Sample records for x10 tixi seismic

  1. Middle and late holocene micromammal pathologies from Cueva Tixi (Tandilia Range, Buenos Aires Province, Argentina).

    PubMed

    Luna, Leandro; Aranda, Claudia; Quintana, Carlos

    2017-09-01

    Paleopathology in bones of very small mammals has rarely been studied. Different types of osseous lesions of mammals weighing under 0.2kg, recovered from the Holocene strata of Cueva Tixi archaeological and paleontological site (Tandilia range, province of Buenos Aires, Argentina), are described and discussed in this report. Several types of trauma, entheseal changes, degenerative joint diseases, and probable osteomyelitis were identified. The lesions were chronic, indicating that the animals were able to survive a period of convalescence, although in many cases the decreased capacity for locomotion likely was significant. These pathological findings open research avenues for very small mammals that usually are not considered in archaeological disease studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. xQuake: A Modern Approach to Seismic Network Analytics

    NASA Astrophysics Data System (ADS)

    Johnson, C. E.; Aikin, K. E.

    2017-12-01

    While seismic networks have expanded over the past few decades, and social needs for accurate and timely information has increased dramatically, approaches to the operational needs of both global and regional seismic observatories have been slow to adopt new technologies. This presentation presents the xQuake system that provides a fresh approach to seismic network analytics based on complexity theory and an adaptive architecture of streaming connected microservices as diverse data (picks, beams, and other data) flow into a final, curated catalog of events. The foundation for xQuake is the xGraph (executable graph) framework that is essentially a self-organizing graph database. An xGraph instance provides both the analytics as well as the data storage capabilities at the same time. Much of the analytics, such as synthetic annealing in the detection process and an evolutionary programing approach for event evolution, draws from the recent GLASS 3.0 seismic associator developed by and for the USGS National Earthquake Information Center (NEIC). In some respects xQuake is reminiscent of the Earthworm system, in that it comprises processes interacting through store and forward rings; not surprising as the first author was the lead architect of the original Earthworm project when it was known as "Rings and Things". While Earthworm components can easily be integrated into the xGraph processing framework, the architecture and analytics are more current (e.g. using a Kafka Broker for store and forward rings). The xQuake system is being released under an unrestricted open source license to encourage and enable sthe eismic community support in further development of its capabilities.

  3. Spatial correlation analysis of seismic noise for STAR X-ray infrastructure design

    NASA Astrophysics Data System (ADS)

    D'Alessandro, Antonino; Agostino, Raffaele; Festa, Lorenzo; Gervasi, Anna; Guerra, Ignazio; Palmer, Dennis T.; Serafini, Luca

    2014-05-01

    The Italian PON MaTeRiA project is focused on the creation of a research infrastructure open to users based on an innovative and evolutionary X-ray source. This source, named STAR (Southern Europe TBS for Applied Research), exploits the Thomson backscattering process of a laser radiation by fast-electron beams (Thomson Back Scattering - TBS). Its main performances are: X-ray photon flux 109-1010 ph/s, Angular divergence variable between 2 and 10 mrad, X-ray energy continuously variable between 8 keV and 150 keV, Bandwidth ΔE/E variable between 1 and 10%, ps time resolved structure. In order to achieve this performances, bunches of electrons produced by a photo-injector are accelerated to relativistic velocities by a linear accelerator section. The electron beam, few hundreds of micrometer wide, is driven by magnetic fields to the interaction point along a 15 m transport line where it is focused in a 10 micrometer-wide area. In the same area, the laser beam is focused after being transported along a 12 m structure. Ground vibrations could greatly affect the collision probability and thus the emittance by deviating the paths of the beams during their travel in the STAR source. Therefore, the study program to measure ground vibrations in the STAR site can be used for site characterization in relation to accelerator design. The environmental and facility noise may affect the X-ray operation especially if the predominant wavelengths in the microtremor wavefield are much smaller than the size of the linear accelerator. For wavelength much greater, all the accelerator parts move in phase, and therefore also large displacements cannot generate any significant effect. On the other hand, for wavelengths equal or less than half the accelerator size several parts could move in phase opposition and therefore small displacements could affect its proper functioning. Thereafter, it is important to characterize the microtremor wavefield in both frequencies and wavelengths domains

  4. 10 CFR 100.23 - Geologic and seismic siting criteria.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Geologic and seismic siting criteria. 100.23 Section 100.23 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) REACTOR SITE CRITERIA Evaluation Factors for Stationary Power Reactor Site Applications on or After January 10, 1997 § 100.23 Geologic and seismic siting...

  5. 10 CFR 100.23 - Geologic and seismic siting criteria.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Geologic and seismic siting criteria. 100.23 Section 100.23 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) REACTOR SITE CRITERIA Evaluation Factors for Stationary Power Reactor Site Applications on or After January 10, 1997 § 100.23 Geologic and seismic siting...

  6. High seismic velocity (7.x) lower crustal layers in cratonic North America: a view from xenoliths and EarthScope seismic data

    NASA Astrophysics Data System (ADS)

    Mahan, K. H.; Barnhart, K. R.; Schulte-Pelkum, V.; Blackburn, T.; Bowring, S. A.; Dudas, F. O.

    2010-12-01

    Continental crust worldwide has local areas with a lowermost layer characterized by unusually high seismic P velocities of over 7 km/s. The presence (or absence) of these high-velocity layers, as well as their thickness, composition and degree of heterogeneity, can have a profound influence on the rheological properties and behavior of the lower crust. These data also provide fundamental information about lithospheric growth and destruction processes. In North America, high-velocity layers have been inferred for portions of a significant number of seismic refraction lines, as well as from surface wave and receiver function studies. However, the 2-D and localized nature of most existing studies leave many open questions regarding the full spatial extent of these layers (e.g. correlations with Archean vs Proterozoic terranes, collisional or accretionary boundaries, rift zones or plume tracks, etc.). EarthScope’s USArray provides an exceptional opportunity to improve our knowledge of the distribution of 7.x layers in North America. Similarly, xenoliths provide a complimentary opportunity to investigate compositional, geochronological, and petrophysical characteristics of the lower crust in selected areas. In Montana and Wyoming, where seismic experiments reveal an anomalously thick (up to 25 km) 7.x layer, our studies emphasize the heterogeneity in modes of formation, physical properties, and age of the lower crust. We highlight an example from xenoliths exhumed by Eocene minettes from the Great Falls Tectonic Zone in central Montana. The suite includes mafic garnet granulites, mafic eclogite, and felsic granulites with peak pressures of 0.8-1.5+ GPa, consistent with derivation from depths of 28-55+ km. Multiple samples preserve evidence for prograde burial and some are polymetamorphic. One sample (likely a restite from melted supracrustal material) contains evidence for an early mid-crustal metamorphic event followed by an increase in pressure from <0.8 to >1.0 GPa

  7. Proceedings of the Annual Seismic Research Symposium (15th) Held in Vail, Colorado on 8-10 September 1993

    DTIC Science & Technology

    1993-08-01

    Inc., 445 Pineda C. Melbourne, FL 32940 Contract No. F19628-91-C-0172 OBJECTIVE The framework for a system for automatic global seismic event...placedinsde hoiona tunlwihi meddi ooeeu lsi mees X5 o w ie f h unl( n 10 mee ai) ah aito atrEahptensda o n tesm sclbtwhaspre manfcto atr * 40 U * I 1 9w...34" - a o * a • * ao * U°o " - x3 20 ’x i, 4, * . St. at l mees n o w ie fttne 5 an10mtradi. ahrdaio pten O is calculated at a semi-circular receiver

  8. 10 CFR 100.21 - Non-seismic siting criteria.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... NUCLEAR REGULATORY COMMISSION (CONTINUED) REACTOR SITE CRITERIA Evaluation Factors for Stationary Power Reactor Site Applications on or After January 10, 1997 § 100.21 Non-seismic siting criteria. Applications for site approval for commercial power reactors shall demonstrate that the proposed site meets the...

  9. 10 CFR 100.21 - Non-seismic siting criteria.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... NUCLEAR REGULATORY COMMISSION (CONTINUED) REACTOR SITE CRITERIA Evaluation Factors for Stationary Power Reactor Site Applications on or After January 10, 1997 § 100.21 Non-seismic siting criteria. Applications for site approval for commercial power reactors shall demonstrate that the proposed site meets the...

  10. Multifractal Analysis of Seismically Induced Soft-Sediment Deformation Structures Imaged by X-Ray Computed Tomography

    NASA Astrophysics Data System (ADS)

    Nakashima, Yoshito; Komatsubara, Junko

    Unconsolidated soft sediments deform and mix complexly by seismically induced fluidization. Such geological soft-sediment deformation structures (SSDSs) recorded in boring cores were imaged by X-ray computed tomography (CT), which enables visualization of the inhomogeneous spatial distribution of iron-bearing mineral grains as strong X-ray absorbers in the deformed strata. Multifractal analysis was applied to the two-dimensional (2D) CT images with various degrees of deformation and mixing. The results show that the distribution of the iron-bearing mineral grains is multifractal for less deformed/mixed strata and almost monofractal for fully mixed (i.e. almost homogenized) strata. Computer simulations of deformation of real and synthetic digital images were performed using the egg-beater flow model. The simulations successfully reproduced the transformation from the multifractal spectra into almost monofractal spectra (i.e. almost convergence on a single point) with an increase in deformation/mixing intensity. The present study demonstrates that multifractal analysis coupled with X-ray CT and the mixing flow model is useful to quantify the complexity of seismically induced SSDSs, standing as a novel method for the evaluation of cores for seismic risk assessment.

  11. Assessing the need for an update of a probabilistic seismic hazard analysis using a SSHAC Level 1 study and the Seismic Hazard Periodic Reevaluation Methodology

    DOE PAGES

    Payne, Suzette J.; Coppersmith, Kevin J.; Coppersmith, Ryan; ...

    2017-08-23

    A key decision for nuclear facilities is evaluating the need for an update of an existing seismic hazard analysis in light of new data and information that has become available since the time that the analysis was completed. We introduce the newly developed risk-informed Seismic Hazard Periodic Review Methodology (referred to as the SHPRM) and present how a Senior Seismic Hazard Analysis Committee (SSHAC) Level 1 probabilistic seismic hazard analysis (PSHA) was performed in an implementation of this new methodology. The SHPRM offers a defensible and documented approach that considers both the changes in seismic hazard and engineering-based risk informationmore » of an existing nuclear facility to assess the need for an update of an existing PSHA. The SHPRM has seven evaluation criteria that are employed at specific analysis, decision, and comparison points which are applied to seismic design categories established for nuclear facilities in United States. The SHPRM is implemented using a SSHAC Level 1 study performed for the Idaho National Laboratory, USA. The implementation focuses on the first six of the seven evaluation criteria of the SHPRM which are all provided from the SSHAC Level 1 PSHA. Finally, to illustrate outcomes of the SHPRM that do not lead to the need for an update and those that do, the example implementations of the SHPRM are performed for nuclear facilities that have target performance goals expressed as the mean annual frequency of unacceptable performance at 1x10 -4, 4x10 -5 and 1x10 -5.« less

  12. Assessing the need for an update of a probabilistic seismic hazard analysis using a SSHAC Level 1 study and the Seismic Hazard Periodic Reevaluation Methodology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Payne, Suzette J.; Coppersmith, Kevin J.; Coppersmith, Ryan

    A key decision for nuclear facilities is evaluating the need for an update of an existing seismic hazard analysis in light of new data and information that has become available since the time that the analysis was completed. We introduce the newly developed risk-informed Seismic Hazard Periodic Review Methodology (referred to as the SHPRM) and present how a Senior Seismic Hazard Analysis Committee (SSHAC) Level 1 probabilistic seismic hazard analysis (PSHA) was performed in an implementation of this new methodology. The SHPRM offers a defensible and documented approach that considers both the changes in seismic hazard and engineering-based risk informationmore » of an existing nuclear facility to assess the need for an update of an existing PSHA. The SHPRM has seven evaluation criteria that are employed at specific analysis, decision, and comparison points which are applied to seismic design categories established for nuclear facilities in United States. The SHPRM is implemented using a SSHAC Level 1 study performed for the Idaho National Laboratory, USA. The implementation focuses on the first six of the seven evaluation criteria of the SHPRM which are all provided from the SSHAC Level 1 PSHA. Finally, to illustrate outcomes of the SHPRM that do not lead to the need for an update and those that do, the example implementations of the SHPRM are performed for nuclear facilities that have target performance goals expressed as the mean annual frequency of unacceptable performance at 1x10 -4, 4x10 -5 and 1x10 -5.« less

  13. Experimental study on impact-induced seismic wave propagation through granular materials

    NASA Astrophysics Data System (ADS)

    Yasui, Minami; Matsumoto, Eri; Arakawa, Masahiko

    2015-11-01

    Impact-induced seismic waves are supposed to cause movements of regolith particles, resulting in modifications of asteroidal surfaces. The imparted seismic energy is thus a key parameter to determining the scale and magnitude of this seismic shaking process. It is important to study the propagation velocity, attenuation rate, and vibration period of the impact-induced seismic wave to estimate the seismic energy. Hence, we conducted impact cratering experiments at Kobe University using a 200-μm glass beads target to simulate a regolith layer, and measured the impact-induced seismic wave using three accelerometers set on the target surface at differences ranging from 3.2 to 12.7 cm. The target was impacted with three kinds of projectiles at ∼100 m s-1 using a one-stage gas gun. The propagation velocity of the seismic wave in the beads target was 108.9 m s-1, and the maximum acceleration, gmax, in the unit of m s-2, measured by each accelerometer showed good correlation with the distance from the impact point normalized by the crater radius, x/R, irrespective of projectile type. They also were fitted by one power-law equation, gmax = 102.19 (x/R)-2.21. The half period of the first peak of the measured seismic waves was ∼0.72 ms, and this duration was almost consistent with the penetration time of each projectile into the target. According to these measurements, we estimated the impact seismic efficiency factor, that is, the ratio of seismic energy to kinetic energy of the projectile, to be almost constant, 5.7 × 10-4 inside the crater rim, while it exponentially decreased with distance from the impact point outside the crater rim. At a distance quadruple of the crater radius, the efficiency factors were 4.4 × 10-5 for polycarbonate projectile and 9.5 × 10-5 for alumina and stainless steel projectiles.

  14. Time-Independent Annual Seismic Rates, Based on Faults and Smoothed Seismicity, Computed for Seismic Hazard Assessment in Italy

    NASA Astrophysics Data System (ADS)

    Murru, M.; Falcone, G.; Taroni, M.; Console, R.

    2017-12-01

    In 2015 the Italian Department of Civil Protection, started a project for upgrading the official Italian seismic hazard map (MPS04) inviting the Italian scientific community to participate in a joint effort for its realization. We participated providing spatially variable time-independent (Poisson) long-term annual occurrence rates of seismic events on the entire Italian territory, considering cells of 0.1°x0.1° from M4.5 up to M8.1 for magnitude bin of 0.1 units. Our final model was composed by two different models, merged in one ensemble model, each one with the same weight: the first one was realized by a smoothed seismicity approach, the second one using the seismogenic faults. The spatial smoothed seismicity was obtained using the smoothing method introduced by Frankel (1995) applied to the historical and instrumental seismicity. In this approach we adopted a tapered Gutenberg-Richter relation with a b-value fixed to 1 and a corner magnitude estimated with the bigger events in the catalogs. For each seismogenic fault provided by the Database of the Individual Seismogenic Sources (DISS), we computed the annual rate (for each cells of 0.1°x0.1°) for magnitude bin of 0.1 units, assuming that the seismic moments of the earthquakes generated by each fault are distributed according to the same tapered Gutenberg-Richter relation of the smoothed seismicity model. The annual rate for the final model was determined in the following way: if the cell falls within one of the seismic sources, we merge the respective value of rate determined by the seismic moments of the earthquakes generated by each fault and the value of the smoothed seismicity model with the same weight; if instead the cells fall outside of any seismic source we considered the rate obtained from the spatial smoothed seismicity. Here we present the final results of our study to be used for the new Italian seismic hazard map.

  15. The Pollino Seismic Sequence: Activated Graben Structures in a Seismic Gap

    NASA Astrophysics Data System (ADS)

    Rößler, Dirk; Passarelli, Luigi; Govoni, Aladino; Bindi, Dino; Cesca, Simone; Hainzl, Sebatian; Maccaferri, Francesco; Rivalta, Eleonora; Woith, Heiko; Dahm, Torsten

    2015-04-01

    The Mercure Basin (MB) and the Castrovillari Fault (CF) in the Pollino range (Southern Apennines, Italy) represent one of the most prominent seismic gaps in the Italian seismic catalogue, with no M>5.5 earthquakes during the last centuries. In historical times several swarm-like seismic sequences occurred in the area including two intense swarms within the past two decades. The most energetic one started in 2010 and has been still active in 2014. The seismicity culminated in autumn 2012 with a M=5 event on 25 October. The range hosts a number of opposing normal faults forming a graben-like structure. Their rheology and their interactions are unclear. Current debates include the potential of the MB and the CF to host large earthquakes and the style of deformation. Understanding the seismicity and the behaviour of the faults is necessary to assess the tectonics and the seismic hazard. The GFZ German Research Centre for Geosciences and INGV, Italy, have jointly monitored the ongoing seismicity using a small-aperture seismic array, integrated in a temporary seismic network. Based on this installation, we located more than 16,000 local earthquakes that occurred between November 2012 and September 2014. Here we investigate quantitatively all the phases of the seismic sequence starting from January 2010. Event locations along with moment tensor inversion constrain spatially the structures activated by the swarm and the migration pattern of the seismicity. The seismicity forms clusters concentrated within the southern part of the MB and along the Pollino Fault linking MB and CF. Most earthquakes are confined to the upper 10 km of the crust in an area of ~15x15 km2. However, sparse seismicity at depths between 15 and 20 km and moderate seismicity further north with deepening hypocenters also exist. In contrast, the CF appears aseismic; only the northern part has experienced micro-seismicity. The spatial distribution is however more complex than the major tectonic structures

  16. Sources of seismic events in the cooling lava lake of Kilauea Iki, Hawaii

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chouet, B.

    1979-05-10

    Seismic surveys conducted in recent years revealed a suprisingly high and sustained activity of local seismic events originating in the partially frozen lava lake of Kilauea Iki crater, Hawaii. About 8000 events per day were counted in 1976 at the center of the lake with a seismograph having a peak magnification of 280,000 at 60 Hz. The activity was found to be uniform over the whole area above the inferred magma lens and very weak in the periphery of the lake. The frequency-amplitude relation for these shocks obeys the Ishimoto-Iida or Gutenberg-Richter law very well, with a b value ofmore » 1.19( +- 0.06). Locations of a few selected events indicate that they occur both above and below the layer of melt, although the seismic activity appears to be much higher in the upper crust. Whenever clear, the first motion is always outward from the source, suggesting that a crack opening under tensile stress owing to cooling is the responsible source mechanism. A simple model of a circular tensile crack nucleating at a point and growing at subsonic velocity can match the far-field P wave from these sources fairly well. Typical parameters for a large event inferred from the model are the following: radius, 2.7 m; maximum static tensile displacement between crack faces, 2.9..mu..; cavity volume, 4.4 x 10/sup -5/ m/sup 3/; and a seismic moment tensor with diagonal elements only, having the values 3.8 x 10/sup 2/exclamation2, 4.5 x 10/sup 12/, and 3.8 x 10/sup 12/ dyn cm. The magnitude of the event is about -1, and its stress drop is of the order of 0.01 bar. A Q as low as 10 is required to satisfy the shape of the observed wave forms. The total cavity volume integrated over all cracks which is generated daily in the upper crust of Kilauea Iki is of the order of 1--20 m/sup 3/. An alternate interpretation of the data, the seismic activity as reflecting the extension by up to several tens of centimeters of long existing cracks rather than the formation of new cracks.« less

  17. Alternative Energy Sources in Seismic Methods

    NASA Astrophysics Data System (ADS)

    Tün, Muammer; Pekkan, Emrah; Mutlu, Sunay; Ecevitoğlu, Berkan

    2015-04-01

    When the suitability of a settlement area is investigated, soil-amplification, liquefaction and fault-related hazards should be defined, and the associated risks should be clarified. For this reason, soil engineering parameters and subsurface geological structure of a new settlement area should be investigated. Especially, faults covered with quaternary alluvium; thicknesses, shear-wave velocities and geometry of subsurface sediments could lead to a soil amplification during an earthquake. Likewise, changes in shear-wave velocities along the basin are also very important. Geophysical methods can be used to determine the local soil properties. In this study, use of alternative seismic energy sources when implementing seismic reflection, seismic refraction and MASW methods in the residential areas of Eskisehir/Turkey, were discussed. Our home developed seismic energy source, EAPSG (Electrically-Fired-PS-Gun), capable to shoot 2x24 magnum shotgun cartridges at once to generate P and S waves; and our home developed WD-500 (500 kg Weight Drop) seismic energy source, mounted on a truck, were developed under a scientific research project of Anadolu University. We were able to reach up to penetration depths of 1200 m for EAPSG, and 800 m for WD-500 in our seismic reflection surveys. WD-500 seismic energy source was also used to perform MASW surveys, using 24-channel, 10 m apart, 4.5 Hz vertical geophone configuration. We were able to reach 100 m of penetration depth in MASW surveys.

  18. Discriminating Induced-Microearthquakes Using New Seismic Features

    NASA Astrophysics Data System (ADS)

    Mousavi, S. M.; Horton, S.

    2016-12-01

    We studied characteristics of induced-microearthquakes on the basis of the waveforms recorded on a limited number of surface receivers using machine-learning techniques. Forty features in the time, frequency, and time-frequency domains were measured on each waveform, and several techniques such as correlation-based feature selection, Artificial Neural Networks (ANNs), Logistic Regression (LR) and X-mean were used as research tools to explore the relationship between these seismic features and source parameters. The results show that spectral features have the highest correlation to source depth. Two new measurements developed as seismic features for this study, spectral centroids and 2D cross-correlations in the time-frequency domain, performed better than the common seismic measurements. These features can be used by machine learning techniques for efficient automatic classification of low energy signals recorded at one or more seismic stations. We applied the technique to 440 microearthquakes-1.7Reference: Mousavi, S.M., S.P. Horton, C. A. Langston, B. Samei, (2016) Seismic features and automatic discrimination of deep and shallow induced-microearthquakes using neural network and logistic regression, Geophys. J. Int. doi: 10.1093/gji/ggw258.

  19. A seismic hazard uncertainty analysis for the New Madrid seismic zone

    USGS Publications Warehouse

    Cramer, C.H.

    2001-01-01

    A review of the scientific issues relevant to characterizing earthquake sources in the New Madrid seismic zone has led to the development of a logic tree of possible alternative parameters. A variability analysis, using Monte Carlo sampling of this consensus logic tree, is presented and discussed. The analysis shows that for 2%-exceedence-in-50-year hazard, the best-estimate seismic hazard map is similar to previously published seismic hazard maps for the area. For peak ground acceleration (PGA) and spectral acceleration at 0.2 and 1.0 s (0.2 and 1.0 s Sa), the coefficient of variation (COV) representing the knowledge-based uncertainty in seismic hazard can exceed 0.6 over the New Madrid seismic zone and diminishes to about 0.1 away from areas of seismic activity. Sensitivity analyses show that the largest contributor to PGA, 0.2 and 1.0 s Sa seismic hazard variability is the uncertainty in the location of future 1811-1812 New Madrid sized earthquakes. This is followed by the variability due to the choice of ground motion attenuation relation, the magnitude for the 1811-1812 New Madrid earthquakes, and the recurrence interval for M>6.5 events. Seismic hazard is not very sensitive to the variability in seismogenic width and length. Published by Elsevier Science B.V.

  20. South-Central Tibetan Seismicity from HiCLIMB Seismic Array Data

    NASA Astrophysics Data System (ADS)

    Carpenter, S.; Nabelek, J.; Braunmiller, J.

    2010-12-01

    The HiCLIMB broadband passive seismic experiment (2002-2005) operated 233 sites along a 800-km long north-south array extending from the Himalayan foreland into the Central Tibetan Plateau and a flanking 350x350 km lateral array in southern Tibet and eastern Nepal. We use data from the experiment’s second phase (June 2004 to August 2005), when stations operated in Tibet, to locate earthquakes in south-central Tibet, a region with no permanent seismic network where little is known about its seismicity. We used the Antelope software for automatic detection and arrival time picking, event-arrival association and event location. Requiring a low detection and event association threshold initially resulted in ~110,000 declared events. The large database size rendered manual inspection unfeasible and we developed automated post-processing modules to weed out spurious detections and erroneous phase and event associations, which stemmed, e.g., from multiple coincident earthquakes within the array or misplaced seismicity from the great 2004 Sumatra earthquake. The resulting database contains ~32,000 events within 5° distance from the closest station. We consider ~7,600 events defined by more than 30 P and S arrivals well located and discuss them here. Seismicity in the subset correlates well with mapped faults and structures seen on satellite imagery attesting to high location quality. This is confirmed by non-systematic, kilometer-scale differences between automatic and manual locations for selected events. Seismicity in south-central Tibet is intense north of the Yarlung-Tsangpo Suture. Almost 90% of events occurred in the Lhasa Terrane mainly along north-south trending rifts. Vigorous activity (>4,800 events) accompanied two M>6 earthquakes in the Payang Basin (84°E), ~100 km west of the linear array. The Tangra-Yum Co (86.5°E) and Pumqu-Xianza (88°E) rifts were very active (~1,000 events) without dominant main shocks indicating swarm like-behavior possibly related

  1. Fluid-filled porosity of magmatic underplates from joint inversion of P and S receiver functions

    NASA Astrophysics Data System (ADS)

    Vinnik, Lev; Oreshin, Sergey; Makeyeva, Larissa; Dündar, Süleyman

    2017-05-01

    Vp/Vs ratio where Vp and Vs are P- and S-wave velocities is an indicator of rock composition, but estimates of Vp/Vs for the lower continental crust remain sparse. We present estimates of Vs, Vp and Vp/Vs in the crust of the Archean-Paleoproterozoic Siberian craton that are obtained by simultaneous inversion of P and S receiver functions from GSN seismograph stations NRIL, YAK and TIXI. These stations are located in the region of the Siberian traps (NRIL), close to the Laptev Sea Rift (TIXI) and the Viluy rift system (YAK). The most conspicuous result of our analysis is a high Vp/Vs ratio (≥2.0) at depths from 20-30 to 40 km. A very high Vp in this layer (from 7 to 8 km s-1) is indicative of magmatic underplating. We find broadly similar data in the western Mediterranean and in India. In a dry lower crust the Vp/Vs ratio is ∼1.8, which is hard to reconcile with the estimates >2.0. A coincidence in depths of zones of high electric conductivity and of anomalously high Vp/Vs in Siberia suggests that both may have the same origin: fluid-filled porosity. The porosity which is required by our seismic observations is on the order of 1 per cent. Origins of the fluids may be linked with processes of magmatic underplating.

  2. Fluid-filled porosity of magmatic underplates from joint inversion of P and S receiver functions

    NASA Astrophysics Data System (ADS)

    Vinnik, Lev; Oreshin, Sergey; Makeyeva, Larissa; Dündar, Süleyman

    2017-04-01

    Vp/Vs ratio where Vp and Vs are P- and S-wave velocities is an indicator of rock composition, but estimates of Vp/Vs for the lower continental crust remain sparse. We present estimates of Vs, Vp and Vp/Vs in the crust of the Archean-Paleoproterozoic Siberian craton that are obtained by simultaneous inversion of P and S receiver functions from GSN seismograph stations NRIL, YAK and TIXI. These stations are located in the region of the Siberian traps (NRIL), close to the Laptev Sea Rift (TIXI) and the Viluy rift system (YAK). The most conspicuous result of our analysis is a high Vp/Vs ratio (≥2.0) at depths from 20-30 km to 40 km. A very high Vp in this layer (from 7 to 8 km/s) is indicative of magmatic underplating. We find broadly similar data in the western Mediterranean and in India. In a dry lower crust the Vp/Vs ratio is 1.8, which is hard to reconcile with the estimates > 2.0. A coincidence in depths of zones of high electric conductivity and of anomalously high Vp/Vs in Siberia suggests that both may have the same origin: fluid-filled porosity. The porosity which is required by our seismic observations is on the order of 1%. Origins of the fluids may be linked with processes of magmatic underplating.

  3. Seismic and Petrological Constraints on Deep Crustal Evolution in North America: Where and What are 7.x Layers?

    NASA Astrophysics Data System (ADS)

    Mahan, K. H.; Schulte-Pelkum, V.; Shen, W.; Ritzwoller, M. H.

    2012-12-01

    Continental crust worldwide has been found to have areas with a lowermost layer characterized by unusually high seismic P velocities of over 7 km/s, often called 7.x layers. Such layers are commonly ascribed to underplating - in some cases by underthrusting, but in most cases by magmatic processes. In North America, high-velocity lower crust underlies upper crust of Archean, Proterozoic, and younger ages. Its presence reflects the tectonic and magmatic processes associated with continental rifting, collision, subduction, and other evolutionary (e.g. thermal) trends, and its occurrence also provides clues on the nature of the underlying mantle. Detection of a lower crustal high-velocity layer stems mostly from seismic refraction and wide-angle reflection experiments, and information on its geographical extent is very spotty. Similarly sparse are age determinations and knowledge of the tectonic processes responsible for construction of these layers. Despite glimpses of 7.x layers on many profiles across the continental U.S. and Canada, there is no systematic geographical and age information on this fundamental process of crustal growth, and many of the existing observations contradict current hypotheses on underplating. We compare compositional and physical property data of lower crustal and uppermost mantle xenoliths from Montana, Wyoming, and other localities with maps of lower crustal and uppermost mantle seismic velocities obtained from joint inversions of receiver functions with surface waves, and to mapped distinct high-velocity lower crustal layers in receiver functions in areas covered by the EarthScope Transportable Array. Xenolith observations from Montana indicate that portions of metasomatized uppermost mantle exist in that area that may be difficult to distinguish from mafic lower crust based on seismic velocities alone, raising the interesting question of whether a 7.x layer may be below rather than above the seismic Moho in some cases. The persistence

  4. Seismic hazard estimation of northern Iran using smoothed seismicity

    NASA Astrophysics Data System (ADS)

    Khoshnevis, Naeem; Taborda, Ricardo; Azizzadeh-Roodpish, Shima; Cramer, Chris H.

    2017-07-01

    This article presents a seismic hazard assessment for northern Iran, where a smoothed seismicity approach has been used in combination with an updated seismic catalog and a ground motion prediction equation recently found to yield good fit with data. We evaluate the hazard over a geographical area including the seismic zones of Azerbaijan, the Alborz Mountain Range, and Kopeh-Dagh, as well as parts of other neighboring seismic zones that fall within our region of interest. In the chosen approach, seismic events are not assigned to specific faults but assumed to be potential seismogenic sources distributed within regular grid cells. After performing the corresponding magnitude conversions, we decluster both historical and instrumental seismicity catalogs to obtain earthquake rates based on the number of events within each cell, and smooth the results to account for the uncertainty in the spatial distribution of future earthquakes. Seismicity parameters are computed for each seismic zone separately, and for the entire region of interest as a single uniform seismotectonic region. In the analysis, we consider uncertainties in the ground motion prediction equation, the seismicity parameters, and combine the resulting models using a logic tree. The results are presented in terms of expected peak ground acceleration (PGA) maps and hazard curves at selected locations, considering exceedance probabilities of 2 and 10% in 50 years for rock site conditions. According to our results, the highest levels of hazard are observed west of the North Tabriz and east of the North Alborz faults, where expected PGA values are between about 0.5 and 1 g for 10 and 2% probability of exceedance in 50 years, respectively. We analyze our results in light of similar estimates available in the literature and offer our perspective on the differences observed. We find our results to be helpful in understanding seismic hazard for northern Iran, but recognize that additional efforts are necessary to

  5. Two applications of time reversal mirrors: seismic radio and seismic radar.

    PubMed

    Hanafy, Sherif M; Schuster, Gerard T

    2011-10-01

    Two seismic applications of time reversal mirrors (TRMs) are introduced and tested with field experiments. The first one is sending, receiving, and decoding coded messages similar to a radio except seismic waves are used. The second one is, similar to radar surveillance, detecting and tracking a moving object(s) in a remote area, including the determination of the objects speed of movement. Both applications require the prior recording of calibration Green's functions in the area of interest. This reference Green's function will be used as a codebook to decrypt the coded message in the first application and as a moving sensor for the second application. Field tests show that seismic radar can detect the moving coordinates (x(t), y(t), z(t)) of a person running through a calibration site. This information also allows for a calculation of his velocity as a function of location. Results with the seismic radio are successful in seismically detecting and decoding coded pulses produced by a hammer. Both seismic radio and radar are highly robust to signals in high noise environments due to the super-stacking property of TRMs. © 2011 Acoustical Society of America

  6. 10' x 10' Supersonic Wind Tunnel Flexwall

    NASA Image and Video Library

    2015-08-10

    The flexwall section of NASA Glenn’s 10x10 supersonic wind tunnel is made up of two movable flexible steel sidewalls. These powerful hydraulic jacks move the walls in and out to control supersonic air speeds in the test section between Mach 2.0 and 3.5.

  7. Asymmetric radiation of seismic waves from an atoll: nuclear tests in French Polynesia

    USGS Publications Warehouse

    Weber, Michael J.; Wicks, Charles W.; Krüger, Frank; Jahnke, Gunnar; Schlittenhardt, Jörg

    1998-01-01

    Seismic records of nuclear tests detonated in the Mururoa Atoll in French Polynesia show large unpredicted arrivals 2.2 and 4.5 seconds (X1 and X2) after the P-wave at the Australian Warramunga Array. These arrivals are not observed at the Canadian Yellowknife Array. X1 and X2 are also absent on Warramunga Array recordings of tests carried out at the Fangataufa Atoll situated 40 km SSE of Mururoa. Array analysis shows that X1 and X2 are produced within the source area. The layered crustal structure of the atoll, significant local inhomogeneities, and focusing effects due to the elongated shape and the steep flanks of the Mururoa Atoll are most likely responsible for X1 and X2. The form of Mururoa (28 × 10 km) and its East-West orientation is due to its location on the Austral Fracture Zone (AFZ). The Fangataufa Atoll on the other hand is almost circular (10 km diameter) and is unaffected by the dynamics along the AFZ. Our observations demonstrate that complicated structures in the source area can significantly alter the wave field at teleseismic distances and produce a large magnitude (mb) bias. A better understanding of the exact cause of these unusual seismic observations will only become possible, if the coordinates of the tests and information on the detailed 3-D structure of the atolls are released.

  8. Seismic fiber optic multiplexed sensors for exploration and reservoir management

    NASA Astrophysics Data System (ADS)

    Houston, Mark H.

    2000-12-01

    Reliable downhole communications, control and sensor networks will dramatically improve oil reservoir management practices and will enable the construction of intelligent or smart-well completions. Fiber optic technology will play a key role in the implementation of these communication, control and sensing systems because of inherent advantages of power, weight and reliability over more conventional electronic-based systems. Field test data, acquired using an array of fiber optic seismic hydrophones within a steam-flood, heavy oil- production filed, showed a significant improvement (10X in this specific case) in subsurface resolution as compared to conventional surface seismic acquisition. These results demonstrate the viability of using multiplexed fiber optic sensors for exploration and reservoir management in 3D vertical seismic profiling (VSP) surveys and in permanent sensor arrays for 4D surveys.

  9. Alsep data processing: How we processed Apollo Lunar Seismic Data

    NASA Technical Reports Server (NTRS)

    Latham, G. V.; Nakamura, Y.; Dorman, H. J.

    1979-01-01

    The Apollo lunar seismic station network gathered data continuously at a rate of 3 x 10 to the 8th power bits per day for nearly eight years until the termination in September, 1977. The data were processed and analyzed using a PDP-15 minicomputer. On the average, 1500 long-period seismic events were detected yearly. Automatic event detection and identification schemes proved unsuccessful because of occasional high noise levels and, above all, the risk of overlooking unusual natural events. The processing procedures finally settled on consist of first plotting all the data on a compressed time scale, visually picking events from the plots, transferring event data to separate sets of tapes and performing detailed analyses using the latter. Many problems remain especially for automatically processing extraterrestrial seismic signals.

  10. Application of a time probabilistic approach to seismic landslide hazard estimates in Iran

    NASA Astrophysics Data System (ADS)

    Rajabi, A. M.; Del Gaudio, V.; Capolongo, D.; Khamehchiyan, M.; Mahdavifar, M. R.

    2009-04-01

    the slope critical acceleration (Ac)x for which a prefixed probability exists that seismic shaking would result in a Dn value equal to a threshold x whose exceedence would cause landslide triggering. The obtained ac values represent the minimum slope resistance required to keep the probability of seismic-landslide triggering within the prefixed value. In particular we calculated the spatial distribution of (Ac)x for x thresholds of 10 and 2 cm in order to represent triggering conditions for coherent slides (e.g., slumps, block slides, slow earth flows) and disrupted slides (e.g., rock falls, rock slides, rock avalanches), respectively. Then we produced a probabilistic national map that shows the spatial distribution of (Ac)10 and (Ac)2, for a 10% probability of exceedence in 50 year, which is a significant level of hazard equal to that commonly used for building codes. The spatial distribution of the calculated (Ac)xvalues can be compared with the in situ actual ac values of specific slopes to estimate whether these slopes have a significant probability of failing under seismic action in the future. As example of possible application of this kind of time probabilistic map to hazard estimates, we compared the values obtained for the Manjil region with a GIS map providing spatial distribution of estimated ac values in the same region. The spatial distribution of slopes characterized by ac < (Ac)10 was then compared with the spatial distribution of the major landslides of coherent type triggered by the Manjil earthquake. This comparison provides indications on potential, problems and limits of the experimented approach for the study area. References Cornell, C.A., 1968: Engineering seismic risk analysis, Bull. Seism. Soc. Am., 58, 1583-1606. Del Gaudio V., Wasowski J., & Pierri P., 2003: An approach to time probabilistic evaluation of seismically-induced landslide hazard. Bull Seism. Soc. Am., 93, 557-569. Jibson, R.W., E.L. Harp and J.A. Michael, 1998: A method for

  11. Surface Deformation and Source Model at Semisopochnoi Volcano from InSAR and Seismic Analysis During the 2014 and 2015 Seismic Swarms

    NASA Astrophysics Data System (ADS)

    DeGrandpre, K.; Pesicek, J. D.; Lu, Z.

    2016-12-01

    During the summer of 2014 and the early spring of 2015 two notable increases in seismic activity at Semisopochnoi volcano in the western Aleutian islands were recorded on AVO seismometers on Semisopochnoi and neighboring islands. These seismic swarms did not lead to an eruption. This study employs differential SAR techniques using TerraSAR-X images in conjunction with more accurately relocating the recorded seismic events through simultaneous inversion of event travel times and a three-dimensional velocity model using tomoDD. The interferograms created from the SAR images exhibit surprising coherence and an island wide spatial distribution of inflation that is then used in a Mogi model in order to define the three-dimensional location and volume change required for a source at Semisopochnoi to produce the observed surface deformation. The tomoDD relocations provide a more accurate and realistic three-dimensional velocity model as well as a tighter clustering of events for both swarms that clearly outline a linear seismic void within the larger group of shallow (<10 km) seismicity. While no direct conclusions as to the relationship of these seismic events and the observed surface deformation can be made at this time, these techniques are both complimentary and efficient forms of remotely monitoring volcanic activity that provide much deeper insights into the processes involved without having to risk hazardous or costly field work.

  12. Seismic Noise Analysis and Reduction through Utilization of Collocated Seismic and Atmospheric Sensors at the GRO Chile Seismic Network

    NASA Astrophysics Data System (ADS)

    Farrell, M. E.; Russo, R. M.

    2013-12-01

    The installation of Earthscope Transportable Array-style geophysical observatories in Chile expands open data seismic recording capabilities in the southern hemisphere by nearly 30%, and has nearly tripled the number of seismic stations providing freely-available data in southern South America. Through the use of collocated seismic and atmospheric sensors at these stations we are able to analyze how local atmospheric conditions generate seismic noise, which can degrade data in seismic frequency bands at stations in the ';roaring forties' (S latitudes). Seismic vaults that are climate-controlled and insulated from the local environment are now employed throughout the world in an attempt to isolate seismometers from as many noise sources as possible. However, this is an expensive solution that is neither practical nor possible for all seismic deployments; and also, the increasing number and scope of temporary seismic deployments has resulted in the collection and archiving of terabytes of seismic data that is affected to some degree by natural seismic noise sources such as wind and atmospheric pressure changes. Changing air pressure can result in a depression and subsequent rebound of Earth's surface - which generates low frequency noise in seismic frequency bands - and even moderate winds can apply enough force to ground-coupled structures or to the surface above the seismometers themselves, resulting in significant noise. The 10 stations of the permanent Geophysical Reporting Observatories (GRO Chile), jointly installed during 2011-12 by IRIS and the Chilean Servicio Sismológico, include instrumentation in addition to the standard three seismic components. These stations, spaced approximately 300 km apart along the length of the country, continuously record a variety of atmospheric data including infrasound, air pressure, wind speed, and wind direction. The collocated seismic and atmospheric sensors at each station allow us to analyze both datasets together, to

  13. Proceedings of the Annual PL/DARPA Seismic Research Symposium (13th), Held in Keystone, Colorado on 8-10 October 1991

    DTIC Science & Technology

    1991-08-30

    PL-TR-91-2208 AD-A241 325Q ~~I 1111111111I IEI N PROCEEDINGS OF THE 13TH ANNUAL PL/DARPA SEISMIC RESEARCH SYMPOSIUM, 8-10 OCTOBER 1991 EDITORS: James...S pTiIUgdjF- SEISMIC RESEARCH S’YMPOSIUMH, 8-10 OCTOBER 1991 PR 2309 6. AUTHOR(S) TA G2 Editors: James F. Lewkowicz Jeanne M. McPhetres 7. PERFORMING...Drive Arlington, VA 22203-1714 11. SUPPLEMENTARY NOTES This research was supported by DARPA under PE 62714E. 12a. DISTRIBUTION / AVAILABILITY STATEMENT

  14. Infrasound and seismic analysis of the SpaceX Falcon9 explosion sequence of 1-September-2016

    NASA Astrophysics Data System (ADS)

    Thompson, G.; McNutt, S. R.; Brown, R. G.; Braunmiller, J.; Mehta, C.

    2017-12-01

    During a static launch test on 1-Sep-2016 at Kennedy Space Center, a SpaceX Falcon 9 rocket exploded causing loss of the rocket and the payload, and extensively damaging the launch complex. The sequence was captured by a 3-element infrasound array and a broadband 3-component seismometer at the Astronaut Beach House, just 0.87 miles (1.4 km) from the launch pad. Manual picking identified 153 impulsive airwave signals over a 26-minute interval and these were compared to video recordings of the sequence. The explosion onset consisted of a moderate signal on both seismic and infrasound (52 Pa) instruments. This corresponds to the rupture of the second-stage fuel tank. We found no signals before this, so we do not believe that there was an external cause. The primary fuel tank ruptured 4 seconds later and was the strongest event by far, producing an infrasound signal that exceeded 1400 Pa ( 2000 Pa in reduced pressure). The seismic signal consists mainly of air-coupled Rayleigh waves with frequencies of 5-23 Hz. The infrasound events occurred in four clusters. The first cluster included the onset and main events and 46 smaller events. This was followed by several minutes without infrasound signals during which a 3.5 minute continuous seismic vibration occurred. Cluster 2 consisted of 4 events ranging from 117-256 Pa. Cluster 3 comprised 96 events of 7-78 Pa. Cluster 4 consisted of 5 events with overpressures of 23-63 Pa. Gaps of several minutes without infrasound and seismic signals occurred between clusters 2 and 3, and 3 and 4. In terms of energy, the main event dominated; in terms of numbers, cluster 3 had the most infrasound events. The seismic and infrasound data are complementary to video recordings of the explosion, and provide additional characterization that may be useful to interpret the sequence of events. Because of the proximity of our array to this rocket explosion, our dataset may be unique.

