulb temperature, wind speed, and temperature fluctuations as a function of height and time. Other quantities, which can be calculated in terms of these, can also be made available in real time. All quantities, measured and calculated, can be printed, plotted, and stored on magnetic tape in the field during the data-acquisition phase of an experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IzMat..81..542Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IzMat..81..542Z"><span>A <span class="hlt">boundary</span>-value problem for a first-order hyperbolic <span class="hlt">system</span> in a two-dimensional domain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhura, N. A.; Soldatov, A. P.</p> <p>2017-06-01</p> <p>We consider a strictly hyperbolic first-order <span class="hlt">system</span> of three equations with constant coefficients in a bounded piecewise-smooth domain. The <span class="hlt">boundary</span> of the domain is assumed to consist of six smooth non-characteristic arcs. A <span class="hlt">boundary</span>-value problem in this domain is posed by alternately prescribing one or two linear combinations of the components of the solution on these arcs. We show that this problem has a unique solution under certain additional conditions on the coefficients of these combinations, the <span class="hlt">boundary</span> of the domain and the behaviour of the solution near the characteristics passing through the corner points of the domain.</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('http://adsabs.harvard.edu/abs/2014EGUGA..16.4707L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.4707L"><span>ADDOSS: Autonomously Deployed Deep-ocean <span class="hlt">Seismic</span> <span class="hlt">System</span> - Communications Gateway for Ocean Observatories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Laske, Gabi; Berger, Jon; Orcutt, John; Babcock, Jeff</p> <p>2014-05-01</p> <p>We describe an autonomously deployable, communications gateway designed to provide long-term and near real-time data from ocean observatories. The key features of this new <span class="hlt">system</span> are its abilities to telemeter sensor data from the seafloor to shore without cables or moorings, and to be deployed without a ship, thereby greatly reducing life-cycle costs. The free-floating surface communications gateway utilizes a Liquid Robotics wave glider comprising a surfboard-sized float towed by a tethered, submerged glider, which converts wave motion into thrust. For navigation, the wave glider is equipped with a small computer, a GPS receiver, a rudder, solar panels and batteries, and an Iridium satellite modem. Acoustic communications connect the subsea instruments and the surface gateway while communications between the gateway and land are provided by the Iridium satellite constellation. Wave gliders have demonstrated trans-oceanic range and long-term station keeping capabilities. The acoustics communications package is mounted in a shallow tow body which utilizes a WHOI micro modem and a Benthos low frequency, directional transducer. A matching modem and transducer is mounted on the ocean bottom package. Tests of the surface gateway in 4350 m of water demonstrated an acoustic efficiency of approximately 396 bits/J. For example, it has the ability to send 4 channels of compressed, 1 sample per second data from the ocean bottom to the gateway with an average power draw of approximately 0.15 W and a latency of less than 3 minutes. This gateway is used to send near real-time data from a broadband ocean bottom <span class="hlt">seismic</span> observatory, first during short week-to-months long test deployments but will ultimately be designed for a two-year operational life. Such data from presently unobserved oceanic areas are critical for both national and international agencies in monitoring and characterizing earthquakes, tsunamis, and nuclear explosions. We present initial results from a two short</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70035394','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70035394"><span>Shallow conduit <span class="hlt">system</span> at Kilauea Volcano, Hawaii, revealed by <span class="hlt">seismic</span> signals associated with degassing bursts</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Chouet, Bernard; Dawson, Phillip</p> <p>2011-01-01</p> <p>Eruptive activity at the summit of Kilauea Volcano, Hawaii, beginning in March, 2008 and continuing to the present time is characterized by episodic explosive bursts of gas and ash from a vent within Halemaumau Pit Crater. These bursts are accompanied by <span class="hlt">seismic</span> signals that are well recorded by a broadband network deployed in the summit caldera. We investigate in detail the dimensions and oscillation modes of the source of a representative burst in the 1−10 s band. An extended source is realized by a set of point sources distributed on a grid surrounding the source centroid, where the centroid position and source geometry are fixed from previous modeling of very-long-period (VLP) data in the 10–50 s band. The source time histories of all point sources are obtained simultaneously through waveform inversion carried out in the frequency domain. Short-scale noisy fluctuations of the source time histories between adjacent sources are suppressed with a smoothing constraint, whose strength is determined through a minimization of the Akaike Bayesian Information Criterion (ABIC). Waveform inversions carried out for homogeneous and heterogeneous velocity structures both image a dominant source component in the form of an east trending dike with dimensions of 2.9 × 2.9 km. The dike extends ∼2 km west and ∼0.9 km east of the VLP centroid and spans the depth range 0.2–3.1 km. The source model for a homogeneous velocity structure suggests the dike is hinged at the source centroid where it bends from a strike E 27°N with northern dip of 85° west of the centroid, to a strike E 7°N with northern dip of 80° east of the centroid. The oscillating behavior of the dike is dominated by simple harmonic modes with frequencies ∼0.2 Hz and ∼0.5 Hz, representing the fundamental mode ν11 and first degenerate mode ν12 = ν21 of the dike. Although not strongly supported by data in the 1–10 s band, a north striking dike segment is required for enhanced compatibility with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008oibi.book..423E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008oibi.book..423E"><span>Open Innovation and the Erosion of the Traditional Information <span class="hlt">Systems</span> Project's <span class="hlt">Boundaries</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elbanna, Amany</p> <p></p> <p>This paper examines the notion of open innovation and its implication on information <span class="hlt">systems</span> management. It investigates a project of an enterprise resource planning <span class="hlt">system</span> implementation in an international organization to unravel the resemblance with the open innovation model. The study shows that the conceptualization of ERP project as an open innovation could reveal the complex architecture of today's organization from which the ERP project cannot be isolated. It argues that the traditional <span class="hlt">boundaries</span> around IS projects are dissolving and the relationship between what used to be outside and what used to be inside the project is increasingly blurred. The study calls for a different perspective of project management that goes beyond single and multiple project management to scan the open space of innovation and actively look for partners, competitors, and collaborators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.T31A0837S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.T31A0837S"><span>The Crustal Structure and <span class="hlt">Seismicity</span> of Eastern Venezuela</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmitz, M.; Martins, A.; Sobiesiak, M.; Alvarado, L.; Vasquez, R.</p> <p>2001-12-01</p> <p>Eastern Venezuela is characterized by a moderate to high <span class="hlt">seismicity</span>, evidenced recently by the 1997 Cariaco earthquake located on the El Pilar Fault, a right lateral strike slip fault which marks the plate <span class="hlt">boundary</span> between the Caribbean and South-American plates in this region. Recently, the <span class="hlt">seismic</span> activity seems to migrate towards the zone of subduction of the Lesser Antilles in the northeast, where a mb 6.0 earthquake occurred in October 2000 at 120 km of depth. Periodical changes in the <span class="hlt">seismic</span> activity are related to the interaction of the stress fields of the strike-slip and the subduction regimes. The <span class="hlt">seismic</span> activity decreases rapidly towards to the south with some disperse events on the northern edge of the Guayana Shield, related to the Guri fault <span class="hlt">system</span>. The crustal models used in the region are derived from the information generated by the national seismological network since 1982 and by microseismicity studies in northeastern Venezuela, coinciding in a crustal thickness of about 35 km in depth. Results of <span class="hlt">seismic</span> refraction measurements for the region were obtained during field campains in 1998 (ECOGUAY) for the Guayana Shield and the Cariaco sedimentary basin and in 2001 (ECCO) for the Oriental Basin. The total crustal thickness decreases from about 45 km on the northern edge of the Guayana Shield to some 36 km close to El Tigre in the center of the Oriental Basin. The average crustal velocity decreases in the same sense from 6.5 to 5.8 km/s. In the Cariaco sedimentary basin a young sedimentary cover of 1 km thickness with a <span class="hlt">seismic</span> velocity of 2 km/s was derived. Towards the northern limit of the South-American plate, no deep <span class="hlt">seismic</span> refraction data are available up to now. The improvement of the crustal models used in that region would constitute a step forward in the analysis of the <span class="hlt">seismic</span> hazard. <span class="hlt">Seismic</span> refraction studies funded by CONICIT S1-97002996 and S1-2000000685 projects and PDVSA (additional drilling and blasting), recording equipment</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160010174','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160010174"><span>Computational Investigation of a <span class="hlt">Boundary</span>-Layer Ingesting Propulsion <span class="hlt">System</span> for the Common Research Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Blumenthal, Brennan T.; Elmiligui, Alaa; Geiselhart, Karl A.; Campbell, Richard L.; Maughmer, Mark D.; Schmitz, Sven</p> <p>2016-01-01</p> <p>The present paper examines potential propulsive and aerodynamic benefits of integrating a <span class="hlt">Boundary</span>-Layer Ingestion (BLI) propulsion <span class="hlt">system</span> into a typical commercial aircraft using the Common Research Model (CRM) geometry and the NASA Tetrahedral Unstructured Software <span class="hlt">System</span> (TetrUSS). The Numerical Propulsion <span class="hlt">System</span> Simulation (NPSS) environment is used to generate engine conditions for CFD analysis. Improvements to the BLI geometry are made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Previous studies have shown reductions of up to 25% in terms of propulsive power required for cruise for other axisymmetric geometries using the BLI concept. An analysis of engine power requirements, drag, and lift coefficients using the baseline and BLI geometries coupled with the NPSS model are shown. Potential benefits of the BLI <span class="hlt">system</span> relating to cruise propulsive power are quantified using a power balance method, and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown and any improvements between subsequent BLI designs presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet and an angle of attack of 2 deg for all geometries. A comparison between available wind tunnel data, previous computational