  15. Estimating the hydraulic parameters of a confined aquifer based on the response of groundwater levels to seismic Rayleigh waves

    NASA Astrophysics Data System (ADS)

    Sun, Xiaolong; Xiang, Yang; Shi, Zheming

    2018-05-01

    Groundwater flow models implemented to manage regional water resources require aquifer hydraulic parameters. Traditional methods for obtaining these parameters include laboratory experiments, field tests and model inversions, and each are potentially hindered by their unique limitations. Here, we propose a methodology for estimating hydraulic conductivity and storage coefficients using the spectral characteristics of the coseismic groundwater-level oscillations and seismic Rayleigh waves. The results from Well X10 are consistent with the variations and spectral characteristics of the water-level oscillations and seismic waves and present an estimated hydraulic conductivity of approximately 1 × 10-3 m s-1 and storativity of 15 × 10-6. The proposed methodology for estimating hydraulic parameters in confined aquifers is a practical and novel approach for groundwater management and seismic precursor anomaly analyses.

  16. X-15 Model in 7x10 FT Tunnel

    NASA Image and Video Library

    1959-09-17

    X-15 launch techniques were investigated using on-twentieth scale models mounted in the 7x10 FT Tunnel. -- Photograph published in Winds of Change, 75th Anniversary NASA publication (page 67), by James Schultz. -- Photograph also published in Sixty Years of Aeronautical Research 1917-1977 - a NASA publication (page 49), by David A. Anderton.

  17. 1/10th Scale Model X-15

    NASA Image and Video Library

    1958-07-08

    A 1/10th Scale Model of the X-15 research plane is prepared in Langley's 7 x 10 Foot Wind Tunnel for studies relating to spin characteristics. -- Photograph published in Winds of Change, 75th Anniversary NASA publication (page 66), by James Schultz.

  18. Ambient seismic noise applications for Titan

    NASA Astrophysics Data System (ADS)

    Jackson, J. M.; Zhan, Z.; Clayton, R. W.; Helmberger, D. V.; Tsai, V. C.

    2010-12-01

    Titan is Saturn’s largest moon and is host to a myriad of surface, crustal, and perhaps interior dynamic processes (e.g., Lunine & Lorenz 2009; Sotin et al. 2009). Although recent gravity data put constraints on the nature of Titan’s deep interior (Iess et al. 2010), details regarding the layering and crustal structure remain poorly constrained. For example, the crustal thickness derived from modeling of the gravity data suggests a value ~100 km, but with a large uncertainty. There may exist a subsurface ocean or reservoirs of liquid that actively connects with Titan’s hyrdrocarbon-bearing lakes and atmosphere. Cross-correlation of ambient seismic noise is an emerging method to study crustal structures (e.g., Shapiro et al. 2005). Recent results show that under certain conditions, such as post-critical reflections, the Moho-reflected shear wave (SmS) can be clearly identified with ambient seismic noise [Zhan et al. 2010]. Titan may represent a plausible planetary body to apply the methods of ambient seismic noise, thereby providing a unique opportunity to better understand the interior of an icy body in our solar system. We will explore the use of ambient seismic noise on Titan and assess its application to determine interior structures, such as signals expected for different crust-(ocean)-mantle boundary depths. References: Iess, L. et al. (2010), Science 327: 1367-1369 Lunine, J.I. and Lorenz, R.D. (2009), Ann. Rev. Earth Planet. Sci. 37: 299-320. Shapiro et al. (2005), Science 307: 1615-1618. Sotin et al. (2009), in Titan from Cassini-Huygens: 61-73. R.H. Brown, J.-P. Lebreton, J. Hunter Waite, Eds. Zhan, Z. et al. (2010), Geophys. J. Int. doi: 10.1111/j/1365-246X.2010.04625.x Acknowledgments: Parts of this work grew out of discussions during a mini study at the Keck Institute for Space Studies, which is funded by the W. M. Keck Foundation.

  19. DigiSeis—A software component for digitizing seismic signals using the PC sound card

    NASA Astrophysics Data System (ADS)

    Amin Khan, Khalid; Akhter, Gulraiz; Ahmad, Zulfiqar

    2012-06-01

    An innovative software-based approach to develop an inexpensive experimental seismic recorder is presented. This approach requires no hardware as the built-in PC sound card is used for digitization of seismic signals. DigiSeis, an ActiveX component is developed to capture the digitized seismic signals from the sound card and deliver them to applications for processing and display. A seismic recorder application software SeisWave is developed over this component, which provides real-time monitoring and display of seismic events picked by a pair of external geophones. This recorder can be used as an educational aid for conducting seismic experiments. It can also be connected with suitable seismic sensors to record earthquakes. The software application and the ActiveX component are available for download. This component can be used to develop seismic recording applications according to user specific requirements.

  20. Evaluation of seismic design spectrum based on UHS implementing fourth-generation seismic hazard maps of Canada

    NASA Astrophysics Data System (ADS)

    Ahmed, Ali; Hasan, Rafiq; Pekau, Oscar A.

    2016-12-01

    Two recent developments have come into the forefront with reference to updating the seismic design provisions for codes: (1) publication of new seismic hazard maps for Canada by the Geological Survey of Canada, and (2) emergence of the concept of new spectral format outdating the conventional standardized spectral format. The fourth -generation seismic hazard maps are based on enriched seismic data, enhanced knowledge of regional seismicity and improved seismic hazard modeling techniques. Therefore, the new maps are more accurate and need to incorporate into the Canadian Highway Bridge Design Code (CHBDC) for its next edition similar to its building counterpart National Building Code of Canada (NBCC). In fact, the code writers expressed similar intentions with comments in the commentary of CHBCD 2006. During the process of updating codes, NBCC, and AASHTO Guide Specifications for LRFD Seismic Bridge Design, American Association of State Highway and Transportation Officials, Washington (2009) lowered the probability level from 10 to 2% and 10 to 5%, respectively. This study has brought five sets of hazard maps corresponding to 2%, 5% and 10% probability of exceedance in 50 years developed by the GSC under investigation. To have a sound statistical inference, 389 Canadian cities are selected. This study shows the implications of the changes of new hazard maps on the design process (i.e., extent of magnification or reduction of the design forces).

  1. Lattice Boltzmann Simulation of Seismic Mobilization of Residual Oil in Sandstone

    NASA Astrophysics Data System (ADS)

    Guo, R.; Jiang, F.; Deng, W.

    2017-12-01

    Seismic stimulation is a promising technology for enhanced oil recovery. However, current mechanism studies are mainly in the single constricted tubes or idealized porous media, and no study has been conducted in real reservoir porous media. We have developed a numerical simulation which uses the lattice Boltzmann method to directly calculate the characteristics of residual oil clusters to quantify seismic mobilization of residual oil in real Berea sandstone in a scale of 400μm x 400μm x 400μm. The residual oil clusters will be firstly obtained by applying the water flooding scheme to the oil-saturated sandstone. Then, we will apply the seismic stimulation to the sandstone by converting the seismic effect to oscillatory inertial force and add to the pore fluids. This oscillatory inertial force causes the mobilization of residual oil by overcoming the capillary force. The response of water and oil to the seismic stimulation will be observed in our simulations. Two seismic oil mobilization mechanisms will be investigated: (1) the passive response of residual oil clusters to the seismic stimulation, and (2) the resonance of oil clusters subject to low frequency seismic stimulation. We will then discuss which mechanism should be the dominant mechanism for the seismic stimulation oil recovery for practical applications.

  2. Synthesis of layered perovskite oxides, ACa[sub 2-x]La[sub x]Nb[sub 3-x]Ti[sub x]O[sub 10] (A = K, Rb, Cs), and characterization of new solid acids, HCa[sub 2-x]La[sub x]Nb[sub 3-x]Ti[sub x]O[sub 10] (O < x [le] 2), exhibiting variable Bronsted acidity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gopalakrishnan, J.; Uma, S.; Bhat, V.

    1993-01-01

    Layered perovskite oxides of the formula ACa[sub 2-x]La[sub x]Nb[sub 3-x]Ti[sub x]O[sub 10] (A = K, Rb, Cs and 0 , x [le] 2) have been prepared. The members adopt the structures of the parent ACa[sub 2]Nb[sub 3]O[sub 10]. Interlayer alkali cations in the niobium-titanium oxide series can be ion-exchanged with Li[sup +], Na[sup +], NG[sub 4][sup +], of H[sup +] to give new derivatives. Intercalation of the protonated derivatives with organic bases reveals that the Bronsted acidity of the solid solution series, HCa[sub 2-x]La[sub x]Nb[sub 3-x]Ti[sub x]O[sub 10], depends on the titanium content. While the x = 1 member (HCaLaNb[submore » 2]TiO[sub 10]) is nearly as acidic as the parent HCa[sub 2]Nb[sub 3]O[sub 10], the x = 2 member (HLA[sub 2]NbTi[sub 2]O[sub 10]) is a weak acid hardly intercalating organic bases with pK[sub a] [approximately] 11.3. The variation of acidity is probably due to an ordering of Nb/Ti atoms in the triple octahedral perovskite slabs, [Ca[sub 2-x]La[sub x]Nb[sub 3-x]Ti[sub x]O[sub 10

  3. A Monolithic Electrochemical Micro Seismic Sensor Capable of Monitoring Three-Dimensional Vibrations

    PubMed Central

    Chen, Lianhong; Sun, Zhenyuan; Li, Guanglei; Chen, Deyong; Wang, Junbo

    2018-01-01

    A monolithic electrochemical micro seismic sensor capable of monitoring three-axial vibrations was proposed in this paper. The proposed micro sensor mainly consisted of four sensing units interconnected within flow channels and by interpreting the voltage outputs of the sensing units, vibrations with arbitrary directions can be quantified. The proposed seismic sensors are fabricated based on MEMS technologies and characterized, which produced sensitivities along x, y, and z axes as 2473.2 ± 184.5 V/(m/s), 2261.7 ± 119.6 V/(m/s), and 3480.7 ± 417.2 V/(m/s) at 30 Hz. In addition, the vibrations in x-y, x-z, and y-z planes were applied to the developed seismic sensors, leading to comparable monitoring results after decoupling calculations with the input velocities. Furthermore, the results have shown its feasibilities for seismic data recording. PMID:29614720

  4. Comets C/2003 X5-X11 and Y2-Y10 (SOHO)

    NASA Astrophysics Data System (ADS)

    Battams, K.; Boschat, M.; Zhou, X.-M.; Hoffman, T.; Leprette, X.; Matson, R.; Kracht, R.; Sachs, J.; Marsden, B. G.; Kisala, R.

    2004-06-01

    Further to IAUC 8356, K. Battams reports measurements for additional Kreutz sungrazing comets found on SOHO website C2 images by M. Boschat (C/2003 X5, X7, Y5, Y8), X.-m. Zhou (C/2003 X6, X9, X11), T. Hoffman (C/2003 X8), X. Leprette (C/2003 X10, Y2), R. Matson (2003 Y3, Y9, Y10), R. Kracht (C/2003 Y4, Y7), and J. Sachs (C/2003 Y6). C/2003 Y6 and Y7 were also visible on C3 images. The reductions by B. G. Marsden (and by R. Kisala for C/2003 Y8, Y9, Y10) and orbital elements by Marsden appear on the MPECs cited below. Comet 2003 UT R.A. (2000) Decl. MPEC C/2003 X5 Dec. 4.896 16 46.9 -24 12 2004-L24 C/2003 X6 6.396 16 52.2 -24 20 2004-L24 C/2003 X7 7.829 16 58.6 -24 27 2004-L24 C/2003 X8 8.246 17 00.9 -24 31 2004-L24 C/2003 X9 8.621 17 02.2 -24 34 2004-L24 C/2003 X10 11.188 17 14.5 -24 41 2004-L25 C/2003 X11 13.588 17 25.7 -24 57 2004-L25 C/2003 Y2 19.621 17 53.6 -25 08 2004-L25 C/2003 Y3 19.979 17 55.0 -25 02 2004-L25 C/2003 Y4 20.729 17 58.8 -25 14 2004-L25 C/2003 Y5 22.771 18 08.5 -25 08 2004-L25 C/2003 Y6 23.571 18 14.3 -27 22 2004-L26 C/2003 Y7 24.638 18 20.0 -27 44 2004-L26 C/2003 Y8 25.288 18 19.6 -25 00 2004-L67 C/2003 Y9 25.479 18 20.7 -24 46 2004-L67 C/2003 Y10 26.064 18 23.5 -24 50 2004-L67

  5. Seismic retrofit guidelines for Utah highway bridges.

    DOT National Transportation Integrated Search

    2009-05-01

    Much of Utahs population dwells in a seismically active region, and many of the bridges connecting transportation lifelines predate the rigorous seismic design standards that have been developed in the past 10-20 years. Seismic retrofitting method...

  6. Microstructure and magnetic microstructure of the Pr 60Al 10Ni 10Cu 20-xFe x ( x=0, 4, 10, 15, 18) alloys observed by magnetic force microscopy

    NASA Astrophysics Data System (ADS)

    Pang, Z. Y.; Han, S. H.; Wang, Y. T.; Wang, W. H.; Han, B. S.

    2005-03-01

    The microstructure and magnetic microstructure of the Pr 60Al 10Ni 10Cu 20-xFe x ( x=0, 4, 10, 15, 18) alloys have been achieved simultaneously by employing a magnetic force microscope directly on the as-cast cylinder rod surface for the first time. By varying the content of Fe, the microstructure of the Pr-based alloy changes progressively from a full glassy state to a composite state with nanocrystalline particles embedded in the glassy matrix, and finally into a nanostructured state. The accompanying magnetic property gradually changes from paramagnetic to hard. The experiment directly evidences the existence of exchange coupling between the crystallites and the variety of the grain-size-dependent magnetic properties can be well explained by Löffler et al.'s new random-anisotropy model (Löffler, et al., Phys. Rev. Lett. 85 (9) (2000) 1990).

  7. Location of the Green Canyon (Offshore Southern Louisiana) Seismic Event of February 10, 2006

    USGS Publications Warehouse

    Dewey, James W.; Dellinger, Joseph A.

    2008-01-01

    We calculated an epicenter for the Offshore Southern Louisiana seismic event of February 10, 2006 (the 'Green Canyon event') that was adopted as the preferred epicenter for the event by the USGS/NEIC. The event is held at a focal depth of 5 km; the focal depth could not be reliably calculated but was most likely between 1 km and 15 km beneath sea level. The epicenter was calculated with a radially symmetric global Earth model similar to that routinely used at the USGS/NEIC for all earthquakes worldwide. The location was calculated using P-waves recorded by seismographic stations from which the USGS/NEIC routinely obtains seismological data, plus data from two seismic exploration arrays, the Atlantis ocean-bottom node array, operated by BP in partnership with BHP Billiton Limited, and the CGG Green Canyon phase VIII multi-client towed-streamer survey. The preferred epicenter is approximately 26 km north of an epicenter earlier published by the USGS/NEIC, which was obtained without benefit of the seismic exploration arrays. We estimate that the preferred epicenter is accurate to within 15 km. We selected the preferred epicenter from a suite of trial calculations that attempted to fit arrival times of seismic energy associated with the Green Canyon event and that explored the effect of errors in the velocity model used to calculate the preferred epicenter. The various trials were helpful in confirming the approximate correctness of the preferred epicenter and in assessing the accuracy of the preferred epicenter, but none of the trial calculations, including that of the preferred epicenter, was able to reconcile arrival-time observations and assumed velocity model as well as is typical for the vast majority of earthquakes in and near the continental United States. We believe that remaining misfits between the preferred solution and the observations reflect errors in interpreted arrival times of emergent seismic phases that are due partly to a temporally extended source

  8. InSAR Surface Deformation and Source Modelling at Semisopochnoi Island During the 2014 and 2015 Seismic Swarms with Constraints from Geochemical and Seismic Analysis

    NASA Astrophysics Data System (ADS)

    DeGrandpre, K.; Pesicek, J. D.; Lu, Z.

    2017-12-01

    During the summer of 2014 and the early spring of 2015 two notable increases in seismic activity at Semisopochnoi Island in the western Aleutian islands were recorded on AVO seismometers on Semisopochnoi and neighboring islands. These seismic swarms did not lead to an eruption. This study employs interferometric synthetic aperture radar (InSAR) techniques using TerraSAR-X images in conjunction with more accurately relocating the recorded seismic events through simultaneous inversion of event travel times and a three-dimensional velocity model using tomoDD. The InSAR images exhibit surprising coherence and an island wide spatial distribution of inflation that is then used in Mogi, Okada, spheroid, and ellipsoid source models in order to define the three-dimensional location and volume change required for a source at the volcano to produce the observed surface deformation. The tomoDD relocations provide a more accurate and realistic three-dimensional velocity model as well as a tighter clustering of events for both swarms that clearly outline a linear seismic void within the larger group of shallow (<10 km) seismicity. The source models are fit to this void and pressure estimates from geochemical analysis are used to verify the storage depth of magmas at Semisopochnoi. Comparisons of calculated source cavity, magma injection, and surface deformation volumes are made in order to assess the reality behind the various modelling estimates. Incorporating geochemical and seismic data to provide constraints on surface deformation source inversions provides an interdisciplinary approach that can be used to make more accurate interpretations of dynamic observations.

  9. Angola seismicity

    NASA Astrophysics Data System (ADS)

    Neto, Francisco António Pereira; França, George Sand; Condori, Cristobal; Sant'Anna Marotta, Giuliano; Chimpliganond, Cristiano Naibert

    2018-05-01

    This work describes the development of the Angolan earthquake catalog and seismicity distribution in the Southwestern African Plate, in Angola. This region is one of the least seismically 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 seismic 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 seismic activity occurs. Although clear differences are found between different areas along the passive margin, in the middle near Porto Amboim city, seismic activity is more frequent compared with northwestern and southwestern regions.

  10. Experimental study on impact-induced seismic wave propagating through quartz sand simulating asteroid regolith

    NASA Astrophysics Data System (ADS)

    Matsue, Kazuma; Arakawa, Masahiko; Yasui, Minami; Matsumoto, Rie; Tsujido, Sayaka; Takano, Shota; Hasegawa, Sunao

    2015-08-01

    Introduction: Recent spacecraft surveys clarified that asteroid surfaces were covered with regolith made of boulders and pebbles such as that found on the asteroid Itokawa. It was also found that surface morphologies of asteroids formed on the regolith layer were modified. For example, the high-resolution images of the asteroid Eros revealed the evidence of the downslope movement of the regolith layer, then it could cause the degradation and the erasure of small impact crater. One possible process to explain these observations is the regolith layer collapse caused by seismic vibration after projectile impacts. The impact-induced seismic wave might be an important physical process affecting the morphology change of regolith layer on asteroid surfaces. Therefore, it is significant for us to know the relationship between the impact energy and the impact-induced seismic wave. So in this study, we carried out impact cratering experiments in order to observe the seismic wave propagating through the target far from the impact crater.Experimental method: Impact cratering experiments were conducted by using a single stage vertical gas gun set at Kobe Univ and a two-stage vertical gas gun set at ISAS. We used quartz sands with the particle diameter of 500μm, and the bulk density of 1.48g/cm3. The projectile was a ball made of polycarbonate with the diameter of 4.75mm and aluminum, titan, zirconia, stainless steel, cupper, tungsten carbide projectile with the diameter of 2mm. These projectiles were launched at the impact velocity from 0.2 to 7km/s. The target was set in a vacuum chamber evacuated below 10 Pa. We measured the seismic wave by using a piezoelectric uniaxial accelerometer.Result: The impact-induced seismic wave was measured to show a large single peak and found to attenuate with the propagation distance. The maximum acceleration of the seismic wave was recognized to have a good relationship with the normalized distance x/R, where x is the propagation distance

  11. Report of reprocessing of reflection seismic profile X-5 Waste Isolation Pilot Plant site, Eddy County, New Mexico

    USGS Publications Warehouse

    Miller, John J.

    1983-01-01

    Seismic reflection profile X-5 exhibits a 7,700 ft long anomalous zone of poor quality to nonexistent reflections between shotpoints 100 and 170, compared to the high-quality, flat-lying, coherent reflections on either side. Results from drill holes in the area suggest 'layer cake' geology with no detectable abnormalities such as faults present. In an attempt to determine whether the anomalous zone of the seismic profile is an artifact or actually indicates a geologic condition, the data were extensively reprocessed using state-of-the-art processing techniques and the following conclusions were made: 1. The field-recorded data in the anomalous zone are of poor quality due to surface conditions and recording parameters used. 2. Reprocessing shows reflectors throughout the anomalous zone at all levels. However, it cannot prove that the reflectors are continuous throughout the anomalous zone. 3. Significant improvement in data quality may be achieved if the line is reshot using carefully determined recording parameters.

  12. High Voltage Seismic Generator

    NASA Astrophysics Data System (ADS)

    Bogacz, Adrian; Pala, Damian; Knafel, Marcin

    2015-04-01

    This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage seismic wave generator. Constructed device uses a high-energy electrical discharge to generate seismic wave in ground. This type of device can be applied in several different methods of seismic measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then released in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate seismic waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated seismic signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes

  13. 1. 8' x 10' enlargement from 4' x 5' negative ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. 8' x 10' enlargement from 4' x 5' negative Kevin Kriesel-Coons, Photographer, November 13, 1990 EXTERIOR OF HYDRO PLANT, SHOWING CURRENT STATE OF DISREPAIR. VIEW FROM WALKWAY OVER TAILRACE OF CROSSCUT CANAL TO THE LARGER, ORIGINAL CROSSCUT HYDRO PLANT. - Crosscut Steam Plant, Ancillary Hydro Unit, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

  14. The seismic traffic footprint: Tracking trains, aircraft, and cars seismically

    NASA Astrophysics Data System (ADS)

    Riahi, Nima; Gerstoft, Peter

    2015-04-01

    Although naturally occurring vibrations have proven useful to probe the subsurface, the vibrations caused by traffic have not been explored much. Such data, however, are less sensitive to weather and low visibility compared to some common out-of-road traffic sensing systems. We study traffic-generated seismic noise measured by an array of 5200 geophones that covered a 7 × 10 km area in Long Beach (California, USA) with a receiver spacing of 100 m. This allows us to look into urban vibrations below the resolution of a typical city block. The spatiotemporal structure of the anthropogenic seismic noise intensity reveals the Blue Line Metro train activity, departing and landing aircraft in Long Beach Airport and their acceleration, and gives clues about traffic movement along the I-405 highway at night. As low-cost, stand-alone seismic sensors are becoming more common, these findings indicate that seismic data may be useful for traffic monitoring.

  15. SpaceX CRS-10 Post Launch News Conference

    NASA Image and Video Library

    2017-02-19

    In the Press Site auditorium of NASA's Kennedy Space Center in Florida, Jessica Jensen, Dragon mission manager for SpaceX, speaks to the news media at a post-launch news conference following the liftoff of SpaceX CRS-10, a commercial resupply services mission to the International Space Station. SpaceX CRS-10 lifted off atop a Falcon 9 rocket from Kennedy's Launch Complex 39A at 9:39 a.m. EST.

  16. Seismicity, arrival time delays of the seismic phases and slowness characteristics study in Abu Dabbab area, Egypt

    NASA Astrophysics Data System (ADS)

    Sami, Mahmoud; Hassoup, Awad; Hosny, Ahmed; Mohamed, Gadelkarem A.

    2013-12-01

    The temporal variations of seismicity from the Abu Dabbab area, 25 km west of the Red Sea coast, are collected from the Egyptian national seismic network (ENSN), which has magnified the detection capability in that area to ML < 1 earthquakes. These data show a sequence of the micro earthquake swarm during 2003-2011. This area has experienced larger shocks up to M = 6 during the 20th century and its seismicity is concentrated in a narrow spatial volume. We analyze the digital waveform data of about 1000 seismograms, recorded by portable network of 10 vertical component seismographs that are employed in a temporary survey experiment in the Abu Dabbab area in 2004, and the results indicate: firstly, there are similar waveform seismograms, which are classified into three groups. In each group a master event is identified. Then, the arrival time delays of the P and S phases (Δtp and Δts, respectively) are measured between the master event and its slave events. Δtp and Δts range between -0.01 and 0.02 s, respectively. These values are used to relocate the studied events. Secondly, the slowness vector (Δs) in 3-dimensional pattern, which is estimated using the genetic algorithms, is found Δsx = 0.0153, Δsy = 0.00093 and Δsz = 0.2086 s/km in the three spatial coordinates (X, Y and Z), respectively. These analyses demonstrate the inhomogeneities within the upper crust of the study area. Also, Δs shows little dependence of lateral distances and reasonably high slowness along the depth extent, which is consistent with the seismic velocity structure variations.

  17. 10 CFR 100.23 - Geologic and seismic siting criteria.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Earthquake Ground Motion, and to permit adequate engineering solutions to actual or potential geologic and..., earthquake recurrence rates, fault geometry and slip rates, site foundation material, and seismically induced... Earthquake Ground Motion for the site, the potential for surface tectonic and nontectonic deformations, the...

  18. 10 CFR 100.23 - Geologic and seismic siting criteria.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Earthquake Ground Motion, and to permit adequate engineering solutions to actual or potential geologic and..., earthquake recurrence rates, fault geometry and slip rates, site foundation material, and seismically induced... Earthquake Ground Motion for the site, the potential for surface tectonic and nontectonic deformations, the...

  19. 10 CFR 100.23 - Geologic and seismic siting criteria.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Earthquake Ground Motion, and to permit adequate engineering solutions to actual or potential geologic and..., earthquake recurrence rates, fault geometry and slip rates, site foundation material, and seismically induced... Earthquake Ground Motion for the site, the potential for surface tectonic and nontectonic deformations, the...

  20. The double seismic zone in downgoing slabs and the viscosity of the mesosphere

    NASA Technical Reports Server (NTRS)

    Sleep, N. H.

    1979-01-01

    The seismic zone beneath several island arcs between about 100 and 200 km depth consists of an upper zone having down-dip compression and a lower zone having down-dip tension. Several numerical models of the Aleutian arc were computed to test the hypothesis that these double seismic zones are due to sagging of the slab under its own weight. This sagging occurs because the asthenosphere (between about 100 and 200 km) provides little support or resistance to the slab, which is supported from below by the more viscous mesosphere and from above by the lithosphere. The viscosity of the mesosphere was constrained to the interval between 0.25 x 10 to the 22nd and 0.5 x 10 to the 22nd P by noting that the slab would have mainly down-dip compression at higher viscosities and mainly down-dip tension at lower viscosities. The deviatoric stress in the slab and the fault plane between the slab and the island arc is about 200-300 bars (expressed as shear stress). The models were calibrated to the observed depth and gravity anomalies in the trench.

  1. SpaceX CRS-10 Liftoff

    NASA Image and Video Library

    2017-02-19

    A SpaceX Falcon 9 rocket lifts off from Launch Complex 39A at NASA's Kenney Space Center in Florida. This is the company's 10th commercial resupply services mission to the International Space Station. Liftoff was at 9:39 a.m. EST from the historic launch site now operated by SpaceX under a property agreement with NASA. The Dragon spacecraft will deliver about 5,500 pounds of supplies to the space station, including the Stratospheric Aerosol and Gas Experiment (SAGE) III instrument to further study ozone in the atmosphere.

  2. [Immobilization of pectawamorine G10x on silichromes].

    PubMed

    Bogatskiĭ, A V; Davidenko, T I; Gren', T A

    1980-01-01

    Immobilization of pectawamorine G10x on silochromes, using cyanuric chloride, 2,4-toluylene diisocyanate, glutaric dialdehyde, thionyl chloride, phosphorus tribromide, titanium tetrachloride, zirconium oxychloride and hafnium oxychloride was studied. The use of glutaric dialdehyde assured the strongest binding and the preatest stability of activity. Properties of the native pectawamorine G10x and immobilized preparations were studied on a comparative basis. Pectawamorine G10x immobilized by means of hafnium oxychloride showed increased stability when stored at 5 degrees C and used repeatedly. In every case, except for cyanuric chloride and glutaric dialdehyde, maximum activity was at a temperature 10 degrees C higher than for the native enzyme, and optimum pH varied for the preparations with different binding reagents.

  3. Fault Specific Seismic Hazard Maps as Input to Loss Reserves Calculation for Attica Buildings

    NASA Astrophysics Data System (ADS)

    Deligiannakis, Georgios; Papanikolaou, Ioannis; Zimbidis, Alexandros; Roberts, Gerald

    2014-05-01

    Athens, using detailed data derived from published papers, neotectonic maps and fieldwork observations. Moreover, we incorporated background seismicity models from the historic record and also the subduction zone earthquakes distribution, for the integration of strong deep earthquakes that could also affect Attica region. We created 4 high spatial resolution seismic hazard maps for the region of Attica, one for each of the intensities VII - X (MM). These maps offer a locality specific shaking recurrence record, which represents the long-term shaking record in a more complete way, since they incorporate several seismic cycles of the active faults that could affect Attica. Each one of these high resolution seismic hazard maps displays both the spatial distribution and the recurrence, over a specific time period, of the relevant intensity. Time - independent probabilities were extracted based on these average recurrence intervals, using the stationary Poisson model P = 1 -e-Λt. The 'Λ' value was provided by the intensities recurrence, as displayed in the seismic hazard maps. However, the insurance contracts usually lack of detailed spatial information and they refer to Postal Codes level, akin to CRESTA zones. To this end, a time-independent probability of shaking at intensities VII - X was calculated for every Postal Code, for a given time period, using the Poisson model. The reserves calculation on buildings portfolio combines the probability of events of specific intensities within the Postal Codes, with the buildings characteristics, such as the building construction type and the insured value. We propose a standard approach for the reserves calculation K(t) for a specific time period: K (t) = x2 ·[x1 ·y1 ·P1(t) + x1 ·y2 ·P2(t) + x1 ·y3 ·P3(t) + x1 ·y4 ·P4(t)] x1 which is a function of the probabilities of occurrence for the seismic intensities VII - X (P1(t) -P4(t)) for the same period, the value of the building x1, the insured value x2 and the

  4. Intensity Based Seismic Hazard Map of Republic of Macedonia

    NASA Astrophysics Data System (ADS)

    Dojcinovski, Dragi; Dimiskovska, Biserka; Stojmanovska, Marta

    2016-04-01

    probability for occurrence of future earthquakes with a defined area distribution of their seismic intensity, depending on the natural characteristics of the terrain. The period of 10.000 years represents the greatest expected seismic threat for the considered area. From the aspect of low-cost construction, it is also necessary to know the seismicity in shorter time periods, as well. Therefore, maps for return time periods of 50, 100, 200, 500 and 1000 years have also been elaborated. The maps show a probability of 63% for occurrence of expected earthquakes with maximum intensities expressed on the MCS scale. The map has been elaborated to the scale of 1: 1.000.000, while the obtained isolines of seismic intensity are drawn with an error of  5 km. The seismic hazard map of R. Macedonia is used for: • The needs of the Rulebook on Technical Norms on Construction of Structures in Seismic Areas and for the needs of physical and urban planning and design. • While defining the seismic design parameters for construction of structures in zones with intensity of I  VII degrees MSK, investigations should be done for detailed seismic zoning and microzoning of the terrain of these zones in compliance with the technical regulations for construction in seismically prone areas. • The areas on the map indicated by intensity X MCS are not regulated by the valid regulations. Therefore, in practice, these should be treated as such in which it is not possible to construct any structures without previous surveys. • Revision of this map is done at a five year period, i.e., after each occurred earthquake whose parameters are such that require modifications and amendments of the map.

  5. MSNoise: a Python Package for Monitoring Seismic Velocity Changes using Ambient Seismic Noise

    NASA Astrophysics Data System (ADS)

    Lecocq, T.; Caudron, C.; Brenguier, F.

    2013-12-01

    Earthquakes occur every day all around the world and are recorded by thousands of seismic stations. In between earthquakes, stations are recording "noise". In the last 10 years, the understanding of this noise and its potential usage have been increasing rapidly. The method, called "seismic interferometry", uses the principle that seismic waves travel between two recorders and are multiple-scattered in the medium. By cross-correlating the two records, one gets an information on the medium below/between the stations. The cross-correlation function (CCF) is a proxy to the Green Function of the medium. Recent developments of the technique have shown those CCF can be used to image the earth at depth (3D seismic tomography) or study the medium changes with time. We present MSNoise, a complete software suite to compute relative seismic velocity changes under a seismic network, using ambient seismic noise. The whole is written in Python, from the monitoring of data archives, to the production of high quality figures. All steps have been optimized to only compute the necessary steps and to use 'job'-based processing. We present a validation of the software on a dataset acquired during the UnderVolc[1] project on the Piton de la Fournaise Volcano, La Réunion Island, France, for which precursory relative changes of seismic velocity are visible for three eruptions betwee 2009 and 2011.

  6. Seismic Catalogue and Seismic Network in Haiti

    NASA Astrophysics Data System (ADS)

    Belizaire, D.; Benito, B.; Carreño, E.; Meneses, C.; Huerfano, V.; Polanco, E.; McCormack, D.

    2013-05-01

    The destructive earthquake occurred on January 10, 2010 in Haiti, highlighted the lack of preparedness of the country to address seismic phenomena. At the moment of the earthquake, there was no seismic network operating in the country, and only a partial control of the past seismicity 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 seismic catalogue providing the necessary input for seismic Hazard Studies. This paper presents the state of the works carried out covering both aspects. First, a seismic 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 seismic network, 3 stations were installed just after the 2010 earthquake by the Canadian Government. The data were sent by telemetry thought the Canadian System CARINA. In 2012, the Spanish IGN together

  7. Post-seismic velocity changes following the 2010 Mw 7.1 Darfield earthquake, New Zealand, revealed by ambient seismic field analysis

    NASA Astrophysics Data System (ADS)

    Heckels, R. EG; Savage, M. K.; Townend, J.

    2018-05-01

    Quantifying seismic velocity changes following large earthquakes can provide insights into fault healing and reloading processes. This study presents temporal velocity changes detected following the 2010 September Mw 7.1 Darfield event in Canterbury, New Zealand. We use continuous waveform data from several temporary seismic networks lying on and surrounding the Greendale Fault, with a maximum interstation distance of 156 km. Nine-component, day-long Green's functions were computed for frequencies between 0.1 and 1.0 Hz for continuous seismic records from immediately after the 2010 September 04 earthquake until 2011 January 10. Using the moving-window cross-spectral method, seismic velocity changes were calculated. Over the study period, an increase in seismic velocity of 0.14 ± 0.04 per cent was determined near the Greendale Fault, providing a new constraint on post-seismic relaxation rates in the region. A depth analysis further showed that velocity changes were confined to the uppermost 5 km of the subsurface. We attribute the observed changes to post-seismic relaxation via crack healing of the Greendale Fault and throughout the surrounding region.

  8. Theory and case studies on solar induced seismicity

    NASA Astrophysics Data System (ADS)

    Duma, Gerald; Freund, Friedemann; Kosovichev, Pavel

    2015-04-01

    Huge electric current vortices are continuously generated in the Earth's lithosphere through electromagnetic induction from powerful ionospheric electric vortex currents that arise from ionization on the sun-lit side of the Earth (Chapman S. and Bartels J., 1940). The circular telluric currents in the Earth's lithosphere interact with the Earth's main magnetic field (H), building up a magnetic moment (M). According to T = [M x H] a mechanic torque (T) results from this interaction that can reach values as high as 5x10exp13 Nm (Duma G. and Ruzhin Y., 2003). We present evidence that this ionospherically induced telluric torque, which reaches deep into the lithosphere, influences the diurnal seismicity patterns in major earthquake zones as documented by earthquakes with magnitudes M ≥ 6.0. Our results confirm observations of distinct time-of-day patterns of seismic activity reported for over a century (Omori F., 1902; Conrad V., 1932 ; Shimshoni M., 1971; Duma G. and Vilardo G., 1998; Schekotov A.Yu., Molchanov O.A. and Hayakawa M., 2005) and even much earlier by Pliny the Elder, 79 A.D. A solar influence on earthquake frequency is apparent not only in diurnal patterns, but also in seasonal (e.g. Lipovics T., 2005) and decadal patterns. The effect can be validated by data recorded continuously at geomagnetic observatories, the INTERMAGNET stations (http://www.intermagnet.org), operating on all continents. The observatories continuously record magnetic variations which arise from the telluric currents in the Earth's lithosphere. Theory and model are presented, starting from the primary source for the effect, which is the varying solar wind speed as measured by satellites. The data are provided by the OMNI 2 directory (NASA, http://omniweb.gsfc.nasa.gov). We offer 7 case studies that deal with seismic activity patterns in the diurnal, seasonal and long term time domains for seismic zones in Asia (Japan, Taiwan, Sumatra), N-America (California), the Mid Atlantic Ridge

  9. Seismicity Induced by Groundwater Recharge at Mt. Hood, Oregon, and its Implications for Hydrogeologic Properties.

    NASA Astrophysics Data System (ADS)

    Saar, M. O.; Manga, M.

    2002-12-01

    Earthquakes induced by human-caused changes in fluid pressure have been documented for many years. Examples include seismicity induced by filling reservoirs and by fluid injection or extraction. Less well-documented are seismic events that potentially are triggered by natural variations in groundwater recharge rates (e.g., Wolf et al., BSSA, 1997; Jimenez and Garcia-Fernandez, JVGR, 2000; Audin et al., GRL, 2002). Large groundwater recharge rates can occur in Volcanic Arcs such as the Oregon Cascades where annual precipitation is > 2 m of which > 50 % infiltrates the ground mostly during snowmelt in spring. As a result, infiltration rates of > 1 m per year concentrated during a few months can occur. Near-surface porosities are about 5-10 %. Thus, groundwater levels may fluctuate annually by about 10-20 m resulting in seasonal pore fluid pressure variations of about 1-2 x 105 Pa. Such large-amplitude, narrow-duration fluid pressure signals may allow investigation of seismicity induced by pore fluid pressure diffusion without the influence of engineered systems such as reservoirs. This kind of in-situ study of natural systems over large representative elementary volumes may allow determination of hydrologic parameters at spatial and temporal scales that are relevant for regional hydrogeology. Furthermore, natural hydrologic triggering of earthquakes that persist for decades provides insight into the state of stress in the crust and suggest long-term near-critical failure conditions. Here, we approximate the temporal variations in groundwater recharge with discharge in runoff-dominated streams at high elevations that show a peak in discharge during snow melt. Seismicity is evaluated as time series of daily number of earthquakes and seismic moments. Both stream discharge and seismicity are compared at equivalent frequency bands by applying segmented least-squares polynomial fits to the data. We find statistically significant correlation between groundwater recharge and

  10. Tomographic Image of a Seismically Active Volcano: Mammoth Mountain, California

    NASA Astrophysics Data System (ADS)

    Dawson, P. B.; Chouet, B. A.; Pitt, A. M.

    2015-12-01

    High-resolution tomographic P wave, S wave, and VP /VS velocity structure models are derived for Mammoth Mountain, California using phase data from the Northern California Seismic Network and a temporary deployment of broadband seismometers. An anomalous volume (˜50 km3) of low P and low S wave velocities is imaged beneath Mammoth Mountain, extending from near the surface to a depth of ˜2 km below sea level. We infer that the reduction in seismic wave velocities is primarily due to the presence of CO2 distributed in oblate-spheroid pores with mean aspect ratio α ˜8 x 10-4 (crack-like pores) and gas volume fraction φ ˜4 x 10-4. The pore density parameter κ = 3φ / (4πα) = na3 = 0.12, where n is the number of pores per cubic meter and a is the mean pore equatorial radius. The total mass of CO2 is estimated to range up to ˜1.6 x 1010 kg if the pores exclusively contain CO2, although he presence of an aqueous phase may lower this estimate by up to one order of magnitude. The local geological structure indicates that the CO2 contained in the pores is delivered to the surface through fractures controlled by faults and remnant foliation of the bedrock beneath Mammoth Mountain. The total volume of CO2 contained in the reservoir suggests that given an emission rate of 5 x 105 kg day-1, the reservoir could supply the emission of CO2 for ˜8 to ˜90 years before depletion. Continued supply of CO2 from an underlying magmatic system would significantly prolong the existence of the reservoir.

  11. Induced Seismicity

    NASA Astrophysics Data System (ADS)

    Keranen, Katie M.; Weingarten, Matthew

    2018-05-01

    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 seismicity. However, the similarity of induced and natural seismicity 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 seismicity will continue to pose a hazard in coming years.

  12. Probabilistic Seismic Hazard Assessment for Iraq

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Onur, Tuna; Gok, Rengin; Abdulnaby, Wathiq

    Probabilistic Seismic Hazard Assessments (PSHA) form the basis for most contemporary seismic provisions in building codes around the world. The current building code of Iraq was published in 1997. An update to this edition is in the process of being released. However, there are no national PSHA studies in Iraq for the new building code to refer to for seismic loading in terms of spectral accelerations. As an interim solution, the new draft building code was considering to refer to PSHA results produced in the late 1990s as part of the Global Seismic Hazard Assessment Program (GSHAP; Giardini et al.,more » 1999). However these results are: a) more than 15 years outdated, b) PGA-based only, necessitating rough conversion factors to calculate spectral accelerations at 0.3s and 1.0s for seismic design, and c) at a probability level of 10% chance of exceedance in 50 years, not the 2% that the building code requires. Hence there is a pressing need for a new, updated PSHA for Iraq.« less

  13. PSHAe (Probabilistic Seismic Hazard enhanced): the case of Istanbul.

    NASA Astrophysics Data System (ADS)

    Stupazzini, Marco; Allmann, Alexander; Infantino, Maria; Kaeser, Martin; Mazzieri, Ilario; Paolucci, Roberto; Smerzini, Chiara

    2016-04-01

    , "Numerical Study on the Role of Basin Geometry and Kinematic Seismic Source in 3D Ground Motion Simulation of the 22 February 2011 M-W 6.2 Christchurch Earthquake", SRL 11/2011; 82(6):767-782. DOI:10.1785/gssrl.82.6.767 Pilz M,Parolai S, Stupazzini M, Paolucci P and Zschau J, "Modelling basin effects on earthquake ground motion in the Santiago de Chile basin by a spectral element code", GJI 11/2011, 187(2):929-945. DOI: 10.1111/j.1365-246X.2011.05183.x Smerzini C and Villani M, "Broadband Numerical Simulations in Complex Near-Field Geological Configurations: The Case of the 2009 Mw 6.3 L'Aquila Earthquake", BSSA 12/2012; 102(6):2436-2451. DOI:10.1785/0120120002 Villani M, Faccioli E, Ordaz M, Stupazzini M, "High-Resolution Seismic Hazard Analysis in a Complex Geological Configuration: The Case of the Sulmona Basin in Central Italy", Earthquake Spectra, 11/2014; 30(4):1801-1824. DOI: 10.1193/112911EQS288M

  14. [X-ray diffraction and infrared spectrum analysis of fault gouge in Wenchuan seismic belt].

    PubMed

    Wang, Zheng-Yang; Cao, Jian-Jin; Luo, Song-Ying; Liao, Yi-Peng

    2014-05-01

    Wenchuan earthquake produced a series of co-seismic surface ruptures in Leigu and Zhaojiagou, and we collected samples of co-seismic fault gouge in the surface ruptures as well as the old gouge in the fault of Nanba. Testing The new and old fault gouge was tested with X-ray diffraction and infrared absorption spectra, and its characteristics such as mineral compositions, clay mineral contents and combinations were comprehensively analyzed. The results display obvious differences between the new and old fault gouge, showing that the old fault gouge is mainly composed of wall rock debris or milled powders, while the main components of new fault gouge are clay minerals. The assemblage of clay minerals composition shows that the environment of the fault activity was mainly warm and humid, and the clay minerals were mainly transformed by low temperature and low pressure dynamic metamorphism. And this also partly indicates that the latest way of the fault activity in this area may be a creeping. However the previous researches on the fault gouge of Wenchuan earthquake fault zone are mainly focused on its mechanical properties as well as its texture and structure, the research in this paper is to determine the physical and chemical environment of fault activity through the mineral compositions and clay mineral contents in the fault gouge characteristics, and this research has important scientific significance to the researches on the evolution of the fault environment and the activity mechanism of the earthquake.

  15. New comprehensive standard seismic noise models and 3D seismic noise variation for Morocco territory, North Africa, obtained using seismic broadband stations

    NASA Astrophysics Data System (ADS)

    El Fellah, Younes; El-Aal, Abd El-Aziz Khairy Abd; Harnafi, Mimoun; Villaseñor, Antonio

    2017-05-01

    In the current work, we constructed new comprehensive standard seismic noise models and 3D temporal-spatial seismic noise level cubes for Morocco in north-west Africa to be used for seismological and engineering purposes. Indeed, the original global standard seismic noise models published by Peterson (1993) and their following updates by Astiz and Creager (1995), Ekström (2001) and Berger et al. (2003) had no contributing seismic stations deployed in North Africa. Consequently, this preliminary study was conducted to shed light on seismic noise levels specific to north-west Africa. For this purpose, 23 broadband seismic stations recently installed in different structural domains throughout Morocco are used to study the nature and characteristics of seismic noise and to create seismic noise models for Morocco. Continuous data recorded during 2009, 2010 and 2011 were processed and analysed to construct these new noise models and 3D noise levels from all stations. We compared the Peterson new high-noise model (NHNM) and low-noise model (NLNM) with the Moroccan high-noise model (MHNM) and low-noise model (MLNM). These new noise models are comparable to the United States Geological Survey (USGS) models in the short period band; however, in the period range 1.2 s to 1000 s for MLNM and 10 s to 1000 s for MHNM display significant variations. This variation is attributed to differences in the nature of seismic noise sources that dominate Morocco in these period bands. The results of this study have a new perception about permanent seismic noise models for this spectacular region and can be considered a significant contribution because it supplements the Peterson models and can also be used to site future permanent seismic stations in Morocco.

  16. Seismic efficiency of meteor airbursts

    NASA Astrophysics Data System (ADS)

    Svetsov, V. V.; Artemieva, N. A.; Shuvalov, V. V.

    2017-08-01

    We present the results of numerical simulation for impacts of relatively small asteroids and ice bodies of 30-100 m in size, decelerated in the atmosphere and exploding before they reach the surface, but still producing seismic effects due to the impact wave reaching the surface. The calculated magnitudes fall within the range of 4 to 6, and average seismic efficiency of these events is 2.5 × 10-5. The results obtained allow the seismic hazard from impacts of cosmic bodies to be estimated.

  17. Deep seismic exploration into the Arctic Lithosphere: Arctic-2012 Russian wide-angle seismic experiment

    NASA Astrophysics Data System (ADS)

    Kashubin, S.

    2013-12-01

    Integrated geological and geophysical studies of the Earth's crust and upper mantle (the Russian project 'Arctic-2012') were carried out in 2012 in the Mendeleev Rise, central Arctic. The set of studies included wide-angle seismic observations along the line crossing the Mendeleev Rise in its southern part. The DSS seismic survey was aimed at the determination of the Mendeleev Rise crust type. A high-power air gun (120 liters or 7320 cu.in) and ocean stations with multi-component recording (X, Y, Z geophone components and a hydrophone) were used for the DSS. The line was studied using a dense system of observation: bottom station spacing was from 10 to 20 km, excitation point spacing (seismic traces interval) was 315 m. Observation data were obtained in 27 location points of bottom stations, the distance between the first and the last stations was 480 km, the length of the excitation line was 740 km. In DSS wave fields, in the first and later arrivals, there are refracted and reflected waves associated with boundaries in the sedimentary cover, with the top of the basement, and with boundaries in the consolidated crust, including its bottom (Moho discontinuity). The waves could be traced for offsets up to 170-240 km. The DSS line coincides with the near-vertical CMP line worked out with the use of a 4500-m-long seismic streamer and with a 50 m shot point interval that allowed essential detalization of the upper part of the section and taking it into account in the construction of a deep crust model. The deep velocity model was constructed using ray-trace modeling of compressional, shear, and converted waves with the use of the SeisWide program. Estimates were obtained for Vp/Vs velocity ratios, which played an important role in determining the type of crust. The results of the interpretation show that the Mendeleev Rise section corresponds to sections of a thin continental crust of shelf seas and a thinned continental crust of submarine ridges and rises.

  18. Appalachian Play Fairway Analysis Seismic Hazards Supporting Data

    DOE Data Explorer

    Frank Horowitz

    2016-07-20

    These are the data used in estimating the seismic hazards (both natural and induced) for candidate direct use geothermal locations in the Appalachian Basin Play Fairway Analysis by Jordan et al. (2015). xMin,yMin -83.1407,36.7461 : xMax,yMax -71.5175,45.1729

  19. 3D Modelling of Seismically Active Parts of Underground Faults via Seismic Data Mining

    NASA Astrophysics Data System (ADS)

    Frantzeskakis, Theofanis; Konstantaras, Anthony

    2015-04-01

    , E. and Papathanassiou, G.: 'Aftershock relocation and frequency-size distribution, stress inversion and seismotectonic setting of the 7 August 2013 M=5.4 earthquake in Kallidromon Mountain, central Greece', Tectonophysics, vol. 617, pp. 101-113, 2014 [4] Maravelakis, E., Bilalis, N., Mantzorou, I., Konstantaras, A. and Antoniadis, A.: '3D modelling of the oldest olive tree of the world', International Journal Of Computational Engineering Research, vol. 2 (2), pp. 340-347, 2012 [5] Konstantaras, A., Katsifarakis, E, Maravelakis, E, Skounakis, E, Kokkinos, E. and Karapidakis, E.: 'Intelligent spatial-clustering of seismicity in the vicinity of the Hellenic seismic arc', Earth Science Research, vol. 1 (2), pp. 1- 10, 2012 [6] Georgoulas, G., Konstantaras, A., Katsifarakis, E., Stylios, C., Maravelakis, E and Vachtsevanos, G.: 'Seismic-mass" density-based algorithm for spatio-temporal clustering', Expert Systems with Applications, vol. 40 (10), pp. 4183-4189, 2013 [7] Konstantaras, A.: 'Classification of Distinct Seismic Regions and Regional Temporal Modelling of Seismicity in the Vicinity of the Hellenic Seismic Arc', Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of', vol. 99, pp. 1-7, 2013

  20. Seismic Structure of Perth Basin (Australia) and surroundings from Passive Seismic Deployments

    NASA Astrophysics Data System (ADS)

    Issa, N.; Saygin, E.; Lumley, D. E.; Hoskin, T. E.

    2016-12-01

    We image the subsurface structure of Perth Basin, Western Australia and surroundings by using ambient seismic noise data from 14 seismic stations recently deployed by University of Western Australia (UWA) and other available permanent stations from Geoscience Australia seismic network and the Australian Seismometers in Schools program. Each of these 14 UWA seismic stations comprises a broadband sensor and a high fidelity 3-component 10 Hz geophone, recording in tandem at 250 Hz and 1000 Hz. The other stations used in this study are equipped with short period and broadband sensors. In addition, one shallow borehole station is operated with eight 3 component geophones at depths of between 2 and 44 m. The network is deployed to characterize natural seismicity in the basin and to try and identify any microseismic activity across Darling Fault Zone (DFZ), bounding the basin to the east. The DFZ stretches to approximately 1000 km north-south in Western Australia, and is one of the longest fault zones on the earth with a limited number of detected earthquakes. We use seismic noise cross- and auto-correlation methods to map seismic velocity perturbations across the basin and the transition from DFZ to the basin. Retrieved Green's functions are stable and show clear dispersed waveforms. Travel times of the surface wave Green's functions from noise cross-correlations are inverted with a two-step probabilistic framework to map the absolute shear wave velocities as a function of depth. The single station auto-correlations from the seismic noise yields P wave reflectivity under each station, marking the major discontinuities. Resulting images show the shear velocity perturbations across the region. We also quantify the variation of ambient seismic noise at different depths in the near surface using the geophones in the shallow borehole array.

  1. SpaceX CRS-10 Prelaunch News Conference

    NASA Image and Video Library

    2017-02-17

    In the Kennedy Space Center’s Press Site auditorium, agency and industry leaders speak to members of the media at a prelaunch news conference for the SpaceX CRS-10 commercial resupply services mission to the International Space Station. Jessica Jensen, director of Dragon mission management for SpaceX, answers questions.

  2. Evolution of the 2015 Cotopaxi eruption revealed by combined geochemical & seismic observations

    USGS Publications Warehouse

    Hidalgo, Silvana; Battaglia, Jean; Arellano, Santiago; Sierra, Daniel; Bernard, Benjamin; Parra, Rene; Kelly, Peter; Dinger, Florian; Barrington, Charlotte; Samaniego, Pablo

    2018-01-01

    Through integration of multiple data streams to monitor volcanic unrest scientists are able to make more robust eruption forecast and to obtain a more holistic interpretation of volcanic systems. We examined gas emission and gas geochemistry, seismic and petrologic data recorded during the 2015 unrest of Cotopaxi (Ecuador) in order to decipher the origin and temporal evolution of this eruption. Identification of families of similar seismic events and the use of seismic amplitude ratios reveals temporal changes in volcanic processes. SO2 (300 to 24000 t/d), BrO/SO2 (5-10 x10-5), SO2/HCl (5.8 ± 4.8 and 6.6 ± 3.0) and CO2/SO2 (0.6 to 2.1) measured throughout the eruption indicate a shallow magmatic source. Bulk ash and glass chemistry indicate a homogenous andesitic (SiO2 wt%=56.94 ± 0.25) magma having undergone extensive S-exsolution and degassing during ascent. These data lead us to interpret this eruption as a magma intrusion and ascend to shallow levels. The intrusion progressively interacted with the hydrothermal system, boiled off water, and produced hydromagmatic explosions. A small volume of this intrusion continued to fragment and produced episodic ash emissions until it was sufficiently degassed and rheologically stiff. Based on the 470 kt of measured SO2 we estimate that ~ 65.3 x106 m3 of magma were required to supply the emitted gases. This volume exceeds the volume of erupted juvenile material by a factor of 50. This result emphasizes the importance of careful monitoring of Cotopaxi to identify the intrusion of a new batch of magma, which could rejuvenate the non-erupted material.

  3. Spots of Seismic Danger Extracted by Properties of Low-Frequency Seismic Noise

    NASA Astrophysics Data System (ADS)

    Lyubushin, Alexey

    2013-04-01

    region of Nankai Trough. The analysis of seismic noise after March 2011 indicates increasing of probability of the 2nd mega-earthquake starting from the middle of 2013 within the region of Nankai Trough which remains to be SSD. References 1. Lyubushin A. Multifractal Parameters of Low-Frequency Microseisms // V. de Rubeis et al. (eds.), Synchronization and Triggering: from Fracture to Earthquake Processes, GeoPlanet: Earth and Planetary Sciences 1, DOI 10.1007/978-3-642-12300-9_15, Springer-Verlag Berlin Heidelberg, 2010, 388p., Chapter 15, pp.253-272. http://www.springerlink.com/content/hj2l211577533261/ 2. Lyubushin A.A. Synchronization of multifractal parameters of regional and global low-frequency microseisms - European Geosciences Union General Assembly 2010, Vienna, 02-07 of May, 2010, Geophysical Research Abstracts, Vol. 12, EGU2010-696, 2010. http://meetingorganizer.copernicus.org/EGU2010/EGU2010-696.pdf 3. Lyubushin A.A. Synchronization phenomena of low-frequency microseisms. European Seismological Commission, 32nd General Assembly, September 06-10, 2010, Montpelier, France. Book of abstracts, p.124, session ES6. http://alexeylyubushin.narod.ru/ESC-2010_Book_of_abstracts.pdf 4. Lyubushin A.A. Seismic Catastrophe in Japan on March 11, 2011: Long-Term Prediction on the Basis of Low-Frequency Microseisms - Izvestiya, Atmospheric and Oceanic Physics, 2011, Vol. 46, No. 8, pp. 904-921. http://www.springerlink.com/content/kq53j2667024w715/ 5. Lyubushin, A. Prognostic properties of low-frequency seismic noise. Natural Science, 4, 659-666.doi: 10.4236/ns.2012.428087. http://www.scirp.org/journal/PaperInformation.aspx?paperID=21656

  4. Seismic hazard assessment in the megacity of Blida (Algeria) and its surrounding regions using parametric-historic procedure

    NASA Astrophysics Data System (ADS)

    Bellalem, Fouzi; Talbi, Abdelhak; Djellit, Hamou; Ymmel, Hayet; Mobarki, Mourad

    2018-03-01

    The region of Blida is characterized by a relatively high seismic activity, pointed especially during the past two centuries. Indeed, it experienced a significant number of destructive earthquakes such as the earthquakes of March 2, 1825 and January 2, 1867, with intensity of X and IX, respectively. This study aims to investigate potential seismic hazard in Blida city and its surrounding regions. For this purpose, a typical seismic catalog was compiled using historical macroseismic events that occurred over a period of a few hundred years, and the recent instrumental seismicity dating back to 1900. The parametric-historic procedure introduced by Kijko and Graham (1998, 1999) was applied to assess seismic hazard in the study region. It is adapted to deal with incomplete catalogs and does not use any subjective delineation of active seismic zones. Because of the lack of recorded strong motion data, three ground prediction models have been considered, as they seem the most adapted to the seismicity of the study region. Results are presented as peak ground acceleration (PGA) seismic hazard maps, showing expected peak accelerations with 10% probability of exceedance in 50-year period. As the most significant result, hot spot regions with high PGA values are mapped. For example, a PGA of 0.44 g has been found in a small geographical area centered on Blida city.

  5. The use of vertical seismic profiles in seismic investigations of the earth

    USGS Publications Warehouse

    Balch, Alfred H.; Lee, M.W.; Miller, J.J.; Ryder, Robert T.

    1982-01-01

    During the past 8 years, the U.S. Geological Survey has conducted an extensive investigation on the use of vertical seismic profiles (VSP) in a variety of seismic exploration applications. Seismic sources used were surface air guns, vibrators, explosives, marine air guns, and downhole air guns. Source offsets have ranged from 100 to 7800 ft. Well depths have been from 1200 to over 10,000 ft. We have found three specific ways in which VSPs can be applied to seismic exploration. First, seismic events observed at the surface of the ground can be traced, level by level, to their point of origin within the earth. Thus, one can tie a surface profile to a well log with an extraordinarily high degree of confidence. Second, one can establish the detectability of a target horizon, such as a porous zone. One can determine (either before or after surface profiling) whether or not a given horizon or layered sequence returns a detectable reflection to the surface. The amplitude and character of the reflection can also be observed. Third, acoustic properties of a stratigraphic sequence can be measured and sometimes correlated to important exploration parameters. For example, sometimes a relationship between apparent attenuation and sand percentage can be established. The technique shows additional promise of aiding surface exploration indirectly through studies of the evolution of the seismic pulse, studies of ghosts and multiples, and studies of seismic trace inversion techniques. Nearly all current seismic data‐processing techniques are adaptable to the processing of VSP data, such as normal moveout (NMO) corrections, stacking, single‐and multiple‐channel filtering, deconvolution, and wavelet shaping.

  6. Three-Dimensional Seismic Image of a Geothermal Prospect: Tinguiririca, Central Andes, Chile

    NASA Astrophysics Data System (ADS)

    Lira, E.; Comte, D.; Giavelli, A.; Clavero, J. E.; Pineda, G.

    2010-12-01

    Seismic monitoring has been widely used by the oil and gas industry, as a valuable input for the reservoir characterization. This tool has also been used in geothermal productive systems, particularly to understand permeability controls usually associated to shallow crustal fault systems that are seismically actives. Faults can be considered either “migration path” or “seals” in Petroleum Systems, depending on their activity story (they are carriers while actives and seals when the activity cease due to diagenetic processes in the fault plain). On the other hand, is well known that seismic velocities are strongly related to rock properties, in particular Vp/Vs and VpVs relationship has been successfully used to emphasize the variations in the physical rock properties due to fluid content and porosity. In geothermal systems, P and S-wave velocities are expected to be noticeably affected by massive hydrothermal alteration and/or to the presence of hot water in the fault related fractures of the rocks. In this job, the results of three months of seismic monitoring and a seismic velocity tomography are presented. Sixteen short period continuous recording, three components seismic stations were deployed in an area of approximately 20x10 Km2, and a large 8.8 magnitude earthquake took place during the recording period. The study area corresponds to the Tinguiririca volcanic complex (70°21''W, 35°48''S), in the high mountain of the Central Andes near the Chile-Argentina border. These preliminary results are complemented with some MT profiles, delineating potentially interesting geothermal features.

  7. Study of earthquakes using a borehole seismic network at Koyna, India

    NASA Astrophysics Data System (ADS)

    Gupta, Harsh; Satyanarayana, Hari VS; Shashidhar, Dodla; Mallika, Kothamasu; Ranjan Mahato, Chitta; Shankar Maity, Bhavani

    2017-04-01

    Koyna, located near the west coast of India, is a classical site of artificial water reservoir triggered earthquakes. Triggered earthquakes started soon after the impoundment of the Koyna Dam in 1962. The activity has continued till now including the largest triggered earthquake of M 6.3 in 1967; 22 earthquakes of M ≥ 5 and several thousands smaller earthquakes. The latest significant earthquake of ML 3.7 occurred on 24th November 2016. In spite of having a network of 23 broad band 3-component seismic stations in the near vicinity of the Koyna earthquake zone, locations of earthquakes had errors of 1 km. The main reason was the presence of 1 km thick very heterogeneous Deccan Traps cover that introduced noise and locations could not be improved. To improve the accuracy of location of earthquakes, a unique network of eight borehole seismic stations surrounding the seismicity was designed. Six of these have been installed at depths varying from 981 m to 1522 m during 2015 and 2016, well below the Deccan Traps cover. During 2016 a total of 2100 earthquakes were located. There has been a significant improvement in the location of earthquakes and the absolute errors of location have come down to ± 300 m. All earthquakes of ML ≥ 0.5 are now located, compared to ML ≥1.0 earlier. Based on seismicity and logistics, a block of 2 km x 2 km area has been chosen for the 3 km deep pilot borehole. The installation of the borehole seismic network has further elucidated the correspondence between rate of water loading/unloading the reservoir and triggered seismicity.

  8. SpaceX CRS-10 Post Launch News Conference

    NASA Image and Video Library

    2017-02-19

    In the Press Site auditorium of NASA's Kennedy Space Center in Florida, NASA and industry leaders speak to media at a post-launch news conference following the liftoff of SpaceX CRS-10, a commercial resupply services mission to the International Space Station. From left are: William Spetch, deputy manager of the International Space Station Transportation Office; Jessica Jensen, Dragon mission manager for SpaceX; and Pam Underwood, manager of the Operations Integration Division of the Federal Aviation Administration Office of Commercial Space Transportation. SpaceX CRS-10 lifted off atop a Falcon 9 rocket from Kennedy's Launch Complex 39A at 9:39 a.m. EST.

  9. SpaceX CRS-10 Post Launch News Conference

    NASA Image and Video Library

    2017-02-19

    In the Press Site auditorium of NASA's Kennedy Space Center in Florida, NASA and industry leaders speak to media at a post-launch news conference following the liftoff of SpaceX CRS-10, a commercial resupply services mission to the International Space Station. From left are: George Diller, NASA Communications; William Spetch, deputy manager of the International Space Station Transportation Office; Jessica Jensen, Dragon mission manager for SpaceX; and Pam Underwood, manager of the Operations Integration Division of the Federal Aviation Administration Office of Commercial Space Transportation. SpaceX CRS-10 lifted off atop a Falcon 9 rocket from Kennedy's Launch Complex 39A at 9:39 a.m. EST.

  10. SpaceX CRS-10 Post Launch Press Conference

    NASA Image and Video Library

    2017-02-19

    In the Press Site auditorium of NASA's Kennedy Space Center in Florida, NASA and industry leaders speak to media at a post-launch news conference following the liftoff of SpaceX CRS-10, a commercial resupply services mission to the International Space Station. From left are: George Diller, NASA Communications; William Spetch, deputy manager of the International Space Station Transportation Office; Jessica Jensen, Dragon mission manager for SpaceX; and Pam Underwood, manager of the Operations Integration Division of the Federal Aviation Administration Office of Commercial Space Transportation. SpaceX CRS-10 lifted off atop a Falcon 9 rocket from Kennedy's Launch Complex 39A at 9:39 a.m. EST.

  11. Tidal Dissipation Compared To Seismic Dissipation: In Small Bodies, Earths, And Super-Earths

    DTIC Science & Technology

    2012-02-20

    The Astrophysical Journal, 746:150 (20pp), 2012 February 20 doi:10.1088/0004-637X/746/2/150 C© 2012. The American Astronomical Society. All rights...becomes more complex, though for sufficiently large super-Earths the same rule applies: the larger the planet, the weaker the tidal dissipation in it...damping) becomes very considerable for large exoplanets (super-Earths). In those, it is much lower than what one might expect from using a seismic

  12. SpaceX CRS-10 Post Launch News Conference

    NASA Image and Video Library

    2017-02-19

    In the Press Site auditorium of NASA's Kennedy Space Center in Florida, William Spetch, deputy manager of the International Space Station Transportation Office, speaks to the news media at a post-launch news conference following the liftoff of SpaceX CRS-10, a commercial resupply services mission to the International Space Station. SpaceX CRS-10 lifted off atop a Falcon 9 rocket from Kennedy's Launch Complex 39A at 9:39 a.m. EST.

  13. Coal-seismic, desktop computer programs in BASIC; Part 5, Perform X-square T-square analysis and plot normal moveout lines on seismogram overlay

    USGS Publications Warehouse

    Hasbrouck, W.P.

    1983-01-01

    Processing of data taken with the U.S. Geological Survey's coal-seismic system is done with a desktop, stand-alone computer. Programs for this computer are written in the extended BASIC language used by the Tektronix 4051 Graphic System. This report presents computer programs to perform X-square/T-square analyses and to plot normal moveout lines on a seismogram overlay.

  14. High-frequency electron-spin-resonance measurements on Mn x Mg1-x O (x = 1.0×10-4) and DPPH at very low temperatures

    NASA Astrophysics Data System (ADS)

    Ishikawa, Y.; Ohya, K.; Miura, S.; Fujii, Y.; Mitsudo, S.; Mizusaki, T.; Fukuda, A.; Matsubara, A.; Kikuchi, H.; Asano, T.; Yamamori, H.; Lee, S.; Vasiliev, S.

    2018-03-01

    We have developed a millimeter-wave electron-spin-resonance (ESR) system for very low temperatures (T < 1 K) that can be employed for nuclear-magnetic-resonance measurements by using dynamic nuclear polarization. The system uses a Fabry-Pérot resonator that works in the frequency range of 125 – 130 GHz and covers the temperature range of 0.09 – 6.5 K. We have performed ESR measurements in the frequency around 128 GHz by using Mn x Mg1-x O (x = 1.0 × 10-4) and free-radical samples of 1, 1-diphenyl-2-picrylhydrazyl (DPPH), because these samples have been proposed as field and sensitivity markers. Temperature dependence of the ESR signal intensity for Mn x Mg1-x O shows anomalies originating from magnetic order are found around 3.5 – 4 K. We estimate the sensitivity of the system for ESR detections to be 6 × 1013 spins/G at 5.8 K. Because DPPH shows no observable shift in the magnetic field, we propose it as a useful standard marker for ESR measurements at very low temperatures.

  15. Seismic sequences in the Sombrero Seismic Zone

    NASA Astrophysics Data System (ADS)

    Pulliam, J.; Huerfano, V. A.; ten Brink, U.; von Hillebrandt, C.

    2007-05-01

    The northeastern Caribbean, in the vicinity of Puerto Rico and the Virgin Islands, has a long and well-documented history of devastating earthquakes and tsunamis, including major events in 1670, 1787, 1867, 1916, 1918, and 1943. Recently, seismicity has been concentrated to the north and west of the British Virgin Islands, in the region referred to as the Sombrero Seismic Zone by the Puerto Rico Seismic Network (PRSN). In the combined seismicity catalog maintained by the PRSN, several hundred small to moderate magnitude events can be found in this region prior to 2006. However, beginning in 2006 and continuing to the present, the rate of seismicity in the Sombrero suddenly increased, and a new locus of activity developed to the east of the previous location. Accurate estimates of seismic hazard, and the tsunamigenic potential of seismic events, depend on an accurate and comprehensive understanding of how strain is being accommodated in this corner region. Are faults locked and accumulating strain for release in a major event? Or is strain being released via slip over a diffuse system of faults? A careful analysis of seismicity patterns in the Sombrero region has the potential to both identify faults and modes of failure, provided the aggregation scheme is tuned to properly identify related events. To this end, we experimented with a scheme to identify seismic sequences based on physical and temporal proximity, under the assumptions that (a) events occur on related fault systems as stress is refocused by immediately previous events and (b) such 'stress waves' die out with time, so that two events that occur on the same system within a relatively short time window can be said to have a similar 'trigger' in ways that two nearby events that occurred years apart cannot. Patterns that emerge from the identification, temporal sequence, and refined locations of such sequences of events carry information about stress accommodation that is obscured by large clouds of

  16. Seismic properties of lawsonite eclogites from the southern Motagua fault zone, Guatemala

    NASA Astrophysics Data System (ADS)

    Kim, Daeyeong; Wallis, Simon; Endo, Shunsuke; Ree, Jin-Han

    2016-05-01

    We present new data on the crystal preferred orientation (CPO) and seismic properties of omphacite and lawsonite in extremely fresh eclogite from the southern Motagua fault zone, Guatemala, to discuss the seismic anisotropy of subducting oceanic crust. The CPO of omphacite is characterized by (010)[001], and it shows P-wave seismic anisotropies (AVP) of 1.4%-3.2% and S-wave seismic anisotropies (AVS) of 1.4%-2.7%. Lawsonite exhibits (001) planes parallel to the foliation and [010] axes parallel to the lineation, and seismic anisotropies of 1.7%-6.6% AVP and 3.4%-14.7% AVS. The seismic anisotropy of a rock mass consisting solely of omphacite and lawsonite is 1.2%-4.1% AVP and 1.8%-6.8% AVS. For events that propagate more or less parallel to the maximum extension direction, X, the fast S-wave velocity (VS) polarization is parallel to the Z in the Y-Z section (rotated from the X-Z section), causing trench-normal seismic anisotropy for orthogonal subduction. Based on the high modal abundance and strong fabric of lawsonite, the AVS of eclogites is estimated as ~ 11.7% in the case that lawsonite makes up ~ 75% of the rock mass. On this basis, we suggest that lawsonite in both blueschist and eclogite may play important roles in the formation of complex pattern of seismic anisotropy observed in NE Japan: weak trench-parallel anisotropy in the forearc basin domains and trench-normal anisotropy in the backarc region.

  17. Sub-10-ms X-ray tomography using a grating interferometer

    NASA Astrophysics Data System (ADS)

    Yashiro, Wataru; Noda, Daiji; Kajiwara, Kentaro

    2017-05-01

    An X-ray phase tomogram was successfully obtained with an exposure time of less than 10 ms by X-ray grating interferometry, an X-ray phase imaging technique that enables high-sensitivity X-ray imaging even of materials consisting of light elements. This high-speed X-ray imaging experiment was performed at BL28B2, SPring-8, where a white X-ray beam is available, and the tomogram was reconstructed from projection images recorded at a frame rate of 100,000 fps. The setup of the experiment will make it possible to realize three-dimensional observation of unrepeatable high-speed phenomena with a time resolution of less than 10 ms.

  18. A//r//m//s AND SEISMIC SOURCE STUDIES.

    USGS Publications Warehouse

    Hanks, T.C.; ,

    1984-01-01

    This paper briefly summarizes some recent developments in studies of seismic source parameter estimation, emphasizing the essential similarities between mining-induced seismogenic-failure and naturally occurring, tectonically driven earthquakes. The root-mean-square acceleration, a//r//m//s, shows much promise as an observational measure of high-frequency ground motion; it is very stable observationally, is insensitive to radiation pattern, and can be related linearly to the dynamic stress differences arising in the faulting process. To interpret a//r//m//s correctly, however, requires knowledge of f//m//a//x, the high-frequency band-limitation of the radiated field of earthquakes. As a practical matter, f//m//a//x can be due to any number of causes, but an essential ambiguity is whether or not f//m//a//x can arise from source properties alone. The interaction of the aftershocks of the Oroville, California, earthquake illustrates how a//r//m//s stress drops may be connected to detailed seismicity patterns.

  19. Seismic monitoring of the unstable rock slope at Aaknes, Norway

    NASA Astrophysics Data System (ADS)

    Roth, M.; Blikra, L. H.

    2009-04-01

    The unstable rock slope at Aaknes has an estimated volume of about 70 million cubic meters, and parts of the slope are moving at a rate between 2-15 cm/year. Amongst many other direct monitoring systems we have installed a small-scale seismic network (8 three-component geophones over an area of 250 x 150 meters) in order to monitor microseismic events related to the movement of the slope. The network has been operational since November 2005 with only a few short-term outages. Seismic data are transferred in real-time from the site to NORSAR for automatic detection processing. The resulting detection lists and charts and the associated waveform are forwarded immediately to the early warning centre of the Municipality of Stranda. Furthermore, we make them available after a delay of about 10-15 minutes on our public project web page (http://www.norsar.no/pc-47-48-Latest-Data.aspx). Seismic monitoring provides independent and complementary data to the more direct monitoring systems at Aaknes. We observe increased seismic activity in periods of heavy rain fall or snow melt, when laser ranging data and extensometer readings indicate temporary acceleration phases of the slope. The seismic network is too small and the velocity structure is too heterogeneous in order to obtain reliable localizations of the microseismic events. In summer 2009 we plan to install a high-sensitive broadband seismometer (60 s - 100 Hz) in the middle of the unstable slope. This will allow us to better constrain the locations of the microseismic events and to investigate potential low-frequency signals associated with the slope movement.

  20. SpaceX CRS-10 Post Launch News Conference

    NASA Image and Video Library

    2017-02-19

    In the Press Site auditorium of NASA's Kennedy Space Center in Florida, Pam Underwood, manager of the Operations Integration Division of the Federal Aviation Administration Office of Commercial Space Transportation, speaks to the news media at a post-launch news conference following the liftoff of SpaceX CRS-10, a commercial resupply services mission to the International Space Station. SpaceX CRS-10 lifted off atop a Falcon 9 rocket from Kennedy's Launch Complex 39A at 9:39 a.m. EST.

  1. Testing & Validating: 3D Seismic Travel Time Tomography (Detailed Shallow Subsurface Imaging)

    NASA Astrophysics Data System (ADS)

    Marti, David; Marzan, Ignacio; Alvarez-Marron, Joaquina; Carbonell, Ramon

    2016-04-01

    A detailed full 3 dimensional P wave seismic velocity model was constrained by a high-resolution seismic tomography experiment. A regular and dense grid of shots and receivers was use to image a 500x500x200 m volume of the shallow subsurface. 10 GEODE's resulting in a 240 channels recording system and a 250 kg weight drop were used for the acquisition. The recording geometry consisted in 10x20m geophone grid spacing, and a 20x20 m stagered source spacing. A total of 1200 receivers and 676 source points. The study area is located within the Iberian Meseta, in Villar de Cañas (Cuenca, Spain). The lithological/geological target consisted in a Neogen sedimentary sequence formed from bottom to top by a transition from gyspum to silstones. The main objectives consisted in resolving the underground structure: contacts/discontinuities; constrain the 3D geometry of the lithology (possible cavities, faults/fractures). These targets were achieved by mapping the 3D distribution of the physical properties (P-wave velocity). The regularly space dense acquisition grid forced to acquire the survey in different stages and with a variety of weather conditions. Therefore, a careful quality control was required. More than a half million first arrivals were inverted to provide a 3D Vp velocity model that reached depths of 120 m in the areas with the highest ray coverage. An extended borehole campaign, that included borehole geophysical measurements in some wells provided unique tight constraints on the lithology an a validation scheme for the tomographic results. The final image reveals a laterally variable structure consisting of four different lithological units. In this methodological validation test travel-time tomography features a high capacity of imaging in detail the lithological contrasts for complex structures located at very shallow depths.

  2. The Caucasus Seismic Network (CNET): Seismic Structure of the Greater and Lesser Caucasus

    NASA Astrophysics Data System (ADS)

    Sandvol, E. A.; Mackey, K. G.; Nabelek, J.; Yetermishli, G.; Godoladze, T.; Babayan, H.; Malovichko, A.

    2017-12-01

    The Greater Caucasus are a portion of the Alpine-Himalayan mountain belt that has undergone rapid uplift in the past 5 million years, thus serving as a unique natural laboratory to study the early stages of orogenesis. Relatively lower resolution seismic velocity models of this region show contradictory lateral variability. Furthermore, recent waveform modeling of seismograms has clearly demonstrated the presence of deep earthquakes (with a maximum hypocentral depth of 175 km) below the Greater Caucasus. The region has been largely unexplored in terms of the detailed uppermost mantle and crustal seismic structure due in part to the disparate data sets that have not yet been merged as well as key portions being sparsely instrumented. We have established collaborative agreements across the region. Building on these agreements we recently deployed a major multi-national seismic array across the Greater Caucasus to address fundamental questions about the nature of continental deformation in this poorly understood region. Our seismic array has two components: (1) a grid of stations spanning the entire Caucasus and (2) two seismic transects consisting of stations spaced at distances of less than 10 km that cross the Greater Caucasus. In addition to the temporary stations, we are working to integrate data from the national networks to produce high resolution images of the seismic structure. Using data from over 106 new seismic stations in Azerbaijan, Armenia, Russia, and Georgia, we hope to gain a better understanding of the recent uplift ( 5 Ma) of the Greater Caucasus and the nature of seismogenic deformation in the region.

  3. Bayesian identification of multiple seismic change points and varying seismic rates caused by induced seismicity

    NASA Astrophysics Data System (ADS)

    Montoya-Noguera, Silvana; Wang, Yu

    2017-04-01

    The Central and Eastern United States (CEUS) has experienced an abnormal increase in seismic activity, which is believed to be related to anthropogenic activities. The U.S. Geological Survey has acknowledged this situation and developed the CEUS 2016 1 year seismic hazard model using the catalog of 2015 by assuming stationary seismicity in that period. However, due to the nonstationary nature of induced seismicity, it is essential to identify change points for accurate probabilistic seismic hazard analysis (PSHA). We present a Bayesian procedure to identify the most probable change points in seismicity and define their respective seismic rates. It uses prior distributions in agreement with conventional PSHA and updates them with recent data to identify seismicity changes. It can determine the change points in a regional scale and may incorporate different types of information in an objective manner. It is first successfully tested with simulated data, and then it is used to evaluate Oklahoma's regional seismicity.

  4. A novel high-pressure vessel for simultaneous observations of seismic velocity and in situ CO2 distribution in a porous rock using a medical X-ray CT scanner

    NASA Astrophysics Data System (ADS)

    Jiang, Lanlan; Nishizawa, Osamu; Zhang, Yi; Park, Hyuck; Xue, Ziqiu

    2016-12-01

    Understanding the relationship between seismic wave velocity or attenuation and CO2 saturation is essential for CO2 storage in deep saline formations. In the present study, we describe a novel upright high-pressure vessel that is designed to keep a rock sample under reservoir conditions and simultaneously image the entire sample using a medical X-ray CT scanner. The pressure vessel is composed of low X-ray absorption materials: a carbon-fibre-enhanced polyetheretherketone (PEEK) cylinder and PEEK vessel closures supported by carbon-fibre-reinforced plastic (CFRP) joists. The temperature was controlled by a carbon-coated film heater and an aramid fibre thermal insulator. The assembled sample cell allows us to obtain high-resolution images of rock samples during CO2 drainage and brine imbibition under reservoir conditions. The rock sample was oriented vertical to the rotation axis of the CT scanner, and seismic wave paths were aligned parallel to the rotation axis to avoid shadows from the acoustic transducers. The reconstructed CO2 distribution images allow us to calculate the CO2 saturation in the first Fresnel zone along the ray path between transducers. A robust relationship between the seismic wave velocity or attenuation and the CO2 saturation in porous rock was obtained from experiments using this pressure vessel.

  5. Comparison of smoothing methods for the development of a smoothed seismicity model for Alaska and the implications for seismic hazard

    NASA Astrophysics Data System (ADS)

    Moschetti, M. P.; Mueller, C. S.; Boyd, O. S.; Petersen, M. D.

    2013-12-01

    In anticipation of the update of the Alaska seismic hazard maps (ASHMs) by the U. S. Geological Survey, we report progress on the comparison of smoothed seismicity models developed using fixed and adaptive smoothing algorithms, and investigate the sensitivity of seismic hazard to the models. While fault-based sources, such as those for great earthquakes in the Alaska-Aleutian subduction zone and for the ~10 shallow crustal faults within Alaska, dominate the seismic hazard estimates for locations near to the sources, smoothed seismicity rates make important contributions to seismic hazard away from fault-based sources and where knowledge of recurrence and magnitude is not sufficient for use in hazard studies. Recent developments in adaptive smoothing methods and statistical tests for evaluating and comparing rate models prompt us to investigate the appropriateness of adaptive smoothing for the ASHMs. We develop smoothed seismicity models for Alaska using fixed and adaptive smoothing methods and compare the resulting models by calculating and evaluating the joint likelihood test. We use the earthquake catalog, and associated completeness levels, developed for the 2007 ASHM to produce fixed-bandwidth-smoothed models with smoothing distances varying from 10 to 100 km and adaptively smoothed models. Adaptive smoothing follows the method of Helmstetter et al. and defines a unique smoothing distance for each earthquake epicenter from the distance to the nth nearest neighbor. The consequence of the adaptive smoothing methods is to reduce smoothing distances, causing locally increased seismicity rates, where seismicity rates are high and to increase smoothing distances where seismicity is sparse. We follow guidance from previous studies to optimize the neighbor number (n-value) by comparing model likelihood values, which estimate the likelihood that the observed earthquake epicenters from the recent catalog are derived from the smoothed rate models. We compare likelihood

  6. Comparison of smoothing methods for the development of a smoothed seismicity model for Alaska and the implications for seismic hazard

    USGS Publications Warehouse

    Moschetti, Morgan P.; Mueller, Charles S.; Boyd, Oliver S.; Petersen, Mark D.

    2014-01-01

    In anticipation of the update of the Alaska seismic hazard maps (ASHMs) by the U. S. Geological Survey, we report progress on the comparison of smoothed seismicity models developed using fixed and adaptive smoothing algorithms, and investigate the sensitivity of seismic hazard to the models. While fault-based sources, such as those for great earthquakes in the Alaska-Aleutian subduction zone and for the ~10 shallow crustal faults within Alaska, dominate the seismic hazard estimates for locations near to the sources, smoothed seismicity rates make important contributions to seismic hazard away from fault-based sources and where knowledge of recurrence and magnitude is not sufficient for use in hazard studies. Recent developments in adaptive smoothing methods and statistical tests for evaluating and comparing rate models prompt us to investigate the appropriateness of adaptive smoothing for the ASHMs. We develop smoothed seismicity models for Alaska using fixed and adaptive smoothing methods and compare the resulting models by calculating and evaluating the joint likelihood test. We use the earthquake catalog, and associated completeness levels, developed for the 2007 ASHM to produce fixed-bandwidth-smoothed models with smoothing distances varying from 10 to 100 km and adaptively smoothed models. Adaptive smoothing follows the method of Helmstetter et al. and defines a unique smoothing distance for each earthquake epicenter from the distance to the nth nearest neighbor. The consequence of the adaptive smoothing methods is to reduce smoothing distances, causing locally increased seismicity rates, where seismicity rates are high and to increase smoothing distances where seismicity is sparse. We follow guidance from previous studies to optimize the neighbor number (n-value) by comparing model likelihood values, which estimate the likelihood that the observed earthquake epicenters from the recent catalog are derived from the smoothed rate models. We compare likelihood

  7. USGS National Seismic Hazard Maps

    USGS Publications Warehouse

    Frankel, A.D.; Mueller, C.S.; Barnhard, T.P.; Leyendecker, E.V.; Wesson, R.L.; Harmsen, S.C.; Klein, F.W.; Perkins, D.M.; Dickman, N.C.; Hanson, S.L.; Hopper, M.G.

    2000-01-01

    The U.S. Geological Survey (USGS) recently completed new probabilistic seismic hazard maps for the United States, including Alaska and Hawaii. These hazard maps form the basis of the probabilistic component of the design maps used in the 1997 edition of the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures, prepared by the Building Seismic Safety Council arid published by FEMA. The hazard maps depict peak horizontal ground acceleration and spectral response at 0.2, 0.3, and 1.0 sec periods, with 10%, 5%, and 2% probabilities of exceedance in 50 years, corresponding to return times of about 500, 1000, and 2500 years, respectively. In this paper we outline the methodology used to construct the hazard maps. There are three basic components to the maps. First, we use spatially smoothed historic seismicity as one portion of the hazard calculation. In this model, we apply the general observation that moderate and large earthquakes tend to occur near areas of previous small or moderate events, with some notable exceptions. Second, we consider large background source zones based on broad geologic criteria to quantify hazard in areas with little or no historic seismicity, but with the potential for generating large events. Third, we include the hazard from specific fault sources. We use about 450 faults in the western United States (WUS) and derive recurrence times from either geologic slip rates or the dating of pre-historic earthquakes from trenching of faults or other paleoseismic methods. Recurrence estimates for large earthquakes in New Madrid and Charleston, South Carolina, were taken from recent paleoliquefaction studies. We used logic trees to incorporate different seismicity models, fault recurrence models, Cascadia great earthquake scenarios, and ground-motion attenuation relations. We present disaggregation plots showing the contribution to hazard at four cities from potential earthquakes with various magnitudes and

  8. Kinematic Seismic Rupture Parameters from a Doppler Analysis

    NASA Astrophysics Data System (ADS)

    Caldeira, Bento; Bezzeghoud, Mourad; Borges, José F.

    2010-05-01

    the seismic rupture velocity vector. J Seismology, DOI 10.1007/s10950-009-9183-x

  9. An analysis of seismic hazard in the Upper Rhine Graben enlightened by the example of the New Madrid seismic zone.

    NASA Astrophysics Data System (ADS)

    Doubre, Cécile; Masson, Frédéric; Mazzotti, Stéphane; Meghraoui, Mustapha

    2014-05-01

    Seismic hazard in the "stable" continental regions and low-level deformation zones is one of the most difficult issues to address in Earth sciences. In these zones, instrumental and historical seismicity are not well known (sparse seismic networks, seismic cycle too long to be covered by the human history, episodic seismic activity) and many active structures remain poorly characterized or unknown. This is the case of the Upper Rhine Graben, the central segment of the European Cenozoic rift system (ECRIS) of Oligocene age, which extends from the North Sea through Germany and France to the Mediterranean coast over a distance of some 1100 km. Even if this region has already experienced some destructive earthquakes, its present-day seismicity is moderate and the deformation observed by geodesy is very small (below the current measurement accuracy). The strain rate does not exceed 10-10 and paleoseismic studies indicate an average return period of 2.5 to 3 103 ka for large earthquakes. The largest earthquake known for this zone is the 1356 Basel earthquake, with a magnitude generally estimated about 6.5 (Meghraoui et al., 2001) but recently re-evaluated between 6.7 and 7.1 (Fäh et al et al., 2009). A comparison of the Upper Rhine Graben with equivalent regions around the world could help improve our evaluation of seismic hazard of this region. This is the case of the New Madrid seismic zone, one of the best studied intraplate system in central USA, which experienced an M 7.0 - 7.5 earthquake in 1811-1812 and shares several characteristics with the Upper Rhine Graben, i.e. the general framework of inherited geological structures (reactivation of a failed rift / graben), seismicity patterns (spatial variability of small and large earthquakes), the null or low rate of deformation, and the location in a "stable" continental interior. Looking at the Upper Rhine Graben as an analogue of the New Madrid seismic zone, we can re-evaluate its seismic hazard and consider the

  10. xLPR Sim Editor 1.0 User's Guide

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mariner, Paul E.