results, and the original CRM model is presented for model verification purposes along with full results for BLI power savings. Results indicate a 14.4% reduction in engine power requirements at cruise for the BLI configuration over the baseline geometry. Minor shaping of the aft portion of the fuselage using CDISC has been shown to increase the benefit from <span class="hlt">Boundary</span>-Layer Ingestion further, resulting in a 15.6% reduction in power requirements for cruise as well as a drag reduction of eighteen counts over the baseline geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160005086','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160005086"><span>Computational Investigation of a <span class="hlt">Boundary</span>-Layer Ingestion Propulsion <span class="hlt">System</span> for the Common Research Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Blumenthal, Brennan</p> <p>2016-01-01</p> <p>This thesis will examine potential propulsive and aerodynamic benefits of integrating a <span class="hlt">boundary</span>-layer ingestion (BLI) propulsion <span class="hlt">system</span> with a typical commercial aircraft using the Common Research Model geometry and the NASA Tetrahedral Unstructured Software <span class="hlt">System</span> (TetrUSS). The Numerical Propulsion <span class="hlt">System</span> Simulation (NPSS) environment will be used to generate engine conditions for CFD analysis. Improvements to the BLI geometry will be made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Previous studies have shown reductions of up to 25% in terms of propulsive power required for cruise for other axisymmetric geometries using the BLI concept. An analysis of engine power requirements, drag, and lift coefficients using the baseline and BLI geometries coupled with the NPSS model are shown. Potential benefits of the BLI <span class="hlt">system</span> relating to cruise propulsive power are quantified using a power balance method and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown and any improvements between subsequent BLI designs presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet and an angle of attack of 2deg for all geometries. A comparison between available wind tunnel data, previous computational results, and the original CRM model is presented for model verification purposes along with full results for BLI power savings. Results indicate a 14.3% reduction in engine power requirements at cruise for the BLI configuration over the baseline geometry. Minor shaping of the aft portion of the fuselage using CDISC has been shown to increase the benefit from <span class="hlt">boundary</span>-layer ingestion further, resulting in a 15.6% reduction in power requirements for cruise as well as a drag reduction of eighteen counts over the baseline geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA573758','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA573758"><span>The CAFE Experiment: A Joint <span class="hlt">Seismic</span> and MT Investigation of the Cascadia Subduction <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2013-02-01</p> <p>In this thesis we present results from inversion of data using dense arrays of collocated <span class="hlt">seismic</span> and magnetotelluric stations located in the Cascadia...implicit in the standard MT inversion provides tools that enable us to generate a more accurate MT model. This final MT model clearly demonstrates...references within, Hacker, 2008) have given us the tools to better interpret geophysical evidence. Improvements in the thermal modeling of subduction zones</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 <span class="hlt">boundary</span> accelerations. 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 acceleration 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('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 <span class="hlt">system</span> 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 acceleration 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 acceleration 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/2005JOptB...7S...1B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JOptB...7S...1B"><span>EDITORIAL: The nonstationary Casimir effect and quantum <span class="hlt">systems</span> with moving <span class="hlt">boundaries</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barton, Gabriel; Dodonov, Victor V.; Man'ko, Vladimir I.</p> <p>2005-03-01</p> <p>This topical issue of Journal of Optics B: Quantum and Semiclassical Optics contains 16 contributions devoted to quantum <span class="hlt">systems</span> with moving <span class="hlt">boundaries</span>. In a broad sense, the papers continue the studies opened exactly 100 years ago by Einstein in his seminal work on the electrodynamics of moving bodies and the quantum nature of light. Another jubilee which we wish to celebrate by launching this issue is the 80th anniversary of the publication of two papers, where the first solutions of the classical Maxwell equations in a one-dimensional cavity with moving <span class="hlt">boundaries</span> were obtained, by T H Havelock (1924 Some dynamical illustrations of the pressure of radiation and of adiabatic invariance Phil. Mag. 47 754-71) and by E L Nicolai (1925 On a dynamical illustration of the pressure of radiation Phil. Mag. 49 171-7). As was shown by Einstein, studying the fluctuations of the electromagnetic field inevitably leads one to its quantum (corpuscular) nature. Many papers in this issue deal with problems where moving <span class="hlt">boundaries</span> produce parametric excitation of vacuum fluctuations of the field, which could result in several different observable effects, like the modification of the famous Casimir force, or the creation of real quanta from the vacuum. It is worth emphasizing that these phenomena, frequently referred to as nonstationary (or dynamical) Casimir effects, are no longer the province only of pure theorists: some experimental groups have already started long-term work aimed at observing such effects in the laboratory. Of course, many difficult problems remain to be resolved before this dream becomes reality. Several papers here show both important progress in this direction, and possible difficulties still to be tackled. Problems that have been considered include, in particular, decoherence, entanglement, and the roles of geometry and polarization. Other papers deal with fundamental problems like the Unruh effect, the interaction of accelerated relativistic atoms with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24592187','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24592187"><span>Multiple positive solutions to nonlinear <span class="hlt">boundary</span> value problems of a <span class="hlt">system</span> for fractional differential equations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhai, Chengbo; Hao, Mengru</p> <p>2014-01-01</p> <p>By using Krasnoselskii's fixed point theorem, we study the existence of at least one or two positive solutions to a <span class="hlt">system</span> of fractional <span class="hlt">boundary</span> value problems given by -D(0+)(ν1)y1(t) = λ1a1(t)f(y1(t), y2(t)), - D(0+)(ν2)y2(t) = λ2a2(t)g(y1(t), y2(t)), where D(0+)(ν) is the standard Riemann-Liouville fractional derivative, ν1, ν2 ∈ (n - 1, n] for n > 3 and n ∈ N, subject to the <span class="hlt">boundary</span> conditions y1((i))(0) = 0 = y ((i))(0), for 0 ≤ i ≤ n - 2, and [D(0+)(α)y1(t)] t=1 = 0 = [D(0+ (α)y2(t)] t=1, for 1 ≤ α ≤ n - 2, or y1((i))(0) = 0 = y ((i))(0), for 0 ≤ i ≤ n - 2, and [D(0+)(α)y1(t)] t=1 = ϕ1(y1), [D(0+)(α)y2(t)] t=1 = ϕ2(y2), for 1 ≤ α ≤ n - 2, ϕ1, ϕ2 ∈ C([0,1], R). Our results are new and complement previously known results. As an application, we also give an example to demonstrate our result.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS53B1204D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS53B1204D"><span><span class="hlt">Seismic</span> Characterization of the Terrebonne Mini-basin, a Hydrate Rich Depositional <span class="hlt">System</span> in the Gulf of Mexico</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dafov, L. N.; Eze, P. C.; Haines, S. S.; Graham, S. A.; McHargue, T.; Hosford Scheirer, A.</p> <p>2017-12-01</p> <p>Natural gas bearing hydrates are a focus of research as a potential source of energy and carbon storage because they occur globally in permafrost regions and marine sediment along every continent. This study focuses on the structural and stratigraphic architecture of the Terrebonne mini-basin, northwest Walker Ridge, Gulf of Mexico, to characterize the depositional architecture and to describe possible migration pathways for petroleum. Questions addressed include: a) continuity of sand layers b) effects of faulting and c) ponding versus fill and spill. To address these questions, seven of forty-two high resolution USGS 2D <span class="hlt">seismic</span> lines were interpreted and then verified with WesternGeco 3D <span class="hlt">seismic</span> data, yielding three qualitative models for the depositional environment of hydrate-bearing sand intervals. Deeper hydrate-bearing sand reservoirs were deposited as sheet-like turbidite lobes. Two shallower hydrate-bearing intervals display two possible depositional <span class="hlt">systems</span> which form reservoirs- 1) sandy to muddy channel sealed laterally by muddy levees with associated sandy crevasse splays, and 2) ponded sandy lobes cut by channels filled with sand lags and mud. Additional observations in the 2D <span class="hlt">seismic</span> include mass transport deposits and possible contourites. Salt movement facilitated mini-basin formation which was then ponded by sediment and followed by episodes of fill-and-spill and erosion. These <span class="hlt">seismic</span> interpretations indicate periodic salt uplift. Overturn of salt along the northwestern edge of the basin resulted in thrust faults. The faults and erosional surfaces act as seals to reservoirs. The greatest volume of sandy reservoir potential occurs in sheet-like turbidite lobes with high lateral continuity, which facilitates updip migration of deep-sourced thermogenic gas along bedding surfaces. Channel levees serve as lateral seals to gas hydrate reservoirs, whereas faults, erosional surfaces, and shales provide vertical seals. Characterization of the Terrebonne</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1323593','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1323593"><span><span class="hlt">Seismic</span> assessment of Technical Area V (TA-V).</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Medrano, Carlos S.</p> <p></p> <p>The Technical Area V (TA-V) <span class="hlt">Seismic</span> Assessment Report was commissioned as part of Sandia National Laboratories (SNL) Self Assessment Requirement per DOE O 414.1, Quality Assurance, for <span class="hlt">seismic</span> impact on existing facilities at Technical Area-V (TA-V). SNL TA-V facilities are located on an existing Uniform Building Code (UBC) <span class="hlt">Seismic</span> Zone IIB Site within the physical <span class="hlt">boundary</span> of the Kirtland Air Force Base (KAFB). The document delineates a summary of the existing facilities with their safety-significant structure, <span class="hlt">system</span> and components, identifies DOE Guidance, conceptual framework, past assessments and the present Geological and <span class="hlt">Seismic</span> conditions. Building upon the past information and themore » evolution of the new <span class="hlt">seismic</span> design criteria, the document discusses the potential impact of the new standards and provides recommendations based upon the current International Building Code (IBC) per DOE O 420.1B, Facility Safety and DOE G 420.1-2, Guide for the Mitigation of Natural Phenomena Hazards for DOE Nuclear Facilities and Non-Nuclear Facilities.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29051528','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29051528"><span>Induced <span class="hlt">seismicity</span> closed-form traffic light <span class="hlt">system</span> for actuarial decision-making during deep fluid injections.