    2017-03-01

    The United States Nuclear Regulatory Commission in cooperation with the Electric Power Research Institute contracted Sandia National Laboratories to develop the framework of a probabilistic fracture mechanics assessment code called xLPR ( Extremely Low Probability of Rupture) Version 2.0 . The purpose of xLPR is to evaluate degradation mechanisms in piping systems at nuclear power plants and to predict the probability of rupture. This report is a user's guide for xLPR Sim Editor 1.0 , a graphical user interface for creating and editing the xLPR Version 2.0 input file and for creating, editing, and using the xLPR Version 2.0 databasemore » files . The xLPR Sim Editor, provides a user - friendly way for users to change simulation options and input values, s elect input datasets from xLPR data bases, identify inputs needed for a simulation, and create and modify an input file for xLPR.« less

  11. Recent Seismicity in the Ceboruco Volcano, Western Mexico

    NASA Astrophysics Data System (ADS)

    Nunez, D.; Chávez-Méndez, M. I.; Nuñez-Cornu, F. J.; Sandoval, J. M.; Rodriguez-Ayala, N. A.; Trejo-Gomez, E.

    2017-12-01

    The Ceboruco volcano is the largest (2280 m.a.s.l) of several volcanoes along the Tepic-Zacoalco rift zone in Nayarit state (Mexico). During the last 1000 years, this volcano had effusive-explosive episodes with eight eruptions providing an average of one eruption each 125 years. Since the last eruption occurred in 1870, 147 years ago, a new eruption likelihood is really high and dangerous due to nearby population centers, important roads and lifelines that traverse the volcano's slopes. This hazards indicates the importance of monitoring the seismicity associated with the Ceboruco volcano whose ongoing activity is evidenced by fumaroles and earthquakes. During 2003 and 2008, this region was registered by just one Lennartz Marslite seismograph featuring a Lennartz Le3D sensor (1 Hz) [Rodríguez Uribe et al. (2013)] where they observed that seismicity rates and stresses appear to be increasing indicating higher levels of activity within the volcano. Until July 2017, a semi-permanent network with three Taurus (Nanometrics) and one Q330 Quanterra (Kinemetrics) digitizers with Lennartz 3Dlite sensors of 1 Hz natural frequency was registering in the area. In this study, we present the most recent seismicity obtained by the semi-permanent network and a temporary network of 21 Obsidians 4X and 8X (Kinemetrics) covering an area of 16 km x 16 km with one station every 2.5-3 km recording from November 2016 to July 2017.

  12. Experimental constraints on coesite abundances in eclogite and implications for the X seismic discontinuity

    NASA Astrophysics Data System (ADS)

    Knapp, Nadia; Woodland, Alan B.; Klimm, Kevin

    2015-07-01

    We have experimentally tested the possibility that the coesite-stishovite transition in eclogite bodies is responsible for the X discontinuity, a locally observed, low-impedance jump in seismic wave velocities at 260-330 km depth. We determined phase relations and free SiO2 abundances in three natural-analog eclogite compositions that simulate different subduction scenarios in terms of pressure-temperature conditions and whether or not melt extraction occurred. Eclogitic compositions representing residues after either shallow or deep melting contain either no coesite or else too little (<4 wt %) to produce the observed impedance contrast for the X discontinuity. Only an unmodified mid-ocean ridge basalt (MORB) composition was found to contain just enough coesite (6-8 wt %) to be consistent with the expected impedance contrast when it transforms to stishovite. However, we assert that MORB cannot remain compositionally unmodified during subduction down to ~300 km. Fluid loss due to dehydration reactions during the transformation from basalt to eclogite lowers bulk SiO2 content. In addition, the MORB wet solidus intersects the coesite-stishovite boundary at ~290 km, implying that at greater depths a melt phase should be present before stishovite stability is reached. Our data indicate that melt generation is an efficient means of lowering the free SiO2 content in the mineral assemblage. This study also confirms previous work indicating that exsolution of SiO2 from the Ca-Eskola (Ca0.5AlSi2O6) component in clinopyroxene is not a feasible mechanism for producing significant stishovite upon reaching its stability field. We conclude that the coesite-stishovite transition in eclogite bodies is not a viable petrological explanation for the X discontinuity.

  13. Fractal Approach to the Regional Seismic Event Discrimination Problem

    DTIC Science & Technology

    2000-01-01

    some H > 0 and this formula might be modified as X(t) = r-HX(rt),t E R (2) where H is the Hurst exponent . Traditionally it is estimated by the...2 3 IogT Figure 2. Hurst exponent H curves for different seismic events: Pakl - nuclear explosion 30.05.98 (Pakistan), ind - nuclear explosion...seismic discrimination. Our findings are summarized in the conclusion section. 261 2 Hurst’s exponents of seismograms We started from the study of self

  14. Using Ambient Seismic Noise to Monitor Post-Seismic Relaxation After the 2010 Mw 7.1 Darfield Earthquake, New Zealand

    NASA Astrophysics Data System (ADS)

    Savage, M. K.; Heckels, R.; Townend, J.

    2015-12-01

    Quantifying seismic velocity changes following large earthquakes can provide insights into the crustal response of the earth. The use of ambient seismic noise to monitor these changes is becoming increasingly widespread. Cross-correlations of long-duration ambient noise records can be used to give stable impulse response functions without the need for repeated seismic events. Temporal velocity changes were detected in the four months following the September 2010 Mw 7.1 Darfield event in South Island, New Zealand, using temporary seismic networks originally deployed to record aftershocks in the region. The arrays consisted of stations lying on and surrounding the fault, with a maximum inter-station distance of 156km. The 2010-2011 Canterbury earthquake sequence occurred largely on previously unknown and buried faults. The Darfield earthquake was the first and largest in a sequence of events that hit the region, rupturing the Greendale Fault. A surface rupture of nearly 30km was observed. The sequence also included the Mw 6.3 February 2011 Christchurch event, which caused widespread damage throughout the city and resulted in almost 200 deaths. Nine-component, day-long Green's functions were computed for frequencies between 0.1 - 1.0 Hz for full waveform seismic data from immediately after the 4th September 2010 earthquake until mid-January 2011. Using the moving window cross-spectral method, stacks of daily functions covering the study period (reference functions), were compared to consecutive 10 day stacks of cross-correlations to measure time delays between them. These were then inverted for seismic velocity changes with respect to the reference functions. Over the study period an increase in seismic velocity of 0.25% ± 0.02% was determined proximal to the Greendale fault. These results are similar to studies in other regions, and we attribute the changes to post-seismic relaxation through crack-healing of the Greendale Fault and throughout the region.

  15. Photocopy of drawing (this photograph is an 8' x 10' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8' x 10' copy of an 8' x 10' negative; 1917 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Building No. 18, Marine Barracks Sheet No. 1 - U.S. Naval Air Station, Marine Barracks, 232 East Avenue, Pensacola, Escambia County, FL

  16. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; microfilm of 1935 architectural drawing located at NARA) Quarters "I" Floor plan, sheet 1 of 1 - U.S. Naval Air Station, Senior Officers' Quarters Q-2, Q-2 North Avenue, Pensacola, Escambia County, FL

  17. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; microfilm of 1908 architectural drawing located at NARA) Plumbing arrangement for quarters G and I - U.S. Naval Air Station, Senior Officers' Quarters Q-2, Q-2 North Avenue, Pensacola, Escambia County, FL

  18. Updated Colombian Seismic Hazard Map

    NASA Astrophysics Data System (ADS)

    Eraso, J.; Arcila, M.; Romero, J.; Dimate, C.; Bermúdez, M. L.; Alvarado, C.

    2013-05-01

    possible to determinate environments and scenarios where the seismic hazard is a function of distance and magnitude and also the principal seismic sources that contribute to the seismic hazard at each site (dissagregation). This project was conducted by the Servicio Geológico Colombiano (Colombian Geological Survey) and the Universidad Nacional de Colombia (National University of Colombia), with the collaboration of national and foreign experts and the National System of Prevention and Attention of Disaster (SNPAD). It is important to stand out that this new seismic hazard map was used in the updated national building code (NSR-10). A new process is ongoing in order to improve and present the Seismic Hazard Map in terms of intensity. This require new knowledge in site effects, in both local and regional scales, checking the existing and develop new acceleration to intensity relationships, in order to obtain results more understandable and useful for a wider range of users, not only in the engineering field, but also all the risk assessment and management institutions, research and general community.

  19. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1987 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) HANDICAP RESTROOM, BUILDING NO. 1, SHEET 1 OF 2 - U.S. Naval Air Station, Ship Carpenter's Workshop, 368 South Avenue, Pensacola, Escambia County, FL

  20. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1923 architectural drawing located at NAS Pensacola, Florida, Building No. 458) PLAN FOR BUILDING NO. 107 WITH DIAGRAM OF AMMONIA REFRIGERATION SYSTEM. - U.S. Naval Air Station, Refrigeration Plant, Center Avenue, Pensacola, Escambia County, FL

  1. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; undated architectural drawing located at NAS Pensacola, Florida, Building No. 458) PLAN AND SECTION OF 23 FOOT EXTENSION TO BUILDING NO. 107. - U.S. Naval Air Station, Refrigeration Plant, Center Avenue, Pensacola, Escambia County, FL

  2. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1968 architectural drawing located at NAS Pensacola, Florida, Building No. 458) PLANS, SECTION, AND DETAILS FOR A FIREPROOF VAULT IN BUILDING NO. 322. - U.S. Naval Air Station, YMCA Building, West Avenue, Pensacola, Escambia County, FL

  3. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1933 architectural drawing located at NAS Pensacola, Florida, Building No. 458) ALTERATIONS TO LIBRARY, BUILDING NO. 322, PANELING DETAILS, SHEET 2 OF 3. - U.S. Naval Air Station, YMCA Building, West Avenue, Pensacola, Escambia County, FL

  4. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 2005 architectural drawing located at NAS Pensacola, Florida, Building No. 51) BUILDING NO. 51, FIRE EXTINGUISHER REPAIR/STORAGE, FIRST LEVEL FLOOR PLAN - U.S. Naval Air Station, Locomotive Shed, South Avenue, Pensacola, Escambia County, FL

  5. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 2005 architectural drawing located at NAS Pensacola, Florida, Building No. 51) BUILDING NO. 51, FIRE EXTINGUISHER REPAIR/STORAGE, SECOND LEVEL FLOOR PLAN - U.S. Naval Air Station, Locomotive Shed, South Avenue, Pensacola, Escambia County, FL

  6. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1956 original architectural drawing located at Building No. 458, NAS, Pensacola, Florida) QUARTERS Q-8 FLOOR PLAN, SHEET 1 OF 1 - U.S. Naval Air Station, Captain's Quarters, Q-8 North Avenue, Pensacola, Escambia County, FL

  7. Analysis of induced seismicity at The Geysers geothermal field, California

    NASA Astrophysics Data System (ADS)

    Emolo, A.; Maercklin, N.; Matrullo, E.; Orefice, A.; Amoroso, O.; Convertito, V.; Sharma, N.; Zollo, A.

    2012-12-01

    Fluid injection, steam extraction, and reservoir stimulation in geothermal systems lead to induced seismicity. While in rare cases induced events may be large enough to pose a hazard, on the other hand the microseismicity provides information on the extent and the space-time varying properties of the reservoir. Therefore, microseismic monitoring is important, both for mitigation of unwanted effects of industrial operations and for continuous assessment of reservoir conditions. Here we analyze induced seismicity at The Geysers geothermal field in California, a vapor-dominated field with the top of the main steam reservoir some 1-3 km below the surface. Commercial exploitation began in the 1960s, and the seismicity increased with increasing field development. We focus our analyses on induced seismicity recorded between August 2007 and October 2011. Our calibrated waveform database contains some 15000 events with magnitudes between 1.0 and 4.5 and recorded by the LBNL Geysers/Calpine surface seismic network. We associated all data with events from the NCEDC earthquake catalog and re-picked first arrival times. Using selected events with at least 20 high-quality P-wave picks, we determined a minimum 1-D velocity model using VELEST. A well-constrained P-velocity model shows a sharp velocity increase at 1-2 km depth (from 3 to 5 km/s) and then a gradient-like trend down to about 5 km depth, where velocities reach values of 6-7 km/s. The station corrections show coherent, relatively high, positive travel time delays in the NW zone, thus indicating a strong lateral variation of the P-wave velocities. We determined an average Vp-to-Vs ratio of 1.67, which is consistent with estimates from other authors for the same time period. The events have been relocated in the new model using a non-linear probabilistic methods. The seismicity appears spatially diffused in a 15x10 km2 area elongated in NW-SE direction, and earthquake depths range between 0 and 6 km. As in previous

  8. The MITMOTION Project - A seismic hazard overview of the Mitidja Basin (Northern Algeria)

    NASA Astrophysics Data System (ADS)

    Borges, José; Ouyed, Merzouk; Bezzeghoud, Mourad; Idres, Mouloud; Caldeira, Bento; Boughacha, Mohamed; Carvalho, João; Samai, Saddek; Fontiela, João; Aissa, Saoussen; Benfadda, Amar; Chimouni, Redouane; Yalaoui, Rafik; Dias, Rui

    2017-04-01

    The Mitidja Basin (MB) is located in northern Algeria and is filled by quaternary sediments with a length of about 100 km on the EW direction and approximately 20 km width. This basin is limited to the south by the Boumerdes - Larbaa - Blida active fault system and to the north by the Thenia - Sahel fault system. Both fault systems are of the reverse type with opposed dips and accommodate a general slip rate of 4 mm/year. This basin is associated with important seismic events that affected northern Algeria since the historical period until the present. The available earthquake catalogues reported numerous destructive earthquakes that struke different regions, such as Algiers (1365, Io= X; 1716, Io = X). Recently, on May 2003 the Bourmedes earthquake (Mw = 6.9) affected the area of Zemmouri and caused 2.271 deaths. The event was caused by the reactivation of the MB boundary faults. The epicenter was located offshore and generated a maximum uplift of 0.8 m along the coast with a horizontal maximum slip of 0.24 m. Recent studies show that the Boumerdes earthquake overloaded the system of adjacent faults with a stress increase between 0.4 and 1.5 bar. This induced an increase of the seismic hazard potential of the region and recommends a more detailed study of this fault system. The high seismogenic potential of the fault system bordering the MB, the exposure to danger of the most densely populated region of Algiers and the amplification effect caused by the basin are the motivation for this project proposal that will focus on the evaluation of the seismic hazard of the region. The general purpose of the project is to improve the seismic hazard assessment on the MB producing realistic predictions of strong ground motion caused by moderate and large earthquakes. To achieve this objective, it is important to make an effort in 3 directions: 1) the development of a detailed 3D velocity/structure model of the MB that includes geological constraints, seismic reflection data

  9. Martian seismicity

    NASA Technical Reports Server (NTRS)

    Phillips, Roger J.; Grimm, Robert E.

    1991-01-01

    The design and ultimate success of network seismology experiments on Mars depends on the present level of Martian seismicity. Volcanic and tectonic landforms observed from imaging experiments show that Mars must have been a seismically active planet in the past and there is no reason to discount the notion that Mars is seismically active today but at a lower level of activity. Models are explored for present day Mars seismicity. Depending on the sensitivity and geometry of a seismic network and the attenuation and scattering properties of the interior, it appears that a reasonable number of Martian seismic 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 seismic events.

  10. Possible artifacts in inferring seismic properties from X-ray data

    NASA Astrophysics Data System (ADS)

    Bosak, A.; Krisch, M.; Chumakov, A.; Abrikosov, I. A.; Dubrovinsky, L.

    2016-11-01

    We consider the experimental and computational artifacts relevant for the extraction of aggregate elastic properties of polycrystalline materials with particular emphasis on the derivation of seismic velocities. We use the case of iron as an example, and show that the improper use of definitions and neglecting the crystalline anisotropy can result in unexpectedly large errors up to a few percent.

  11. Photocopy of drawing (this photograph is an 8' x 10' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8' x 10' copy of an 8' x 10' negative; 1996 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Marine Complex, Building No. 18 Toilet/Shower room elevations, Sheet no. 21 - U.S. Naval Air Station, Marine Barracks, 232 East Avenue, Pensacola, Escambia County, FL

  12. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1963 architectural drawing located at NAS Pensacola, Florida, Building No. 458) BUILDING NO. 107 EQUIPMENT LOCATION FOR ADDITIONAL PROCESS FACILITIES, SHEET 3 OF 7. - U.S. Naval Air Station, Refrigeration Plant, Center Avenue, Pensacola, Escambia County, FL

  13. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1962 architectural drawing located at NAS Pensacola, Florida, Building No. 458) BUILDING NO. 322, RENOVATION FOR OCCUPANCY BY PEN-AIR CREDIT UNION, ELECTRICAL PLANS. - U.S. Naval Air Station, YMCA Building, West Avenue, Pensacola, Escambia County, FL

  14. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1955 architectural drawing located at NAS Pensacola, Florida, Building No. 458) ROMAN CATHOLIC CHAPEL, BUILDING NO. 322, FLOOR PLAN AND ELEVATIONS, SHEET 1 OF 1. - U.S. Naval Air Station, YMCA Building, West Avenue, Pensacola, Escambia County, FL

  15. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1916 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) FREIGHT ELEVATOR, BUILDING NO. 1, GENERAL ARRANGEMENT, SHEET 1 OF 1 - U.S. Naval Air Station, Ship Carpenter's Workshop, 368 South Avenue, Pensacola, Escambia County, FL

  16. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1965 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Quarters 3 floor plans, Sheet 1 of 1 - U.S. Naval Air Station, Senior Officers' Quarters Q-3, Q-3 North Avenue, Pensacola, Escambia County, FL

  17. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1972 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Alterations to Quarters 2, sheet 1 of 2 - U.S. Naval Air Station, Senior Officers' Quarters Q-2, Q-2 North Avenue, Pensacola, Escambia County, FL

  18. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1935 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Quarters 3 floor plans, Sheet 1 of 1 - U.S. Naval Air Station, Senior Officers' Quarters Q-3, Q-3 North Avenue, Pensacola, Escambia County, FL

  19. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1964 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Quarters 2 electrical plan, sheet 1 of 1 - U.S. Naval Air Station, Senior Officers' Quarters Q-2, Q-2 North Avenue, Pensacola, Escambia County, FL

  20. Seismic Ecology

    NASA Astrophysics Data System (ADS)

    Seleznev, V. S.; Soloviev, V. M.; Emanov, A. F.

    The paper is devoted to researches of influence of seismic actions for industrial and civil buildings and people. The seismic 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 seismic actions (first of all of earthquakes) on people and various constructions. This work is devoted to study weak, but long seismic actions on various buildings and people. There is a need to take into account seismic oscillations, acting on the territory, at construction of various buildings on urbanized territories. Essential influence, except for violent earthquakes, man-caused seismic actions: the explosions, seismic 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 seismicity in a number of regions in Russia, which earlier were not seismic, are presented in the paper. Along with maps of seismic microzoning maps to be built indicating a variation of amplitude spectra of seismic 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 seismically 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

  1. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1993 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) REPAIR AND RESTORATION OF BUILDING NO. 74, ARCHITECTURAL FLOOR PLAN, SHEET 5 OF 17 - U.S. Naval Air Station, Seaplane Hangar, 521 South Avenue, Pensacola, Escambia County, FL

  2. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1991 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Replace windows, Building No. 45, Architectural building elevations, Sheet 2 of 2 - U.S. Naval Air Station, Equipment Shops & Offices, 206 South Avenue, Pensacola, Escambia County, FL

  3. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1983 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) CORRECT FIRE/SAFETY DEFICIENCIES, BUILDING NO. 1, SECTIONS AND DETAILS, SHEET 3 OF 3 - U.S. Naval Air Station, Ship Carpenter's Workshop, 368 South Avenue, Pensacola, Escambia County, FL

  4. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; ca. 1910 original architectural drawing located at National Archives and Records Administration NARA) PLAN OF BUILDING NO.1 BOAT, SHIPWRIGHT AND JOINER SHOP, SHEET 2 OF 4 - U.S. Naval Air Station, Ship Carpenter's Workshop, 368 South Avenue, Pensacola, Escambia County, FL

  5. Photocopy of drawing (this photograph is an 8' x 10' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8' x 10' copy of an 8' x 10' negative; 1996 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Marine Complex, Building No. 18, Plumbing, First floor plan- Area A, Sheet No. 35 - U.S. Naval Air Station, Marine Barracks, 232 East Avenue, Pensacola, Escambia County, FL

  6. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1963 architectural drawing located at NAS Pensacola, Florida, Building No. 458) BUILDING NO. 107 PLANS, DETAILS, AND SCHEDULES FOR ADDITIONAL PROCESS FACILITIES, SHEET 2 OF 7. - U.S. Naval Air Station, Refrigeration Plant, Center Avenue, Pensacola, Escambia County, FL

  7. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1963 architectural drawing located at NAS Pensacola, Florida, Building No. 458) BUILDING NO. 107 ELEVATIONS AND WLL SECTION FOR ADDITIONAL PROCESS FACILITIES, SHEET 1 OF 7. - U.S. Naval Air Station, Refrigeration Plant, Center Avenue, Pensacola, Escambia County, FL

  8. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1960 architectural drawing located at NAS Pensacola, Florida, Building No. 458) BUILDING NO. 107 DETAILS OF EXTRUDER, RUBBER PRESS AND VENTILATION INSTALLATIONS, SHEET 3 OF 6. - U.S. Naval Air Station, Refrigeration Plant, Center Avenue, Pensacola, Escambia County, FL

  9. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1996 architectural drawing located at NAS Pensacola, Florida, Building No. 458) MARINE COMPLEX, BUILDING NO. 52, FIRST AND SECOND FLOOR PLANS INDICATING COMMUNICATION LINES AND CONNECTIONS, SHEET45. - U.S. Naval Air Station, Paint Shop, 222 East Avenue, Pensacola, Escambia County, FL

  10. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1975 architectural drawing located at NAS Pensacola, Florida, Building No. 458) MECHANICAL PLAN, ELECTRICAL PLAN, FLOOR PLAN AND DETAILS FOR ALTERATIONS TO BUILDING NO. 322, SHEET 1 OF 1. - U.S. Naval Air Station, YMCA Building, West Avenue, Pensacola, Escambia County, FL

  11. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1945 architectural drawing located at NAS Pensacola, Florida, Building No. 458) ROMAN CATHOLIC CHAPEL, BUILDING NO. 322, PLAN AND SECTIONS FOR VENTILATION IMPROVEMENTS, SHEET 1 OF 1. - U.S. Naval Air Station, YMCA Building, West Avenue, Pensacola, Escambia County, FL

  12. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1923 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) PLAN OF BUILDING NO. 1 JOINER, FABRIC AND PAINT SHOP, PROPOSED LOCATION OF RADIATORS - U.S. Naval Air Station, Ship Carpenter's Workshop, 368 South Avenue, Pensacola, Escambia County, FL

  13. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1983 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) CORRECT FIRE/SAFETY DEFICIENCIES, BUILDING NO. 1, FIRE PROTECTION CEILING PLANS, SHEET 2 OF 3 - U.S. Naval Air Station, Ship Carpenter's Workshop, 368 South Avenue, Pensacola, Escambia County, FL

  14. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1875 original architectural drawing located at NARA) Officers quarters US Navy Yard Pensacola, partition wall quarters B, C,D,E,H,K,M - U.S. Naval Air Station, Senior Officers' Quarters Q-2, Q-2 North Avenue, Pensacola, Escambia County, FL

  15. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1987 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Quarters 3, Exterior painting, legends and floor plans, Sheet 1 of 3 - U.S. Naval Air Station, Senior Officers' Quarters Q-3, Q-3 North Avenue, Pensacola, Escambia County, FL

  16. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1871 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Temporary Officers Quarters Ground plans of kitchens to officers quarters - U.S. Naval Air Station, Senior Officers' Quarters Q-3, Q-3 North Avenue, Pensacola, Escambia County, FL

  17. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; undated architectural drawing located at NAS Pensacola, Florida, Building No. 38-A) DESIGN FOR BOILER AND DYNAMO ROOMS. C AND R DEPARTMENT AT U.S. NAVY YARD, PENSACOLA FLA. - U.S. Naval Air Station, Blacksmith Shop, South Avenue, Pensacola, Escambia County, FL

  18. 70. Photocopy of 4' 10 x 3'10 Propeller, U.S. Coast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    70. Photocopy of 4' 10 x 3'10 Propeller, U.S. Coast Guard 133 Ft. Tender. Columbian Bronze Corporation, Freeport, Long Island, New York, Coast Guard Headquarters Drawing No. 540-WAGL-4400-4, dated July 1953. Original drawing property of the U.S. Coast Guard. - U.S. Coast Guard Cutter WHITE HEATH, USGS Integrated Support Command Boston, 427 Commercial Street, Boston, Suffolk County, MA

  19. Comparison of the 10x10 and the 8x6 Supersonic Wind Tunnels at the NASA Glenn Research Center for Low-Speed (Subsonic) Operation

    NASA Technical Reports Server (NTRS)

    Hoffman, Thomas R.; Johns, Albert L.; Bury, Mark E.

    2002-01-01

    NASA Glenn Research Center and Lockheed Martin tested an aircraft model in two wind tunnels to compare low-speed (subsonic) flow characteristics. Test objectives were to determine and document similarities and uniqueness of the tunnels and to verify that the 10- by 10-Foot Supersonic Wind Tunnel (10x10 SWT) is a viable low-speed test facility when compared to the 8- by 6-Foot Supersonic Wind Tunnel (8x6 SWT). Conclusions are that the data from the two facilities compares very favorably and that the 10-by 10-Foot Supersonic Wind Tunnel at NASA Glenn Research Center is a viable low-speed wind tunnel.

  20. Development of the 10-11 July 2015 two-stage sequence of multiple emplacements of pyroclastic density currents at Volcán de Colima, México: Insight from associated seismic signals

    NASA Astrophysics Data System (ADS)

    Zobin, Vyacheslav M.

    2018-02-01

    The 10-11 July 2015 partial collapses of the lava dome in the crater of Volcán de Colima, México, were accompanied by a sequence of two-stage multiple PDCs, separated by a 15-h interval, with a total bulk volume of 14.2 × 106 m3 of fragmentary material and runout distances reaching 9.1 and 10.3 km, respectively (Reyes-Dávila et al., 2016). Broad-band seismic signals, associated with the PDCs and recorded at seismic station EZ5 installed at a distance of 4 km from the crater, were used for analysis of the 20-h eruption process. This process included two stages of the multiple PDCs emplacements, two one-hour periods of preliminary events to each of the stages, and the inter-stage period. Analysis of seismic signals allowed us to identify the types of volcanic events composing this eruption episode and estimate their quantitative characteristics and spectral parameters of generated seismic signals. It was shown that the seismic signals produced by PDCs emplacements, recorded during the two stages, were characterized by different characteristics. The second stage PDCs had radiated greater seismic energy than the PDCs emplaced during the first stage. Spectral analysis of the seismic signals, produced by PDCs, indicates a clearly separation in frequency content at 1.95 Hz between the higher-frequency events of the first stage and the lower-frequency events of the second stage of the PDCs emplacements. The obtained difference in the spectral contents of the seismic signals, produced by the movement of two multiple PDCs, may be supposed as a consequence of the proposed relative difference in the volumes of the PDCs of two multiple sequences due to a difference in the level of radiated seismic energy and a change in bottom conditions of the ravines during their passing along the ravines. Results of seismic study were used in discussion of the nature of the two-stage eruptive process.

  1. Flux free single crystal growth and characterization of FeTe1-xSx (x=0.00 and 0.10) crystals

    NASA Astrophysics Data System (ADS)

    Maheshwari, P. K.; Awana, V. P. S.

    2018-05-01

    We report synthesis of S doped FeTe1-xSx (x = 0.00 and 0.10) single crystals using flux free method via solid state reaction. Single crystal XRD patterns of FeTe1-xSx (x = 0.00 and 0.10) confirm the single crystalline property, as the crystals are grown in (00l) plane only. Powder XRD result of FeTe1-xSx (x = 0.00 and 0.10) crystals show that crystalline in tetragonal structure having P4/nmm space group. Rietveld refinement results show that both a and c lattice parameters decreases with S doping of 10% at Te site in FeTe1-xSx. Detailed scanning electron microscopy (SEM) image of FeTe0.90S0.10 shows that the growth of crystal is in slab-like morphology. Electrical resistivity measurement results onset confirm the superconductivity in S doped 10% sample at Te site and superconducting transition Tconset occurs at 9.5K and Tcoffset(ρ=0) occurs at 6.5K. ρ-T measurement has been performed under various magnetic field up to 12 Tesla down to 2K. Upper critical field Hc2(0), for x=0.10, which comes around 70Tesla, 60Tesla and 45Tesla of normal resistivity criterion ρn = 90%, 50% and 10% criterion respectively.

  2. Experimental study on the impact-induced seismic wave propagating through granular materials: Implications for a future asteroid mission

    NASA Astrophysics Data System (ADS)

    Yasui, M.; Matsumoto, E.; Arakawa, M.; Matsue, K.; Kobayashi, N.

    2014-07-01

    with a diameter of 10 mm and a height of 10 mm, and stainless steel and alumina balls with a diameter of 3 mm. The stainless steel and alumina projectiles were accelerated with a sabot made of polyethylene. The impact velocity was from 20 to 100 m/s. The target was a non-cohesive glass bead with a mean particle diameter of 200 μ m prepared by putting the particles into a container with a diameter of 300 mm and a height of 100 mm, up to 80 mm depth. The target porosity was about 40%. A chamber that we set the target in was evacuated below 1000 Pa. Three accelerometers (response frequency < 10 kHz) were set on the target surface at different distances from the impact point. The observed seismic waves were recorded on a data logger (A/D conversion rate 100 kHz). Experimental results: First, we examined the propagation velocity of the seismic wave by using the traveling time from the impact point to the site of the accelerometer, then the impact velocity was obtained to be 105 ± 15 m/s. Next, we discovered that the maximum acceleration, g_max, had a good relationship to the normalized distance, x/R (x: distance from impact point, R: crater radius) and it was fitted by the following equation, g_max=268(x/R)^{-2.8}, irrespective of projectile types. These results mean that the seismic wave attenuates with a similar waveform scaled by the crater radius on the same target. The duration keeping the maximum acceleration was measured to have a half width of g_max peak on the waveform, and it was estimated to be ˜0.3 ms. This value is almost consistent with the penetration time of projectiles estimated by the model proposed by Niimi et al. (2011). McGarr et al. (1969) studied the momentum conversion efficiency from the projectile momentum to the target momentum transferred by the seismic wave and obtained it as the ratio of the momentum calculated by the particle motion, I, to the projectile momentum, I_p. In our study, the I/I_p was obtained to be 0.23-1.56. This range was

  3. Development of 3-axis precise positioning seismic physical modeling system in the simulation of marine seismic exploration

    NASA Astrophysics Data System (ADS)

    Kim, D.; Shin, S.; Ha, J.; Lee, D.; Lim, Y.; Chung, W.

    2017-12-01

    Seismic physical modeling is a laboratory-scale experiment that deals with the actual and physical phenomena that may occur in the field. In seismic 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 seismic physical modeling system 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 Seismic. 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 system 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 seismic physical modeling system developed in this study, single channel and

  4. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5”archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MAY 5, 1933 PHOTOGRAPH NO. 10 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PILE RIG AT PIER C. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  5. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JULY 10, 1933 PHOTOGRAPH NO. 27 OF CONTRACT NO. 5 SHOWING EAST APPROACH – PEDESTALS AND FORMS FOR HIGHWAY ABUTMENT. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  6. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1989 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Interior renovation, Navy recruiting orientation unit, Building No. 45, Architectural floor plan and window details, Sheet 3 of 29 - U.S. Naval Air Station, Equipment Shops & Offices, 206 South Avenue, Pensacola, Escambia County, FL

  7. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1969 original architectural drawing, for 1969 addition, located at Building No. 458, NAS Pensacola, Florida) ARCHITECTURAL ELEVATIONS FOR ADDITION TO BUILDING NO. 604 FOR A CONSOLIDATED PLATING FACILITY, SHEET 7 OF 135. - U.S. Naval Air Station, Assembly & Repair Shop, East Avenue, Pensacola, Escambia County, FL

  8. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1989 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Interior renovation, Navy recruiting orientation unit, Building No. 45, Architectural second floor plan, Sheet 4 of 29 - U.S. Naval Air Station, Equipment Shops & Offices, 206 South Avenue, Pensacola, Escambia County, FL

  9. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1989 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Interior renovation, Navy recruiting orientation unit, Building No. 45, Architectural third floor plan, Sheet 5 of 29 - U.S. Naval Air Station, Equipment Shops & Offices, 206 South Avenue, Pensacola, Escambia County, FL

  10. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1987 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) RENOVATED STORAGE AREA, MEZZANINE LEVEL, BUILDING NO. 1, ARCHITECTURAL FLOOR PLAN AND DETAILS, SHEET 1 OF 2 - U.S. Naval Air Station, Ship Carpenter's Workshop, 368 South Avenue, Pensacola, Escambia County, FL

  11. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1991 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) INTERIOR MODIFICATION SECOND FLOOR, BUILDING NO. 1, ARCHITECTURAL PLANS, SECTIONS AND SCHEDULES, SHEET 1 OF 3 - U.S. Naval Air Station, Ship Carpenter's Workshop, 368 South Avenue, Pensacola, Escambia County, FL

  12. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1990 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Quarters "4" as built floor plans, architectural floor plan (first floor), sheet 1 of 2 - U.S. Naval Air Station, Senior Officers' Quarters Q-4, Q-4 North Avenue, Pensacola, Escambia County, FL

  13. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1989 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Interior renovation, Navy recruiting orientation unit, Building No. 45, Architectural floor plan and general notes, Sheet 2 of 29 - U.S. Naval Air Station, Equipment Shops & Offices, 206 South Avenue, Pensacola, Escambia County, FL

  14. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1990 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Quarters "4" as built floor plans, architectural floor plan (second floor), sheet 2 of 2 - U.S. Naval Air Station, Senior Officers' Quarters Q-4, Q-4 North Avenue, Pensacola, Escambia County, FL

  15. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1949 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) INSTALLATION OF FREIGHT ELEVATOR, BUILDING NO. 1, PLANS, SECTIONS, AND DETAILS OF EXISTING HOISTWAY, SHEET 1 OF 1 - U.S. Naval Air Station, Ship Carpenter's Workshop, 368 South Avenue, Pensacola, Escambia County, FL

  16. Photocopy of drawing (this photograph is an 8' x 10' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8' x 10' copy of an 8' x 10' negative; 1952 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Conversion of Building No. 18 for overhaul and repair department electronics shop, second floor equipment plan, sheet 7 of 21 - U.S. Naval Air Station, Marine Barracks, 232 East Avenue, Pensacola, Escambia County, FL

  17. Photocopy of drawing (this photograph is an 8' x 10' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8' x 10' copy of an 8' x 10' negative; 1952 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Conversion of Building No. 18 for overhaul and repair department electronics shop, section, elevations and details, sheet 3 of 21 - U.S. Naval Air Station, Marine Barracks, 232 East Avenue, Pensacola, Escambia County, FL

  18. Photocopy of drawing (this photograph is an 8' x 10' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8' x 10' copy of an 8' x 10' negative; 1952 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Conversion of Building No. 18 for overhaul and repair department electronics shop, elevations and details, sheet 2 of 21 - U.S. Naval Air Station, Marine Barracks, 232 East Avenue, Pensacola, Escambia County, FL

  19. Photocopy of drawing (this photograph is an 8' x 10' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8' x 10' copy of an 8' x 10' negative; 1944 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Photographic school building No. 18, air conditioning small dark room, first floor plan, sheet 1 of 2 - U.S. Naval Air Station, Marine Barracks, 232 East Avenue, Pensacola, Escambia County, FL

  20. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; microfilm of 1908 architectural drawing located at National Archives and Records Administration at College Park, Maryland) Plumbing arrangement for Quarters G and I, Sheet 4 of 4 - U.S. Naval Air Station, Senior Officers' Quarters Q-3, Q-3 North Avenue, Pensacola, Escambia County, FL

  1. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1938 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Quarters "I" Alterations to west porch, floor plan and details, sheet 1 of 1 - U.S. Naval Air Station, Senior Officers' Quarters Q-2, Q-2 North Avenue, Pensacola, Escambia County, FL

  2. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1977 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Repairs of various quarters, Quarters No. 3, plans, elevations and details, Sheet 2 of 4 - U.S. Naval Air Station, Senior Officers' Quarters Q-3, Q-3 North Avenue, Pensacola, Escambia County, FL

  3. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1936 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Quarters "I" Alterations to west porch, floor plan and details, sheet 1 of 1 - U.S. Naval Air Station, Senior Officers' Quarters Q-2, Q-2 North Avenue, Pensacola, Escambia County, FL

  4. Back-Projection Imaging of extended, high-frequency pre-, co-, and post-eruptive seismicity at El Jefe Geyser, El Tatio Geyser Field, Chile

    NASA Astrophysics Data System (ADS)

    Kelly, C. L.; Lawrence, J. F.; Beroza, G. C.

    2017-12-01

    El Tatio Geyser Field in northern Chile is the third largest geyser field in the world. It is comprised of 3 basins that span 10 km x 10 km at an average elevation of 4250 m and contains at least 80 active geysers. Heavy tourist traffic and previous geothermal exploration make the field relatively non-pristine and ideal for performing minimally invasive geophysical experiments. We deployed a dense array of 51 L-28 3-component geophones (1-10 m spacing, corner frequency 4.5 Hz, 1000 Hz sample rate), and 6 Trillium 120 broadband seismometers (2-20 m spacing, long period corner 120 s, 500 Hz sample rate) in a 50 m x 50 m grid in the central Upper Geyser Basin (the largest basin in area at 5 km x 5 km) during October 2012 as part of a collaborative study of hydrothermal systems between Stanford University; U.C. Berkeley; U. of Chile, Santiago; U. of Tokyo; and the USGS. The seismic array was designed to target at El Jefe Geyser (EJG), a columnar geyser (eruption height 1-1.5 m) with a consistent periodic eruption cycle of 132 +/- 3 s. Seismicity at EJG was recorded continuously for 9 days during which 6000 total eruptions occurred. Excluding periods of high anthropogenic noise (i.e. tourist visits, field work), the array recorded 2000 eruptions that we use to create 4D time-lapse images of the evolution of seismic source locations before, during and after EJG eruptions. We use a new back-projection processing technique to locate geyser signals, which tend to be harmonic and diffuse in nature, during characteristic phases of the EJG eruption cycle. We obtain Vp and Vs from ambient-field tomography and estimates of P and S propagation from a hammer source recorded by the array. We use these velocities to back-project and correlate seismic signals from all available receiver-pairs to all potential source locations in a subsurface model assuming straight-line raypaths. We analyze results for individual and concurrent geyser sources throughout an entire EJG eruption cycle

  5. Structure of the San Bernardino Basin Along Two Seismic Transects: Rialto-Colton Fault to the San Andreas Fault and Along the I-215 Freeway (I-10 to SR30)

    USGS Publications Warehouse

    Catchings, R.D.; Rymer, M.J.; Goldman, M.R.; Gandhok, G.; Steedman, C.E.

    2008-01-01

    In this report, we present seismic data and acquisition parameters for two seismic profiles acquired in the San Bernardino, California area in May and October 2003. We refer to these seismic profiles as the San Bernardino Regional (SBR) and San Bernardino High-Resolution (SBHR) seismic profiles. We present both un-interpreted and interpreted seismic images so that the structure of the area can independently interpreted by others. We explain the rationale for our interpretations within the text of this report, and in addition, we provide a large body of supporting evidence. The SBR seismic profile extended across the San Bernardino Basin approximately N30?E from the town of Colton to the town of Highland. The data were acquired at night when the signal-to-noise ratios were reasonably good, and for the larger shots, seismic energy propagated across the ~20-km-long array. Tomographic velocity data are available to depths of about 4 km, and low-fold reflection data are available to depths in excess of 5 km. The SBR seismic data reveal an asymmetric, fault-bound basin to about 5 km depth. The SBHR seismic profile trended along the I-215 freeway from its intersection with the Santa Ana River to approximately State Road 30 in San Bernardino. Seismic data acquired along the I-215 freeway provide detailed images, with CDP spacing of approximately 2.5 m along an approximately 8.2-km-long profile; shot and geophone spacing was 5 m. For logistical reasons, the high-resolution (SBHR) seismic data were acquired during daylight hours on the shoulder of the I-215 freeway and within 5 to 10 m of high-traffic volumes, resulting in low signal-to-noise ratios. The limited offset at which refracted first-arrivals could be measured along the SBHR seismic profile limited our measurements of tomographic refraction velocities to relatively shallow (< 150 m) depths. The SBHR reflection data reveal a basin with complex structural details within the upper kilometer. The two seismic profiles

  6. SpaceX CRS-10 What's on Board Science Briefing

    NASA Image and Video Library

    2017-02-17

    During the SpaceX CRS-10 "What's On Board?" Science Briefing inside the Press Site Auditorium, members of social media learned about the science aboard the Dragon spacecraft. The briefing focused on growth of crystals in microgravity planned for the International Space Station following the arrival of a Dragon spacecraft. The Dragon is scheduled to be launched from Kennedy’s Launch Complex 39A on Feb. 18 atop a SpaceX Falcon 9 rocket on the company's 10th Commercial Resupply Services mission to the space station.

  7. Seismic reflection evidence for a northeast-dipping Hayward fault near Fremont, California: Implications for seismic hazard

    USGS Publications Warehouse

    Williams, R.A.; Simpson, R.W.; Jachens, R.C.; Stephenson, W.J.; Odum, J.K.; Ponce, D.A.

    2005-01-01

    A 1.6-km-long seismic reflection profile across the creeping trace of the southern Hayward fault near Fremont, California, images the fault to a depth of 650 m. Reflector truncations define a fault dip of about 70 degrees east in the 100 to 650 m depth range that projects upward to the creeping surface trace, and is inconsistent with a nearly vertical fault in this vicinity as previously believed. This fault projects to the Mission seismicity trend located at 4-10 km depth about 2 km east of the surface trace and suggests that the southern end of the fault is as seismically active as the part north of San Leandro. The seismic hazard implication is that the Hayward fault may have a more direct connection at depth with the Calaveras fault, affecting estimates of potential event magnitudes that could occur on the combined fault surfaces, thus affecting hazard assessments for the south San Francisco Bay region.

  8. The X-Ray Binary Population of the Nearby Dwarf Starburst Galaxy IC 10: Variable and Transient X-Ray Sources

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Laycock, Silas; Cappallo, Rigel; Williams, Benjamin F.

    We have monitored the Cassiopeia dwarf galaxy (IC 10) in a series of 10 Chandra ACIS-S observations to capture its variable and transient X-ray source population, which is expected to be dominated by High Mass X-ray Binaries (HMXBs). We present a sample of 21 X-ray sources that are variable between observations at the 3 σ level, from a catalog of 110 unique point sources. We find four transients (flux variability ratio greater than 10) and a further eight objects with ratios >5. The observations span the years 2003–2010 and reach a limiting luminosity of >10{sup 35} erg s{sup −1}, providingmore » sensitivity to X-ray binaries in IC 10 as well as flare stars in the foreground Milky Way. The nature of the variable sources is investigated from light curves, X-ray spectra, energy quantiles, and optical counterparts. The purpose of this study is to discover the composition of the X-ray binary population in a young starburst environment. IC 10 provides a sharp contrast in stellar population age (<10 My) when compared to the Magellanic Clouds (40–200 My) where most of the known HMXBs reside. We find 10 strong HMXB candidates, 2 probable background Active Galactic Nuclei, 4 foreground flare-stars or active binaries, and 5 not yet classifiable sources. Complete classification of the sample requires optical spectroscopy for radial velocity analysis and deeper X-ray observations to obtain higher S/N spectra and search for pulsations. A catalog and supporting data set are provided.« less

  9. Hyper-X Mach 10 Trajectory Reconstruction

    NASA Technical Reports Server (NTRS)

    Karlgaard, Christopher D.; Martin, John G.; Tartabini, Paul V.; Thornblom, Mark N.

    2005-01-01

    This paper discusses the formulation and development of a trajectory reconstruction tool for the NASA X-43A/Hyper-X high speed research vehicle, and its implementation for the reconstruction and analysis of flight test data. Extended Kalman filtering techniques are employed to reconstruct the trajectory of the vehicle, based upon numerical integration of inertial measurement data along with redundant measurements of the vehicle state. The equations of motion are formulated in order to include the effects of several systematic error sources, whose values may also be estimated by the filtering routines. Additionally, smoothing algorithms have been implemented in which the final value of the state (or an augmented state that includes other systematic error parameters to be estimated) and covariance are propagated back to the initial time to generate the best-estimated trajectory, based upon all available data. The methods are applied to the problem of reconstructing the trajectory of the Hyper-X vehicle from data obtained during the Mach 10 test flight, which occurred on November 16th 2004.

  10. A seismic hazard overview of the Mitidja Basin (Northern Algeria)

    NASA Astrophysics Data System (ADS)

    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.

    2017-12-01

    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 system, respectively. Both fault systems 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 boundary 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 system with a stress increase between 0.4 and 1.5 bar. The stress change recommends a detailed study of mentioned faults system due to the increase of the seismic hazard. The high seismogenic potential of the fault system 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 seismic hazard of the region. To achieve seismic 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, seismic reflection data acquired on wells, refraction velocities and seismic noise data, and determination of the attenuation laws based on instrumental records; 2) evaluate the seismic 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 seismic sources. To acquire seismic noise were used

  11. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1969 original architectural drawing, for 1969 addition, located at Building No. 458, NAS Pensacola, Florida) ARCHITECTURAL FIRST FLOOR PLAN FOR ADDITION TO BUILDING NO. 604 FOR A CONSOLIDATED PLATING FACILITY, SHEET 4 OF 135. - U.S. Naval Air Station, Assembly & Repair Shop, East Avenue, Pensacola, Escambia County, FL

  12. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1969 original architectural drawing, for 1969 addition, located at Building No. 458, NAS Pensacola, Florida) ARCHITECTURAL SECOND FLOOR PLAN FOR ADDITION TO BUILDING NO. 604 FOR A CONSOLIDATED PLATING FACILITY, SHEET 5 OF 135. - U.S. Naval Air Station, Assembly & Repair Shop, East Avenue, Pensacola, Escambia County, FL

  13. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1989 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Renovation and revised office layout, Building No. 45, third floor, architectural floor plans, details and schedules, Sheet 1 of 3 - U.S. Naval Air Station, Equipment Shops & Offices, 206 South Avenue, Pensacola, Escambia County, FL

  14. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" copy of an 8" x 10" negative; 1963 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) QUARTERS 5, NEW ELECTRIC SERVICE, NEW MAIN DISTRIBUTION PANEL AND NEW RISER DIAGRAM, ELECTRICAL PLAN, SHEET 1 OF 1 - U.S. Naval Air Station, Senior Officers' Quarters, Q-5 North Avenue, Pensacola, Escambia County, FL

  15. Photocopy of drawing (this photograph is an 8' x 10' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8' x 10' copy of an 8' x 10' negative; 1952 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Conversion of Building No. 18 for overhaul and repair department electronics shop, existing first and second floor plan, sheet 9 of 21 - U.S. Naval Air Station, Marine Barracks, 232 East Avenue, Pensacola, Escambia County, FL

  16. Photocopy of drawing (this photograph is an 8' x 10' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8' x 10' copy of an 8' x 10' negative; 1952 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Conversion of Building No. 18 for overhaul and repair department electronics shop. first and second floor plan sheet 1 of 21 - U.S. Naval Air Station, Marine Barracks, 232 East Avenue, Pensacola, Escambia County, FL

  17. Reassessment of the Seismicity and seismic hazards of Libya

    NASA Astrophysics Data System (ADS)

    Ben Suleman, A.; Elmeladi, A.

    2009-04-01

    The tectonic evolution of Libya, located at the northern extreme of the African continent, has yielded a complex crustal structure that is composed of a series of basins and uplifts. The present day deformation of Libya is the result of the Eurasia-Africa continental collision. At the end of the year 2005, The Libyan National Seismological Network was established to monitor local, regional and teleseismic activities, as well as to provide high quality data for research projects both locally and on the regional and global scale. This study aims to discuss the seismicity of Libya by using the new data from the Libyan national seismological network and to focus on the seismic hazards. At first glance the seismic activity map shows dominant trends of seismicity with most of the seismic activity concentrated along the northern coastal areas. Four major seismic trends were quite noticeable. A first trend is a NW-SE direction coinciding with the eastern boarder of the Hun Graben. A second trend is also a NW-SE direction in the offshore area and might be a continuation of this trend. The other two trends were located in the western Gulf of Sirt and Cyrenaica platform. The rest of seismicity is diffuse either offshore or in land, with no good correlation with well-mapped faults. Detailed investigations of the Libyan seismicity indicates that the Libya has experienced earthquakes of varying magnitudes and that there is definitely a certain amount of seismic risk involved in engineering projects, particularly in the northern regions. Detailed investigation of the distribution of the Libyan earthquakes in space and time along with all other geological considerations suggested the classification of the country into four seismic zones with the Hun graben zone being the most seismically active zone.

  18. Patterned basal seismicity shows sub-ice stream bedforms

    NASA Astrophysics Data System (ADS)

    Barcheck, C. G.; Tulaczyk, S. M.; Schwartz, S. Y.

    2017-12-01

    Patterns in seismicity emanating from the bottom of fast-moving ice streams and glaciers may indicate localized patches of higher basal resistance— sometimes called 'sticky spots', or otherwise varying basal properties. These seismogenic basal areas resist an unknown portion of the total driving stress of the Whillans Ice Plain (WIP), in West Antarctica, but may play an important role in the WIP stick-slip cycle and ice stream slowdown. To better understand the mechanism and importance of basal seismicity beneath the WIP, we analyze seismic data collected by a small aperture (< 3km) network of 8 surface and 5 borehole seismometers installed in the main central sticky spot of the WIP. We use a network beamforming technique to detect and roughly locate thousands of small (magnitude < 0), local basal micro-earthquakes in Dec 2014, and we compare the resulting map of seismicity to ice bottom depth measured by airborne radar. The number of basal earthquakes per area within the network is spatially heterogeneous, but a pattern of two 400m wide streaks of high seismicity rates is evident, with >50-500 earthquakes detected per 50x50m grid cell in 2 weeks. These seismically active streaks are elongated approximately in the ice flow direction with a spacing of 750m. Independent airborne radar measurements of ice bottom depth from Jan 2013 show a low-amplitude ( 5m) undulation in the basal topography superposed on a regional gradient in ice bottom depth. The flow-perpendicular wavelength of these low-amplitude undulations is comparable to the spacing of the high seismicity bands, and the streaks of high seismicity intersect local lows in the undulating basal topography. We interpret these seismic and radar observations as showing seismically active sub-ice stream bedforms that are low amplitude and elongated in the direction of ice flow, comparable to the morphology of mega scale glacial lineations (MSGLs), with high basal seismicity rates observed in the MSGL troughs

  19. 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

  20. Quantitative risk analysis of oil storage facilities in seismic areas.

    PubMed

    Fabbrocino, Giovanni; Iervolino, Iunio; Orlando, Francesca; Salzano, Ernesto

    2005-08-31

    Quantitative risk analysis (QRA) of industrial facilities has to take into account multiple hazards threatening critical equipment. Nevertheless, engineering procedures able to evaluate quantitatively the effect of seismic action are not well established. Indeed, relevant industrial accidents may be triggered by loss of containment following ground shaking or other relevant natural hazards, either directly or through cascade effects ('domino effects'). The issue of integrating structural seismic risk into quantitative probabilistic seismic risk analysis (QpsRA) is addressed in this paper by a representative study case regarding an oil storage plant with a number of atmospheric steel tanks containing flammable substances. Empirical seismic fragility curves and probit functions, properly defined both for building-like and non building-like industrial components, have been crossed with outcomes of probabilistic seismic hazard analysis (PSHA) for a test site located in south Italy. Once the seismic failure probabilities have been quantified, consequence analysis has been performed for those events which may be triggered by the loss of containment following seismic action. Results are combined by means of a specific developed code in terms of local risk contour plots, i.e. the contour line for the probability of fatal injures at any point (x, y) in the analysed area. Finally, a comparison with QRA obtained by considering only process-related top events is reported for reference.

  1. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 4, 1935 PHOTOGRAPH NO. 152 OF CONTRACT NO. 4 SHOWING COMPLETED HIGHWAY. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  2. Seismic reflection imaging of shallow oceanographic structures

    NASA Astrophysics Data System (ADS)

    Piété, Helen; Marié, Louis; Marsset, Bruno; Thomas, Yannick; Gutscher, Marc-André

    2013-05-01

    Multichannel seismic (MCS) reflection profiling can provide high lateral resolution images of deep ocean thermohaline fine structure. However, the shallowest layers of the water column (z < 150 m) have remained unexplored by this technique until recently. In order to explore the feasibility of shallow seismic oceanography (SO), we reprocessed and analyzed four multichannel seismic reflection sections featuring reflectors at depths between 10 and 150 m. The influence of the acquisition parameters was quantified. Seismic data processing dedicated to SO was also investigated. Conventional seismic acquisition systems were found to be ill-suited to the imaging of shallow oceanographic structures, because of a high antenna filter effect induced by large offsets and seismic trace lengths, and sources that typically cannot provide both a high level of emission and fine vertical resolution. We considered a test case, the imagery of the seasonal thermocline on the western Brittany continental shelf. New oceanographic data acquired in this area allowed simulation of the seismic acquisition. Sea trials of a specifically designed system were performed during the ASPEX survey, conducted in early summer 2012. The seismic device featured: (i) four seismic streamers, each consisting of six traces of 1.80 m; (ii) a 1000 J SIG sparker source, providing a 400 Hz signal with a level of emission of 205 dB re 1 μPa @ 1 m. This survey captured the 15 m thick, 30 m deep seasonal thermocline in unprecedented detail, showing images of vertical displacements most probably induced by internal waves.

  3. Short-Period Seismic Noise in Vorkuta (Russia)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kishkina, S B; Spivak, A A; Sweeney, J J

    Cultural development of new subpolar areas of Russia is associated with a need for detailed seismic research, including both mapping of regional seismicity and seismic monitoring of specific mining enterprises. Of special interest are the northern territories of European Russia, including shelves of the Kara and Barents Seas, Yamal Peninsula, and the Timan-Pechora region. Continuous seismic studies of these territories are important now because there is insufficient seismological knowledge of the area and an absence of systematic data on the seismicity of the region. Another task of current interest is the necessity to consider the seismic environment in the design,more » construction, and operation of natural gas extracting enterprises such as the construction of the North European Gas Pipeline. Issues of scientific importance for seismic studies in the region are the complex geodynamical setting, the presence of permafrost, and the complex tectonic structure. In particular, the Uralian Orogene (Fig. 1) strongly affects the propagation of seismic waves. The existing subpolar seismic stations [APA (67,57{sup o}N; 33,40{sup o}E), LVZ (67,90{sup o}N; 34,65{sup o}E), and NRIL (69,50{sup o}N; 88,40{sup o}E)] do not cover the extensive area between the Pechora and Ob Rivers (Fig. 1). Thus seismic observations in the Vorkuta area, which lies within the area of concern, represent a special interest. Continuous recording at a seismic station near the city of Vorkuta (67,50{sup o}N; 64,11{sup o}E) [1] has been conducted since 2005 for the purpose of regional seismic monitoring and, more specifically, detection of seismic signals caused by local mining enterprises. Current surveys of local seismic noise [7,8,9,11], are particularly aimed at a technical survey for the suitability of the site for installation of a small-aperture seismic array, which would include 10-12 recording instruments, with the Vorkuta seismic station as the central element. When constructed, this

  4. Validating induced seismicity forecast models—Induced Seismicity Test Bench

    NASA Astrophysics Data System (ADS)

    Király-Proag, Eszter; Zechar, J. Douglas; Gischig, Valentin; Wiemer, Stefan; Karvounis, Dimitrios; Doetsch, Joseph

    2016-08-01

    Induced earthquakes often accompany fluid injection, and the seismic hazard they pose threatens various underground engineering projects. Models to monitor and control induced seismic hazard with traffic light systems should be probabilistic, forward-looking, and updated as new data arrive. In this study, we propose an Induced Seismicity Test Bench to test and rank such models; this test bench can be used for model development, model selection, and ensemble model building. We apply the test bench to data from the Basel 2006 and Soultz-sous-Forêts 2004 geothermal stimulation projects, and we assess forecasts from two models: Shapiro and Smoothed Seismicity (SaSS) and Hydraulics and Seismics (HySei). These models incorporate a different mix of physics-based elements and stochastic representation of the induced sequences. Our results show that neither model is fully superior to the other. Generally, HySei forecasts the seismicity rate better after shut-in but is only mediocre at forecasting the spatial distribution. On the other hand, SaSS forecasts the spatial distribution better and gives better seismicity rate estimates before shut-in. The shut-in phase is a difficult moment for both models in both reservoirs: the models tend to underpredict the seismicity rate around, and shortly after, shut-in.

  5. Subbottom seismic profiling survey of Lake Azuei, Haiti: Seismic signature of paleo-shorelines in a transpressional environment and possible tectonic implications

    NASA Astrophysics Data System (ADS)

    Sloan, H.; Cormier, M. H.; Boisson, D.; Brown, B.; Guerrier, K.; Hearn, C. K.; Heil, C. W., Jr.; Hines, L.; Kelly, R. P.; King, J. W.; Knotts, P.; Lucier, O. F.; Momplaisir, R.; Stempel, R.; Symithe, S. J.; Ulysse, S. M. J.; Wattrus, N. J.

    2017-12-01

    The left-lateral Enriquillo-Plantain Garden Fault (EPGF) is one of two major transform faults that form the North American-Caribbean plate boundary. GPS measurements indicate that relative motion evolves from nearly pure strike-slip in western Haiti to highly transpressional near Lake Azuei in eastern Haiti, where the EPGF may terminate against a south-dipping oblique reverse fault. Lake Azuei, one of the largest lakes in the Caribbean region (10 km x 23 km), is surrounded by two high-elevation sierras (> 2,000 m). Because the lake has no outlet to the sea, its level is sensitive to variations in precipitation and is thought to have fluctuated by 10's of meters during the Holocene. A rise of 5 m over the past 10 years has had a devastating impact, submerging villages, farmland, and roads. A grid of high-resolution ( 10 cm) subbottom seismic (CHIRP) profiles acquired in January 2017 captures the subtle signature of the 5 m-deep shoreline and also images a prominent paleo-shoreline at 10 m water depth. This 10 m paleo-shoreline is well expressed in the CHIRP data suggesting it was occupied for a long period of time. It is buried beneath a thin (< 20 cm-thick) veneer of sediments, indicating that it was submerged centuries to millennia ago. This paleo-shoreline represents a key horizontal marker that may have been warped by local transpressional tectonics. We therefore catalogued its varying seismic signature with the goal of detecting any subtle but systematic depth variations of the associated shoreline angle around the periphery of the lake. Two sediment cores, collected in water depths of 14 m and 17 m, each bottomed 80-90 cm below the lakebed into a distinctively coarser bed. On-going radiometric dating is expected to constrain the age of this distinctive layer. Should this layer be tied to the perduring 10-m lowstand of the lake, determining its age could help quantify vertical deformation rates around Lake Azuei.

  6. Seismicity parameters preceding moderate to major earthquakes

    NASA Astrophysics Data System (ADS)

    von Seggern, David; Alexander, Shelton S.; Baag, Chang-Eob

    1981-10-01

    Seismic events reported in the bulletins of the two large arrays, LASA and NORSAR, were merged with those from the NEIS bulletin for the period 1970-1977. Using a lower cutoff of mb = 5.8, 510 `main shocks' within the P range of LASA or NORSAR were selected for this period; and various seismicity trends prior to them were investigated. A search for definite foreshocks, based on a significantly short time delay to the main shock, revealed that the true rate of foreshock occurrence was less than 20%. Foreshocks are almost exclusively associated with shallow (h < 100 km) main shocks. To establish common features, a method of averaging seismicity from many regions was used to suppress the randomness of the seismic behavior of each region. This averaging shows that the seismicity level around the main shock increases somewhat for 10 days before main shocks; this feature peaks in the last 3-4 hours prior to the main shocks. The averaging also reveals that the mean magnitude of events near the main shock increases prior to main shocks but only by a few hundredths of a magnitude unit. Again by averaging, the seismicity about main shocks is shown to tend with time toward the main shock as its origin time is approached, but the average effect is small (˜10% change). By expanding or contracting each region's time scale before averaging to relate to the magnitude of the main shock, these features are enhanced. Using a new variable to track the departures from both spatial and temporal randomness, the Poisson-like behavior of deeper seismicity (>100 km) was demonstrated. For shallow events (<100 km) this variable reveals numerous instances of clustering and spatial-temporal seismic gaps, with little tendency toward a uniformity of behavior prior to main shocks. A statistical test of the validity of seismic precursors was performed for approximately 90 main shock regions which had sufficient seismicity. Using a five-variable vector (interevent time, interevent distance

  7. Seismic modeling of Earth's 3D structure: Recent advancements

    NASA Astrophysics Data System (ADS)

    Ritsema, J.

    2008-12-01

    Global models of Earth's seismic structure continue to improve due to the growth of seismic data sets, implementation of advanced wave propagations theories, and increased computational power. In my presentation, I will summarize seismic tomography results from the past 5-10 years. I will compare the most recent P and S velocity models, discuss model resolution and model interpretation, and present an, admittedly biased, list of research directions required to develop the next generation 3D models.

  8. Extraction of Pn seismic signals from air-gun shots recorded by the Cascadia Amphibious seismic experiment

    NASA Astrophysics Data System (ADS)

    Rathnayaka, S.; Gao, H.

    2017-12-01

    The goal of this study is to extract Pn (head wave) seismic waveforms recorded by both offshore and onshore (broadband and short period) seismic stations and evaluate the data quality. Two offshore active-source seismic experiments, MGL 1211 and MGL 1212, were conducted from 13th June to 24th July 2012, during the first year deployment of the Cascadia Initiative Amphibious Array. In total, we choose 110 ocean bottom seismometers and 209 inland stations that are located along the entire Cascadia subduction zone. We first remove the instrument response, and then explore the potential frequency ranges and the diurnal effect. We make the common receiver gathering for each seismic station and filter the seismic waveforms at multiple frequency bands, ranging from 3-5 Hz, 5-10 Hz, 10-20 Hz, to 20-40 Hz, respectively. To quantitatively evaluate the data quality, we calculate the signal-to-noise ratio (SNR) of the waveforms for usable stations that record clear Pn arrivals at multiple frequency bands. Our results show that most offshore stations located at deep water (>1.5 km) record clear air-gun shot signals at frequencies higher than 3 Hz and up to 550 km away from the source. For most stations located on the shallow continental shelf, the seismic recordings appear much noisier at all the frequencies compared to stations at deep water. Three general trends are observed for the SNR distribution; First, the SNR ratio increases from lower to higher frequency bands; Second, the ratio decreases with the increasing source-to-receiver distance; And third, the ratio increases from shallow to deep water. We also observe a rough negative relationship of the signal-to-noise ratio with the thickness of the marine sediment. Only 5 inland stations record clear air-gun shot arrivals up to 200 km away from the source. More detailed data quality analysis with more results will also be present.

  9. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MAY 20, 1933 PHOTOGRAPH NO. 12 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE FALSEWORK MATERIAL READY FOR USE. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  10. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MAY 26, 1933 PHOTOGRAPH NO. 13 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE DRIVING SHEET PILING AT PIER V. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  11. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. APRIL 3, 1933 PHOTOGRAPH NO. 6 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE WILLOW TREE MATTRESS FOR PIER NO. 1. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  12. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MAY 12, 1933 PHOTOGRAPH NO. 11 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE FALSEWORK AT PIER V. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  13. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. AUGUST 21, 1933 PHOTOGRAPH NO. 25 OF CONTRACT NO. 3 SHOWING ERECTION OF STEEL SHELL AT RIVER PIER III. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  14. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. APRIL 7, 1933 PHOTOGRAPH NO. 7 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE BORING RIG AT PIER I DOWNSTREAM. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  15. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. SEPTEMBER 20, 1933 PHOTOGRAPH NO. 12 OF CONTRACT NO. 6 SHOWING EAST APPROACH – GROUT AROUND RUST JOINT. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  16. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MAY 28, 1934 PHOTOGRAPH NO. 162 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE GENERAL VIEW OF PIERS A TO IV. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  17. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MAY 28, 1934 PHOTOGRAPH NO. 164 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PIER A COMPLETE. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  18. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 28, 1934 PHOTOGRAPH NO. 198 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE GENERAL VIEW OF PIERS. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  19. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. DECEMBER 18, 1934 PHOTOGRAPH NO. 181 OF CONTRACT NO. 5 SHOWING WEST APPROACH – GRADING TRAFFIC CIRCLE. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  20. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5”archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 23, 1934 PHOTOGRAPH NO. 193 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE – CONCRETE PLANT AT PIER IV. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  1. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JUNE 30, 1933 PHOTOGRAPH NO. 3 OF CONTRACT NO. 6 SHOWING EAST APPROACH – ERECTING STEELWORK, TOWER NO. 1 AND NO. 2. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  2. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 5, 1934 PHOTOGRAPH NO. 43 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE CANTILEVER STRUCTURE ERECTION AT PIER II. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  3. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 2, 1933 PHOTOGRAPH NO. 45 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PLACING COFFERDAM AT PIER NO. V. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  4. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. SEPTEMBER 25, 1933 PHOTOGRAPH NO. 41 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PLACING SAND ISLAND FILL AT PIER NO. III. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  5. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 13, 1933 PHOTOGRAPH NO. 69 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE DREDGING THIRD LIFT OF CAISSON AT PIER III. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  6. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 6, 1933 PHOTOGRAPH NO. 68 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PIER II FIRST LIFT OF FORMS. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  7. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. AUGUST 12, 1935 PHOTOGRAPH NO. 133 OF CONTRACT NO. 4 SHOWING GENERAL VIEW OF EAST APPROACH TO BRIDGE. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  8. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 7, 1935 PHOTOGRAPH NO. 145 OF CONTRACT NO. 4 SHOWING ERECTION OF 330 FOOT DECK SPAN. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  9. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. AUGUST 28, 1933 PHOTOGRAPH NO. 37 OF CONTRACT NO. 5 SHOWING EAST APPROACH – PLACING CONCRETE AT BENT NO. 108. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  10. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4 x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 13, 1933 PHOTOGRAPH NO. 72 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PIER II SECOND LIFT OF FORMS. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  11. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 22, 1934 PHOTOGRAPH NO. 41 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE STEEL ERECTION AT PIER II. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  12. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 28, 1934 PHOTOGRAPH NO. 199 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE GENERAL VIEW OF PIERS. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  13. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. APRIL 30, 1934 PHOTOGRAPH NO. 151 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE CONCRETING SHAFT AT PIER III. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  14. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 11, 1933 PHOTOGRAPH NO. 49 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE CONSTRUCTION OF FOOTING AT PIER C. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  15. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. AUGUST 21, 1933 PHOTOGRAPH NO. 32 OF CONTRACT NO. 5 SHOWING EAST APPROACH – CONCRETING AT BENT NO. 105. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  16. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 6, 1933 PHOTOGRAPH NO. 67 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE SHAFT PIER C. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  17. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 23, 1933 PHOTOGRAPH NO. 88 OF CONTRACT NO. 5 SHOWING WEST APPROACH – CONCRETING PEDESTAL BENT NO. 9. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  18. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 26, 1933 PHOTOGRAPH NO. 78 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE SETTING GRANITE ON PIER V. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  19. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JUNE 30, 1933 PHOTOGRAPH NO. 25 OF CONTRACT NO. 5 SHOWING EAST APPROACH – EXCAVATION, BENT 41 AT JEFFERSON HIGHWAY. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  20. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JANUARY 8, 1934 PHOTOGRAPH NO. 97 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PIER C COMPLETED. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  1. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MARCH 12, 1934 PHOTOGRAPH NO. 130 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE DRIVING FALSEWORK PILES AT PIER IV. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  2. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. SEPTEMBER 5, 1933 PHOTOGRAPH NO. 31 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE ERECTION OF SHELL. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  3. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MARCH 19, 1934 PHOTOGRAPH NO. 134 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE ERECTING FORMS PIER D. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  4. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” X 5”inch archival negative made from print. Original photographer unknown. Original 8” X 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 4, 1935 PHOTOGRAPH NO. 151 OF CONTRACT NO. 4 SHOWING PORTAL OF MAIN CANTILEVER BRIDGE. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  5. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JANUARY 28, 1935 PHOTOGRAPH NO. 70 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE DISMANTLING FASLEWORK BENT AT LA 8 EAST ANCHOR ARM. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  6. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 23, 1933 PHOTOGRAPH NO. 93 OF CONTRACT NO. 5 SHOWING EAST APPROACH – HIGHWAY FILL. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  7. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. SEPTEMBER 25, 1933 PHOTOGRAPH NO. 42 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE REMOVAL OF FORMS AT CAISSON PIER NO. V. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  8. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 14, 1933 PHOTOGRAPH NO. 82 OF CONTRACT NO. 5 SHOWING EAST APPROACH – HIGHWAY EMBANKMENT. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  9. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. FEBRUARY 5, 1934 PHOTOGRAPH NO. 112 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE SETTING CUTTING EDGE AT PIER I. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  10. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JUNE 16, 1933 PHOTOGRAPH NO. 22 OF CONTRACT NO. 5 SHOWING EAST APPROACH – CONCRETE PLANT AT BENT NO. 28. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  11. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 20, 1933 PHOTOGRAPH NO. 73 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE TOP OF CAISSON AT ELEVATION -35.O FEET. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  12. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 15, 1934 PHOTOGRAPH NO. 192 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE TOPPING OUT AT PIER I. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  13. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. AUGUST 12, 1935 PHOTOGRAPH NO. 135 OF CONTRACT NO. 4 SHOWING RAILROAD DECK WEST ANCHOR ARM. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  14. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 23, 1933 PHOTOGRAPH NO. 59 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PLACING OF CUTTING EDGE AT PIER A. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  15. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. DECEMBER 4, 1933 PHOTOGRAPH NO. 80 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE CONCRETING SHAFT AT PIER C. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  16. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 29, 1934 PHOTOGRAPH NO. 194 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE ERECTING SHAFT FORMS AT PIER IV. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  17. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. AUGUST 26, 1935 PHOTOGRAPH NO. 139 OF CONTRACT NO. 4 SHOWING RAILROAD DECK BETWEEN PIERS D TO V. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  18. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MAY 15, 1934 PHOTOGRAPH NO. 156 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE SHAFT FORMS PIER II. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  19. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MARCH 27, 1934 PHOTOGRAPH NO. 4 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE START OF PLACING ERECTING DERRICK SPAN V-B. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  20. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 20, 1933 PHOTOGRAPH NO. 75 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE SETTING FORMS FOR SHAFT PIER C. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  1. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MAY 15, 1934 PHOTOGRAPH NO. 8 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE SPAN BETWEEN PIERS V AND B. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  2. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. FEBRUARY 19, 1934 PHOTOGRAPH NO. 118 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE CUTTING EDGE FORMS AT PIER I. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  3. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JULY 27, 1934 PHOTOGRAPH NO. 171 OF CONTRACT NO. 5 SHOWING WEST APPROACH – PLACING HIGHWAY FILL. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  4. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. FEBRUARY 26, 1934 PHOTOGRAPH NO. 124 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE ERECTING FORMS AT PIER SHAFT PIER A. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  5. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 30, 1933 PHOTOGRAPH NO. 62 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE DRIVING SHEET PILING AT PIER B. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  6. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 17, 1933 PHOTOGRAPH NO. 57A OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PLACING OF SAND FILL AT PIER NO. II. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  7. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 23, 1933 PHOTOGRAPH NO. 58 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PLACING OF CUTTING EDGE AT PIER NO. II. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  8. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 2, 1933 PHOTOGRAPH NO. 55 OF CONTRACT NO. 5 SHOWING WEST APPROACH – PILE DRIVER AT BENT NO. 24. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  9. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JUNE 18, 1934 PHOTOGRAPH NO. 170 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PIER III COMPLETE. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  10. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. DECEMBER 26, 1933 PHOTOGRAPH NO. 91 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE EXCAVATING AROUND PILES, PIER D. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  11. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JULY 27, 1934 PHOTOGRAPH NO. 170 OF CONTRACT NO. 5 SHOWING WEST APPROACH – PLACING FILL AT HIGHWAY ABUTMENT. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  12. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. DECEMBER 11, 1933 PHOTOGRAPH NO. 83 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE COPING FORMS AT PIER C. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  13. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. DECEMBER 4, 1934 PHOTOGRAPH NO. 50 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE ERECTING FALSEWORK BENT WEST ANCHOR ARM. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  14. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JANUARY 20, 1933 PHOTOGRAPH NO. 1 OF CONTRACT NO. 5 SHOWING EAST APPROACH – FIRST TEST PILE – FOOTING 3 RIGHT. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  15. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. DECEMBER 4, 1933 PHOTOGRAPH NO. 81 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE EXCAVATING PIER B. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  16. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. AUGUST 6, 1934 PHOTOGRAPH NO. 26 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE ERECTING HIGHWAY STEEL SPAN BETWEEN PIERS B AND C. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  17. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. DECEMBER 18, 1933 PHOTOGRAPH NO. 87 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE SAND ISLAND FILL PIER I. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  18. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JANUARY 15, 1934 PHOTOGRAPH NO. 102 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE BUILDING COFFERDAM AT PIER A. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  19. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. AUGUST 28, 1933 PHOTOGRAPH NO. 29 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PLACING OF WELL FORMS AT PIER NO. IV. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  20. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 30, 1933 PHOTOGRAPH NO. 62 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE DRIVING SHEET PILING AT PIER A. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  1. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JULY 16, 1934 PHOTOGRAPH NO. 179 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE DREDGING PIER IV. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  2. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. AUGUST 6, 1934 PHOTOGRAPH NO. 27 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE FALSEWORK BEND AND DERRICK AT PIER II. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  3. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. APRIL 15, 1935 PHOTOGRAPH NO. 92 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE GENERAL VIEW OF BRIDGE. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  4. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. SEPTEMBER 24, 1934 PHOTOGRAPH NO. 189 OF CONTRACT NO. 3 SHOWING MAIN SETTING GRANITE AT PIER IV. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  5. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JUNE 25, 1934 PHOTOGRAPH NO. 172 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE CONCRETING COPING PIER II. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  6. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JANUARY 7, 1935 PHOTOGRAPH NO. 64 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE STEEL ERECTION PIER I. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  7. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JANUARY 22, 1934 PHOTOGRAPH NO. 107 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE ERECTING COFFERDAM AT PIER III. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  8. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. FEBRUARY 5, 1934 PHOTOGRAPH NO. 114 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PIER NO. V. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  9. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JULY 1, 1935 PHOTOGRAPH NO. 116 OF CONTRACT NO. 4 SHOWING RAILROAD DECK WEST ANCHOR ARM. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  10. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. APRIL 30, 1934 PHOTOGRAPH NO. 150 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PIER D COMPLETE. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  11. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MARCH 11, 1935 PHOTOGRAPH NO. 83A OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE GENERAL VIEW OF BRIDGE. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  12. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. FEBRUARY 12, 1934 PHOTOGRAPH NO. 116 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE SETTING SHAFT FORM AT PIER III. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  13. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JANUARY 22, 1934 PHOTOGRAPH NO. 106 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE ERECTING COPING FORMS AT PIER V. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  14. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. MARCH 12, 1934 PHOTOGRAPH NO. 152 OF CONTRACT NO. 5 SHOWING WEST APPROACH – CONCRETING FOOTING AT BENT NO. 94. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  15. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. DECEMBER 31, 1934 PHOTOGRAPH NO. 61 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE UPSTREAM CONCRETE ROADWAY. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  16. x 10” and white photographic print made from original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” and white photographic print made from original 1935, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JANUARY 28, 1935 PHOTOGRAPH NO. 72 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE COMPLETED HIGHWAY SLAB BETWEEN PIERS V TO B. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  17. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. DECEMBER 11, 1933 PHOTOGRAPH NO. 85 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE SETTING GRANITE ON RIVER PIER. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  18. Seismic array observations for monitoring phreatic eruptions in Iwojima Island, Japan

    NASA Astrophysics Data System (ADS)

    Ueda, H.; Kawaguchi, R.; Chiba, K.; Fujita, E.; Tanada, T.

    2015-12-01

    Iwojima is an active volcanic island located within a 10 km wide submarine caldera about 1250 km to the south of Tokyo, Japan. The volcanic activity is characterized by intensive earthquake activity associated with an island-wide uplift with high uplift rate (30~40 cm/year) and hydrothermal activity. In the last 10 years, phreatic eruptions took place in and near the island in 2012, 2013, and 2015. In such restless volcano, predictions and detections of occurrence points of phreatic eruptions are important for ensuring safety of residents. In the previous studies, we found that the earthquake activity of Iwojima highly correlates with the island wide large uplift, but the precursory activity of the phreatic eruption in 2012 was deviated from the correlation (Ueda et al. 2013 AGU Fall Meeting). For prediction of occurrence points of phreatic eruptions and investigation of the eruption mechanism, we began observation by seismic arrays at two areas in December 2014. The seismic arrays enable to locate epicenters of volcanic tremors, which are not well located by existing seismic stations. In May and June 2015, Japan Maritime Self-Defense Force stayed in Iwojima and a live camera of Japan Meteorological Agency found very small phreatic eruptions occurred at the northern beach. Existing seismic stations could not detect seismic signals related with the eruptions. The seismic array could detect weak seismic signals related with the eruptions. Although the seismic arrays could not detect precursory signals because of too small eruption, we expect the seismic arrays can detect precursory seismic signals suggesting occurrence points of small or medium-sized phreatic eruptions. The seismic arrays also detected epicenters of harmonic and monotonic tremors took place at an active fumarolic field in the north earthen part of Iwojima. The apparent velocity of seismic waves (~1km/s) strongly suggests that the tremors relate with hydrothermal activity near ground surface.

  19. Lattice damage and compositional changes in Xe ion irradiated In{sub x}Ga{sub 1-x}N (x = 0.32−1.0) single crystals

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Limin, E-mail: zhanglm@lzu.edu.cn; Peng, Jinxin; Ai, Wensi

    2016-06-28

    Lattice disorder and compositional changes in In{sub x}Ga{sub 1-x}N (x = 0.32, 0.47, 0.7, 0.8, and 1.0) films on GaN/Al{sub 2}O{sub 3} substrates, induced by room-temperature irradiation of 5 MeV Xe ions, have been investigated using both Rutherford backscattering spectrometry under ion-channeling conditions and time-of-flight secondary ion mass spectrometry. The results show that for a fluence of 3 × 10{sup 13 }cm{sup −2}, the relative level of lattice disorder in In{sub x}Ga{sub 1-x}N increases monotonically from 59% to 90% with increasing indium concentration x from 0.32 to 0.7; a further increase in x up to 1.0 leads to little increase in the disorder level. In contrastmore » to Ga-rich In{sub x}Ga{sub 1-x}N (x = 0.32 and 0.47), significant volume swelling of up to ∼25% accompanied with oxidation in In-rich In{sub x}Ga{sub 1-x}N (x = 0.7, 0.8, and 1.0) is observed. In addition, irradiation-induced atomic mixing occurs at the interface of In-rich In{sub x}Ga{sub 1-x}N and GaN. The results from this study indicate an extreme susceptibility of the high In-content In{sub x}Ga{sub 1-x}N to heavy-ion irradiation, and suggest that cautions must be exercised in applying ion-implantation techniques to these materials at room temperature. Further studies of the irradiation behavior at elevated temperatures are warranted.« less

  20. Active seismic experiment

    NASA Technical Reports Server (NTRS)

    Kovach, R. L.; Watkins, J. S.; Talwani, P.

    1972-01-01

    The Apollo 16 active seismic experiment (ASE) was designed to generate and monitor seismic waves for the study of the lunar near-surface structure. Several seismic energy sources are used: an astronaut-activated thumper device, a mortar package that contains rocket-launched grenades, and the impulse produced by the lunar module ascent. Analysis of some seismic signals recorded by the ASE has provided data concerning the near-surface structure at the Descartes landing site. Two compressional seismic velocities have so far been recognized in the seismic data. The deployment of the ASE is described, and the significant results obtained are discussed.

  1. Evaluation of seismic hazard at the northwestern part of Egypt

    NASA Astrophysics Data System (ADS)

    Ezzelarab, M.; Shokry, M. M. F.; Mohamed, A. M. E.; Helal, A. M. A.; Mohamed, Abuoelela A.; El-Hadidy, M. S.

    2016-01-01

    The objective of this study is to evaluate the seismic hazard at the northwestern Egypt using the probabilistic seismic hazard assessment approach. The Probabilistic approach was carried out based on a recent data set to take into account the historic seismicity and updated instrumental seismicity. A homogenous earthquake catalogue was compiled and a proposed seismic sources model was presented. The doubly-truncated exponential model was adopted for calculations of the recurrence parameters. Ground-motion prediction equations that recently recommended by experts and developed based upon earthquake data obtained from tectonic environments similar to those in and around the studied area were weighted and used for assessment of seismic hazard in the frame of logic tree approach. Considering a grid of 0.2° × 0.2° covering the study area, seismic hazard curves for every node were calculated. Hazard maps at bedrock conditions were produced for peak ground acceleration, in addition to six spectral periods (0.1, 0.2, 0.3, 1.0, 2.0 and 3.0 s) for return periods of 72, 475 and 2475 years. The unified hazard spectra of two selected rock sites at Alexandria and Mersa Matruh Cities were provided. Finally, the hazard curves were de-aggregated to determine the sources that contribute most of hazard level of 10% probability of exceedance in 50 years for the mentioned selected sites.

  2. Seismic imaging of gas hydrate reservoir heterogeneities

    NASA Astrophysics Data System (ADS)

    Huang, Jun-Wei

    range of 528 to 768x10 6 m3/km2 of natural gas trapped within hydrate, nearly an order of magnitude lower than earlier estimates which excluded effects of small-scale heterogeneities. Further, the petrophysical models are combined with a 3-D Finite Difference method to study seismic attenuation. Thus a framework is built to further tune the models of gas hydrate reservoirs with constraints from well logs other disciplinary data.

  3. Seismic hazard maps of Mexico, the Caribbean, and Central and South America

    USGS Publications Warehouse

    Tanner, J.G.; Shedlock, K.M.

    2004-01-01

    The growth of megacities in seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures due to an insufficient knowledge of existing seismic hazard and/or economic constraints. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. We have produced a suite of seismic hazard estimates for Mexico, the Caribbean, and Central and South America. One of the preliminary maps in this suite served as the basis for the Caribbean and Central and South America portion of the Global Seismic Hazard Map (GSHM) published in 1999, which depicted peak ground acceleration (pga) with a 10% chance of exceedance in 50 years for rock sites. Herein we present maps depicting pga and 0.2 and 1.0 s spectral accelerations (SA) with 50%, 10%, and 2% chances of exceedance in 50 years for rock sites. The seismicity catalog used in the generation of these maps adds 3 more years of data to those used to calculate the GSH Map. Different attenuation functions (consistent with those used to calculate the U.S. and Canadian maps) were used as well. These nine maps are designed to assist in global risk mitigation by providing a general seismic hazard framework and serving as a resource for any national or regional agency to help focus further detailed studies required for regional/local needs. The largest seismic hazard values in Mexico, the Caribbean, and Central and South America generally occur in areas that have been, or are likely to be, the sites of the largest plate boundary earthquakes. High hazard values occur in areas where shallow-to-intermediate seismicity occurs frequently. ?? 2004 Elsevier B.V. All rights reserved.

  4. Photocopy of drawing (this photograph is and 8' x10' copy ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is and 8' x10' copy of an 8' x 10' negative; 1907 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Central power station building No. 47, General arrangement of machinery - U.S. Naval Air Station, Power Plant, 328 South Avenue, Pensacola, Escambia County, FL

  5. Gamma rays of energy or = 10(15) eV from Cyg X-3

    NASA Technical Reports Server (NTRS)

    Kifune, T.; Nishijima, K.; Hara, T.; Hatano, Y.; Hayashida, N.; Honda, M.; Kamata, K.; Matsubara, Y.; Mori, M.; Nagano, M.

    1985-01-01

    The experimental data of extensive air showers observed at Akeno have been analyzed to detect the gamma ray signal from Cyg X-3. After muon poor air showers are selected, the correlation of data acquisition time with 4.8 hours X-ray period is studied, giving the data concentration near the phase 0.6, the time of X-ray maximum. The probability that uniform backgrounds create the distribution is 0.2%. The time averaged integral gamma ray flux is estimated as (1.1 + or - 0.4)x 10 to the -14th power cm(-2) sec(-1) for Eo 10 to the 15th power eV and (8.8 + or - 5.0)x 10 to the 14th power cm(-2) sec(-1) for Eo 6 x 10 to the 14th power eV.

  6. Updating Hawaii Seismicity Catalogs with Systematic Relocations and Subspace Detectors

    NASA Astrophysics Data System (ADS)

    Okubo, P.; Benz, H.; Matoza, R. S.; Thelen, W. A.

    2015-12-01

    We continue the systematic relocation of seismicity recorded in Hawai`i by the United States Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO), with interests in adding to the products derived from the relocated seismicity catalogs published by Matoza et al., (2013, 2014). Another goal of this effort is updating the systematically relocated HVO catalog since 2009, when earthquake cataloging at HVO was migrated to the USGS Advanced National Seismic System Quake Management Software (AQMS) systems. To complement the relocation analyses of the catalogs generated from traditional STA/LTA event-triggered and analyst-reviewed approaches, we are also experimenting with subspace detection of events at Kilauea as a means to augment AQMS procedures for cataloging seismicity to lower magnitudes and during episodes of elevated volcanic activity. Our earlier catalog relocations have demonstrated the ability to define correlated or repeating families of earthquakes and provide more detailed definition of seismogenic structures, as well as the capability for improved automatic identification of diverse volcanic seismic sources. Subspace detectors have been successfully applied to cataloging seismicity in situations of low seismic signal-to-noise and have significantly increased catalog sensitivity to lower magnitude thresholds. We anticipate similar improvements using event subspace detections and cataloging of volcanic seismicity that include improved discrimination among not only evolving earthquake sequences but also diverse volcanic seismic source processes. Matoza et al., 2013, Systematic relocation of seismicity on Hawai`i Island from 1992 to 2009 using waveform cross correlation and cluster analysis, J. Geophys. Res., 118, 2275-2288, doi:10.1002/jgrb.580189 Matoza et al., 2014, High-precision relocation of long-period events beneath the summit region of Kīlauea Volcano, Hawai`i, from 1986 to 2009, Geophys. Res. Lett., 41, 3413-3421, doi:10.1002/2014GL059819

  7. Probabilistic Seismic Hazard Assessment for Northeast India Region

    NASA Astrophysics Data System (ADS)

    Das, Ranjit; Sharma, M. L.; Wason, H. R.