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mignan, A; Broccardo, M; Wiemer, S; Giardini, D</p> <p>2017-10-19</p> <p>The rise in the frequency of anthropogenic earthquakes due to deep fluid injections is posing serious economic, societal, and legal challenges to many geo-energy and waste-disposal projects. Existing tools to assess such problems are still inherently heuristic and mostly based on expert elicitation (so-called clinical judgment). We propose, as a complementary approach, an adaptive traffic light <span class="hlt">system</span> (ATLS) that is function of a statistical model of induced <span class="hlt">seismicity</span>. It offers an actuarial judgement of the risk, which is based on a mapping between earthquake magnitude and risk. Using data from six underground reservoir stimulation experiments, mostly from Enhanced Geothermal <span class="hlt">Systems</span>, we illustrate how such a data-driven adaptive forecasting <span class="hlt">system</span> could guarantee a risk-based safety target. The proposed model, which includes a linear relationship between <span class="hlt">seismicity</span> rate and flow rate, as well as a normal diffusion process for post-injection, is first confirmed to be representative of the data. Being integrable, the model yields a closed-form ATLS solution that is both transparent and robust. Although simulations verify that the safety target is consistently ensured when the ATLS is applied, the model from which simulations are generated is validated on a limited dataset, hence still requiring further tests in additional fluid injection environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930090964','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930090964"><span>Generalization of <span class="hlt">Boundary</span>-Layer Momentum-Integral Equations to Three-Dimensional Flows Including Those of Rotating <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mager, Arthur</p> <p>1952-01-01</p> <p>The Navier-Stokes equations of motion and the equation of continuity are transformed so as to apply to an orthogonal curvilinear coordinate <span class="hlt">system</span> rotating with a uniform angular velocity about an arbitrary axis in space. A usual simplification of these equations as consistent with the accepted <span class="hlt">boundary</span>-layer theory and an integration of these equations through the <span class="hlt">boundary</span> layer result in <span class="hlt">boundary</span>-layer momentum-integral equations for three-dimensional flows that are applicable to either rotating or nonrotating fluid <span class="hlt">boundaries</span>. These equations are simplified and an approximate solution in closed integral form is obtained for a generalized <span class="hlt">boundary</span>-layer momentum-loss thickness and flow deflection at the wall in the turbulent case. A numerical evaluation of this solution carried out for data obtained in a curving nonrotating duct shows a fair quantitative agreement with the measures values. The form in which the equations are presented is readily adaptable to cases of steady, three-dimensional, incompressible <span class="hlt">boundary</span>-layer flow like that over curved ducts or yawed wings; and it also may be used to describe the <span class="hlt">boundary</span>-layer flow over various rotating surfaces, thus applying to turbomachinery, propellers, and helicopter blades.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70195140','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70195140"><span>Quake warnings, <span class="hlt">seismic</span> culture</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Allen, Richard M.; Cochran, Elizabeth S.; Huggins, Tom; Miles, Scott; Otegui, Diego</p> <p>2017-01-01</p> <p>Since 1990, nearly one million people have died from the impacts of earthquakes. Reducing those impacts requires building a local <span class="hlt">seismic</span> culture in which residents are aware of earthquake risks and value efforts to mitigate harm. Such efforts include earthquake early warning (EEW) <span class="hlt">systems</span> that provide seconds to minutes notice of pending shaking. Recent events in Mexico provide an opportunity to assess performance and perception of an EEW <span class="hlt">system</span> and highlight areas for further improvement. We have learned that EEW <span class="hlt">systems</span>, even imperfect ones, can help people prepare for earthquakes and build local <span class="hlt">seismic</span> culture, both beneficial in reducing earthquake-related losses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1710388C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1710388C"><span>An Earth <span class="hlt">system</span> view on <span class="hlt">boundaries</span> for human perturbation of the N and P cycles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cornell, Sarah; de Vries, Wim</p> <p>2015-04-01</p> <p>The appropriation and transformation of land, water, and living resources can alter Earth <span class="hlt">system</span> functioning, and potentially undermine the basis for the sustainability of our societies. Human activities have greatly increased the flows of reactive forms of nitrogen (N) and phosphorus (P) in the Earth <span class="hlt">system</span>. These non-substitutable nutrient elements play a fundamental role in the human food <span class="hlt">system</span>. Furthermore, the current mode of social and economic globalization, and its effect on the present-day energy <span class="hlt">system</span>, also has large effects including large NOx-N emissions through combustion. Until now, this perturbation of N and P cycles has been treated largely as a local/regional issue, and managed in terms of direct impacts (water, land or air pollution). However, anthropogenic N and P cycle changes affect physical Earth <span class="hlt">system</span> feedbacks (through greenhouse gas and aerosol changes) and biogeochemical feedbacks (via ecosystem changes, links to the carbon cycle, and altered nutrient limitation) with impacts that can be far removed from the direct sources. While some form of N and P management at the global level seems likely to be needed for continued societal development, the current local-level and sectorial management is often problematically simplistic, as seen in the tensions between divergent N management needs for climate change mitigation, air pollution control, food production, and ecosystem conservation. We require a step change in understanding complex biogeochemical, physical and socio-economic interactions in order to analyse these effects together, and inform policy trade-offs to minimize emergent <span class="hlt">systemic</span> risks. Planetary <span class="hlt">boundaries</span> for N and P cycle perturbation have recently been proposed. We discuss the current status of these precautionary <span class="hlt">boundaries</span> and how we may improve on these preliminary assessments. We present an overview of the human perturbation of the global biogeochemical cycles of N and P and its interaction with the functioning of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70157323','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70157323"><span><span class="hlt">Seismic</span> seiches</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; Gupta, Harsh K.</p> <p>2011-01-01</p> <p><span class="hlt">Seismic</span> seiche is a term first used by Kvale (1955) to discuss oscillations of lake levels in Norway and England caused by the Assam earthquake of August 15, 1950. This definition has since been generalized to apply to standing waves set up in closed, or partially closed, bodies of water including rivers, shipping channels, lakes, swimming pools and tanks due to the passage of <span class="hlt">seismic</span> waves from an earthquake.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhDT........17J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhDT........17J"><span>Immersed <span class="hlt">Boundary</span> Methods for Optimization of Strongly Coupled Fluid-Structure <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jenkins, Nicholas J.</p> <p></p> <p>Conventional methods for design of tightly coupled multidisciplinary <span class="hlt">systems</span>, such as fluid-structure interaction (FSI) problems, traditionally rely on manual revisions informed by a loosely coupled linearized analysis. These approaches are both inaccurate for a multitude of applications, and they require an intimate understanding of the assumptions and limitations of the procedure in order to soundly optimize the design. Computational optimization, in particular topology optimization, has been shown to yield remarkable results for problems in solid mechanics using density interpolations schemes. In the context of FSI, however, well defined <span class="hlt">boundaries</span> play a key role in both the design problem and the mechanical model. Density methods neither accurately represent the material <span class="hlt">boundary</span>, nor provide a suitable platform to apply appropriate interface conditions. This thesis presents a new framework for shape and topology optimization of FSI problems that uses for the design problem the Level Set method (LSM) to describe the geometry evolution in the optimization process. The Extended Finite Element method (XFEM) is combined with a fictitiously deforming fluid domain (stationary arbitrary Lagrangian-Eulerian method) to predict the FSI response. The novelty of the proposed approach lies in the fact that the XFEM explicitly captures the material <span class="hlt">boundary</span> defined by the level set iso-surface. Moreover, the XFEM provides a means to discretize the governing equations, and weak immersed <span class="hlt">boundary</span> conditions are applied with Nitsche's Method to couple the fields. The flow is predicted by the incompressible Navier-Stokes equations, and a finite-deformation solid model is developed and tested for both hyperelastic and linear elastic problems. Transient and stationary numerical examples are presented to validate the FSI model and numerical solver approach. Pertaining to the optimization of FSI problems, the parameters of the discretized level set function are defined as explicit</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1255155-multiple-plates-subducting-beneath-colombia-illuminated-seismicity-velocity-from-joint-inversion-seismic-gravity-data','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1255155-multiple-plates-subducting-beneath-colombia-illuminated-seismicity-velocity-from-joint-inversion-seismic-gravity-data"><span>Multiple plates subducting beneath Colombia, as illuminated by <span class="hlt">seismicity</span> and velocity from the joint inversion of <span class="hlt">seismic</span> and gravity data</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Syracuse, Ellen M.; Maceira, Monica; Prieto, German A.; ...</p> <p>2016-04-12</p> <p>Subduction beneath the northernmost Andes in Colombia is complex. Based on <span class="hlt">seismicity</span> distributions, multiple segments of slab appear to be subducting, and arc volcanism ceases north of 5° N. Here, we illuminate the subduction <span class="hlt">system</span> through hypocentral relocations and Vp and Vs models resulting from the joint inversion of local body wave arrivals, surface wave dispersion measurements, and gravity data. The simultaneous use of multiple data types takes advantage of the differing sensitivities of each data type, resulting in velocity models that have improved resolution at both shallower and deeper depths than would result from traditional travel time tomography alone.more » The relocated earthquake dataset and velocity model clearly indicate a tear in the Nazca slab at 5° N, corresponding to a 250-km shift in slab <span class="hlt">seismicity</span> and the termination of arc volcanism. North of this tear, the slab is flat, and it comprises slabs of two sources: the Nazca and Caribbean plates. The Bucaramanga nest, a small region of among the most intense intermediate-depth <span class="hlt">seismicity</span> globally, is associated with the <span class="hlt">boundary</span> between these two plates and possibly with a zone of melting or elevated water content, based on reduced Vp and increased Vp/Vs. As a result, we also use relocated <span class="hlt">seismicity</span> to identify two new faults in the South American plate, one related to plate convergence and one highlighted by induced <span class="hlt">seismicity</span>.« less</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/2013AGUFM.T43D2696B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T43D2696B"><span>Plate <span class="hlt">boundary</span> and major fault <span class="hlt">system</span> in the overriding plate within the Shumagin gap at the Alaska-Aleutian 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>Becel, A.; Shillington, D. J.; Nedimovic, M. R.; Keranen, K. M.; Li, J.; Webb, S. C.; Kuehn, H.</p> <p>2013-12-01</p> <p>Structure in the overriding plate is one of the parameters that may increase the tsunamigenic potential of a subduction zone but also influence the seismogenic behavior and segmentation of great earthquake rupture. The Alaska-Aleutian margin is characterized by along-strike changes in plate interface coupling over relatively small distances. Here, we present trench normal multichannel <span class="hlt">seismic</span> (MCS) profiles acquired across the Shumagin gap that has not broken in many decades and appears to be weakly coupled. The high fold, deep penetration (636 channel, 8-km long streamer, 6600 cu.in airgun source) MCS data were acquired as part of the ALEUT project. This dataset gives us critical new constraints on the interplate <span class="hlt">boundary</span> that can be traced over ~100 km distance beneath the forearc with high variation in its reflection response with depth. These profiles also reveal the detailed upper plate fault structure and forearc morphology. Clear reflections in the overriding plate appear to delineate one or more large faults that cross the shelf and the upper slope. These faults are observed 75 km back from the trench and seem to branch at depth and connect to the plate interface within this gap at ~11 s twtt. We compare the reflective structure of these faults to that of the plate <span class="hlt">boundary</span> and examine where it intersects the megathrust with respect of the expected downdip limit of coupling. We also compare this major structure with the <span class="hlt">seismicity</span> recorded in this sector. The imaged fault <span class="hlt">system</span> is associated with a large deep basin (~6s twt) that is an inherited structure formed during the pre-Aleutian period. Basins faults appear to have accommodated primarily normal motion, although folding of sediments near the fault and complicated fault geometries in the shallow section may indicate that this fault has accommodated other types of motion during its history that may reflect the stress-state at the megathrust over time. The deformation within the youngest sediment also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSM.S41A..02C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSM.S41A..02C"><span>Mexican <span class="hlt">Seismic</span> Alert <span class="hlt">System</span>'s SAS-I algorithm review considering strong earthquakes felt in Mexico City since 1985</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cuellar Martinez, A.; Espinosa Aranda, J.; Suarez, G.; Ibarrola Alvarez, G.; Ramos Perez, S.; Camarillo Barranco, L.</p> <p>2013-05-01</p> <p>The <span class="hlt">Seismic</span> Alert <span class="hlt">System</span> of Mexico (SASMEX) uses three algorithms for alert activation that involve the distance between the <span class="hlt">seismic</span> sensing field station (FS) and the city to be alerted; and the forecast for earthquake early warning activation in the cities integrated to the <span class="hlt">system</span>, for example in Mexico City, the earthquakes occurred with the highest accelerations, were originated in the Pacific Ocean coast, whose distance this <span class="hlt">seismic</span> region and the city, favors the use of algorithm called Algorithm SAS-I. This algorithm, without significant changes since its beginning in 1991, employs the data that generate one or more FS during P wave detection until S wave detection plus a period equal to the time employed to detect these phases; that is the double S-P time, called 2*(S-P). In this interval, the algorithm performs an integration process of quadratic samples from FS which uses a triaxial accelerometer to get two parameters: amplitude and growth rate measured until 2*(S-P) time. The parameters in SAS-I are used in a Magnitude classifier model, which was made from Guerrero Coast earthquakes time series, with reference to Mb magnitude mainly. This algorithm activates a Public or Preventive Alert if the model predicts whether Strong or Moderate earthquake. The SAS-I algorithm has been operating for over 23 years in the subduction zone of the Pacific Coast of Mexico, initially in Guerrero and followed by Oaxaca; and since March 2012 in the <span class="hlt">seismic</span> region of Pacific covering the coasts among Jalisco, Colima, Michoacan, Guerrero and Oaxaca, where this algorithm has issued 16 Public Alert and 62 Preventive Alerts to the Mexico City where its soil conditions increase damages by earthquake such as the occurred in September 1985. This work shows the review of the SAS-I algorithm and possible alerts that it could generate from major earthquakes recordings detected by FS or seismometers near the earthquakes, coming from Pacific Ocean Coast whose have been felt in Mexico</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S31B0811F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S31B0811F"><span>A <span class="hlt">seismic</span> hazard overview of the Mitidja Basin (Northern Algeria)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fontiela, J. F.; Borges, J.; Ouyed, M.; Bezzeghoud, M.; Idres, M.; Caldeira, B.; Boughacha, M. S.; Carvalho, J.; Samai, S.; Aissa, S.; Benfadda, A.; Chimouni, R.; Yalaoui, R.; Dias, R.</p> <p>2017-12-01</p> <p>The Mitidja Basin (MB) is located in N Algeria and it is filled by quaternary sediments with a length of 100 km on the EW direction and around 20 km width. The S and N limites comprise the Boumerdes-Larbaa-Blida, and the Thenia-Sahel active fault <span class="hlt">system</span>, respectively. Both fault <span class="hlt">systems</span> are of the reverse type with opposed dips and accommodate a general slip rate of ˜4 mm/year. In the basin occurred earthquakes that caused severe damage and losses such as the ones of Algiers (1365, Io=X; 1716, Io=X) and the Bourmedes earthquake (Mw 6.9; May 2003) that affected the area of Zemmouri and caused 2.271 deaths. The event was caused by the reactivation of the MB <span class="hlt">boundary</span> faults. The earthquake generated a max uplift of 0.8m along the coast and a horizontal max. slip of 0.24m.Recent studies show that the Boumerdes earthquake overloaded the adjacent faults <span class="hlt">system</span> with a stress increase between 0.4 and 1.5 bar. The stress change recommends a detailed study of mentioned faults <span class="hlt">system</span> due to the increase of the <span class="hlt">seismic</span> hazard. The high seismogenic potential of the fault <span class="hlt">system</span> bordering the MB, increases the vulnerability of densely populated areas of Algiers and the amplification effect caused by the basin are the motivation of this project that will focus on the evaluation of the <span class="hlt">seismic</span> hazard of the region. To achieve <span class="hlt">seismic</span> hazard assessment on the MB, through realistic predictions of strong ground motion, caused by moderate and large earthquakes, it is important 1) develop a detailed 3D velocity/structure model of the MB that includes geological constraints, <span class="hlt">seismic</span> reflection data acquired on wells, refraction velocities and <span class="hlt">seismic</span> noise data, and determination of the attenuation laws based on instrumental records; 2) evaluate the <span class="hlt">seismic</span> potential and parameters of the main active faults of the MB; 3) develop numerical methods (deterministic and stochastic) to simulate strong ground motions produced by extended <span class="hlt">seismic</span> sources. To acquire <span class="hlt">seismic</span> noise were used</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000GeoJI.143..239N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000GeoJI.143..239N"><span>Effects of volcano topography on <span class="hlt">seismic</span> broad-band waveforms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neuberg, Jürgen; Pointer, Tim</p> <p>2000-10-01</p> <p>Volcano seismology often deals with rather shallow <span class="hlt">seismic</span> sources and <span class="hlt">seismic</span> stations deployed in their near field. The complex stratigraphy on volcanoes and near-field source effects have a strong impact on the <span class="hlt">seismic</span> wavefield, complicating the interpretation techniques that are usually employed in earthquake seismology. In addition, as most volcanoes have a pronounced topography, the interference of the <span class="hlt">seismic</span> wavefield with the stress-free surface results in severe waveform perturbations that affect <span class="hlt">seismic</span> interpretation methods. In this study we deal predominantly with the surface effects, but take into account the impact of a typical volcano stratigraphy as well as near-field source effects. We derive a correction term for plane <span class="hlt">seismic</span> waves and a plane-free surface such that for smooth topographies the effect of the free surface can be totally removed. Seismo-volcanic sources radiate energy in a broad frequency range with a correspondingly wide range of different Fresnel zones. A 2-D <span class="hlt">boundary</span> element method is employed to study how the size of the Fresnel zone is dependent on source depth, dominant wavelength and topography in order to estimate the limits of the plane wave approximation. This approximation remains valid if the dominant wavelength does not exceed twice the source depth. Further aspects of this study concern particle motion analysis to locate point sources and the influence of the stratigraphy on particle motions. Furthermore, the deployment strategy of <span class="hlt">seismic</span> instruments on volcanoes, as well as the direct interpretation of the broad-band waveforms in terms of pressure fluctuations in the volcanic plumbing <span class="hlt">system</span>, are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...639142M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...639142M"><span>Modeling quorum sensing trade-offs between bacterial cell density and <span class="hlt">system</span> extension from open <span class="hlt">boundaries</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marenda, Mattia; Zanardo, Marina; Trovato, Antonio; Seno, Flavio; Squartini, Andrea</p> <p>2016-12-01</p> <p>Bacterial communities undergo collective behavioural switches upon producing and sensing diffusible signal molecules; a mechanism referred to as Quorum Sensing (QS). Exemplarily, biofilm organic matrices are built concertedly by bacteria in several environments. QS scope in bacterial ecology has been debated for over 20 years. Different perspectives counterpose the role of density reporter for populations to that of local environment diffusivity probe for individual cells. Here we devise a model <span class="hlt">system</span> where tubes of different heights contain matrix-embedded producers and sensors. These tubes allow non-limiting signal diffusion from one open end, thereby showing that population spatial extension away from an open <span class="hlt">boundary</span> can be a main critical factor in QS. Experimental data, successfully recapitulated by a comprehensive mathematical model, demonstrate how tube height can overtake the role of producer density in triggering sensor activation. The biotic degradation of the signal is found to play a major role and to be species-specific and entirely feedback-independent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PrICA...1..118V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PrICA...1..118V"><span>A <span class="hlt">Boundary</span> Delineation <span class="hlt">System</span> for the Bureau of Ocean Energy Management</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vandegraft, Douglas L.