    2016-08-01

    Northeast India bounded by latitudes 20°-30°N and longitudes 87°-98°E is one of the most seismically active areas in the world. This region has experienced several moderate-to-large-sized earthquakes, including the 12 June, 1897 Shillong earthquake ( M w 8.1) and the 15 August, 1950 Assam earthquake ( M w 8.7) which caused loss of human lives and significant damages to buildings highlighting the importance of seismic hazard assessment for the region. Probabilistic seismic hazard assessment of the region has been carried out using a unified moment magnitude catalog prepared by an improved General Orthogonal Regression methodology (Geophys J Int, 190:1091-1096, 2012; Probabilistic seismic hazard assessment of Northeast India region, Ph.D. Thesis, Department of Earthquake Engineering, IIT Roorkee, Roorkee, 2013) with events compiled from various databases (ISC, NEIC,GCMT, IMD) and other available catalogs. The study area has been subdivided into nine seismogenic source zones to account for local variation in tectonics and seismicity characteristics. The seismicity parameters are estimated for each of these source zones, which are input variables into seismic hazard estimation of a region. The seismic hazard analysis of the study region has been performed by dividing the area into grids of size 0.1° × 0.1°. Peak ground acceleration (PGA) and spectral acceleration ( S a) values (for periods of 0.2 and 1 s) have been evaluated at bedrock level corresponding to probability of exceedance (PE) of 50, 20, 10, 2 and 0.5 % in 50 years. These exceedance values correspond to return periods of 100, 225, 475, 2475, and 10,000 years, respectively. The seismic hazard maps have been prepared at the bedrock level, and it is observed that the seismic hazard estimates show a significant local variation in contrast to the uniform hazard value suggested by the Indian standard seismic code [Indian standard, criteria for earthquake-resistant design of structures, fifth edition, Part

  8. High-resolution seismic reflection survey at Dover AFB: A comparison of three seismic sources

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cardimona, S.; Kadinsky-Cade, K.; Miller, R.

    1996-11-01

    In June of 1995, the Earth Sciences Division of the Air Force Phillips Lab, with survey equipment from the University of Delaware and assisted by the Kansas Geological Survey and Elohi Geophysics, conducted a geophysical site characterization of the SERDP-funded Groundwater Remediation Field Lab (GRFL) located at Dover AFB, Delaware and administered by Applied Research Associates for USAF Armstrong Lab. Seismic data were collected in order to (1) compare the results using three different compressional sources and (2) cover the field site well enough to characterize the seismic response of the shallow subsurface. This paper will focus primarily on themore » first of these two goals. Seismic data were collected along three north-south profiles set 10 meters apart, each profile with a different compressional source: a 5.5kg sledgehammer, a 12-gauge firing rod from Betsy Seisgun Inc. shooting 150 grain blanks, and a portable piezoelectrically driven vibrator, developed by Elohi Geophysics, operating with a 90Hz-450Hz sweep. An east-west cross line was collected using the sledgehammer source in order to tie the three profiles together. A laser theodolite provided station location and elevation control. The primary targets were the water table (that had been marked on maps at a depth of about 3 meters) and a sand-clay interface at about 15 meters depth. We collected 24-channel CMP data using a half meter spacing of both source and 100Hz geophones. Field C after initial walkaway noise testing with each source did not show any one source to be outstanding A practical early result of the seismic survey showed the water table to be at just over 10 meters. We have associated the strongest reflection event with the water-table interface. Seismic data comparison in this study is based on spectral content, total energy and signal-to-noise ratios, as well as a discussion of coherency of the primary reflection event at the water table.« less

  9. Specification goals for a Mars seismic network

    NASA Technical Reports Server (NTRS)

    Davis, Paul M.

    1990-01-01

    A seismic network on Mars should have enough stations (e.g., 24) to characterize the seismicity of the planet for comparison with a diversity of structural features; be comprised of low noise stations, preferably underground, 3 to 4 orders of magnitude more sensitive than those used on Viking; record over a sufficient band-width (DC-30 Hz) to detect micro-earthquakes to normal modes; and record for a sufficient duration (10 years) and data rate (10(exp 8) Mb/day/station) to obtain a data set comparable to that from the Apollo mission to the Moon so that locations of major internal boundaries can be inferred, such as those in the Earth, i.e., crust - lithosphere - asthenosphere - upper - lower phase transitions - outer - inner core. The proposed Mars Global Network Mission provides an opportunity to sense the dynamics and probe the interior of the planet. The seismic objectives, the availability of the instrumentation and trade-offs to meet them are discussed.

  10. Progressive Seismic Failure, Seismic Gap, and Great Seismic Risk across the Densely Populated North China Basin

    NASA Astrophysics Data System (ADS)

    Yin, A.; Yu, X.; Shen, Z.

    2014-12-01

    Although the seismically active North China basin has the most complete written records of pre-instrumentation earthquakes in the world, this information has not been fully utilized for assessing potential earthquake hazards of this densely populated region that hosts ~200 million people. In this study, we use the historical records to document the earthquake migration pattern and the existence of a 180-km seismic gap along the 600-km long right-slip Tangshan-Hejian-Cixian (THC) fault zone that cuts across the North China basin. The newly recognized seismic gap, which is centered at Tianjin with a population of 11 million people and ~120 km from Beijing (22 million people) and Tangshan (7 million people), has not been ruptured in the past 1000 years by M≥6 earthquakes. The seismic migration pattern in the past millennium suggests that the epicenters of major earthquakes have shifted towards this seismic gap along the THC fault, which implies that the 180- km gap could be the site of the next great earthquake with M≈7.6 if it is ruptured by a single event. Alternatively, the seismic gap may be explained by aseismic creeping or seismic strain transfer between active faults.

  11. Dehydration kinetics of talc and 10 Å phase: Consequences for subduction zone seismicity

    NASA Astrophysics Data System (ADS)

    Chollet, Mélanie; Daniel, Isabelle; Koga, Kenneth T.; Petitgirard, Sylvain; Morard, Guillaume

    2009-06-01

    The process of dehydration embrittlement is usually proposed as an explanation for the presence of intermediate-depth earthquakes in subduction zones. It assumes that the release of water by hydrous mineral breakdown is fast enough to provoke brittle failure. We performed high-pressure, high-temperature, dehydration experiments of talc and 10 Å phase coupled with in situ measurement of reaction kinetics using synchrotron X-ray diffraction. Newly developed, X-ray transparent, pressure-sealed, titanium capsule ensured a closed thermochemical environment. From isothermal kinetics data fitted to the Avrami's equation and from the texture of reaction products, we conclude that dehydration rates of these minerals are limited by diffusion. Predicted minimum rates of fluid release range from 10 - 4 to 9 × 10 - 6 m 3fluid m - 3 rock s - 1 , and are fast enough to provoke hydraulic rupture since Maxwell relaxation rate of rocks relevant of subduction zones are slower than the rate of fluid release. These rates are comparable between talc, 10 Å phase and antigorite also [Perrillat, J.-P., Daniel, I., Koga, K.T., Reynard, B., Cardon, H., Crichton, W.A., 2005. Kinetics of antigorite dehydration: a real-time X-ray diffraction study. Earth Planet. Sci. Lett. 236, 899-913]. Consequently, we suggest that the dehydration of hydrous minerals may eventually be fast enough to trigger the intermediate-depth earthquakes, and that the deepest among intermediate-depth earthquakes may actually locate the limits for dehydration of hydrous minerals in the downgoing lithosphere.

  12. Photocopy of drawing (this photograph is an 8" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8" x 10" enlargement from a 4" x 5" negative; November 1993 revision of a November 10, 1973 as-built drawing by F. Marquez, in possession of the Highway System Administration Office of the Puerto Rico Highway and Transportation Authority). BRIDGE OVER HONDO RIVER ROUTE NO. 156 K.M. 28.9, COMERIO, P.R. - Puente Rio Hondo, Spanning Hondo River on PR Road 156, Barrio Rio Hondo, Comerio, Comerio Municipio, PR

  13. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. FEBRUARY 24, 1933 PHOTOGRAPH NO. 1 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE CONSTRUCTION TRESTLE ON EAST BANK LOOKING SOUTHEAST TOWARD WEST BANK. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  14. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1933, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. JULY 28, 1933 PHOTOGRAPH NO. 21 OF CONTRACT NO. 3 SHOWING PROGRESS OF WORK AT PIER C AS OF JULY 15, 1933 ON EAST BANK. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  15. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. APRIL 23, 1934 PHOTOGRAPH NO. 8 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE FALSEWORK BENT THAT WAS SCOURED OUT BETWEEN PIER IV AND V. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  16. x 10” black and white photographic print made from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    x 10” black and white photographic print made from original 1934, 8” x 10” black and white photographic negative. New 4” x 5” archival negative made from print. Original photographer unknown. Original 8” x 10” negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. NOVEMBER 5, 1934 PHOTOGRAPH NO. 44 OF CONTRACT NO. 4 SHOWING BRIDGE SUPERSTRUCTURE ERECTING HIGHWAY FORMS UPSTREAM ROADWAY BETWEEN PIERS V TO D. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  17. Photocopy of drawing (this photograph is and 8' x10' copy ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is and 8' x10' copy of an 8' x 10' negative; 1993 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Repair chimney, building No. 47, architectural elevations, exterior plan, details, genera notes, sheet 2 of 3 - U.S. Naval Air Station, Power Plant, 328 South Avenue, Pensacola, Escambia County, FL

  18. Photocopy of drawing (this photograph is and 8' x10' copy ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is and 8' x10' copy of an 8' x 10' negative; 1907 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Plan showing floor for basement and support for machinery foundations, central power house building No. 47 - U.S. Naval Air Station, Power Plant, 328 South Avenue, Pensacola, Escambia County, FL

  19. Receiver deghosting in the t-x domain based on super-Gaussianity

    NASA Astrophysics Data System (ADS)

    Lu, Wenkai; Xu, Ziqiang; Fang, Zhongyu; Wang, Ruiliang; Yan, Chengzhi

    2017-01-01

    Deghosting methods in the time-space (t-x) domain have attracted a lot of attention because of their flexibility for various source/receiver configurations. Based on the well-known knowledge that the seismic signal has a super-Gaussian distribution, we present a Super-Gaussianity based Receiver Deghosting (SRD) method in the t-x domain. In our method, we denote the upgoing wave and its ghost (downgoing wave) as a single seismic signal, and express the relationship between the upgoing wave and its ghost using two ghost parameters: the sea surface reflection coefficient and the time-shift between the upgoing wave and its ghost. For a single seismic signal, we estimate these two parameters by maximizing the super-Gaussianity of the deghosted output, which is achieved by a 2D grid search method using an adaptively predefined discrete solution space. Since usually a large number of seismic signals are mixed together in a seismic trace, in the proposed method we divide the seismic trace into overlapping frames using a sliding time window with a step of one time sample, and consider each frame as a replacement for a single seismic signal. For a 2D seismic gather, we obtain two 2D maps of the ghost parameters. By assuming that these two parameters vary slowly in the t-x domain, we apply a 2D average filter to these maps, to improve their reliability further. Finally, these deghosted outputs are merged to form the final deghosted result. To demonstrate the flexibility of the proposed method for arbitrary variable depths of the receivers, we apply it to several synthetic and field seismic datasets acquired by variable depth streamer.

  20. Seismic monitoring at Cascade Volcanic Centers, 2004?status and recommendations

    USGS Publications Warehouse

    Moran, Seth C.

    2004-01-01

    The purpose of this report is to assess the current (May, 2004) status of seismic monitoring networks at the 13 major Cascade volcanic centers. Included in this assessment are descriptions of each network, analyses of the ability of each network to detect and to locate seismic activity, identification of specific weaknesses in each network, and a prioritized list of those networks that are most in need of additional seismic stations. At the outset it should be recognized that no Cascade volcanic center currently has an adequate seismic network relative to modern-day networks at Usu Volcano (Japan) or Etna and Stromboli volcanoes (Italy). For a system the size of Three Sisters, for example, a modern-day, cutting-edge seismic network would ideally consist of a minimum of 10 to 12 short-period three-component seismometers (for determining particle motions, reliable S-wave picks, moment tensor inversions, fault-plane solutions, and other important seismic parameters) and 7 to 10 broadband sensors (which, amongst other considerations, enable detection and location of very long period (VLP) and other low-frequency events, moment tensor inversions, and, because of their wide dynamic range, on-scale recording of large-amplitude events). Such a dense, multi component seismic network would give the ability to, for example, detect in near-real-time earthquake migrations over a distance of ~0.5km or less, locate tremor sources, determine the nature of a seismic source (that is, pure shear, implosive, explosive), provide on-scale recordings of very small and very large-amplitude seismic signals, and detect localized changes in seismic stress tensor orientations caused by movement of magma bodies. However, given that programmatic resources are currently limited, installation of such networks at this time is unrealistic. Instead, this report focuses on identifying what additional stations are needed to guarantee that anomalous seismicity associated with volcanic unrest will be

  1. SpaceX CRS-10 "What's On Board" Science Briefing

    NASA Image and Video Library

    2017-02-17

    Mike Cisewski, Stratospheric Aerosol and Gas Experiment (SAGE) III Project manager at NASA’s Langley Research Center in Hampton, Virginia, speaks to members of social media in the Kennedy Space Center’s Press Site auditorium. The briefing focused on instruments to be delivered to the International Space Station on the SpaceX CRS-10 mission. Cisewski explained that the SAGE III is designed to study ozone in the atmosphere. A Dragon spacecraft is scheduled to be launched from Kennedy’s Launch Complex 39A on Feb. 18 atop a SpaceX Falcon 9 rocket on the company's 10th Commercial Resupply Services mission to the space station.

  2. SpaceX CRS-10 "What's On Board" Science Briefing

    NASA Image and Video Library

    2017-02-17

    Dr. Richard Blakeslee of NASA’s Marshall Space Flight Center in Huntsville, Alabama, speaks to members of social media in the Kennedy Space Center’s Press Site auditorium. The briefing focused on instruments to be delivered to the International Space Station on the SpaceX CRS-10 mission. Blakeslee explained that the Lightning Imaging Sensor (LIS) is designed to measure the amount, rate and energy of lightning around the world. A Dragon spacecraft is scheduled to be launched from Kennedy’s Launch Complex 39A on Feb. 18 atop a SpaceX Falcon 9 rocket on the company's 10th Commercial Resupply Services mission to the space station.

  3. Comment on "How can seismic hazard around the New Madrid seismic zone be similar to that in California?" by Arthur Frankel

    USGS Publications Warehouse

    Wang, Z.; Shi, B.; Kiefer, J.D.

    2005-01-01

    PSHA is the method used most to assess seismic hazards for input into various aspects of public and financial policy. For example, PSHA was used by the U.S. Geological Survey to develop the National Seismic Hazard Maps (Frankel et al., 1996, 2002). These maps are the basis for many national, state, and local seismic safety regulations and design standards, such as the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures, the International Building Code, and the International Residential Code. Adoption and implementation of these regulations and design standards would have significant impacts on many communities in the New Madrid area, including Memphis, Tennessee and Paducah, Kentucky. Although "mitigating risks to society from earthquakes involves economic and policy issues" (Stein, 2004), seismic hazard assessment is the basis. Seismologists should provide the best information on seismic hazards and communicate them to users and policy makers. There is a lack of effort in communicating the uncertainties in seismic hazard assessment in the central U.S., however. Use of 10%, 5%, and 2% PE in 50 years causes confusion in communicating seismic hazard assessment. It would be easy to discuss and understand the design ground motions if the true meaning of the ground motion derived from PSHA were presented, i.e., the ground motion with the estimated uncertainty or the associated confidence level.

  4. Angola Seismicity MAP

    NASA Astrophysics Data System (ADS)

    Neto, F. A. P.; Franca, G.

    2014-12-01

    The purpose of this job was to study and document the Angola natural seismicity, establishment of the first database seismic data to facilitate consultation and search for information on seismic activity in the country. The study was conducted based on query reports produced by National Institute of Meteorology and Geophysics (INAMET) 1968 to 2014 with emphasis to the work presented by Moreira (1968), that defined six seismogenic zones from macro seismic data, with highlighting is Zone of Sá da Bandeira (Lubango)-Chibemba-Oncócua-Iona. This is the most important of Angola seismic zone, covering the epicentral Quihita and Iona regions, geologically characterized by transcontinental structure tectono-magmatic activation of the Mesozoic with the installation of a wide variety of intrusive rocks of ultrabasic-alkaline composition, basic and alkaline, kimberlites and carbonatites, strongly marked by intense tectonism, presenting with several faults and fractures (locally called corredor de Lucapa). The earthquake of May 9, 1948 reached intensity VI on the Mercalli-Sieberg scale (MCS) in the locality of Quihita, and seismic active of Iona January 15, 1964, the main shock hit the grade VI-VII. Although not having significant seismicity rate can not be neglected, the other five zone are: Cassongue-Ganda-Massano de Amorim; Lola-Quilengues-Caluquembe; Gago Coutinho-zone; Cuima-Cachingues-Cambândua; The Upper Zambezi zone. We also analyzed technical reports on the seismicity of the middle Kwanza produced by Hidroproekt (GAMEK) region as well as international seismic bulletins of the International Seismological Centre (ISC), United States Geological Survey (USGS), and these data served for instrumental location of the epicenters. All compiled information made possible the creation of the First datbase of seismic data for Angola, preparing the map of seismicity with the reconfirmation of the main seismic zones defined by Moreira (1968) and the identification of a new seismic

  5. Phonons of Fe-based superconductor Ca 10Pt 4As 8(Fe 1-xPt xAs) 10

    DOE PAGES

    Ikeuchi, K.; Kobayashi, Y.; Suzuki, K.; ...

    2015-10-28

    In this paper, we report the results of inelastic neutron scattering measurements on particular phonons of a superconducting (SC) Ca10Pt 4As 8(Fe 1-xPt xAs) 10 with the onset transition temperature T c ~ 33 K to investigate mainly what roles orbital fluctuation plays in Cooper pairing, where we observed a slight softening of the in-plane transverse acoustic mode corresponding to the elastic constant C 66. This softening starts at temperature T well above the superconducting T c, as T decreases. An anomalously strong change of the scattering intensity of in-plane optical modes was observed at the M point of themore » pseudo tetragonal reciprocal space in the range of 35 < ω < 40 meV with decreasing T from far above T c. Finally, because this ω region mainly corresponds to the motion of Fe and As atoms in the FeAs planes, the finding presents information on the coupling between the orbital fluctuation of Fe 3d electrons and the lattice system, useful for studying the possible roles of orbital fluctuation in the pairing mechanism and/or the appearance of the so-called nematic phase.« less

  6. GEODIS: A Portable Ocean Bottom Very Broadband Seismic Station

    NASA Astrophysics Data System (ADS)

    KARCZEWSKI, J.; MONTAGNER, J.; BEGUERY, L.; STUTZMANN, E.; ROULT, G.; LOGNONNE, P.; CACHO, S.; KOENIG, J.; SAVARY, J.

    2001-12-01

    The last ten years have seen the simultaneous development of a global seismic network coordinated through the FDSN (Federation of Digital Seismograph Networks) and of portable broadband seismic arrays. The same approach can be followed for improving our scientific understanding of the Earth processes below oceanic areas. Both components of ocean bottom geophysical networks, will be coordinated by ION (international Ocean Network). They are complementary since they enable to investigate the Earth structure and processes at different spatial and temporal scales. Geophysical Ocean bottom observatories (hereafter referred as GOBO) and portable seismic stations are sharing common technological problems. However, the issues of power supply and real-time data transmission are more crucial for a GOBO than for a portable temporary station. Since 1999, our group is developing a new "portable" geophysical ocean bottom autonomous station, named GEODIS. This station might be a basic element for a GOBO. It relies on the use of adapted VBB sensors issued from space experiments and technology and on improved electronics compared with previous ocean bottom experiments (SISMOBS/OFM 1992; MOISE 1997). The main characteristics of GEODIS are the following: - 3 axes VBB seismic sensors with a classical flat velocity response 360-0.2s. at 2500V/m/s (intrinsic noise level smaller than LNM). - Automatic (under software control) installation, levelling, centring of the 3 component seismic sensors. - 24 bit digitiser recording at 20sps, 3 seismic component and 1 infrasonic sensor. - Recording by a 16 bit converter at 1sps of the sea temperature in the vicinity of the instrument and housekeeping parameters (temperature, inclinations, power,...). - 1 year autonomy by using Lithium batteries. - Storage of data on Flash card and recording on hard disk every day. - Weight of GEODIS: 186kg in air and 110kg in water. - Overall dimensions: 930 x 930 x 440 mm. GEODIS can be easily installed by a

  7. Photocopy of drawing (this photograph is and 8' x10' copy ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is and 8' x10' copy of an 8' x 10' negative; 1939 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Central power plant, installation of turbo-alternator and air compressor, plan above basement, sheet 1 of 6 - U.S. Naval Air Station, Power Plant, 328 South Avenue, Pensacola, Escambia County, FL

  8. SpaceX CRS-10 Prelaunch News Conference

    NASA Image and Video Library

    2017-02-17

    In the Kennedy Space Center’s Press Site auditorium, agency and industry leaders speak to members of the media at a prelaunch news conference for the SpaceX CRS-10 commercial resupply services mission to the International Space Station. Tara Ruttley, associate scientist for the International Space Station Program at Johnson Space Center in Houston, answers questions.

  9. SpaceX CRS-10 Prelaunch News Conference

    NASA Image and Video Library

    2017-02-17

    In the Kennedy Space Center’s Press Site auditorium, agency and industry leaders speak to members of the media at a prelaunch news conference for the SpaceX CRS-10 commercial resupply services mission to the International Space Station. Tara Ruttley, associate scientist for the International Space Station Program at Johnson Space Center in Houston answers questions.

  10. The effects of variations in Reynolds number between 3.0 x 10sub6 and 25.0 x 10sub6 upon the aerodynamic characteristics of a number of NACA 6-series airfoil sections

    NASA Technical Reports Server (NTRS)

    Loftin, Laurence K, Jr; Bursnall, William J

    1950-01-01

    Results are presented of an investigation made to determine the two-dimensional lift and drag characteristics of nine NACA 6-series airfoil section at Reynolds numbers of 15.0 x 10sub6, 20.0 x 10sub6, and 25.0 x 10sub6. Also presented are data from NACA Technical Report 824 for the same airfoils at Reynolds numbers of 3.0 x 10sub6, 6.0 x 10sub6, and 9.0 x 10sub6. The airfoils selected represent sections having variations in the airfoil thickness, thickness form, and camber. The characteristics of an airfoil with a split flap were determined in one instance, as was the effect of surface roughness. Qualitative explanations in terms of flow behavior are advanced for the observed types of scale effect.

  11. Flood, Seismic or Volcanic Deposits? New Insights from X-Ray Computed Tomography

    NASA Astrophysics Data System (ADS)

    Van Daele, M. E.; Moernaut, J.; Vermassen, F.; Llurba, M.; Praet, N.; Strupler, M. M.; Anselmetti, F.; Cnudde, V.; Haeussler, P. J.; Pino, M.; Urrutia, R.; De Batist, M. A. O.

    2014-12-01

    Event deposits, such as e.g. turbidites incorporated in marine or lacustrine sediment sequences, may be caused by a wide range of possible triggering processes: failure of underwater slopes - either spontaneous or in response to earthquake shaking, hyperpycnal flows and floods, volcanic processes, etc. Determining the exact triggering process remains, however, a major challenge. Especially when studying the event deposits on sediment cores, which typically have diameters of only a few cm, only a small spatial window is available to analyze diagnostic textural and facies characteristics. We have performed X-ray CT scans on sediment cores from Chilean, Alaskan and Swiss lakes. Even when using relatively low-resolution CT scans (0.6 mm voxel size), many sedimentary structures and fabrics that are not visible by eye, are revealed. For example, the CT scans allow to distinguish tephra layers that are deposited by fall-out, from those that reached the basin by river transport or mud flows and from tephra layers that have been reworked and re-deposited by turbidity currents. The 3D data generated by the CT scans also allow to examine relative orientations of sedimentary structures (e.g. convolute lamination) and fabrics (e.g. imbricated mud clasts), which can be used to reconstruct flow directions. Such relative flow directions allow to determine whether a deposit (e.g. a turbidite) had one or several source areas, the latter being typical for seismically triggered turbidites. When the sediment core can be oriented (e.g. using geomagnetic properties), absolute flow directions can be reconstructed. X-ray CT scanning, at different resolution, is thus becoming an increasingly important tool for discriminating the exact origin of EDs, as it can help determining whether e.g. an ash layer was deposited as fall out from an ash cloud or fluvially washed into the lake, or whether a turbidite was triggered by an earthquake or a flood.

  12. Structural and relaxor-like dielectric properties of unfilled tungsten bronzes Ba5-5xSm5xTi5xNb10-5xO30

    NASA Astrophysics Data System (ADS)

    Wei, T.; Dong, Z.; Zhao, C. Z.; Guo, Y. Y.; Zhou, Q. J.; Li, Z. P.

    2016-03-01

    New unfilled tetragonal tungsten bronze (TTB) oxides, Ba5-5xSm5xTi5xNb10-5xO30 (BSTN-x), where 0.10x ≤ 0.35, have been synthesized in this work. Their crystal structure was determined and analyzed based on Rietveld structural refinement. It is found that single TTB phase can be formed in a particular x range (i.e., 0.15 ≤ x ≤ 0.3) due to the competition interaction between tolerance factor and electronegativity difference. Furthermore, dielectric and ferroelectric results indicate that phase transitions and ferroelectric states are sensitive to x. Referring to the local chemistry, we suggest that the raise of vacancies at the A2-site compared with that of A1-site will intensely depress the normal ferroelectric phase and is in favor of relaxor ferroelectric state. Macroscopically, previous A-site size difference standpoint on fill TTB compounds cannot give a reasonable explanation about the variation of dielectric maximum temperature (Tm) for present BSTN-x compounds. Alternatively, tetragonality (c/a) is adopted which can well describe the variation of Tm in whole x range. In addition, one by one correspondence between tetragonality and electrical features can be found, and the compositions involving high c/a are usually stabilized in normal ferroelectric phase. It is believed that c/a is a more appropriate parameter to illustrate the variation of ferroelectric properties for unfilled TTB system.

  13. INDUCED SEISMICITY. Seismicity triggered by fluid injection-induced aseismic slip.

    PubMed

    Guglielmi, Yves; Cappa, Frédéric; Avouac, Jean-Philippe; Henry, Pierre; Elsworth, Derek

    2015-06-12

    Anthropogenic fluid injections are known to induce earthquakes. The mechanisms involved are poorly understood, and our ability to assess the seismic hazard associated with geothermal energy or unconventional hydrocarbon production remains limited. We directly measure fault slip and seismicity induced by fluid injection into a natural fault. We observe highly dilatant and slow [~4 micrometers per second (μm/s)] aseismic slip associated with a 20-fold increase of permeability, which transitions to faster slip (~10 μm/s) associated with reduced dilatancy and micro-earthquakes. Most aseismic slip occurs within the fluid-pressurized zone and obeys a rate-strengthening friction law μ = 0.67 + 0.045ln(v/v₀) with v₀ = 0.1 μm/s. Fluid injection primarily triggers aseismic slip in this experiment, with micro-earthquakes being an indirect effect mediated by aseismic creep. Copyright © 2015, American Association for the Advancement of Science.

  14. Expected Seismicity and the Seismic Noise Environment of Europa

    NASA Astrophysics Data System (ADS)

    Panning, Mark P.; Stähler, Simon C.; Huang, Hsin-Hua; Vance, Steven D.; Kedar, Sharon; Tsai, Victor C.; Pike, William T.; Lorenz, Ralph D.

    2018-01-01

    Seismic data will be a vital geophysical constraint on internal structure of Europa if we land instruments on the surface. Quantifying expected seismic activity on Europa both in terms of large, recognizable signals and ambient background noise is important for understanding dynamics of the moon, as well as interpretation of potential future data. Seismic energy sources will likely include cracking in the ice shell and turbulent motion in the oceans. We define a range of models of seismic activity in Europa's ice shell by assuming each model follows a Gutenberg-Richter relationship with varying parameters. A range of cumulative seismic moment release between 1016 and 1018 Nm/yr is defined by scaling tidal dissipation energy to tectonic events on the Earth's moon. Random catalogs are generated and used to create synthetic continuous noise records through numerical wave propagation in thermodynamically self-consistent models of the interior structure of Europa. Spectral characteristics of the noise are calculated by determining probabilistic power spectral densities of the synthetic records. While the range of seismicity models predicts noise levels that vary by 80 dB, we show that most noise estimates are below the self-noise floor of high-frequency geophones but may be recorded by more sensitive instruments. The largest expected signals exceed background noise by ˜50 dB. Noise records may allow for constraints on interior structure through autocorrelation. Models of seismic noise generated by pressure variations at the base of the ice shell due to turbulent motions in the subsurface ocean may also generate observable seismic noise.

  15. Seismic Forecasting of Eruptions at Dormant StratoVolcanoes

    NASA Astrophysics Data System (ADS)

    White, R. A.

    2015-12-01

    Seismic monitoring data provide important constraints on tracking magmatic ascent and eruption. Based on direct experience with over 25 and review of over 10 additional eruption sequences at 24 volcanoes, we have identified 4 phases of precursory seismicity. 1) Deep (>20 km) low frequency (DLF) earthquakes occur near the base of the crust as magma rises toward crustal reservoirs. This seismicity is the most difficult to observe, owing to generally small magnitudes (M<2.5) the significant depth. 2) Distal volcano-tectonic (DVT) earthquakes occur on tectonic faults from a 2 to 30+ km distance laterally from (not beneath) the eventual eruption site as magma intrudes into and rises out of upper crustal reservoirs to depths of 2-3 km. A survey of 111 eruptions of 83 previously dormant volcanoes, (including all eruptions of VEI >4 since 1955) shows they were all preceded by significant DVT seismicity, usually felt. This DVT seismicity is easily observed owing to magnitudes generally reaching M>3.5. The cumulative DVT energy correlates to the intruding magma volume. 3) Low frequency (LF) earthquakes, LF tremor and contained explosions occur as magma interacts with the shallow hydrothermal system (<2 km depth), while the distal seismicity dies off.4) Shortly after this, repetitive self-similar proximal seismicity may occur and may dominate the seismic records as magma rises to the surface. We present some examples of this seismic progression to demonstrate that data from a single short-period vertical station are often sufficient to forecast eruption onsets.

  16. Quantitative Estimation of Seismic Velocity Changes Using Time-Lapse Seismic Data and Elastic-Wave Sensitivity Approach

    NASA Astrophysics Data System (ADS)

    Denli, H.; Huang, L.

    2008-12-01

    Quantitative monitoring of reservoir property changes is essential for safe geologic carbon sequestration. Time-lapse seismic 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 seismic velocity changes using time-lapse seismic 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 seismic-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 boundary conditions to simultaneously solve the elastic-wave equations and the elastic sensitivity equations. By elastic-wave sensitivities, a linear relationship between relative seismic velocity changes in the reservoir and time-lapse seismic data at receiver locations can be derived, which leads to an over-determined system of equations. We solve this system 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 seismic 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 seismic velocities within a reservoir due to CO2 injection/migration.

  17. Seismic hazard and seismic risk assessment based on the unified scaling law for earthquakes: Himalayas and adjacent regions

    NASA Astrophysics Data System (ADS)

    Nekrasova, A. K.; Kossobokov, V. G.; Parvez, I. A.

    2015-03-01

    For the Himalayas and neighboring regions, the maps of seismic hazard and seismic risk are constructed with the use of the estimates for the parameters of the unified scaling law for earthquakes (USLE), in which the Gutenberg-Richter law for magnitude distribution of seismic events within a given area is applied in the modified version with allowance for linear dimensions of the area, namely, log N( M, L) = A + B (5 - M) + C log L, where N( M, L) is the expected annual number of the earthquakes with magnitude M in the area with linear dimension L. The spatial variations in the parameters A, B, and C for the Himalayas and adjacent regions are studied on two time intervals from 1965 to 2011 and from 1980 to 2011. The difference in A, B, and C between these two time intervals indicates that seismic activity experiences significant variations on a scale of a few decades. With a global consideration of the seismic belts of the Earth overall, the estimates of coefficient A, which determines the logarithm of the annual average frequency of the earthquakes with a magnitude of 5.0 and higher in the zone with a linear dimension of 1 degree of the Earth's meridian, differ by a factor of 30 and more and mainly fall in the interval from -1.1 to 0.5. The values of coefficient B, which describes the balance between the number of earthquakes with different magnitudes, gravitate to 0.9 and range from less than 0.6 to 1.1 and higher. The values of coefficient C, which estimates the fractal dimension of the local distribution of epicenters, vary from 0.5 to 1.4 and higher. In the Himalayas and neighboring regions, the USLE coefficients mainly fall in the intervals of -1.1 to 0.3 for A, 0.8 to 1.3 for B, and 1.0 to 1.4 for C. The calculations of the local value of the expected peak ground acceleration (PGA) from the maximal expected magnitude provided the necessary basis for mapping the seismic hazards in the studied region. When doing this, we used the local estimates of the

  18. Photocopy of drawing (this photograph is and 8' x10' copy ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is and 8' x10' copy of an 8' x 10' negative; 1940 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Central power plant building No. 47, electrical work, salt water pumps, auxiliary bus and fire pump, plan, details and changes, sheet 1 of 1. - U.S. Naval Air Station, Power Plant, 328 South Avenue, Pensacola, Escambia County, FL

  19. Seismic search for strange quark nuggets

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Herrin, Eugene T.; Rosenbaum, Doris C.; Teplitz, Vigdor L.

    2006-02-15

    Bounds on masses and abundances of Strange Quark Nuggets (SQNs) are inferred from a seismic search on Earth. Potential SQN bounds from a possible seismic search on the Moon are reviewed and compared with Earth capabilities. Bounds are derived from the data taken by seismometers implanted on the Moon by the Apollo astronauts. We show that the Apollo data implies that the abundance of SQNs in the region of 10 kg to 1 ton must be at least an order of magnitude less than would saturate the dark matter in the solar neighborhood.

  20. Seismic Wave Propagation on the Tablet Computer

    NASA Astrophysics Data System (ADS)

    Emoto, K.

    2015-12-01

    Tablet computers widely used in recent years. The performance of the tablet computer is improving year by year. Some of them have performance comparable to the personal computer of a few years ago with respect to the calculation speed and the memory size. The convenience and the intuitive operation are the advantage of the tablet computer compared to the desktop PC. I developed the iPad application of the numerical simulation of the seismic wave propagation. The numerical simulation is based on the 2D finite difference method with the staggered-grid scheme. The number of the grid points is 512 x 384 = 196,608. The grid space is 200m in both horizontal and vertical directions. That is the calculation area is 102km x 77km. The time step is 0.01s. In order to reduce the user waiting time, the image of the wave field is drawn simultaneously with the calculation rather than playing the movie after the whole calculation. P and S wave energies are plotted on the screen every 20 steps (0.2s). There is the trade-off between the smooth simulation and the resolution of the wave field image. In the current setting, it takes about 30s to calculate the 10s wave propagation (50 times image updates). The seismogram at the receiver is displayed below of the wave field updated in real time. The default medium structure consists of 3 layers. The layer boundary is defined by 10 movable points with linear interpolation. Users can intuitively change to the arbitrary boundary shape by moving the point. Also users can easily change the source and the receiver positions. The favorite structure can be saved and loaded. For the advance simulation, users can introduce the random velocity fluctuation whose spectrum can be changed to the arbitrary shape. By using this application, everyone can simulate the seismic wave propagation without the special knowledge of the elastic wave equation. So far, the Japanese version of the application is released on the App Store. Now I am preparing the

  1. Evaluation of induced seismicity forecast models in the Induced Seismicity Test Bench

    NASA Astrophysics Data System (ADS)

    Király, Eszter; Gischig, Valentin; Zechar, Jeremy; Doetsch, Joseph; Karvounis, Dimitrios; Wiemer, Stefan

    2016-04-01

    Induced earthquakes often accompany fluid injection, and the seismic hazard they pose threatens various underground engineering projects. Models to monitor and control induced seismic hazard with traffic light systems should be probabilistic, forward-looking, and updated as new data arrive. Here, we propose an Induced Seismicity Test Bench to test and rank such models. We apply the test bench to data from the Basel 2006 and Soultz-sous-Forêts 2004 geothermal stimulation projects, and we assess forecasts from two models that incorporate a different mix of physical understanding and stochastic representation of the induced sequences: Shapiro in Space (SiS) and Hydraulics and Seismics (HySei). SiS is based on three pillars: the seismicity rate is computed with help of the seismogenic index and a simple exponential decay of the seismicity; the magnitude distribution follows the Gutenberg-Richter relation; and seismicity is distributed in space based on smoothing seismicity during the learning period with 3D Gaussian kernels. The HySei model describes seismicity triggered by pressure diffusion with irreversible permeability enhancement. Our results show that neither model is fully superior to the other. HySei forecasts the seismicity rate well, but is only mediocre at forecasting the spatial distribution. On the other hand, SiS forecasts the spatial distribution well but not the seismicity rate. The shut-in phase is a difficult moment for both models in both reservoirs: the models tend to underpredict the seismicity rate around, and shortly after, shut-in. Ensemble models that combine HySei's rate forecast with SiS's spatial forecast outperform each individual model.

  2. Microzonation of Seismic Hazard Potential in Taipei, Taiwan

    NASA Astrophysics Data System (ADS)

    Liu, K. S.; Lin, Y. P.

    2017-12-01

    The island of Taiwan lies at the boundary between the Philippine Sea plate and the Eurasia plate. Accordingly, the majority of seismic energy release near Taiwan originates from the two subduction zones. It is therefore not surprising that Taiwan has repeatedly been struck by large earthquakes such as 1986 Hualien earthquake, 1999 Chi Chi and 2002 Hualien earthquake. Microzonation of seismic hazard potential becomes necessary in Taipei City for the Central Geological Survey announced the Sanchiao active fault as Category II. In this study, a catalog of more than 2000 shallow earthquakes occurred from 1900 to 2015 with Mw magnitudes ranging from 5.0 to 8.2, and 11 disastrous earthquakes occurred from 1683-1899, as well as Sanchiao active fault in the vicinity are used to estimate the seismic hazard potential in Taipei City for seismic microzonation. Furthermore, the probabilities of seismic intensity exceeding CWB intensity 5, 6, 7 and MMI VI, VII, VIII in 10, 30, and 50-year periods in the above areas are also analyzed for the seismic microzonation. Finally, by comparing with the seismic zoning map of Taiwan in current building code that was revised after 921 earthquakes, Results of this study will show which areas with higher earthquake hazard potential in Taipei City. They provide a valuable database for the seismic design of critical facilities. It will help mitigate Taipei City earthquake disaster loss in the future, as well as provide critical information for emergency response plans.

  3. Pore pressure evolution and induced seismicity within the Permian Basin, Southeast New Mexico USA

    NASA Astrophysics Data System (ADS)

    Person, M. A.; Zhang, Y.; Mozley, P.; Broadhead, R.; Bilek, S.; Edel, S.

    2015-12-01

    We used three-dimensional hydrologic modeling to assess the potential linkages between crystalline basement seismicity (up to M3.2) beneath the Dagger Draw oil field in response to saline water reinjection. Production began in 2004 and preceded an increase in seismicity by about 5 years. Reinjection of produced brines occurred within the basal Ellenberger Group carbonate reservoir (yellow square). Published core permeability measurements for the Ellenberger vary between about 10-15 to 10-12 m2. Evidence for seismicity being triggered by injection include observations that the largest injection rates (> 106 barrels/month) occurred within wells closest to the induced seismicity (red circle about 15 km to the west of the injection well in A-C). Arguing against triggered seismicity is the apparent lack of temporal correlation between peak injection and felt seismicity as well as the extreme depth of the earthquakes (about 10-12 km below land surface). We conducted a numerical sensitivity study in which we varied the permeability of the basal reservoir as well as the crystalline basement rocks over several orders of magnitude. Assuming a crystalline basement permeability of 10-16 m2 and a basal reservoir permeability of 10-13 m2 produced about 50 m of excess heads in the seismogenic crust about 1900 days (D) after injection started. Prior studies suggest that excess heads of only a few meters could induce failure along critically stressed faults. The lag between injection and seismicity can be explained by the time required for the pressure envelope to propagate laterally 15 km and downward into the crystalline basement 11 km. Peak injection occurred 1900 days before recent increases in seismicity were observed. Future work will include assessing the potential role of relatively permeable Proterozoic faults in transmitting high fluid pressures into the crystalline basement.

  4. Gas and seismicity within the Istanbul seismic gap.

    PubMed

    Géli, L; Henry, P; Grall, C; Tary, J-B; Lomax, A; Batsi, E; Riboulot, V; Cros, E; Gürbüz, C; Işık, S E; Sengör, A M C; Le Pichon, X; Ruffine, L; Dupré, S; Thomas, Y; Kalafat, D; Bayrakci, G; Coutellier, Q; Regnier, T; Westbrook, G; Saritas, H; Çifçi, G; Çağatay, M N; Özeren, M S; Görür, N; Tryon, M; Bohnhoff, M; Gasperini, L; Klingelhoefer, F; Scalabrin, C; Augustin, J-M; Embriaco, D; Marinaro, G; Frugoni, F; Monna, S; Etiope, G; Favali, P; Bécel, A

    2018-05-01

    Understanding micro-seismicity is a critical question for earthquake hazard assessment. Since the devastating earthquakes of Izmit and Duzce in 1999, the seismicity along the submerged section of North Anatolian Fault within the Sea of Marmara (comprising the "Istanbul seismic gap") has been extensively studied in order to infer its mechanical behaviour (creeping vs locked). So far, the seismicity has been interpreted only in terms of being tectonic-driven, although the Main Marmara Fault (MMF) is known to strike across multiple hydrocarbon gas sources. Here, we show that a large number of the aftershocks that followed the M 5.1 earthquake of July, 25 th 2011 in the western Sea of Marmara, occurred within a zone of gas overpressuring in the 1.5-5 km depth range, from where pressurized gas is expected to migrate along the MMF, up to the surface sediment layers. Hence, gas-related processes should also be considered for a complete interpretation of the micro-seismicity (~M < 3) within the Istanbul offshore domain.

  5. Field-induced antiferroelectric to ferroelectric transitions in (Pb 1–xLa x)(Zr 0.90Ti 0.10) 1–x/ 4O 3 investigated by in situ X-ray diffraction

    DOE PAGES

    Ciuchi, Ioana V.; Chung, Ching -Chang; Fancher, Christopher M.; ...

    2017-06-17

    Phase transitions and field-induced preferred orientation in (Pb 1-xLa x)(Zr 0.90Ti 0.10) 1–x/ 4O 3 (PLZT x/90/10) ceramics upon electric field cycling using in situ X-ray diffraction were studied. The evolution of the {200} pc and {111} pc diffraction line profiles indicate that PLZT 4/90/10 and PLZT 3/90/10 compositions undergo an antiferroelectric (AFE)–ferroelectric (FE) phase switching. Both PLZT 4/90/10 and PLZT 3/90/10 exhibit irreversible preferred orientation after experiencing the field-induced AFE-to-FE phase switching. An electric field-induced structure develops in both compositions which has a reversible character during the field decreasing in PLZT 4/90/10 and an irreversible character in PLZT 3/90/10.more » In addition, structural analysis of pre-poled PLZT 3/90/10 ceramics show that it is possible to induce consecutive FE-to-AFE and AFE-to-FE transitions when fields of reversed polarity are applied in sequence. The field range required to induce the AFE phase is broad, and the phase transition is kinetically slow. In conclusion, this kind of transition has rarely been reported before.« less

  6. Field-induced antiferroelectric to ferroelectric transitions in (Pb 1–xLa x)(Zr 0.90Ti 0.10) 1–x/ 4O 3 investigated by in situ X-ray diffraction

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ciuchi, Ioana V.; Chung, Ching -Chang; Fancher, Christopher M.