</p> <p>2018-05-01</p> <p>Federal government mapping of the offshore areas of the United States in support of the development of oil and gas resources began in 1954. The first mapping <span class="hlt">system</span> utilized a network of rectangular blocks defined by State Plane coordinates which was later revised to utilize the Universal Transverse Mercator grid. Creation of offshore <span class="hlt">boundaries</span> directed by the Submerged Lands Act and Outer Continental Shelf Lands Act were mathematically determined using early computer programs that performed the required computations, but required many steps. The Bureau of Ocean Energy Management has revised these antiquated methods using GIS technology which provide the required accuracy and produce the mapping products needed for leasing of energy resources, including renewable energy projects, on the outer continental shelf. (Note: this is an updated version of a paper of the same title written and published in 2015).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994DyAtO..21...83K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994DyAtO..21...83K"><span>Numerical modelling of the Black Sea eigen-oscillations on a curvilinear <span class="hlt">boundary</span> fitted coordinate <span class="hlt">system</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koychev Demirov, Encho</p> <p>1994-12-01</p> <p>The paper presents a numerical solution of barotropic and two-layer eigen-oscillation problems for the Black Sea on a <span class="hlt">boundary</span> fitted coordinate <span class="hlt">system</span>. This solution is compared with model and empirical data obtained by other workers. Frequencies of the eigen-oscillations found by the numerical solution of spectral problem are compared with the data obtained by spectral analysis of the sea-level oscillations measured near the town of Achtopol and Cape Irakli in stormy sea on 17-21 February 1979. Extreme oscillations of the sea-level result from resonant amplifications of three eigenmodes of the Black Sea of 68.3 -1, 36.6 -1 and 27.3 -1 cycles h -1 frequency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJWC.12206005I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJWC.12206005I"><span>Coupled-rearrangement-channels calculation of the three-body <span class="hlt">system</span> under the absorbing <span class="hlt">boundary</span> condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iwasaki, M.; Otani, R.; Ito, M.; Kamimura, M.</p> <p>2016-06-01</p> <p>We formulate the absorbing <span class="hlt">boundary</span> condition (ABC) in the coupled rearrangement-channels variational method (CRCVM) for the three-body problem. The absorbing potential is introduced in the <span class="hlt">system</span> of the identical three-bosons, on which the boson symmetry is explicitly imposed by considering the rearrangement channels. The resonance parameters and the strength of the monopole breakup are calculated by the CRCVM + ABC method, and the results are compared with the complex scaling method (CSM). We have found that the results of the ABC method are consistent with the CSM results. The effect of the boson symmetry, which is often neglected in the calculation of the triple α reactions, is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27966657','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27966657"><span>Modeling quorum sensing trade-offs between bacterial cell density and <span class="hlt">system</span> extension from open <span class="hlt">boundaries</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Marenda, Mattia; Zanardo, Marina; Trovato, Antonio; Seno, Flavio; Squartini, Andrea</p> <p>2016-12-14</p> <p>Bacterial communities undergo collective behavioural switches upon producing and sensing diffusible signal molecules; a mechanism referred to as Quorum Sensing (QS). Exemplarily, biofilm organic matrices are built concertedly by bacteria in several environments. QS scope in bacterial ecology has been debated for over 20 years. Different perspectives counterpose the role of density reporter for populations to that of local environment diffusivity probe for individual cells. Here we devise a model <span class="hlt">system</span> where tubes of different heights contain matrix-embedded producers and sensors. These tubes allow non-limiting signal diffusion from one open end, thereby showing that population spatial extension away from an open <span class="hlt">boundary</span> can be a main critical factor in QS. Experimental data, successfully recapitulated by a comprehensive mathematical model, demonstrate how tube height can overtake the role of producer density in triggering sensor activation. The biotic degradation of the signal is found to play a major role and to be species-specific and entirely feedback-independent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22451164-dual-nature-localization-guiding-systems-randomly-corrugated-boundaries-anderson-type-versus-entropic','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22451164-dual-nature-localization-guiding-systems-randomly-corrugated-boundaries-anderson-type-versus-entropic"><span>Dual nature of localization in guiding <span class="hlt">systems</span> with randomly corrugated <span class="hlt">boundaries</span>: Anderson-type versus entropic</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tarasov, Yu.V., E-mail: yutarasov@ire.kharkov.ua; Shostenko, L.D.</p> <p></p> <p>A unified theory for the conductance of an infinitely long multimode quantum wire whose finite segment has randomly rough lateral <span class="hlt">boundaries</span> is developed. It enables one to rigorously take account of all feasible mechanisms of wave scattering, both related to <span class="hlt">boundary</span> roughness and to contacts between the wire rough section and the perfect leads within the same technical frameworks. The rough part of the conducting wire is shown to act as a mode-specific randomly modulated effective potential barrier whose height is governed essentially by the asperity slope. The mean height of the barrier, which is proportional to the average slopemore » squared, specifies the number of conducting channels. Under relatively small asperity amplitude this number can take on arbitrary small, up to zero, values if the asperities are sufficiently sharp. The consecutive channel cut-off that arises when the asperity sharpness increases can be regarded as a kind of localization, which is not related to the disorder per se but rather is of entropic or (equivalently) geometric origin. The fluctuating part of the effective barrier results in two fundamentally different types of guided wave scattering, viz., inter- and intramode scattering. The intermode scattering is shown to be for the most part very strong except in the cases of (a) extremely smooth asperities, (b) excessively small length of the corrugated segment, and (c) the asperities sharp enough for only one conducting channel to remain in the wire. Under strong intermode scattering, a new set of conducting channels develops in the corrugated waveguide, which have the form of asymptotically decoupled extended modes subject to individual solely intramode random potentials. In view of this fact, two transport regimes only are realizable in randomly corrugated multimode waveguides, specifically, the ballistic and the localized regime, the latter characteristic of one-dimensional random <span class="hlt">systems</span>. Two kinds of localization are thus</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CSR...153...64C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CSR...153...64C"><span>Geochemistry and magnetic sediment distribution at the western <span class="hlt">boundary</span> upwelling <span class="hlt">system</span> of southwest Atlantic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cruz, Anna P. S.; Barbosa, Catia F.; Ayres-Neto, Arthur; Munayco, Pablo; Scorzelli, Rosa B.; Amorim, Nívea Santos; Albuquerque, Ana L. S.; Seoane, José C. S.</p> <p>2018-02-01</p> <p>In order to investigate the chemical and magnetic characteristics of sediments of the western <span class="hlt">boundary</span> upwelling <span class="hlt">system</span> of Southwest Atlantic we analyzed magnetic susceptibility, grain size distribution, total organic carbon, heavy mineral abundance, Fe associated with Mössbauer spectra, and Fe and Mn of pore water to evaluate the deposition patterns of sediments. Four box-cores were collected along a cross-shelf transect. Brazil Current and coastal plume exert a primary control at the inner and outer shelf cores, which exhibited similar depositional patterns characterized by a high abundance of heavy minerals (mean 0.21% and 0.08%, respectively) and very fine sand, whereas middle shelf cores presented low abundances of heavy minerals (mean 0.03%) and medium silt. The inner shelf was dominated by sub-angular grains, while in middle and outer shelf cores well-rounded grains were found. The increasing Fe3+:Fe2+ ratio from the inner to the outer shelf reflects farther distance to the sediment source. The outer shelf presented well-rounded minerals, indicating abrasive processes as a result of transport by the Brazil Current from the source areas. In the middle shelf, cold-water intrusion of the South Atlantic Central Water contributes to the primary productivity, resulting in higher deposition of fine sediment and organic carbon accumulation. The high input of organic carbon and the decreased grain size are indicative of changes in the hydrodynamics and primary productivity fueled by the western <span class="hlt">boundary</span> upwelling <span class="hlt">system</span>, which promotes loss of magnetization due to the induction of diagenesis of iron oxide minerals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSG...105...18M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSG...105...18M"><span>Characterization of the <span class="hlt">seismically</span> imaged Tuscarora fold <span class="hlt">system</span> and implications for layer parallel shortening in the Pennsylvania salient</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mount, Van S.; Wilkins, Scott; Comiskey, Cody S.</p> <p>2017-12-01</p> <p>The Tuscarora fold <span class="hlt">system</span> (TFS) is located in the Pennsylvania salient in the foreland of the Valley and Ridge province. The TFS is imaged in high quality 3D <span class="hlt">seismic</span> data and comprises a <span class="hlt">system</span> of small-scale folds within relatively flat-lying Lower Silurian Tuscarora Formation strata. We characterize the TFS structures and infer layer parallel shortening (LPS) directions and magnitudes associated with deformation during the Alleghany Orogeny. Previously reported LPS data in our study area are from shallow Devonian and Carboniferous strata (based on outcrop and core analyses) above the shallowest of three major detachments recognized in the region. <span class="hlt">Seismic</span> data allows us to characterize LPS at depth in strata beneath the shallow detachment. Our LPS data (orientations and inferred magnitudes) are consistent with the shallow data leading us to surmise that LPS during Alleghanian deformation fanned around the salient and was distributed throughout the stratigraphic section - and not isolated to strata above the shallow detachment. We propose that a NW-SE oriented Alleghanian maximum principal stress was perturbed by deep structure associated with the non-linear margin of Laurentia resulting in fanning of shortening directions within the salient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T23C0622S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T23C0622S"><span>Core-Log-<span class="hlt">Seismic</span> investigations of the Surveyor Fan and Channel <span class="hlt">system</span> during the Pleistocene; IODP Exp. 341</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Somchat, K.; Reece, R.; Gulick, S. P. S.