    Phase transitions and field-induced preferred orientation in (Pb 1-xLa x)(Zr 0.90Ti 0.10) 1–x/ 4O 3 (PLZT x/90/10) ceramics upon electric field cycling using in situ X-ray diffraction were studied. The evolution of the {200} pc and {111} pc diffraction line profiles indicate that PLZT 4/90/10 and PLZT 3/90/10 compositions undergo an antiferroelectric (AFE)–ferroelectric (FE) phase switching. Both PLZT 4/90/10 and PLZT 3/90/10 exhibit irreversible preferred orientation after experiencing the field-induced AFE-to-FE phase switching. An electric field-induced structure develops in both compositions which has a reversible character during the field decreasing in PLZT 4/90/10 and an irreversible character in PLZT 3/90/10.more » In addition, structural analysis of pre-poled PLZT 3/90/10 ceramics show that it is possible to induce consecutive FE-to-AFE and AFE-to-FE transitions when fields of reversed polarity are applied in sequence. The field range required to induce the AFE phase is broad, and the phase transition is kinetically slow. In conclusion, this kind of transition has rarely been reported before.« less

  7. Seismic hazard map of the western hemisphere

    USGS Publications Warehouse

    Shedlock, K.M.; Tanner, J.G.

    1999-01-01

    Vulnerability to natural disasters increases with urbanization and development of associated support systems (reservoirs, power plants, etc.). Catastrophic earthquakes account for 60% of worldwide casualties associated with natural disasters. Economic damage from earthquakes is increasing, even in technologically advanced countries with some level of seismic 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 seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures, due to an insufficient knowledge of existing seismic hazard. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. National, state, and local governments, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require seismic 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 seismic 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 seismic hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This seismic 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 seismic provisions specify the

  8. Seismicity and strain transients in the Gulf of Corinth (Greece)

    NASA Astrophysics Data System (ADS)

    Canitano, A.; Bernard, P.; Linde, A. T.; Sacks, S. I.; Boudin, F.

    2009-12-01

    The Gulf of Corinth (Greece) is one of the most seismic regions in Europe, producing some earthquakes of magnitude greater than 5.8 in the last 35 years, 1 to 1.5 cm/yr of north-south extension, and frequent seismic swarms. This structure is a 110 km long, N110°E oriented graben bounded by systems of very recent normal faults. This zone thus provides an ideal site for investigating in situ the physics of earthquake sources and for developing efficient seismic hazard reduction procedures. The Corinth Rift Laboratory (CRL) project is concentrated in the western part of the rift, around the city of Aigion, where instrumental seismicity and strain rate is highest. The CRL Network is made up about fifteen seismic stations as well as tiltmeters, strainmeters or GPS in order to study the local seismicity, and to observe and model the short and long term mechanics of the normal fault system. The instrumental seismicity in the Aigion zone clearly shows a strong concentration of small earthquakes between 5 and 10 km. In order to study slow transient deformation, two borehole strainmeters have been installed in the Gulf (Trizonia, Monasteraki). The strainmeter installed in the Trizonia island is continuously recording the horizontal strain at 150m depth with a resolution better than 10-9. The dominant signal is the earth and sea tidal effects (few 10-7 strain), this one is modulated by the mechanical effects of the free oscillations of the Gulf with periods between 8 and 40 min. The barometric pressure fluctuations acts in combination with the mean sea level variation at longer periods and both effects are not independant. The comparison between the strain data and the two forcing signals (sea-level, barometric pressure) shows clearly a non zero phase delay of the sea-level. The analysis of time correlations between the signals in differents frequency range exhibits that the sea level delay and the strainmeter/sea-level coupling coefficient are increasing with period (about

  9. Combined GPS and seismic monitoring of a 12-story structure in a region of induced seismicity in Oklahoma

    NASA Astrophysics Data System (ADS)

    Haase, J. S.; Soliman, M.; Kim, H.; Jaiswal, P.; Saunders, J. K.; Vernon, F.; Zhang, W.

    2017-12-01

    This work focuses on quantifying ground motions and their effects in Oklahoma near the location of the 2016 Mw 5.8 Pawnee earthquake, where seismicity has been increasing due to wastewater injection related to oil and natural gas production. Much of the building inventory in Oklahoma was constructed before the increase in seismicity and before the implementation of earthquake design and detailing provisions for reinforced concrete (RC) structures. We will use combined GPS/seismic monitoring techniques to measure ground motion in the field and the response of structures to this ground motion. Several Oklahoma State University buildings experienced damage due to the Pawnee earthquake. The USGS Shake Map product estimated peak ground acceleration (PGA) ranging from 0.12g to 0.15g at campus locations. We are deploying a high-rate GPS sensor and accelerometer on the roof and another accelerometer at ground level of a 12-story RC structure and at selected field sites in order to collect ambient noise data and nearby seismicity. The longer period recording characteristics of the GPS/seismic system are particularly well adapted to monitoring these large structures in the event of a significant earthquake. Gross characteristics of the structural system are described, which consists of RC columns and RC slabs in all stories. We conducted a preliminary structural analysis including modal analysis and response spectrum analysis based on a finite element (FE) simulation, which indicated that the period associated with the first X-axis bending, first torsional, and first Y-axis bending modes are 2.2 s, 2.1 s, and 1.8 s, respectively. Next, a preliminary analysis was conducted to estimate the range of expected deformation at the roof level for various earthquake excitations. The earthquake analysis shows a maximum roof displacement of 5 and 7 cm in the horizontal directions resulting from earthquake loads with PGA of 0.2g, well above the noise level of the combined GPS/seismic

  10. Structural and magnetic aspects of La4(Co1-xNix)3O10+δ (0 ≤ x ≤ 1)

    NASA Astrophysics Data System (ADS)

    Nagell, Marius Uv; Kumar, Susmit; Sørby, Magnus H.; Fjellvåg, Helmer; Olafsen Sjåstad, Anja

    2015-10-01

    The Ruddlesden-Popper (RP3) type oxides, La4Co3O10+δ and La4Ni3O10+δ, form a complete solid solution. Powder X-ray and neutron diffraction data show that La4(Co1-xNix)3O10+δ is isostructural to the monoclinic La4Co3O10+δ structure (P21/a) described for all compositions without any further structural distortions as suggested in the literature. A slight elongation of the Co/Ni-O bonds facing the rock salt interlayer occurs for Ni-rich compositions. The magnetic properties of the solid solution series are mapped in the temperature range from 4 to 300 K, and the results are presented in a magnetic phase diagram. Three regimes with antiferromagnetic order (AF) exist at low temperatures, TN < 10 - 30 K. For x = 0.00, the AF is ascribed to Co(II), whereas a broader AF regime around x = 0.50 is ascribed mainly to Ni(II). Pauli paramagnetism is observed close to metallic La4Ni3O10+δ, x > 0.80. The possibility to tune the oxidation state of the transition metal atoms is demonstrated for La4Co3O10+δ, and exemplified by weakening of a temperature-induced spin transition at around 480 K.

  11. Seismicity of Cascade Volcanoes: Characterization and Comparison

    NASA Astrophysics Data System (ADS)

    Thelen, W. A.

    2016-12-01

    Here we summarize and compare the seismicity around each of the Very High Threat Volcanoes of the Cascade Range of Washington, Oregon and California as defined by the National Volcanic Early Warning System (NVEWS) threat assessment (Ewert et al., 2005). Understanding the background seismic activity and processes controlling it is critical for assessing changes in seismicity and their implications for volcanic hazards. Comparing seismicity at different volcanic centers can help determine what critical factors or processes affect the observed seismic behavior. Of the ten Very High Threat Volcanoes in the Cascade Range, five volcanoes are consistently seismogenic when considering earthquakes within 10 km of the volcanic center or caldera edge (Mount Rainier, Mount St. Helens, Mount Hood, Newberry Caldera, Lassen Volcanic Center). Other Very High Threat volcanoes (South Sister, Mount Baker, Glacier Peak, Crater Lake and Mount Shasta) have comparatively low rates of seismicity and not enough recorded earthquakes to calculate catalog statistics. Using a swarm definition of 3 or more earthquakes occurring in a day with magnitudes above the largest of the network's magnitude of completenesses (M 0.9), we find that Lassen Volcanic Center is the "swarmiest" in terms of percent of seismicity occurring in swarms, followed by Mount Hood, Mount St. Helens and Rainier. The predominance of swarms at Mount Hood may be overstated, as much of the seismicity is occurring on surrounding crustal faults (Jones and Malone, 2005). Newberry Caldera has a relatively short record of seismicity since the permanent network was installed in 2011, however there have been no swarms detected as defined here. Future work will include developing discriminates for volcanic versus tectonic seismicity to better filter the seismic catalog and more precise binning of depths at some volcanoes so that we may better consider different processes. Ewert J. W., Guffanti, M. and Murray, T. L. (2005). An

  12. Seismic hazard assessment for Guam and the Northern Mariana Islands

    USGS Publications Warehouse

    Mueller, Charles S.; Haller, Kathleen M.; Luco, Nicholas; Petersen, Mark D.; Frankel, Arthur D.

    2012-01-01

    We present the results of a new probabilistic seismic hazard assessment for Guam and the Northern Mariana Islands. The Mariana island arc has formed in response to northwestward subduction of the Pacific plate beneath the Philippine Sea plate, and this process controls seismic activity in the region. Historical seismicity, the Mariana megathrust, and two crustal faults on Guam were modeled as seismic sources, and ground motions were estimated by using published relations for a firm-rock site condition. Maps of peak ground acceleration, 0.2-second spectral acceleration for 5 percent critical damping, and 1.0-second spectral acceleration for 5 percent critical damping were computed for exceedance probabilities of 2 percent and 10 percent in 50 years. For 2 percent probability of exceedance in 50 years, probabilistic peak ground acceleration is 0.94 gravitational acceleration at Guam and 0.57 gravitational acceleration at Saipan, 0.2-second spectral acceleration is 2.86 gravitational acceleration at Guam and 1.75 gravitational acceleration at Saipan, and 1.0-second spectral acceleration is 0.61 gravitational acceleration at Guam and 0.37 gravitational acceleration at Saipan. For 10 percent probability of exceedance in 50 years, probabilistic peak ground acceleration is 0.49 gravitational acceleration at Guam and 0.29 gravitational acceleration at Saipan, 0.2-second spectral acceleration is 1.43 gravitational acceleration at Guam and 0.83 gravitational acceleration at Saipan, and 1.0-second spectral acceleration is 0.30 gravitational acceleration at Guam and 0.18 gravitational acceleration at Saipan. The dominant hazard source at the islands is upper Benioff-zone seismicity (depth 40–160 kilometers). The large probabilistic ground motions reflect the strong concentrations of this activity below the arc, especially near Guam.

  13. Spatial extent of a hydrothermal system at Kilauea Volcano, Hawaii, determined from array analyses of shallow long-period seismicity 2. Results

    USGS Publications Warehouse

    Almendros, J.; Chouet, B.; Dawson, P.

    2001-01-01

    Array data from a seismic experiment carried out at Kilauea Volcano, Hawaii, in February 1997, are analyzed by the frequency-slowness method. The slowness vectors are determined at each of three small-aperture seismic antennas for the first arrivals of 1129 long-period (LP) events and 147 samples of volcanic tremor. The source locations are determined by using a probabilistic method which compares the event azimuths and slownesses with a slowness vector model. The results show that all the LP seismicity, including both discrete LP events and tremor, was generated in the same source region along the east flank of the Halemaumau pit crater, demonstrating the strong relation that exists between the two types of activities. The dimensions of the source region are approximately 0.6 X 1.0 X 0.5 km. For LP events we are able to resolve at least three different clusters of events. The most active cluster is centered ???200 m northeast of Halemaumau at depths shallower than 200 m beneath the caldera floor. A second cluster is located beneath the northeast quadrant of Halemaumau at a depth of ???400 m. The third cluster is <200 m deep and extends southeastward from the northeast quadrant of Halemaumau. Only one source zone is resolved for tremor. This zone is coincident with the most active source zone of LP events, northeast of Halemaumau. The location, depth, and size of the source region suggest a hydrothermal origin for all the analyzed LP seismicity. Copyright 2001 by the American Geophysical Union.

  14. X-15A-2 and HL-10 parked on NASA ramp

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Both the HL-10 and X-15A2, shown here parked beside one another on the NASA ramp in 1966, underwent modifications. The X-15 No. 2 had been damaged in a crash landing in November 1962. Subsequently, the fuselage was lengthened, and it was outfitted with two large drop tanks. These modifications allowed the X-15A-2 to reach the speed of Mach 6.7. On the HL-10, the stability problems that appeared on the first flight at the end of 1966 required a reshaping of the fins' leading edges to eliminate the separated airflow that was causing the unstable flight. By cambering the leading edges of the fins, the HL-10 team achieved attached flow and stable flight. The HL-10 was one of five heavyweight lifting-body designs flown at NASA's Flight Research Center (FRC--later Dryden Flight Research Center), Edwards, California, from July 1966 to November 1975 to study and validate the concept of safely maneuvering and landing a low lift-over-drag vehicle designed for reentry from space. Northrop Corporation built the HL-10 and M2-F2, the first two of the fleet of 'heavy' lifting bodies flown by the NASA Flight Research Center. The contract for construction of the HL-10 and the M2-F2 was $1.8 million. 'HL' stands for horizontal landing, and '10' refers to the tenth design studied by engineers at NASA's Langley Research Center, Hampton, Va. After delivery to NASA in January 1966, the HL-10 made its first flight on Dec. 22, 1966, with research pilot Bruce Peterson in the cockpit. Although an XLR-11 rocket engine was installed in the vehicle, the first 11 drop flights from the B-52 launch aircraft were powerless glide flights to assess handling qualities, stability, and control. In the end, the HL-10 was judged to be the best handling of the three original heavy-weight lifting bodies (M2-F2/F3, HL-10, X-24A). The HL-10 was flown 37 times during the lifting body research program and logged the highest altitude and fastest speed in the Lifting Body program. On Feb. 18, 1970, Air Force

  15. Seismic gradiometry using ambient seismic noise in an anisotropic Earth

    NASA Astrophysics Data System (ADS)

    de Ridder, S. A. L.; Curtis, A.

    2017-05-01

    We introduce a wavefield gradiometry technique to estimate both isotropic and anisotropic local medium characteristics from short recordings of seismic signals by inverting a wave equation. The method exploits the information in the spatial gradients of a seismic wavefield that are calculated using dense deployments of seismic arrays. The application of the method uses the surface wave energy in the ambient seismic field. To estimate isotropic and anisotropic medium properties we invert an elliptically anisotropic wave equation. The spatial derivatives of the recorded wavefield are evaluated by calculating finite differences over nearby recordings, which introduces a systematic anisotropic error. A two-step approach corrects this error: finite difference stencils are first calibrated, then the output of the wave-equation inversion is corrected using the linearized impulse response to the inverted velocity anomaly. We test the procedure on ambient seismic noise recorded in a large and dense ocean bottom cable array installed over Ekofisk field. The estimated azimuthal anisotropy forms a circular geometry around the production-induced subsidence bowl. This conforms with results from studies employing controlled sources, and with interferometry correlating long records of seismic noise. Yet in this example, the results were obtained using only a few minutes of ambient seismic noise.

  16. Search for gluon saturation at Bjorken-x of 10-6-10-5 with the LHCb detector

    NASA Astrophysics Data System (ADS)

    da Silva, Cesar; LHCb Collaboration

    2017-09-01

    Gluon saturation at small Byorken- x has been in the minds of particle and nuclear physicists for decades. This state can explain several recent observations such as 1) particle collectivity observed in p+p, p+A and A+A collisions at RHIC and LHC; and 2) depleted yield of particles coming from soft gluons. Previous results from DIS experiments at HERA show a fast increase of gluons as their fractional momentum x decreases. The LHCb experiment is a forward spectrometer with vertexing, tracking, p, K, pi , e, μ identification and calorimetry in the rapidity region 1.6 < η < 4.9. LHCb is the only experiment in the world which can probe x 10-6 -10-5 , up to two orders of magnitude smaller than HERA. A direct probe of gluons at small-x and small Q2 can be performed with γ+jet correlation measurements. The current detector acceptance is not optimized for soft particles coming from Q2 < 10 [GeV/c]2 processes, where gluon saturation is expected. R&D is underway for a new tracking detector to be placed inside the LHCb magnet, the Magnet Station (MS), which will enable measurements of these soft particles. This talk is going to report the status of the analysis efforts aimed at finding the gluon saturation scale at LHCb, and details of the MS. Los Alamos National Lab LDRD program.

  17. Adding seismic broadband analysis to characterize Andean backarc seismicity in Argentina

    NASA Astrophysics Data System (ADS)

    Alvarado, P.; Giuliano, A.; Beck, S.; Zandt, G.

    2007-05-01

    Characterization of the highly seismically active Andean backarc is crucial for assessment of earthquake hazards in western Argentina. Moderate-to-large crustal earthquakes have caused several deaths, damage and drastic economic consequences in Argentinean history. We have studied the Andean backarc crust between 30°S and 36°S using seismic broadband data available from a previous ("the CHARGE") IRIS-PASSCAL experiment. We collected more than 12 terabytes of continuous seismic data from 22 broadband instruments deployed across Chile and Argentina during 1.5 years. Using free software we modeled full regional broadband waveforms and obtained seismic moment tensor inversions of crustal earthquakes testing for the best focal depth for each event. We also mapped differences in the Andean backarc crustal structure and found a clear correlation with different types of crustal seismicity (i.e. focal depths, focal mechanisms, magnitudes and frequencies of occurrence) and previously mapped terrane boundaries. We now plan to use the same methodology to study other regions in Argentina using near-real time broadband data available from the national seismic (INPRES) network and global seismic networks operating in the region. We will re-design the national seismic network to optimize short-period and broadband seismic station coverage for different network purposes. This work is an international effort that involves researchers and students from universities and national government agencies with the goal of providing more information about earthquake hazards in western Argentina.

  18. Analyzing crack development pattern of masonry structure in seismic oscillation by digital photography

    NASA Astrophysics Data System (ADS)

    Zhang, Guojian; Yu, Chengxin; Ding, Xinhua

    2018-01-01

    In this study, digital photography is used to monitor the instantaneous deformation of a masonry wall in seismic oscillation. In order to obtain higher measurement accuracy, the image matching-time baseline parallax method (IM-TBPM) is used to correct errors caused by the change of intrinsic and extrinsic parameters of digital cameras. Results show that the average errors of control point C5 are 0.79mm, 0.44mm and 0.96mm in X, Z and comprehensive direction, respectively. The average errors of control point C6 are 0.49mm, 0.44mm and 0.71mm in X, Z and comprehensive direction, respectively. These suggest that IM-TBPM can meet the accuracy requirements of instantaneous deformation monitoring. In seismic oscillation the middle to lower of the masonry wall develops cracks firstly. Then the shear failure occurs on the middle of masonry wall. This study provides technical basis for analyzing the crack development pattern of masonry structure in seismic oscillation and have significant implications for improved construction of masonry structures in earthquake prone areas.

  19. Effects on Chilean Vertical Reference Frame due to the Maule Earthquake co-seismic and post-seismic effects

    NASA Astrophysics Data System (ADS)

    Montecino, Henry D.; de Freitas, Silvio R. C.; Báez, Juan C.; Ferreira, Vagner G.

    2017-12-01

    The Maule Earthquake (Mw = 8.8) of February 27, 2010 is among the strongest earthquakes that occurred in recent years throughout the world. The crustal deformation caused by this earthquake has been widely studied using GNSS, InSAR and gravity observations. However, there is currently no estimation of the possible vertical deformations produced by co-seismic and post-seismic effects in segments of the Chilean Vertical Reference Frame (CHVRF). In this paper, we present an estimation of co-seismic and post-seismic deformations on the CHVRF using an indirect approach based on GNSS and Gravity Recovery and Climate Experiment (GRACE) data as well as by applying a trajectory model. GNSS time series were used from 10 continuous GNSS stations in the period from 2007 to 2015, as well as 28 GNSS temporary stations realized before and after the earthquake, and 34 vertical deformation vectors in the region most affected by the earthquake. We considered a set of 147 monthly solutions of spherical harmonic gravity field that were expanded up to degree, as well as order 96 of the GRACE mission provided by Center for Space Research, University of Texas at Austin (UT-CSR) process center. The magnitude of vertical deformation was estimated in part of the Chilean vertical network due to the co-seismic and post-seismic effects. Once we evaluated the hydrological effect, natural and artificial jumps, and the effect of glacial isostatic adjustment in GNSS and GRACE time series, the maximum values associated to co- and post-seismic deformations on orthometric height were found to be ∼-34 cm and 5 cm, respectively. Overall, the deformation caused by the Maule earthquake in orthometric heights is almost entirely explained by the variation in the ellipsoidal heights (over 85% in co-seismic jump); however, coseismic jump in the geoid reached -3.3 mm, and could influence the maintenance of a modern vertical reference network in a medium to long term. We evaluated the consistency for a

  20. Europa's small impactor flux and seismic detection predictions

    NASA Astrophysics Data System (ADS)

    Tsuji, Daisuke; Teanby, Nicholas A.

    2016-10-01

    Europa is an attractive target for future lander missions due to its dynamic surface and potentially habitable sub-surface environment. Seismology has the potential to provide powerful new constraints on the internal structure using natural sources such as faults or meteorite impacts. Here we predict how many meteorite impacts are likely to be detected using a single seismic station on Europa to inform future mission planning efforts. To this end, we derive: (1) the current small impactor flux on Europa from Jupiter impact rate observations and models; (2) a crater diameter versus impactor energy scaling relation for icy moons by merging previous experiments and simulations; and (3) scaling relations for seismic signal amplitudes as a function of distance from the impact site for a given crater size, based on analogue explosive data obtained on Earth's ice sheets. Finally, seismic amplitudes are compared to predicted noise levels and seismometer performance to determine detection rates. We predict detection of 0.002-20 small local impacts per year based on P-waves travelling directly through the ice crust. Larger regional and global-scale impact events, detected through mantle-refracted waves, are predicted to be extremely rare (10-8-1 detections per year), so are unlikely to be detected by a short duration mission. Estimated ranges include uncertainties from internal seismic attenuation, impactor flux, and seismic amplitude scaling. Internal attenuation is the most significant unknown and produces extreme uncertainties in the mantle-refracted P-wave amplitudes. Our nominal best-guess attenuation model predicts 0.002-5 local direct P detections and 6 × 10-6-0.2 mantle-refracted detections per year. Given that a plausible Europa landed mission will only last around 30 days, we conclude that impacts should not be relied upon for a seismic exploration of Europa. For future seismic exploration, faulting due to stresses in the rigid outer ice shell is likely to be a

  1. New seismic hazard maps for Puerto Rico and the U.S. Virgin Islands

    USGS Publications Warehouse

    Mueller, C.; Frankel, A.; Petersen, M.; Leyendecker, E.

    2010-01-01

    The probabilistic methodology developed by the U.S. Geological Survey is applied to a new seismic hazard assessment for Puerto Rico and the U.S. Virgin Islands. Modeled seismic sources include gridded historical seismicity, subduction-interface and strike-slip faults with known slip rates, and two broad zones of crustal extension with seismicity rates constrained by GPS geodesy. We use attenuation relations from western North American and worldwide data, as well as a Caribbean-specific relation. Results are presented as maps of peak ground acceleration and 0.2- and 1.0-second spectral response acceleration for 2% and 10% probabilities of exceedance in 50 years (return periods of about 2,500 and 500 years, respectively). This paper describes the hazard model and maps that were balloted by the Building Seismic Safety Council and recommended for the 2003 NEHRP Provisions and the 2006 International Building Code. ?? 2010, Earthquake Engineering Research Institute.

  2. Mapping seismic azimuthal anisotropy of the Japan subduction zone

    NASA Astrophysics Data System (ADS)

    Zhao, D.; Liu, X.

    2016-12-01

    :10.1002/2016JB013116. Zhao, D., S. Yu, X. Liu (2016) Seismic anisotropy tomography: New insight into subduction dynamics. Gondwana Res. 33, 24-43.

  3. Missile impacts as sources of seismic energy on the moon

    USGS Publications Warehouse

    Latham, G.V.; McDonald, W.G.; Moore, H.J.

    1970-01-01

    Seismic signals recorded from impacts of missiles at the White Sands Missile Range are radically different from the signal recorded from the Apollo 12 lunar module impact. This implies that lunar structure to depths of at least 10 to 20 kilometers is quite different from the typical structure of the earth's crust. Results obtained from this study can be used to predict seismic wave amplitudes from future man-made lunar impacts. Seismic energy and crater dimensions from impacts are compared with measurements from chemical explosions.

  4. Seismic hazard in the Nation's breadbasket

    USGS Publications Warehouse

    Boyd, Oliver; Haller, Kathleen; Luco, Nicolas; Moschetti, Morgan P.; Mueller, Charles; Petersen, Mark D.; Rezaeian, Sanaz; Rubinstein, Justin L.

    2015-01-01

    The USGS National Seismic Hazard Maps were updated in 2014 and included several important changes for the central United States (CUS). Background seismicity sources were improved using a new moment-magnitude-based catalog; a new adaptive, nearest-neighbor smoothing kernel was implemented; and maximum magnitudes for background sources were updated. Areal source zones developed by the Central and Eastern United States Seismic Source Characterization for Nuclear Facilities project were simplified and adopted. The weighting scheme for ground motion models was updated, giving more weight to models with a faster attenuation with distance compared to the previous maps. Overall, hazard changes (2% probability of exceedance in 50 years, across a range of ground-motion frequencies) were smaller than 10% in most of the CUS relative to the 2008 USGS maps despite new ground motion models and their assigned logic tree weights that reduced the probabilistic ground motions by 5–20%.

  5. Seismic Methods

    EPA Pesticide Factsheets

    Seismic methods are the most commonly conducted geophysical surveys for engineering investigations. Seismic refraction provides engineers and geologists with the most basic of geologic data via simple procedures with common equipment.

  6. Using micro-seismicity and seismic velocities to map subsurface geologic and hydrologic structure within the Coso geothermal field, California

    USGS Publications Warehouse

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

    2012-01-01

    Geothermal reservoirs derive their capacity for fluid and heat transport in large part from faults and fractures. Micro-seismicity generated on such faults and fractures can be used to map larger fault structures as well as secondary fractures that add access to hot rock, fluid storage and recharge capacity necessary to have a sustainable geothermal resource. Additionally, inversion of seismic velocities from micro-seismicity permits imaging of regions subject to the combined effects of fracture density, fluid pressure and steam content, among other factors. We relocate 14 years of seismicity (1996-2009) in the Coso geothermal field using differential travel times and simultaneously invert for seismic velocities to improve our knowledge of the subsurface geologic and hydrologic structure. We utilize over 60,000 micro-seismic events using waveform cross-correlation to augment to expansive catalog of P- and S-wave differential travel times recorded at Coso. We further carry out rigorous uncertainty estimation and find that our results are precise to within 10s of meters of relative location error. We find that relocated micro-seismicity outlines prominent, through-going faults in the reservoir in some cases. We also find that a significant portion of seismicity remains diffuse and does not cluster into more sharply defined major structures. The seismic velocity structure reveals heterogeneous distributions of compressional (Vp) and shear (Vs) wave speed, with Vp generally lower in the main field when compared to the east flank and Vs varying more significantly in the shallow portions of the reservoir. The Vp/Vs ratio appears to outline the two main compartments of the reservoir at depths of -0.5 to 1.5 km (relative to sea-level), with a ridge of relatively high Vp/Vs separating the main field from the east flank. In the deeper portion of the reservoir this ridge is less prominent. Our results indicate that high-precision relocations of micro-seismicity can provide

  7. SpaceX CRS-10 "What's On Board" Science Briefing

    NASA Image and Video Library

    2017-02-17

    Speaking to members of the media in the Kennedy Space Center’s Press Site auditorium, Dr. Michael Freilich of the Earth Science Division at NASA Headquarters in Washington, D.C., left, and Dr. Richard Blakeslee of NASA’s Marshall Space Flight Center in Huntsville, Alabama, discussed instruments to be delivered to the International Space Station on the SpaceX CRS-10 mission. The Lightning Imaging Sensor (LIS) is to measure the amount, rate and energy of lightning around the world. The SAGE III instrument is designed to study ozone in the atmosphere. A Dragon spacecraft is scheduled to be launched from Kennedy’s Launch Complex 39A on Feb. 18 atop a SpaceX Falcon 9 rocket on the company's 10th Commercial Resupply Services mission to the space station.

  8. The Great Maule earthquake: seismicity prior to and after the main shock from amphibious seismic networks

    NASA Astrophysics Data System (ADS)

    Lieser, K.; Arroyo, I. G.; Grevemeyer, I.; Flueh, E. R.; Lange, D.; Tilmann, F. J.

    2013-12-01

    The Chilean subduction zone is among the seismically most active plate boundaries in the world and its coastal ranges suffer from a magnitude 8 or larger megathrust earthquake every 10-20 years. The Constitución-Concepción or Maule segment in central Chile between ~35.5°S and 37°S was considered to be a mature seismic gap, rupturing last in 1835 and being seismically quiet without any magnitude 4.5 or larger earthquakes reported in global catalogues. It is located to the north of the nucleation area of the 1960 magnitude 9.5 Valdivia earthquake and to the south of the 1928 magnitude 8 Talca earthquake. On 27 February 2010 this segment ruptured in a Mw=8.8 earthquake, nucleating near 36°S and affecting a 500-600 km long segment of the margin between 34°S and 38.5°S. Aftershocks occurred along a roughly 600 km long portion of the central Chilean margin, most of them offshore. Therefore, a network of 30 ocean-bottom-seismometers was deployed in the northern portion of the rupture area for a three month period, recording local offshore aftershocks between 20 September 2010 and 25 December 2010. In addition, data of a network consisting of 33 landstations of the GeoForschungsZentrum Potsdam were included into the network, providing an ideal coverage of both the rupture plane and areas affected by post-seismic slip as deduced from geodetic data. Aftershock locations are based on automatically detected P wave onsets and a 2.5D velocity model of the combined on- and offshore network. Aftershock seismicity analysis in the northern part of the survey area reveals a well resolved seismically active splay fault in the accretionary prism of the Chilean forearc. Our findings imply that in the northernmost part of the rupture zone, co-seismic slip most likely propagated along the splay fault and not the subduction thrust fault. In addition, the updip limit of aftershocks along the plate interface can be verified to about 40 km landwards from the deformation front. Prior to

  9. Causality between expansion of seismic cloud and maximum magnitude of induced seismicity in geothermal field

    NASA Astrophysics Data System (ADS)

    Mukuhira, Yusuke; Asanuma, Hiroshi; Ito, Takatoshi; Häring, Markus

    2016-04-01

    Occurrence of induced seismicity with large magnitude is critical environmental issues associated with fluid injection for shale gas/oil extraction, waste water disposal, carbon capture and storage, and engineered geothermal systems (EGS). Studies for prediction of the hazardous seismicity and risk assessment of induced seismicity has been activated recently. Many of these studies are based on the seismological statistics and these models use the information of the occurrence time and event magnitude. We have originally developed physics based model named "possible seismic moment model" to evaluate seismic activity and assess seismic moment which can be ready to release. This model is totally based on microseismic information of occurrence time, hypocenter location and magnitude (seismic moment). This model assumes existence of representative parameter having physical meaning that release-able seismic moment per rock volume (seismic moment density) at given field. Seismic moment density is to be estimated from microseismic distribution and their seismic moment. In addition to this, stimulated rock volume is also inferred by progress of microseismic cloud at given time and this quantity can be interpreted as the rock volume which can release seismic energy due to weakening effect of normal stress by injected fluid. Product of these two parameters (equation (1)) provide possible seismic moment which can be released from current stimulated zone as a model output. Difference between output of this model and observed cumulative seismic moment corresponds the seismic moment which will be released in future, based on current stimulation conditions. This value can be translated into possible maximum magnitude of induced seismicity in future. As this way, possible seismic moment can be used to have feedback to hydraulic stimulation operation in real time as an index which can be interpreted easily and intuitively. Possible seismic moment is defined as equation (1), where D

  10. 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.

  11. Photocopy of drawing (this photograph is an 8” x 10” ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing (this photograph is an 8” x 10” copy of an 8” x 10” negative; 1962 original architectural drawing located at Building No. 458, NAS Pensacola, Florida) Air conditioning in building No. 27, plan, elevations and vicinity map, Sheet 1 of 4 - U.S. Naval Air Station, Coal Shed, 499 South Avenue, Pensacola, Escambia County, FL

  12. Using Seismic Interferometry to Investigate Seismic Swarms

    NASA Astrophysics Data System (ADS)

    Matzel, E.; Morency, C.; Templeton, D. C.

    2017-12-01

    Seismicity provides a direct means of measuring the physical characteristics of active tectonic features such as fault zones. Hundreds of small earthquakes often occur along a fault during a seismic swarm. This seismicity helps define the tectonically active region. When processed using novel geophysical techniques, we can isolate the energy sensitive to the fault, itself. Here we focus on two methods of seismic interferometry, ambient noise correlation (ANC) and the virtual seismometer method (VSM). ANC is based on the observation that the Earth's background noise includes coherent energy, which can be recovered by observing over long time periods and allowing the incoherent energy to cancel out. The cross correlation of ambient noise between a pair of stations results in a waveform that is identical to the seismogram that would result if an impulsive source located at one of the stations was recorded at the other, the Green function (GF). The calculation of the GF is often stable after a few weeks of continuous data correlation, any perturbations to the GF after that point are directly related to changes in the subsurface and can be used for 4D monitoring.VSM is a style of seismic interferometry that provides fast, precise, high frequency estimates of the Green's function (GF) between earthquakes. VSM illuminates the subsurface precisely where the pressures are changing and has the potential to image the evolution of seismicity over time, including changes in the style of faulting. With hundreds of earthquakes, we can calculate thousands of waveforms. At the same time, VSM collapses the computational domain, often by 2-3 orders of magnitude. This allows us to do high frequency 3D modeling in the fault region. Using data from a swarm of earthquakes near the Salton Sea, we demonstrate the power of these techniques, illustrating our ability to scale from the far field, where sources are well separated, to the near field where their locations fall within each other

  13. Magnetic and structural properties of Mn1-xCrxAlGe (0 ≤ x1.0)

    NASA Astrophysics Data System (ADS)

    Masumitsu, Hayato; Yoshinaga, Soshi; Mitsui, Yoshifuru; Umetsu, Rie Y.; Hiroi, Masahiko; Uwatoko, Yoshiya; Koyama, Keiichi

    2018-06-01

    The magnetic and structural properties of Mn1-xCrxAlGe (0 ≤ x1.0) compounds were investigated. The spontaneous magnetization Ms and Curie temperature TC of Mn1-xCrxAlGe has a cusp at x = 0.2. The maximum values of Ms and TC are 1.74 μB/f.u. and 601 K, respectively. It was found that the tetragonal Cu2Sb-type structure was stable for 0 ≤ x ≤ 0.75, whereas orthorhombic TiSi2-type structure was observed for x ≥ 0.8. The reciprocal susceptibility as a function of temperature suggested that the magnetic moment of Cr is antiferromagnetically coupled with that of Mn in Cu2Sb-type structure.

  14. Seismic Signals of the 2014 Landslide near Oso, Washington

    NASA Astrophysics Data System (ADS)

    Allstadt, K.; Moran, S. C.; Malone, S. D.; Iverson, R. M.; George, D. L.

    2014-12-01

    The 22 March 2014 landslide near Oso, Washington rapidly moved a large volume of material (~8 million m^3), resulting in the efficient generation of seismic waves that were recorded over 350 km away. Analysis of these seismic signals significantly improves our understanding of the dynamics and timing of events. In contrast to the double couple mechanism of earthquakes, at long periods, the equivalent mechanism of a landslide is a single force. Inversion of the long-period waves for the forces exerted on the earth by the landslide yields a time-series that peaks at nearly 10^10 N and lasts ~1.5 minutes. This result, when combined with higher-frequency wave analysis, eyewitness reports, and field observations, implies a complex failure sequence. The earliest force pulses begin before the buildup in high-frequency energy, suggesting the slide began coherently before transitioning within a minute into the highly disrupted and destructive debris-avalanche flow that killed 43 people. This transition may have been due to a collapse of additional material that loaded the material downslope. Seismically observable "aftershock" landslides continued for weeks. The first and largest occurred a few minutes after the main failure sequence, and was followed by 15 more over the next ~4 hours that were observable at the closest seismic station (11 km away). Three USGS "spiders" equipped with GPS and seismic sensors were deployed by helicopter 10 days later as part of a monitoring effort. Due to their proximity, these seismometers detected signals from even minor collapses, some visually identified by human observers. This augmented network revealed interesting temporal patterns in the post-slide activity, which was dominated by sloughing of material from the headscarp, but also creep of the upper block of the failure mass at a rate of about 1 cm/day. This study shows the value of seismic analysis in landslide investigations to provide timing constraints and help improve our

  15. Forecasting the evolution of seismicity in southern California: Animations built on earthquake stress transfer

    USGS Publications Warehouse

    Toda, S.; Stein, R.S.; Richards-Dinger, K.; Bozkurt, S.B.

    2005-01-01

    We develop a forecast model to reproduce the distibution of main shocks, aftershocks and surrounding seismicity observed during 1986-200 in a 300 ?? 310 km area centered on the 1992 M = 7.3 Landers earthquake. To parse the catalog into frames with equal numbers of aftershocks, we animate seismicity in log time increments that lengthen after each main shock; this reveals aftershock zone migration, expansion, and densification. We implement a rate/state algorithm that incorporates the static stress transferred by each M ??? 6 shock and then evolves. Coulomb stress changes amplify the background seismicity, so small stress changes produce large changes in seismicity rate in areas of high background seismicity. Similarly, seismicity rate declines in the stress shadows are evident only in areas with previously high seismicity rates. Thus a key constituent of the model is the background seismicity rate, which we smooth from 1981 to 1986 seismicity. The mean correlation coefficient between observed and predicted M ??? 1.4 shocks (the minimum magnitude of completeness) is 0.52 for 1986-2003 and 0.63 for 1992-2003; a control standard aftershock model yields 0.54 and 0.52 for the same periods. Four M ??? 6.0 shocks struck during the test period; three are located at sites where the expected seismicity rate falls above the 92 percentile, and one is located above the 75 percentile. The model thus reproduces much, but certainly not all, of the observed spatial and temporal seismicity, from which we infer that the decaying effect of stress transferred by successive main shocks influences seismicity for decades. Finally, we offer a M ??? 5 earthquake forecast for 2005-2015, assigning probabilities to 324 10 ?? 10 km cells.

  16. Reevaluation of the Seismicity and seismic hazards of Northeastern Libya

    NASA Astrophysics Data System (ADS)

    Ben Suleman, abdunnur; Aousetta, Fawzi

    2014-05-01

    Libya, located at the northern margin of the African continent, underwent many episodes of orogenic activities. These episodes of orogenic activities affected and shaped the geological setting of the country. This study represents a detailed investigation that aims to focus on the seismicity and its implications on earthquake hazards of Northeastern Libya. At the end of year 2005 the Libyan National Seismological Network starts functioning with 15 stations. The Seismicity of the area under investigation was reevaluated using data recorded by the recently established network. The Al-Maraj earthquake occurred in May 22nd 2005was analyzed. This earthquake was located in a known seismically active area. This area was the sight of the well known 1963 earthquake that kills over 200 people. Earthquakes were plotted and resulting maps were interpreted and discussed. The level of seismic activity is higher in some areas, such as the city of Al-Maraj. The offshore areas north of Al-Maraj seem to have higher seismic activity. It is highly recommended that the recent earthquake activity is considered in the seismic hazard assessments for the northeastern part of Libya.

  17. New Observations of Seismic Group Velocities in the Western Solomon Islands from Cross-Correlation of Ambient Seismic Noise

    NASA Astrophysics Data System (ADS)

    Ku, C. S.; You, S. H.; Kuo, Y. T.; Huang, B. S.; Wu, Y. M.; Chen, Y. G.; Taylor, F. W.

    2015-12-01

    A MW 8.1 earthquake occurred on 1 April 2007 in the western Solomon Islands. Following this event, a damaging tsunami was induced and hit the Island Gizo where the capital city of Western Province of Solomon Islands located. Several buildings of this city were destroyed and several peoples lost their lives during this earthquake. However, during this earthquake, no near source seismic instrument has been installed in this region. The seismic evaluations for the aftershock sequence, the possible earthquake early warning and tsunami warning were unavailable. For the purpose of knowing more detailed information about seismic activity in this region, we have installed 9 seismic stations (with Trillium 120PA broadband seismometer and Q330S 24bit digitizer) around the rupture zone of the 2007 earthquake since September of 2009. Within a decade, it has been demonstrated both theoretically and experimentally that the Green's function or impulse response between two seismic stations can be retrieved from the cross-correlation of ambient noise. In this study, 6 stations' observations which are more complete during 2011/10 ~ 2012/12 period, were selected for the purpose of the cross-correlation analysis of ambient seismic noise. The group velocities at period 2-20 seconds of 15 station-pairs were extracted by using multiple filter technique (MFT) method. The analyzed results of this study presented significant results of group velocities with higher frequency contents than other studies (20-60 seconds in usually cases) and opened new opportunities to study the shallow crustal structure of the western Solomon Islands.

  18. X-15A-2 and HL-10 parked on NASA ramp

    NASA Technical Reports Server (NTRS)

    1966-01-01

    The HL-10 is shown next to the X-15A-2 in 1966. Both aircraft later went on to set records. On October 3, 1967, the X-15A-2 reached a speed of Mach 6.7, which was the highest speed achieved by a piloted aircraft until the Space Shuttles far exceeded that speed in 1981 and afterwards. The HL-10 later became the fastest piloted lifting body when it flew at a speed of Mach 1.86 on February 18, 1970. The HL-10 was one of five heavyweight lifting-body designs flown at NASA's Flight Research Center (FRC--later Dryden Flight Research Center), Edwards, California, from July 1966 to November 1975 to study and validate the concept of safely maneuvering and landing a low lift-over-drag vehicle designed for reentry from space. Northrop Corporation built the HL-10 and M2-F2, the first two of the fleet of 'heavy' lifting bodies flown by the NASA Flight Research Center. The contract for construction of the HL-10 and the M2-F2 was $1.8 million. 'HL' stands for horizontal landing, and '10' refers to the tenth design studied by engineers at NASA's Langley Research Center, Hampton, Va. After delivery to NASA in January 1966, the HL-10 made its first flight on Dec. 22, 1966, with research pilot Bruce Peterson in the cockpit. Although an XLR-11 rocket engine was installed in the vehicle, the first 11 drop flights from the B-52 launch aircraft were powerless glide flights to assess handling qualities, stability, and control. In the end, the HL-10 was judged to be the best handling of the three original heavy-weight lifting bodies (M2-F2/F3, HL-10, X-24A). The HL-10 was flown 37 times during the lifting body research program and logged the highest altitude and fastest speed in the Lifting Body program. On Feb. 18, 1970, Air Force test pilot Peter Hoag piloted the HL-10 to Mach 1.86 (1,228 mph). Nine days later, NASA pilot Bill Dana flew the vehicle to 90,030 feet, which became the highest altitude reached in the program. Some new and different lessons were learned through the successful

  19. Geomorphology and seismic risk

    NASA Astrophysics Data System (ADS)

    Panizza, Mario

    1991-07-01

    The author analyses the contributions provided by geomorphology in studies suited to the assessment of seismic risk: this is defined as function of the seismic hazard, of the seismic susceptibility, and of the vulnerability. The geomorphological studies applicable to seismic risk assessment can be divided into two sectors: (a) morpho-neotectonic investigations conducted to identify active tectonic structures; (b) geomorphological and morphometric analyses aimed at identifying the particular situations that amplify or reduce seismic susceptibility. The morpho-neotectonic studies lead to the identification, selection and classification of the lineaments that can be linked with active tectonic structures. The most important geomorphological situations that can condition seismic susceptibility are: slope angle, debris, morphology, degradational slopes, paleo-landslides and underground cavities.