</p> <p>2017-12-01</p> <p>The Chugach-St. Elias mountain range is the product of the ongoing subduction and collision of the Yakutat microplate with the North America Plate. The presence of this high topography close to the shoreline creates a unique source-to-sink <span class="hlt">system</span> in which glacial eroded sediment is transported directly to the sea and preserved offshore in a deep sea fan without intervening storage. Surveyor Fan and Channel <span class="hlt">system</span> is the product of this <span class="hlt">system</span>. In this study we will focus on the four tributary channels that form at the head of the Surveyor Channel complex and merge into the main channel trunk 200 km from the shelf edge. We integrated drill core and 2D <span class="hlt">seismic</span> reflection data to study the evolution of these tributaries in order to decipher glacial history along the southern Alaskan margin since the mid-Pleistocene (1.2 Ma). An age model from Integrated Ocean Drilling Program Expedition 341 Site U1418 provides a higher resolution chronology of sediment delivery to the Surveyor Fan than previous studies. We regionally mapped the <span class="hlt">seismic</span> subunits previously identified by Exp. 341 scientists starting from Site U1418 and analyzed regional patterns of sediment deposition. Channel migrations are observable between 1.2-0.5 Ma which could be the result of increasing glacial ice volume onshore due to onset of the MPT. Two-way travel time (isopach) maps of the three subunits show that sediment depocenter began to move eastward since 1.2 Ma with a trend of overall sediment flux increase in all tributary channels. Changes in sediment flux in each <span class="hlt">system</span> represent the changes in volume of glacial ice over successive glacial intervals. Additionally, <span class="hlt">seismic</span> analysis of channel geomorphology shows that each <span class="hlt">system</span> contains distinct geomorphological evolutions that respond to the glacially eroded sediment flux at different times. Since glacial erosional processes is the driver of this source-to-sink <span class="hlt">system</span>, a history of glacial ice onshore since the Pleistocene can be inferred from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptCo.410....1C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptCo.410....1C"><span>Performance improvement of 64-QAM coherent optical communication <span class="hlt">system</span> by optimizing symbol decision <span class="hlt">boundary</span> based on support vector machine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Wei; Zhang, Junfeng; Gao, Mingyi; Shen, Gangxiang</p> <p>2018-03-01</p> <p>High-order modulation signals are suited for high-capacity communication <span class="hlt">systems</span> because of their high spectral efficiency, but they are more vulnerable to various impairments. For the signals that experience degradation, when symbol points overlap on the constellation diagram, the original linear decision <span class="hlt">boundary</span> cannot be used to distinguish the classification of symbol. Therefore, it is advantageous to create an optimum symbol decision <span class="hlt">boundary</span> for the degraded signals. In this work, we experimentally demonstrated the 64-quadrature-amplitude modulation (64-QAM) coherent optical communication <span class="hlt">system</span> using support-vector machine (SVM) decision <span class="hlt">boundary</span> algorithm to create the optimum symbol decision <span class="hlt">boundary</span> for improving the <span class="hlt">system</span> performance. We investigated the influence of various impairments on the 64-QAM coherent optical communication <span class="hlt">systems</span>, such as the impairments caused by modulator nonlinearity, phase skew between in-phase (I) arm and quadrature-phase (Q) arm of the modulator, fiber Kerr nonlinearity and amplified spontaneous emission (ASE) noise. We measured the bit-error-ratio (BER) performance of 75-Gb/s 64-QAM signals in the back-to-back and 50-km transmission. By using SVM to optimize symbol decision <span class="hlt">boundary</span>, the impairments caused by I/Q phase skew of the modulator, fiber Kerr nonlinearity and ASE noise are greatly mitigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.S33B0325S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.S33B0325S"><span>Southern California <span class="hlt">Seismic</span> Network: New Design and Implementation of Redundant and Reliable Real-time Data Acquisition <span class="hlt">Systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saleh, T.; Rico, H.; Solanki, K.; Hauksson, E.; Friberg, P.</p> <p>2005-12-01</p> <p>The Southern California <span class="hlt">Seismic</span> Network (SCSN) handles more than 2500 high-data rate channels from more than 380 <span class="hlt">seismic</span> stations distributed across southern California. These data are imported real-time from dataloggers, earthworm hubs, and partner networks. The SCSN also exports data to eight different partner networks. Both the imported and exported data are critical for emergency response and scientific research. Previous data acquisition <span class="hlt">systems</span> were complex and difficult to operate, because they grew in an ad hoc fashion to meet the increasing needs for distributing real-time waveform data. To maximize reliability and redundancy, we apply best practices methods from computer science for implementing the software and hardware configurations for import, export, and acquisition of real-time <span class="hlt">seismic</span> data. Our approach makes use of failover software designs, methods for dividing labor diligently amongst the network nodes, and state of the art networking redundancy technologies. To facilitate maintenance and daily operations we seek to provide some separation between major functions such as data import, export, acquisition, archiving, real-time processing, and alarming. As an example, we make waveform import and export functions independent by operating them on separate servers. Similarly, two independent servers provide waveform export, allowing data recipients to implement their own redundancy. The data import is handled differently by using one primary server and a live backup server. These data import servers, run fail-over software that allows automatic role switching in case of failure from primary to shadow. Similar to the classic earthworm design, all the acquired waveform data are broadcast onto a private network, which allows multiple machines to acquire and process the data. As we separate data import and export away from acquisition, we are also working on new approaches to separate real-time processing and rapid reliable archiving of real-time data</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009GeoJI.179.1301A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009GeoJI.179.1301A"><span><span class="hlt">Seismically</span> active column and volcanic plumbing <span class="hlt">system</span> beneath the island arc of the Izu-Bonin 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>Špičák, Aleš; Vaněk, Jiří; Hanuš, Václav</p> <p>2009-12-01</p> <p>A detailed spatio-temporal analysis of teleseismic earthquake occurrence (mb > 4.0) along the convergent margin of the Izu-Bonin-Mariana arc <span class="hlt">system</span> reveals an anomalously high concentration of events between 27° and 30.5°N, beneath a chain of seamounts between Tori-shima and Nishino-shima volcanoes. This <span class="hlt">seismicity</span> is dominated by the 1985/1986 earthquake swarm represented in the Engdahl—van der Hilst—Buland database by 146 earthquakes in the body wave magnitude range 4.3-5.8 and focal depth range 1-100 km. The epicentral cluster of the swarm is elongated parallel to the volcanic chain. Available focal mechanisms are consistent with an extensional tectonic regime and reveal nodal planes with azimuths close to that of the epicentral cluster. Earthquakes of the 1985/1986 swarm occurred in seven time phases. <span class="hlt">Seismic</span> activity migrated in space from one phase to the other. Earthquake foci belonging to individual phases of the swarm aligned in vertically disposed <span class="hlt">seismically</span> active columns. The epicentral zones of the columns are located in the immediate vicinity of seamounts Suiyo and Mokuyo, recently reported by the Japanese Meteorological Agency as volcanically active. The three observations—episodic character of earthquake occurrence, column-like vertically arranged <span class="hlt">seismicity</span> pattern, and existence of volcanic seamounts at the seafloor above the earthquake foci—led us to interpret the 1985/1986 swarm as a consequence of subduction-related magmatic and/or fluid activity. A modification of the shallow earthquake swarm magmatic model of D. Hill fits earthquake foci distribution, tectonic stress orientation and fault plane solutions. The 1985/1986 deep-rooted earthquake swarm in the Izu-Bonin region represents an uncommon phenomenon of plate tectonics. The portion of the lithospheric wedge that was affected by the swarm should be composed of fractured rigid, brittle material so that the source of magma and/or fluids which might induce the swarm should be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009GeoJI.179.1301S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009GeoJI.179.1301S"><span><span class="hlt">Seismically</span> active column and volcanic plumbing <span class="hlt">system</span> beneath the island arc of the Izu-Bonin 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>Špičák, Aleš; Vaněk, Jiří; Hanuš, Václav</p> <p>2009-12-01</p> <p>A detailed spatio-temporal analysis of teleseismic earthquake occurrence (mb > 4.0) along the convergent margin of the Izu-Bonin-Mariana arc <span class="hlt">system</span> reveals an anomalously high concentration of events between 27° and 30.5°N, beneath a chain of seamounts between Tori-shima and Nishino-shima volcanoes. This <span class="hlt">seismicity</span> is dominated by the 1985/1986 earthquake swarm represented in the Engdahl-van der Hilst-Buland database by 146 earthquakes in the body wave magnitude range 4.3-5.8 and focal depth range 1-100 km. The epicentral cluster of the swarm is elongated parallel to the volcanic chain. Available focal mechanisms are consistent with an extensional tectonic regime and reveal nodal planes with azimuths close to that of the epicentral cluster. Earthquakes of the 1985/1986 swarm occurred in seven time phases. <span class="hlt">Seismic</span> activity migrated in space from one phase to the other. Earthquake foci belonging to individual phases of the swarm aligned in vertically disposed <span class="hlt">seismically</span> active columns. The epicentral zones of the columns are located in the immediate vicinity of seamounts Suiyo and Mokuyo, recently reported by the Japanese Meteorological Agency as volcanically active. The three observations-episodic character of earthquake occurrence, column-like vertically arranged <span class="hlt">seismicity</span> pattern, and existence of volcanic seamounts at the seafloor above the earthquake foci-led us to interpret the 1985/1986 swarm as a consequence of subduction-related magmatic and/or fluid activity. A modification of the shallow earthquake swarm magmatic model of D. Hill fits earthquake foci distribution, tectonic stress orientation and fault plane solutions. The 1985/1986 deep-rooted earthquake swarm in the Izu-Bonin region represents an uncommon phenomenon of plate tectonics. The portion of the lithospheric wedge that was affected by the swarm should be composed of fractured rigid, brittle material so that the source of magma and/or fluids which might induce the swarm should be situated at a</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 <span class="hlt">systems</span> 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('http://adsabs.harvard.edu/abs/2012CoPhC.183.2019A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012CoPhC.183.2019A"><span>The Ndynamics package—Numerical analysis of dynamical <span class="hlt">systems</span> and the fractal dimension of <span class="hlt">boundaries</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Avellar, J.; Duarte, L. G. S.; da Mota, L. A. C. P.; de Melo, N.; Skea, J. E. F.</p> <p>2012-09-01</p> <p>A set of Maple routines is presented, fully compatible with the new releases of Maple (14 and higher). The package deals with the numerical evolution of dynamical <span class="hlt">systems</span> and provide flexible plotting of the results. The package also brings an initial conditions generator, a numerical solver manager, and a focusing set of routines that allow for better analysis of the graphical display of the results. The novelty that the package presents an optional C interface is maintained. This allows for fast numerical integration, even for the totally inexperienced Maple user, without any C expertise being required. Finally, the package provides the routines to calculate the fractal dimension of <span class="hlt">boundaries</span> (via box counting). New version program summary Program Title: Ndynamics Catalogue identifier: %Leave blank, supplied by Elsevier. Licensing provisions: no. Programming language: Maple, C. Computer: Intel(R) Core(TM) i3 CPU M330 @ 2.13 GHz. Operating <span class="hlt">system</span>: Windows 7. RAM: 3.0 GB Keywords: Dynamical <span class="hlt">systems</span>, Box counting, Fractal dimension, Symbolic computation, Differential equations, Maple. Classification: 4.3. Catalogue identifier of previous version: ADKH_v1_0. Journal reference of previous version: Comput. Phys. Commun. 119 (1999) 256. Does the new version supersede the previous version?: Yes. Nature of problem Computation and plotting of numerical solutions of dynamical <span class="hlt">systems</span> and the determination of the fractal dimension of the <span class="hlt">boundaries</span>. Solution method The default method of integration is a fifth-order Runge-Kutta scheme, but any method of integration present on the Maple <span class="hlt">system</span> is available via an argument when calling the routine. A box counting [1] method is used to calculate the fractal dimension [2] of the <span class="hlt">boundaries</span>. Reasons for the new version The Ndynamics package met a demand of our research community for a flexible and friendly environment for analyzing dynamical <span class="hlt">systems</span>. All the user has to do is create his/her own Maple session, with the <span class="hlt">system</span> to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JCoPh.350..759R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JCoPh.350..759R"><span>Multi-domain <span class="hlt">boundary</span> element method for axi-symmetric layered linear acoustic <span class="hlt">systems</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reiter, Paul; Ziegelwanger, Harald</p> <p>2017-12-01</p> <p>Homogeneous porous materials like rock wool or synthetic foam are the main tool for acoustic absorption. The conventional absorbing structure for sound-proofing consists of one or multiple absorbers placed in front of a rigid wall, with or without air-gaps in between. Various models exist to describe these so called multi-layered acoustic <span class="hlt">systems</span> mathematically for incoming plane waves. However, there is no efficient method to calculate the sound field in a half space above a multi layered acoustic <span class="hlt">system</span> for an incoming spherical wave. In this work, an axi-symmetric multi-domain <span class="hlt">boundary</span> element method (BEM) for absorbing multi layered acoustic <span class="hlt">systems</span> and incoming spherical waves is introduced. In the proposed BEM formulation, a complex wave number is used to model absorbing materials as a fluid and a coordinate transformation is introduced which simplifies singular integrals of the conventional BEM to non-singular radial and angular integrals. The radial and angular part are integrated analytically and numerically, respectively. The output of the method can be interpreted as a numerical half space Green's function for grounds consisting of layered materials.</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('https://pubs.usgs.gov/of/2006/1158/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2006/1158/"><span><span class="hlt">Seismic</span> constraints and coulomb stress changes of a blind thrust fault <span class="hlt">system</span>, 2: Northridge, 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>Stein, Ross S.; Lin, Jian</p> <p>2006-01-01</p> <p>We review <span class="hlt">seismicity</span>, surface faulting, and Coulomb stress changes associated with the 1994 Northridge, California, earthquake. All of the observed surface faulting is shallow, extending meters to tens of meters below the surface. Relocated aftershocks reveal no <span class="hlt">seismicity</span> shallower than 2 km depth. Although many of the aftershocks lie along the thrust fault and its up-dip extension, there are also a significant number of aftershocks in the core of the gentle anticline above the thrust, and elsewhere on the up-thrown block. These aftershocks may be associated with secondary ramp thrusts or flexural slip faults at a depth of 2-4 km. The geological structures typically associated with a blind thrust fault, such as anticlinal uplift and an associated syncline, are obscured and complicated by surface thrust faults associated with the San Fernando fault that overly the Northridge structures. Thus the relationship of the geological structure and topography to the underlying thrust fault is much more complex for Northridge than it is for the 1983 Coalinga, California, earthquake. We show from a Coulomb stress analysis that secondary surface faulting, diffuse aftershocks, and triggered sequences of moderate-sized mainshocks, are expected features of moderate-sized blind thrust earthquakes.</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/2015Tectp.651...66C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Tectp.651...66C"><span><span class="hlt">Seismic</span> properties and mineral crystallographic preferred orientations from EBSD data: Results from a crustal-scale detachment <span class="hlt">system</span>, Aegean region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cossette, Élise; Schneider, David; Audet, Pascal; Grasemann, Bernhard; Habler, Gerlinde</p> <p>2015-05-01</p> <p>The crystallographic preferred orientations (CPOs) were measured on a suite of samples representative of different structural depths along the West Cycladic Detachment <span class="hlt">System</span>, Greece. Electron backscatter diffraction (EBSD) analyses were conducted on calcitic and mica schists, impure quartzites, and a blueschist, and the average <span class="hlt">seismic</span> properties of the rocks were calculated with the Voigt-Reuss-Hill average of the single minerals' elastic stiffness tensor. The calcitic and quartzitic rocks have P- and S-wave velocity anisotropies (AVp, AVs) averaging 8.1% and 7.1%, respectively. The anisotropy increases with depth represented by the blueschist, with AVp averaging 20.3% and AVs averaging 14.5%, due to the content of aligned glaucophane and mica, which strongly control the <span class="hlt">seismic</span> properties of the rocks. Localised anisotropies of very high magnitudes are caused by the presence of mica schists as they possess the strongest anisotropies, with values of ~ 25% for AVp and AVs. The direction of the fast and slow P-wave velocities occurs parallel and perpendicular to the foliation, respectively, for most samples. The fast propagation has the same NE-SW orientation as the lithospheric stretching direction experienced in the Cyclades since the Late Oligocene. The maximum shear wave anisotropy is subhorizontal, similarly concordant with mineral alignment that developed during extension in the Aegean. Radial anisotropy in the Aegean mid-crust is strongly favoured to azimuthal anisotropy by our results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70028373','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70028373"><span>Association of the 1886 Charleston, South Carolina, earthquake and <span class="hlt">seismicity</span> near Summervile with a 12º bend in the East Coast fault <span class="hlt">system</span> and triple-fault junctions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Marple, R.; Miller, R.</p> <p>2006-01-01</p> <p><span class="hlt">Seismic</span>-reflection data were integrated with other geophysical, geologic, and <span class="hlt">seismicity</span> data to better determine the location and nature of buried faults in the Charleston, South Carolina, region. Our results indicate that the 1886 Charleston, South Carolina, earthquake and <span class="hlt">seismicity</span> near Summerville are related to local stresses caused by a 12?? bend in the East Coast fault <span class="hlt">system</span> (ECFS) and two triple-fault junctions. One triple junction is formed by the intersection of the northwest-trending Ashley River fault with the two segments of the ECFS north and south of the bend. The other triple junction is formed by the intersection of the northeast-trending Summerville fault and a newly discovered northwest-trending Berkeley fault with the ECFS about 10 km north of the bend. The Summerville fault is a northwest-dipping border fault of the Triassic-age Jedburg basin that is undergoing reverse-style reactivation. This reverse-style reactivation is unusual because the Summerville fault parallels the regional stress field axis, suggesting that the reactivation is from stresses applied by dextral motion on the ECFS. The southwest-dip and reverse-type motion of the Berkeley fault are interpreted from <span class="hlt">seismicity</span> data and a <span class="hlt">seismic</span>-reflection profile in the western part of the study area. Our results also indicate that the East Coast fault <span class="hlt">system</span> is a Paleozoic basement fault and that its reactivation since early Mesozoic time has fractured through the overlying allochthonous terranes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A13E2111N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A13E2111N"><span>Effects of resolved <span class="hlt">boundary</span> layer turbulence on near-ground rotation in simulated quasi-linear convective <span class="hlt">systems</span> (QLCSs)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nowotarski, C. J.</p> <p>2017-12-01</p> <p>Though most strong to violent tornadoes are associated with supercell thunderstorms, quasi-linear convective <span class="hlt">systems</span> (QLCSs) pose a risk of tornadoes, often at times and locations where supercell tornadoes are less common. Because QLCS low-level mesocyclones and tornado signatures tend to be less coherent, forecasting such tornadoes remains particularly difficult. The majority of simulations of such storms rely on horizontally homogeneous base states lacking resolved <span class="hlt">boundary</span> layer turbulence and surface fluxes. Previous work has suggested that heterogeneities associated with <span class="hlt">boundary</span> layer turbulence in the form of horizontal convective rolls can influence the evolution and characteristics of low-level mesocyclones in supercell thunderstorms. This study extends methods for generating <span class="hlt">boundary</span> layer convection to idealized simulations of QLCSs. QLCS simulations with resolved <span class="hlt">boundary</span> layer turbulence will be compared against a control simulation with a laminar <span class="hlt">boundary</span> layer. Effects of turbulence, the resultant heterogeneity in the near-storm environment, and surface friction on bulk storm characteristics and the intensity, morphology, and evolution of low-level rotation will be presented. Although maximum surface vertical vorticity values are similar, when <span class="hlt">boundary</span> layer turbulence is included, a greater number of miso- and meso-scale vortices develop along the QLCS gust front. The source of this vorticity is analyzed using Eulerian decomposition of vorticity tendency terms and trajectory analysis to delineate the relative importance of surface friction and baroclinicity in generating QLCS vortices. The role of anvil shading in suppressing <span class="hlt">boundary</span> layer turbulence in the near-storm environment and subsequent effects on QLCS vortices will also be presented. Finally, implications of the results regarding inclusion of more realistic <span class="hlt">boundary</span> layers in future idealized simulations of deep convection will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1174985','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1174985"><span>Methods and apparatus of suppressing tube waves within a bore hole and <span class="hlt">seismic</span> surveying <span class="hlt">systems</span> incorporating same</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>West, Phillip B.; Haefner, Daryl</p> <p>2004-08-17</p> <p>Methods and apparatus for attenuating waves in a bore hole, and <span class="hlt">seismic</span> surveying <span class="hlt">systems</span> incorporating the same. In one embodiment, an attenuating device includes a soft compliant bladder coupled to a pressurized gas source. A pressure regulating <span class="hlt">system</span> reduces the pressure of the gas from the gas source prior to entering the bladder and operates in conjunction with the hydrostatic pressure of the fluid in a bore hole to maintain the pressure of the bladder at a specified pressure relative to the surrounding bore hole pressure. Once the hydrostatic pressure of the bore hole fluid exceeds that of the gas source, bore hole fluid may be admitted into a vessel of the gas source to further compress and displace the gas contained therein. In another embodiment, a water-reactive material may be used to provide gas to the bladder wherein the amount of gas generated by the water-reactive material may depend on the hydrostatic pressure of the bore hole fluid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1175574','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1175574"><span>Methods and apparatus of suppressing tube waves within a bore hole and <span class="hlt">seismic</span> surveying <span class="hlt">systems</span> incorporating same</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>West, Phillip B.; Haefner, Daryl</p> <p>2005-12-13</p> <p>Methods and apparatus for attenuating waves in a bore hole, and <span class="hlt">seismic</span> surveying <span class="hlt">systems</span> incorporating the same. In one embodiment, an attenuating device includes a soft compliant bladder coupled to a pressurized gas source. A pressure regulating <span class="hlt">system</span> reduces the pressure of the gas from the gas source prior to entering the bladder and operates in conjunction with the hydrostatic pressure of the fluid in a bore hole to maintain the pressure of the bladder at a specified pressure relative to the surrounding bore hole pressure. Once the hydrostatic pressure of the bore hole fluid exceeds that of the gas source, bore hole fluid may be admitted into a vessel of the gas source to further compress and displace the gas contained therein. In another embodiment, a water-reactive material may be used to provide gas to the bladder wherein the amount of gas generated by the water-reactive material may depend on the hydrostatic pressure of the bore hole fluid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120016762','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016762"><span>Creation of an Upper Stage Trajectory Capability <span class="hlt">Boundary</span> to Enable Booster <span class="hlt">System</span> Trade Space Exploration</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Walsh, Ptrick; Coulon, Adam; Edwards, Stephen; Mavris, Dimitri N.</p> <p>2012-01-01</p> <p>The problem of trajectory optimization is important in all space missions. The solution of this problem enables one to specify the optimum thrust steering program which should be followed to achieve a specified mission objective, simultaneously satisfying the constraints.1 It is well known that whether or not the ascent trajectory is optimal can have a significant impact on propellant usage for a given payload, or on payload weight for the same gross vehicle weight.2 Consequently, ascent guidance commands are usually optimized in some fashion. Multi-stage vehicles add complexity to this analysis process as changes in vehicle properties in one stage propagate to the other stages through gear ratios and changes in the optimal trajectory. These effects can cause an increase in analysis time as more variables are added and convergence of the optimizer to <span class="hlt">system</span> closure requires more analysis iterations. In this paper, an approach to simplifying this multi-stage problem through the creation of an upper stage capability <span class="hlt">boundary</span> is presented. This work was completed as part of a larger study focused on trade space exploration for the advanced booster <span class="hlt">system</span> that will eventually form a part of NASA s new Space Launch <span class="hlt">System</span>.3 The approach developed leverages Design of Experiments and Surrogate Modeling4 techniques to create a predictive model of the SLS upper stage performance. The design of the SLS core stages is considered fixed for the purposes of this study, which results in trajectory parameters such as staging conditions being the only variables relevant to the upper stage. Through the creation of a surrogate model, which takes staging conditions as inputs and predicts the payload mass delivered by the SLS upper stage to a reference orbit as the response, it is possible to identify a "surface" of staging conditions which all satisfy the SLS requirement of placing 130 metric tons into low-Earth orbit (LEO).3 This identified surface represents the 130 metric ton</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA33A2593M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA33A2593M"><span>Understanding the Effects of Lower <span class="hlt">Boundary</span> Conditions and Eddy Diffusion on the Ionosphere-Thermosphere <span class="hlt">System</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malhotra, G.; Ridley, A. J.; Marsh, D. R.; Wu, C.; Paxton, L. J.</p> <p>2017-12-01</p> <p>The exchange of energy between lower atmospheric regions with the ionosphere-thermosphere (IT) <span class="hlt">system</span> is not well understood. A number of studies have observed day-to-day and seasonal variabilities in the difference between data and model output of various IT parameters. It is widely speculated that the forcing from the lower atmosphere, variability in weather <span class="hlt">systems</span> and gravity waves that propagate upward from troposphere into the upper mesosphere and lower thermosphere (MLT) may be responsible for these spatial and temporal variations in the IT region, but their exact nature is unknown. These variabilities can be interpreted in two ways: variations in state (density, temperature, wind) of the upper mesosphere or spatial and temporal changes in the small-scale mixing, or Eddy diffusion that is parameterized within the model.In this study, firstly, we analyze the sensitivity of the thermospheric and ionospheric states - neutral densities, O/N2, total electron content (TEC), peak electron density, and peak electron height - to various lower <span class="hlt">boundary</span> conditions in the Global Ionosphere Thermosphere Model (GITM). We use WACCM-X and GSWM to drive the lower atmospheric <span class="hlt">boundary</span> in GITM at 100 km, and compare the results with the current MSIS-driven version of GITM, analyzing which of these simulations match the measurements from GOCE, GUVI, CHAMP, and GPS-derived TEC best. Secondly, we analyze the effect of eddy diffusion in the IT <span class="hlt">system</span>. The turbulence due to eddy mixing cannot be directly measured and it is a challenge to completely characterize its linear and non-linear effects from other influences, since the eddy diffusion both influences the composition through direct mixing and the temperature structure due to turbulent conduction changes. In this study we input latitudinal and seasonal profiles of eddy diffusion into GITM and then analyze the changes in the thermospheric and ionospheric parameters. These profiles will be derived from both WACC-X simulations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AREPS..46..149K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AREPS..46..149K"><span>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>Keranen, Katie M.; Weingarten, Matthew</p> <p>2018-05-01</p> <p>The ability of fluid-generated subsurface stress changes to trigger earthquakes has long been recognized. However, the dramatic rise in the rate of human-induced earthquakes in the past decade has created abundant opportunities to study induced earthquakes and triggering processes. This review briefly summarizes early studies but focuses on results from induced earthquakes during the past 10 years related to fluid injection in petroleum fields. Study of these earthquakes has resulted in insights into physical processes and has identified knowledge gaps and future research directions. Induced earthquakes are challenging to identify using seismological methods, and faults and reefs strongly modulate spatial and temporal patterns of induced <span class="hlt">seismicity</span>. However, the similarity of induced and natural <span class="hlt">seismicity</span> provides an effective tool for studying earthquake processes. With continuing development of energy resources, increased interest in carbon sequestration, and construction of large dams, induced <span class="hlt">seismicity</span> will continue to pose a hazard in coming years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.2772D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.2772D"><span>The experience of the Antarctic <span class="hlt">Seismic</span> Data Library <span class="hlt">System</span> (SDLS) as a hub for researchers in antarctic crustal studies.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diviacco, Paolo; Wardell, Nigel</p> <p>2010-05-01</p> <p>The SDLS was created in April 1991 under the auspices of the Scientific Committee on Antarctic Research to provide open access to Antarctic multichannel <span class="hlt">seismic</span>-reflection data (MCS) for use in cooperative research projects. The SDLS operates under the mandates of the Antarctic Treaty <span class="hlt">System</span>, by which all institutions that collect MCS data in Antarctica must submit their MCS data to the SDLS. The SDLS has library branches worldwide at which researchers may view and study the MCS data. MCS data are submitted to the SDLS within 4 years of collection and remain in the library under SDLS guidelines until 8 years after collection. Thereafter, the data go to World Data Centers or equivalents for unrestricted use. The SDLS offers a clearing house, based at Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) where data are processed when needed and georeferenced, so that the end user can be provided with usable, although basic, post-stack <span class="hlt">seismic</span> sections. Re-processing of data is beyond the scope of the SDLS, so that if a researcher is interested in reviewing pre-stack data he/she must resort to the data owner. So far 228,000 km of <span class="hlt">seismic</span> data have been made public in all sectors of the Antar