  20. Alaska Seismic Hazards Safety Commission

    Science.gov Websites

    State Employees ASHSC State of Alaska search Alaska Seismic Hazards Safety Commission View of Anchorage and Commissions Alaska Seismic Hazards Safety Commission (ASHSC) main contant Alaska Seismic Hazards Safety Commission logo Alaska Seismic Hazards Safety Commission (ASHSC) - Mission The Alaska Seismic

  1. Influence of Sm doping on structural and dielectric properties of Y{sub 1-x}Sm{sub x}MnO{sub 3} (x = 0, 0.10, 0.20) manganites

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dar, Mashkoor Ahmad, E-mail: darmashkoor.phst@gmail.com; Dar, Hilal Ahmad; Varshney, Dinesh, E-mail: vdinesh33@rediffmail.com

    2016-05-06

    Structural and dielectric properties of polycrystalline YMnO{sub 3} (x = 0.0, 0.10 and 0.20) which was prepared by solid-state reaction route, have been investigated. The X-ray diffraction pattern reveals that all the samples are in single phase and show hexagonal structure with P63cm space group. The particle size decreases with increase in Sm doping while to that X-ray density increases with increasing x. The dielectric constant (ε’) of Y{sub 1-x}Sm{sub x}MnO{sub 3} measured in the frequency range 10 Hz to 1MHz is much higher at lower frequencies (≤ 1KHz) and its value decreases with enhanced frequency. At very high frequencies, ε’more » becomes frequency independent and is attributed to Maxwell Wagner type of interfacial polarization model. A very high value of dielectric constant ∼18642 is observed for x = 10%. The dielectric loss (tan δ) decreases wit increase in Sm doping.« less

  2. Seismic isolation of nuclear power plants using sliding isolation bearings

    NASA Astrophysics Data System (ADS)

    Kumar, Manish

    Nuclear power plants (NPP) are designed for earthquake shaking with very long return periods. Seismic isolation is a viable strategy to protect NPPs from extreme earthquake shaking because it filters a significant fraction of earthquake input energy. This study addresses the seismic isolation of NPPs using sliding bearings, with a focus on the single concave Friction Pendulum(TM) (FP) bearing. Friction at the sliding surface of an FP bearing changes continuously during an earthquake as a function of sliding velocity, axial pressure and temperature at the sliding surface. The temperature at the sliding surface, in turn, is a function of the histories of coefficient of friction, sliding velocity and axial pressure, and the travel path of the slider. A simple model to describe the complex interdependence of the coefficient of friction, axial pressure, sliding velocity and temperature at the sliding surface is proposed, and then verified and validated. Seismic hazard for a seismically isolated nuclear power plant is defined in the United States using a uniform hazard response spectrum (UHRS) at mean annual frequencies of exceedance (MAFE) of 10-4 and 10 -5. A key design parameter is the clearance to the hard stop (CHS), which is influenced substantially by the definition of the seismic hazard. Four alternate representations of seismic hazard are studied, which incorporate different variabilities and uncertainties. Response-history analyses performed on single FP-bearing isolation systems using ground motions consistent with the four representations at the two shaking levels indicate that the CHS is influenced primarily by whether the observed difference between the two horizontal components of ground motions in a given set is accounted for. The UHRS at the MAFE of 10-4 is increased by a design factor (≥ 1) for conventional (fixed base) nuclear structure to achieve a target annual frequency of unacceptable performance. Risk oriented calculations are performed for

  3. Background noise model development for seismic stations of KMA

    NASA Astrophysics Data System (ADS)

    Jeon, Youngsoo

    2010-05-01

    The background noise recorded at seismometer is exist at any seismic signal due to the natural phenomena of the medium which the signal passed through. Reducing the seismic noise is very important to improve the data quality in seismic studies. But, the most important aspect of reducing seismic noise is to find the appropriate place before installing the seismometer. For this reason, NIMR(National Institution of Meteorological Researches) starts to develop a model of standard background noise for the broadband seismic stations of the KMA(Korea Meteorological Administration) using a continuous data set obtained from 13 broadband stations during the period of 2007 and 2008. We also developed the model using short period seismic data from 10 stations at the year of 2009. The method of Mcmara and Buland(2004) is applied to analyse background noise of Korean Peninsula. The fact that borehole seismometer records show low noise level at frequency range greater than 1 Hz compared with that of records at the surface indicate that the cultural noise of inland Korean Peninsula should be considered to process the seismic data set. Reducing Double Frequency peak also should be regarded because the Korean Peninsula surrounded by the seas from eastern, western and southern part. The development of KMA background model shows that the Peterson model(1993) is not applicable to fit the background noise signal generated from Korean Peninsula.

  4. North American X-15 model tested in 300MPH Low Speed 7x10 Tunnel

    NASA Image and Video Library

    1958-09-07

    A one-twentieth scale model of the X-15 originally suspended beneath the wing of a B-52 is observed by a scientist of the National Aeronautics and Space Administration (NASA) as it leaves the bomber model in tests to determine the release characteristics and drop motion of the research airplane. Caption: The aerodynamics of air launching the North American X-15 being investigated in the 300MPH Low Speed 7x10 Tunnel, about 1957. Photograph published in Engineer in Charge: A History of the Langley Aeronautical Laboratory, 1917-1958 by James R. Hansen. Page 366. Photograph also published in Sixty Years of Aeronautical Research 1917-1977 By David A. Anderton. A NASA publication. Page 49.

  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. Advanced Seismic While Drilling System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    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

  7. Development of the Multi-Level Seismic Receiver (MLSR)

    NASA Astrophysics Data System (ADS)

    Sleefe, G. E.; Engler, B. P.; Drozda, P. M.; Franco, R. J.; Morgan, Jeff

    1995-02-01

    The Advanced Geophysical Technology Department (6114) and the Telemetry Technology Development Department (2664) have, in conjunction with the Oil Recovery Technology Partnership, developed a Multi-Level Seismic Receiver (MLSR) for use in crosswell seismic surveys. The MLSR was designed and evaluated with the significant support of many industry partners in the oil exploration industry. The unit was designed to record and process superior quality seismic data operating in severe borehole environments, including high temperature (up to 200 C) and static pressure (10,000 psi). This development has utilized state-of-the-art technology in transducers, data acquisition, and real-time data communication and data processing. The mechanical design of the receiver has been carefully modeled and evaluated to insure excellent signal coupling into the receiver.

  8. Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn 1 - x In x Te for x ≥ 0.10

    DOE PAGES

    Smylie, M. P.; Claus, H.; Kwok, W. -K.; ...

    2018-01-19

    The temperature dependence of the London penetration depth Δλ(T) in the superconducting doped topological crystalline insulator Sn 1-xIn x Te was measured down to 450 mK for two different doping levels, x ≈ 0.45 (optimally doped) and x ≈ 0.10 (underdoped), bookending the range of cubic phase in the compound. The results indicate no deviation from fully gapped BCS-like behavior, eliminating several candidate unconventional gap structures. Critical field values below 1 K and other superconducting parameters are also presented. The introduction of disorder by repeated particle irradiation with 5 MeV protons does not enhance T c, indicating that ferroelectric interactionsmore » do not compete with superconductivity.« less

  9. Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn 1 - x In x Te for x ≥ 0.10

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smylie, M. P.; Claus, H.; Kwok, W. -K.

    The temperature dependence of the London penetration depth Δλ(T) in the superconducting doped topological crystalline insulator Sn 1-xIn x Te was measured down to 450 mK for two different doping levels, x ≈ 0.45 (optimally doped) and x ≈ 0.10 (underdoped), bookending the range of cubic phase in the compound. The results indicate no deviation from fully gapped BCS-like behavior, eliminating several candidate unconventional gap structures. Critical field values below 1 K and other superconducting parameters are also presented. The introduction of disorder by repeated particle irradiation with 5 MeV protons does not enhance T c, indicating that ferroelectric interactionsmore » do not compete with superconductivity.« less

  10. SiSeRHMap v1.0: a simulator for mapped seismic response using a hybrid model

    NASA Astrophysics Data System (ADS)

    Grelle, G.; Bonito, L.; Lampasi, A.; Revellino, P.; Guerriero, L.; Sappa, G.; Guadagno, F. M.

    2015-06-01

    SiSeRHMap is a computerized methodology capable of drawing up prediction maps of seismic response. It was realized on the basis of a hybrid model which combines different approaches and models in a new and non-conventional way. These approaches and models are organized in a code-architecture composed of five interdependent modules. A GIS (Geographic Information System) Cubic Model (GCM), which is a layered computational structure based on the concept of lithodynamic units and zones, aims at reproducing a parameterized layered subsoil model. A metamodeling process confers a hybrid nature to the methodology. In this process, the one-dimensional linear equivalent analysis produces acceleration response spectra of shear wave velocity-thickness profiles, defined as trainers, which are randomly selected in each zone. Subsequently, a numerical adaptive simulation model (Spectra) is optimized on the above trainer acceleration response spectra by means of a dedicated Evolutionary Algorithm (EA) and the Levenberg-Marquardt Algorithm (LMA) as the final optimizer. In the final step, the GCM Maps Executor module produces a serial map-set of a stratigraphic seismic response at different periods, grid-solving the calibrated Spectra model. In addition, the spectra topographic amplification is also computed by means of a numerical prediction model. This latter is built to match the results of the numerical simulations related to isolate reliefs using GIS topographic attributes. In this way, different sets of seismic response maps are developed, on which, also maps of seismic design response spectra are defined by means of an enveloping technique.

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

    USGS Publications Warehouse

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

    2014-01-01

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

  12. Seismic reflection images of shallow faulting, northernmost Mississippi embayment, north of the New Madrid seismic zone

    USGS Publications Warehouse

    McBride, J.H.; Nelson, W.J.

    2001-01-01

    High-resolution seismic reflection surveys document tectonic faults that displace Pleistocene and older strata just beyond the northeast termination of the New Madrid seismic zone, at the northernmost extent of the Mississippi embayment. These faults, which are part of the Fluorspar Area fault complex in southeastern Illinois, are directly in line with the northeast-trending seismic zone. The reflection data were acquired using an elastic weight-drop source recorded to 500 msec by a 48-geophone array (24-fold) with a 10-ft (??3.0m) station interval. Recognizable reflections were recorded to about 200 msec (100-150 m). The effects of multiple reflections, numerous diffractions, low apparent velocity (i.e., steeply dipping) noise, and the relatively low-frequency content of the recorded signal provided challenges for data processing and interpreting subtle fault offsets. Data processing steps that were critical to the detection of faults included residual statics, post-stack migration, deconvolution, and noise-reduction filtering. Seismic migration was crucial for detecting and mitigating complex fault-related diffraction patterns, which produced an apparent 'folding' of reflectors on unmigrated sections. Detected individual offsets of shallow reflectors range from 5 to 10 m for the top of Paleozoic bedrock and younger strata. The migrated sections generally indicate vertical to steeply dipping normal and reverse faults, which in places outline small horsts and/or grabens. Tilting or folding of stratal reflectors associated with faulting is also locally observed. At one site, the observed faulting is superimposed over a prominent antiformal structure, which may itself be a product of the Quaternary deformation that produced the steep normal and reverse faults. Our results suggest that faulting of the Paleozoic bedrock and younger sediments of the northern Mississippi embayment is more pervasive and less localized than previously thought.

  13. Patterns of significant seismic quiescence in the Pacific Mexican coast

    NASA Astrophysics Data System (ADS)

    Muñoz-Diosdado, Alejandro; Rudolf-Navarro, Adolfo; Barrera-Ferrer, Amilcar; Angulo-Brown, Fernando

    2014-05-01

    quiescence in the Guerrero seismic-gap, which are apparently correlated with the occurrence of silent earthquakes in 2002, 2006 and 2011 recently discovered by GPS technology. In fact, a possible silent earthquake with Mw =7.6 occurred at this gap in 2002 which lasted for approximately 4 months and was detected by continuous GPS receivers located over an area of ~550x250 square kilometers.

  14. Seismic amplification within the Seattle Basin, Washington State: Insights from SHIPS seismic tomography experiments

    USGS Publications Warehouse

    Snelson, C.M.; Brocher, T.M.; Miller, K.C.; Pratt, T.L.; Trehu, A.M.

    2007-01-01

    Recent observations indicate that the Seattle sedimentary basin, underlying Seattle and other urban centers in the Puget Lowland, Washington, amplifies long-period (1-5 sec) weak ground motions by factors of 10 or more. We computed east-trending P- and S-wave velocity models across the Seattle basin from Seismic Hazard Investigations of Puget Sound (SHIPS) experiments to better characterize the seismic hazard the basin poses. The 3D tomographic models, which resolve features to a depth of 10 km, for the first time define the P- and S-wave velocity structure of the eastern end of the basin. The basin, which contains sedimentary rocks of Eocene to Holocene, is broadly symmetric in east-west section and reaches a maximum thickness of 6 km along our profile beneath north Seattle. A comparison of our velocity model with coincident amplification curves for weak ground motions produced by the 1999 Chi-Chi earthquake suggests that the distribution of Quaternary deposits and reduced velocity gradients in the upper part of the basement east of Seattle have significance in forecasting variations in seismic-wave amplification across the basin. Specifically, eastward increases in the amplification of 0.2- to 5-Hz energy correlate with locally thicker unconsolidated deposits and a change from Crescent Formation basement to pre-Tertiary Cascadia basement. These models define the extent of the Seattle basin, the Seattle fault, and the geometry of the basement contact, giving insight into the tectonic evolution of the Seattle basin and its influence on ground shaking.

  15. The Southern Kansas Seismic Network

    NASA Astrophysics Data System (ADS)

    Terra, F. M.

    2015-12-01

    Historically aseismic Harper and Sumner counties in Southern Kansas experienced a dramatic increase in seismicity beginning in early 2014, coincident with the development of new oil production in the Mississippi Lime Play. In order to better understand the potential relationships between seismicity and oil development, the USGS installed a real-time telemetered seismic network in cooperation with the Kansas Geological Survey, the Kansas Corporation Commission, the Kansas Department of Health and Environment, Harper County, and the Oklahoma Geological Survey. The network began operation in March 2014 with an initial deployment of 5 NetQuakes accelerometers and by July 2014 had expanded to include 10 broadband sites. The network currently has 14 stations, all with accelerometers and 12 with broadband seismometers. The network has interstation spacing of 15 - 25 km and typical azimuthal gap of 80 for well-located events. Data are continuously streamed to IRIS at 200 samples per second from most sites. Earthquake locations are augmented with additional stations from the USGS National Network, Oklahoma Geological Survey Seismic Network, Kansas Seismic Monitoring Network and the Enid Oklahoma Network. Since the spring of 2014 over 7500 earthquakes have been identified with data from this network, 1400 of which have been manually timed and cataloged. Focal depths for earthquakes typically range between 2 and 7 km. The catalog is available at earthquake.usgs.gov/earthquakes/search/ under network code 'Ismpkansas'. The network recorded the largest known earthquake in Harper County, Mw 4.3, on October 2, 2014 and in Sumner County, Mw 4.9, on November 12, 2014. Recorded ground motions at the epicenter of the October earthquake were 0.70 g (PGA) and 12 cm/s (PGV). These high ground motion values agree with near-source recordings made by other USGS temporary deployments in the U. S. midcontinent, indicating a significant shaking hazard from such shallow, moderate

  16. Rescaled Range analysis of Induced Seismicity: rapid classification of clusters in seismic crisis

    NASA Astrophysics Data System (ADS)

    Bejar-Pizarro, M.; Perez Lopez, R.; Benito-Parejo, M.; Guardiola-Albert, C.; Herraiz, M.

    2017-12-01

    Different underground fluid operations, mainly gas storing, fracking and water pumping, can trigger Induced Seismicity (IS). This seismicity is normally featured by small-sized earthquakes (M<2.5), although particular cases reach magnitude as great as 5. It has been up for debate whether earthquakes greater than 5 can be triggered by IS or this level of magnitude only corresponds to tectonic earthquakes caused by stress change. Whatever the case, the characterization of IS for seismic clusters and seismic series recorded close but not into the gas storage, is still under discussion. Time-series of earthquakes obey non-linear patterns where the Hurst exponent describes the persistency or anti-persistency of the sequence. Natural seismic sequences have an H-exponent close to 0.7, which combined with the b-value time evolution during the time clusters, give us valuable information about the stationarity of the phenomena. Tectonic earthquakes consist in a main shock with a decay of time-occurrence of seismic shocks obeying the Omori's empirical law. On the contrary, IS does not exhibit a main shock and the time occurrence depends on the injection operations instead of on the tectonic energy released. In this context, the H-exponent can give information about the origin of the sequence. In 2013, a seismic crisis was declared from the Castor underground gas storing located off-shore in the Mediterranean Sea, close to the Northeastern Spanish cost. The greatest induced earthquake was 3.7. However, a 4.2 earthquake, probably of tectonic origin, occurred few days after the operations stopped. In this work, we have compared the H-exponent and the b-value time evolution according to the timeline of gas injection. Moreover, we have divided the seismic sequence into two groups: (1) Induced Seismicity and (2) Triggered Seismicity. The rescaled range analysis allows the differentiation between natural and induced seismicity and gives information about the persistency and long

  17. Intricate Li-Sn Disorder in Rare-Earth Metal-Lithium Stannides. Crystal Chemistry of RE3Li4- xSn4+ x (RE = La-Nd, Sm; x < 0.3) and Eu7Li8- xSn10+ x ( x ≈ 2.0).

    PubMed

    Suen, Nian-Tzu; Guo, Sheng-Ping; Hoos, James; Bobev, Svilen

    2018-05-07

    Reported are the syntheses, crystal structures, and electronic structures of six rare-earth metal-lithium stannides with the general formulas RE 3 Li 4- x Sn 4+ x (RE = La-Nd, Sm) and Eu 7 Li 8- x Sn 10+ x . These new ternary compounds have been synthesized by high-temperature reactions of the corresponding elements. Their crystal structures have been established using single-crystal X-ray diffraction methods. The RE 3 Li 4- x Sn 4+ x phases crystallize in the orthorhombic body-centered space group Immm (No. 71) with the Zr 3 Cu 4 Si 4 structure type (Pearson code oI22), and the Eu 7 Li 8- x Sn 10+ x phase crystallizes in the orthorhombic base-centered space group Cmmm (No. 65) with the Ce 7 Li 8 Ge 10 structure type (Pearson code oC50). Both structures can be consdered as part of the [RESn 2 ] n [RELi 2 Sn] m homologous series, wherein the structures are intergrowths of imaginary RESn 2 (AlB 2 -like structure type) and RELi 2 Sn (MgAl 2 Cu-like structure type) fragments. Close examination the structures indicates complex occupational Li-Sn disorder, apparently governed by the drive of the structure to achieve an optimal number of valence electrons. This conclusion based on experimental results is supported by detailed electronic structure calculations, carried out using the tight-binding linear muffin-tin orbital method.

  18. Seismicity at Old Faithful Geyser: an isolated source of geothermal noise and possible analogue of volcanic seismicity

    NASA Astrophysics Data System (ADS)

    Kieffer, Susan Werner

    1984-09-01

    Old Faithful Geyser in Yellowstone National Park, U.S.A., is a relatively isolated source of seismic noise and exhibits seismic behavior similar to that observed at many volcanoes, including "bubblequakes" that resemble B-type "earthquakes", harmonic tremor before and during eruptions, and periods of seismic quiet prior to eruptions. Although Old Faithful differs from volcanoes in that the conduit is continuously open, that rock-fracturing is not a process responsible for seismicity, and that the erupting fluid is inviscid H 2O rather than viscous magma, there are also remarkable similarities in the problems of heat and mass recharge to the system, in the eruption dynamics, and in the seismicity. Water rises irregularly into the immediate reservoir of Old Faithful as recharge occurs, a fact that suggests that there are two enlarged storage regions: one between 18 and 22 m (the base of the immediate reservoir) and one between about 10 and 12 m depth. Transport of heat from hot water or steam entering at the base of the recharging water column into cooler overlying water occurs by migration of steam bubbles upward and their collapse in the cooler water, and by episodes of convective overturn. An eruption occurs when the temperature of the near-surface water exceeds the boiling point if the entire water column is sufficiently close to the boiling curve that the propagation of pressure-release waves (rarefactions) down the column can bring the liquid water onto the boiling curve. The process of conversion of the liquid water in the conduit at the onset of an eruption into a two-phase liquid-vapor mixture takes on the order of 30 s. The seismicity is directly related to the sequence of filling and heating during the recharge cycle, and to the fluid mechanics of the eruption. Short (0.2-0.3 s), monochromatic, high-frequency events (20-60 Hz) resembling unsustained harmonic tremor and, in some instances, B-type volcanic earthquakes, occur when exploding or imploding

  19. Porosity, Fracturing and Alteration of Young Oceanic Crust: New Seismic Analyses at Borehole 504B

    NASA Astrophysics Data System (ADS)

    Gregory, E. P. M.; Hobbs, R. W.; Peirce, C.; Wilson, D. J.

    2017-12-01

    DSDP/ODP borehole 504B, drilled 2111 m into 6.9 Ma oceanic crust, provides in-situ core and logging measurements of the lithology, fracturing and porosity of crust originally formed at the Costa Rica Rift and its subsequent alteration by hydrothermal fluids. A recent active seismic survey over the borehole and surrounding area reveals wider spatial variations in velocity that can be related to this porosity and fracturing. Over 10,000 airgun shots were fired in a 30 x 30 km grid over the borehole region, using both high-frequency and low-frequency airgun arrays. The shots were recorded on a 4.5 km-long streamer and 24 ocean-bottom seismographs, each equipped with a three-component geophone and an hydrophone. A vertical hydrophone array recorded the downgoing source wavelet, and underway gravity, magnetic field and multibeam bathymetry data were also recorded. This combined dataset enables the most comprehensive geophysical analysis of this area of crust to date, while the ground-truthing provided by 504B enables us to address the questions of what do the seismic oceanic crustal layers represent and what controls their characteristics as the crust ages? Wide-angle seismic modelling with a Monte Carlo based uncertainty analysis reveals new 2D and 3D Vp and Vs models of the area, which show relatively homogeneous crust around borehole 504B, and place the seismic layer 2B/2C, and seismic layer 2/3 boundaries coincident with fracturing and alteration fronts rather than the lithological boundaries between lavas and dykes, and dykes and gabbros, respectively. Analysis of Poisson's ratio, seismic anisotropy and particle motions reveal patterns in fracturing and porosity across the survey area, and locate possible fossilised hydrothermal circulation cells. These cells appear to have influenced the porosity of the crust through alteration and mineralisation processes, with faults inherited from initial crustal accretion influencing basement topographic highs and providing

  20. Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn 1 - x In x Te for x ≥ 0.10

    DOE PAGES

    Smylie, M. P.; Claus, H.; Kwok, W. -K.; ...

    2018-01-19

    In this paper, the temperature dependence of the London penetration depth Δλ(T) in the superconducting doped topological crystalline insulator Sn 1-xIn xTe was measured down to 450 mK for two different doping levels, x ≈ 0.45 (optimally doped) and x ≈ 0.10 (underdoped), bookending the range of cubic phase in the compound. The results indicate no deviation from fully gapped BCS-like behavior, eliminating several candidate unconventional gap structures. Critical field values below 1 K and other superconducting parameters are also presented. Finally, the introduction of disorder by repeated particle irradiation with 5 MeV protons does not enhance T c, indicatingmore » that ferroelectric interactions do not compete with superconductivity.« less

  1. Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn 1 - x In x Te for x ≥ 0.10

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smylie, M. P.; Claus, H.; Kwok, W. -K.

    In this paper, the temperature dependence of the London penetration depth Δλ(T) in the superconducting doped topological crystalline insulator Sn 1-xIn xTe was measured down to 450 mK for two different doping levels, x ≈ 0.45 (optimally doped) and x ≈ 0.10 (underdoped), bookending the range of cubic phase in the compound. The results indicate no deviation from fully gapped BCS-like behavior, eliminating several candidate unconventional gap structures. Critical field values below 1 K and other superconducting parameters are also presented. Finally, the introduction of disorder by repeated particle irradiation with 5 MeV protons does not enhance T c, indicatingmore » that ferroelectric interactions do not compete with superconductivity.« less

  2. 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.

  3. Reconstructing the Seismic Wavefield using Curvelets and Distributed Acoustic Sensing

    NASA Astrophysics Data System (ADS)

    Muir, J. B.; Zhan, Z.

    2017-12-01

    Distributed Acoustic Sensing (DAS) offers an opportunity to produce cost effective and uniquely dense images of the surface seismic wavefield - DAS also produces extremely large data volumes that require innovative methods of data reduction and seismic parameter inversion to handle efficiently. We leverage DAS and the super-Nyquist sampling enabled by compressed sensing of the wavefield in the curvelet domain to produce accurate images of the horizontal velocity within a target region, using only short ( 1-10 minutes) records of either active seismic sources or ambient seismic signals. Once the wavefield has been fully described, modern "tomographic" techniques, such as Helmholtz tomography or Wavefield Gradiometry, can be employed to determine seismic parameters of interest such as phase velocity. An additional practical benefit of employing a wavefield reconstruction step is that multiple heterogeneous forms of instrumentation can be naturally combined - therefore in this study we also explore the addition of three component nodal seismic data into the reconstructed wavefield. We illustrate these techniques using both synthetic examples and data taken from the Brady Geothermal Field in Nevada during the PoroTomo (U. Wisconsin Madison) experiment of 2016.

  4. Seismic Design of a Single Bored Tunnel: Longitudinal Deformations and Seismic Joints

    NASA Astrophysics Data System (ADS)

    Oh, J.; Moon, T.

    2018-03-01

    The large diameter bored tunnel passing through rock and alluvial deposits subjected to seismic loading is analyzed for estimating longitudinal deformations and member forces on the segmental tunnel liners. The project site has challenges including high hydrostatic pressure, variable ground profile and high seismic loading. To ensure the safety of segmental tunnel liner from the seismic demands, the performance-based two-level design earthquake approach, Functional Evaluation Earthquake and Safety Evaluation Earthquake, has been adopted. The longitudinal tunnel and ground response seismic analyses are performed using a three-dimensional quasi-static linear elastic and nonlinear elastic discrete beam-spring elements to represent segmental liner and ground spring, respectively. Three components (longitudinal, transverse and vertical) of free-field ground displacement-time histories evaluated from site response analyses considering wave passage effects have been applied at the end support of the strain-compatible ground springs. The result of the longitudinal seismic analyses suggests that seismic joint for the mitigation measure requiring the design deflection capacity of 5-7.5 cm is to be furnished at the transition zone between hard and soft ground condition where the maximum member forces on the segmental liner (i.e., axial, shear forces and bending moments) are induced. The paper illustrates how detailed numerical analyses can be practically applied to evaluate the axial and curvature deformations along the tunnel alignment under difficult ground conditions and to provide the seismic joints at proper locations to effectively reduce the seismic demands below the allowable levels.

  5. Imaging the West Bohemia Seismic Zone

    NASA Astrophysics Data System (ADS)

    Alexandrakis, C.; Calo, M.; Bouchaala, F.; Vavrycuk, V.

    2013-12-01

    swarms, 2008 and 2011, are used in this study. P-wave, S-wave and P-to-S ratio WAMs (P-to-S ratios are calculated directly from the P and S WAMs) reveal interesting features which correlate with the shallowest earthquakes. These features are interpreted in relation to the role of fluids in Nový Kostel. References: Calò, M., C. Dorbath, F. Cornet, & N. Cuenot, 2011. Geophys. J. Int., doi: 10.1111/j.1365-246X.2011.05108.x. Fischer, T., J. Horálek, J. Michálek & A. Boušková, 2010. J. Seismol., 14: 665-682. Fischer, T. & J. Michálek, 2008. Stud. Geophys. Geod., 52: 493-511. Vavryčuk, V., 2011. Earth Planet. Sci. Lett., 305: 290-296. Zhang, H. & C.H. Thurber, 2003. Bull. Seism. Soc. Am., 93: 1175-1189.

  6. Method of migrating seismic records

    DOEpatents

    Ober, Curtis C.; Romero, Louis A.; Ghiglia, Dennis C.

    2000-01-01

    The present invention provides a method of migrating seismic records that retains the information in the seismic records and allows migration with significant reductions in computing cost. The present invention comprises phase encoding seismic records and combining the encoded seismic records before migration. Phase encoding can minimize the effect of unwanted cross terms while still allowing significant reductions in the cost to migrate a number of seismic records.

  7. Deep Seismic Reflection Images of the Sumatra Seismic and Aseismic Gaps

    NASA Astrophysics Data System (ADS)

    Singh, S. C.; Hananto, N. D.; Chauhan, A.; Carton, H. D.; Midenet, S.; Djajadihardja, Y.

    2009-12-01

    The Sumatra subduction zone is seismically most active region on the Earth, and has been the site of three great earthquakes only in the last four years. The first of the series, the 2004 Boxing Day earthquake, broke 1300 km of the plate boundary and produced the devastating tsunami around the Indian Ocean. The second great earthquake occurred three months later in March 2005, about 150 km SE of the 2004 event. The Earth waited for three years, and then broke again in September 2007 at 1300 km SE of the 2004 event producing a twin earthquake of magnitudes of 8.5 and 7.9 at an interval of 12 hours, leaving a seismic gap of about 600 km between the second and third earthquake, the Sumatra Seismic Gap. Seismological and geodetic studies suggest that this gap is fully locked and may break any time. In order to study the seismic and tsunami risk in this locked region, a deep seismic reflection survey (Tsunami Investigation Deep Evaluation Seismic -TIDES) was carried out in May 2009 using the CGGVeritas vessel Geowave Champion towing a 15 long streamer, the longest ever used during a seismic survey, to image the nature of the subducting plate and associated features, including the seismogenic zone, from seafloor down to 50 km depth. A total of 1700 km of deep seismic reflection data were acquired. Three dip lines traverse the Sumatra subduction zone; one going through the Sumatra Seismic Gap, one crossing the region that broke during the 2007 great earthquake, and one going through the aseismic zone. These three dip profiles should provide insight about the locking mechanism and help us to understand why an earthquake occurs in one zone and not in aseismic zone. A strike-line was shot in the forearc basin connecting the locked zone with broken zone profiles, which should provide insight about barriers that might have stopped propagation of 2007 earthquake rupture further northward.

  8. Deterministic seismic hazard macrozonation of India

    NASA Astrophysics Data System (ADS)

    Kolathayar, Sreevalsa; Sitharam, T. G.; Vipin, K. S.

    2012-10-01

    Earthquakes are known to have occurred in Indian subcontinent from ancient times. This paper presents the results of seismic hazard analysis of India (6°-38°N and 68°-98°E) based on the deterministic approach using latest seismicity data (up to 2010). The hazard analysis was done using two different source models (linear sources and point sources) and 12 well recognized attenuation relations considering varied tectonic provinces in the region. The earthquake data obtained from different sources were homogenized and declustered and a total of 27,146 earthquakes of moment magnitude 4 and above were listed in the study area. The sesismotectonic map of the study area was prepared by considering the faults, lineaments and the shear zones which are associated with earthquakes of magnitude 4 and above. A new program was developed in MATLAB for smoothing of the point sources. For assessing the seismic hazard, the study area was divided into small grids of size 0.1° × 0.1° (approximately 10 × 10 km), and the hazard parameters were calculated at the center of each of these grid cells by considering all the seismic sources within a radius of 300 to 400 km. Rock level peak horizontal acceleration (PHA) and spectral accelerations for periods 0.1 and 1 s have been calculated for all the grid points with a deterministic approach using a code written in MATLAB. Epistemic uncertainty in hazard definition has been tackled within a logic-tree framework considering two types of sources and three attenuation models for each grid point. The hazard evaluation without logic tree approach also has been done for comparison of the results. The contour maps showing the spatial variation of hazard values are presented in the paper.

  9. Hydrogeological and Seismic Responses to Incoming Materials at the Non-Accreting Margin, Offshore the Osa Peninsula, Costa Rica

    NASA Astrophysics Data System (ADS)

    Harris, R. N.; Kameda, J.; Shimizu, M.; Ujiie, K.; Tsutsumi, A.; Ikehara, M.; Uno, M.; Yamaguchi, A.; Hamada, Y.; Namiki, Y.; Kimura, G.

    2015-12-01

    The relationship between temperature and the updip limit of seismicity has been demonstrated for accretionary margins where the incoming sediment is thick relative to basement relief (e.g., Oleskevich et al., JGR 1999). Here we show an example offshore the Osa Peninsula where this relationship does not appear to hold. At this non-accreting margin, the incoming sediment thickness is thin and the basement relief is substantial. The MW 6.4, 16 June 2002, Osa, Costa Rica earthquake occurred along the plate interface, 25 km landward of the trench at a depth of approximately 5-10 km (Arroyo et al., G3, 2014). Two-dimensional thermal models indicate that the temperature at this position is approximately 70-90° C (Harris et al., G3, 2010), and is cooler than the reported correlation between temperature and the updip limit of seismicity. We estimate the incoming fluid budget based on the 100 m section from the Costa Rica Seismogenesis Project reference site (IODP Exp. 334 Site U1381) using porosity and bulk mineral assemblage based on X-ray diffraction analysis of core samples. The porosity (76%) combined with the water content in smectite (~40 vol.%) and biogenic silica (~24 vol.%), leads to a total sedimentary water influx estimate of 6.9 m3/yr per m of trench length. The dehydration source term is calculated with respect to silica diagenesis and clay diagenesis using the thermal model. Peak mineral dehydration occurs at temperatures of approximately ~100 °C, 40-30 km landward of the trench and 5-10 km landward of the shallowest seismicity (Arroyo et al., G3, 2014). These results suggest that in this region the presence of subducting bathymetric relief may be more important in influencing the updip extent of seismicity than the thermal regime. This interpretation is consistent with the observed patchy seismicity (Bilek et al. Geology, 2003) and emphasizes the importance of frictional heterogeneities along the subduction thrust (Bilek and Lay, GRL, 2002).

  10. Seismic-wave attenuation associated with crustal faults in the New Madrid seismic zone

    USGS Publications Warehouse

    Hamilton, R.M.; Mooney, W.D.

    1990-01-01

    The attenuation of upper crustal seismic waves that are refracted with a velocity of about 6 kilometers per second varies greatly among profiles in the area of the New Madrid seismic zone in the central Mississippi Valley. The waves that have the strongest attenuation pass through the seismic trend along the axis of the Reelfoot rift in the area of the Blytheville arch. Defocusing of the waves in a low-velocity zone and/ or seismic scattering and absorption could cause the attenuation; these effects are most likely associated with the highly deformed rocks along the arch. Consequently, strong seismic-wave attenuation may be a useful criterion for identifying seismogenic fault zones.

  11. Apex-4 for SpaceX CRS-10

    NASA Image and Video Library

    2017-02-16

    APEX-04, or Advanced Plant EXperiments-04, is being prepared in a cold room in the Kennedy Space Center Processing Facility for SpaceX-10. The 30 petri plates are bundled into groups of 10 and placed into one of three science kits. The science kits allow easy handling when the crew removes the plates from cold stowage on station. Dr. Anna Lisa Paul of the University of Florida is the principal investigator for APEX-04. Apex-04 is an experiment involving Arabidopsis in petri plates inside the Veggie facility aboard the International Space Station. Since Arabidopsis is the genetic model of the plant world, it is a perfect sample organism for performing genetic studies in spaceflight. The experiment is the result of a grant from NASA’s Space Life and Physical Sciences division.

  12. Seismic hazard assessment: Issues and alternatives

    USGS Publications Warehouse

    Wang, Z.

    2011-01-01

    Seismic hazard and risk are two very important concepts in engineering design and other policy considerations. Although seismic hazard and risk have often been used inter-changeably, they are fundamentally different. Furthermore, seismic risk is more important in engineering design and other policy considerations. Seismic hazard assessment is an effort by earth scientists to quantify seismic hazard and its associated uncertainty in time and space and to provide seismic hazard estimates for seismic risk assessment and other applications. Although seismic hazard assessment is more a scientific issue, it deserves special attention because of its significant implication to society. Two approaches, probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA), are commonly used for seismic hazard assessment. Although PSHA has been pro-claimed as the best approach for seismic hazard assessment, it is scientifically flawed (i.e., the physics and mathematics that PSHA is based on are not valid). Use of PSHA could lead to either unsafe or overly conservative engineering design or public policy, each of which has dire consequences to society. On the other hand, DSHA is a viable approach for seismic hazard assessment even though it has been labeled as unreliable. The biggest drawback of DSHA is that the temporal characteristics (i.e., earthquake frequency of occurrence and the associated uncertainty) are often neglected. An alternative, seismic hazard analysis (SHA), utilizes earthquake science and statistics directly and provides a seismic hazard estimate that can be readily used for seismic risk assessment and other applications. ?? 2010 Springer Basel AG.

  13. Seismic hazard in the Intermountain West

    USGS Publications Warehouse

    Haller, Kathleen; Moschetti, Morgan P.; Mueller, Charles; Rezaeian, Sanaz; Petersen, Mark D.; Zeng, Yuehua

    2015-01-01

    The 2014 national seismic-hazard model for the conterminous United States incorporates new scientific results and important model adjustments. The current model includes updates to the historical catalog, which is spatially smoothed using both fixed-length and adaptive-length smoothing kernels. Fault-source characterization improved by adding faults, revising rates of activity, and incorporating new results from combined inversions of geologic and geodetic data. The update also includes a new suite of published ground motion models. Changes in probabilistic ground motion are generally less than 10% in most of the Intermountain West compared to the prior assessment, and ground-motion hazard in four Intermountain West cities illustrates the range and magnitude of change in the region. Seismic hazard at reference sites in Boise and Reno increased as much as 10%, whereas hazard in Salt Lake City decreased 5–6%. The largest change was in Las Vegas, where hazard increased 32–35%.

  14. Very-long-period seismic signals - filling the gap between deformation and seismicity

    NASA Astrophysics Data System (ADS)

    Neuberg, Jurgen; Smith, Paddy

    2013-04-01

    Good broadband seismic sensors are capable to record seismic transients with dominant wavelengths of several tens or even hundreds of seconds. This allows us to generate a multi-component record of seismic volcanic events that are located in between the conventional high to low-frequency seismic spectrum and deformation signals. With a much higher temporal resolution and accuracy than e.g. GPS records, these signals fill the gap between seismicity and deformation studies. In this contribution we will review the non-trivial processing steps necessary to retrieve ground deformation from the original velocity seismogram and explore which role the resulting displacement signals have in the analysis of volcanic events. We use examples from Soufriere Hills volcano in Montserrat, West Indies, to discuss the benefits and shortcomings of such methods regarding new insights into volcanic processes.

  15. Seismic and Geodetic Monitoring of the Nicoya, Costa Rica, Seismic Gap

    NASA Astrophysics Data System (ADS)

    Protti, M.; Gonzalez, V.; Schwartz, S.; Dixon, T.; Kato, T.; Kaneda, Y.; Simila, G.; Sampson, D.

    2007-05-01

    The Nicoya segment of the Middle America Trench has been recognized as a mature seismic gap with potential to generate a large earthquake in the near future (it ruptured with large earthquakes in 1853, 1900 and 1950). Low level of background seismicity and fast crustal deformation of the forearc are indicatives of strong coupling along the plate interface. Given its high seismic potential, the available data and especially the fact that the Nicoya peninsula extends over large part of the rupture area, this gap was selected as one of the two sites for a MARGINS-SEIZE experiment. With the goal of documenting the evolution of loading and stress release along this seismic gap, an international effort involving several institutions from Costa Rica, the United States and Japan is being carried out for over a decade in the region. This effort involves the installation of temporary and permanent seismic and geodetic networks. The seismic network includes short period, broad band and strong motion instruments. The seismic monitoring has provided valuable information on the geometry and characteristics of the plate interface. The geodetic network includes temporary and permanent GPS stations as well as surface and borehole tiltmeters. The geodetic networks have helped quantify the extend and degree of coupling. A continuously recording, three- station GPS network on the Nicoya Peninsula, Costa Rica, recorded what we believe is the first slow slip event observed along the plate interface of the Costa Rica subduction zone. We will present results from these monitoring networks. Collaborative international efforts are focused on expanding these seismic and geodetic networks to provide improved resolution of future creep events, to enhanced understanding of the mechanical behavior of the Nicoya subduction segment of the Middle American Trench and possibly capture the next large earthquake and its potential precursor deformation.

  16. Seismic Hazard Assessment of Tehran Based on Arias Intensity

    NASA Astrophysics Data System (ADS)

    Amiri, G. Ghodrati; Mahmoodi, H.; Amrei, S. A. Razavian

    2008-07-01

    In this paper probabilistic seismic hazard assessment of Tehran for Arias intensity parameter is done. Tehran is capital and most populated city of Iran. From economical, political and social points of view, Tehran is the most significant city of Iran. Since in the previous centuries, catastrophic earthquakes have occurred in Tehran and its vicinity, probabilistic seismic hazard assessment of this city for Arias intensity parameter is useful. Iso-intensity contour lines maps of Tehran on the basis of different attenuation relationships for different earthquake periods are plotted. Maps of iso-intensity points in the Tehran region are presented using proportional attenuation relationships for rock and soil beds for 2 hazard levels of 10% and 2% in 50 years. Seismicity parameters on the basis of historical and instrumental earthquakes for a time period that initiate from 4th century BC and ends in the present time are calculated using Tow methods. For calculation of seismicity parameters, the earthquake catalogue with a radius of 200 km around Tehran has been used. SEISRISKIII Software has been employed. Effects of different parameters such as seismicity parameters, length of fault rupture relationships and attenuation relationships are considered using Logic Tree.

  17. Detailed seismic velocity structure beneath the Hokkaido corner, NE Japan: Collision process of the forearc sliver

    NASA Astrophysics Data System (ADS)

    Kita, S.; Hasegawa, A.; Okada, T.; Nakajima, J.; Matsuzawa, T.; Katsumata, K.

    2010-12-01

    1. Introduction In south-eastern Hokkaido, the Kuril forearc sliver is colliding with the northeastern Japan arc due to the oblique subduction of the Pacific plate. This collision causes the formation of the Hidaka mountain range since the late Miocene (Kimura, 1986) and delamination of the lower-crust materials of the Kuril forearc sliver, which would be expected to descend into the mantle wedge below (e.g., Ito 2000; Ito and Iwasaki, 2002). In this study, we precisely investigated the three-dimensional seismic velocity structure beneath the Hokkaido corner to examine the collision of two forearcs in this area by using both of data from a dense temporary seismic network deployed in this area (Katsumata et al. [2006]) and those from the Kiban observation network, which covers the entire Japanese Islands with a station separation of 15-20 km. 2. Data and method The double-difference tomography method (Zhang and Thurber, 2003; 2006) was applied to a large number of arrival time data of 201,527 for P-waves and 150,963 for S-waves that were recorded at 125 stations from 10,971 earthquakes that occurred from 1999 to 2010. Grid intervals were set at 10 km in the along-arc direction, 12.5 km perpendicular to it, and 5-10 km in the vertical direction. 3. Results and discussion Inhomogeneous seismic velocity structure was clearly imaged in the Hokkaido corner at depths of 0-120 km. A high-velocity anomaly of P- and S- waves with a volume of 20 km x 90 km x 35km was detected just beneath the main zone of the Hidaka metamorphic belt at depths of 0-35 km. This high-velocity anomaly is continuously distributed from the depths of the mantle wedge to the surface. The western edge of the anomaly exactly corresponds to the Hidaka main thrust (HMT) at the surface. The highest velocity value in the anomaly corresponds to those of the uppermost mantle material (e.g. peridotite). The location of them at depths of 0-35km is also consistent with that of the Horoman-Peridotite belt, which

  18. Berkeley Seismological Laboratory Seismic Moment Tensor Report for the August 6, 2007 M3.9 Seismic event in central Utah

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ford, S; Dreger, D; Hellweg, P

    2007-08-08

    We have performed a complete moment tensor analysis of the seismic event, which occurred on Monday August 6, 2007 at 08:48:40 UTC 21 km from Mt.Pleasant, Utah. In our analysis we utilized complete three-component seismic records recorded by the USArray, University of Utah, and EarthScope seismic arrays. The seismic waveform data was integrated to displacement and filtered between 0.02 to 0.10 Hz following instrument removal. We used the Song et al. (1996) velocity model to compute Green's functions used in the moment tensor inversion. A map of the stations we used and the location of the event is shown inmore » Figure 1. In our moment tensor analysis we assumed a shallow source depth of 1 km consistent with the shallow depth reported for this event. As shown in Figure 2 the results point to a source mechanism with negligible double-couple radiation and is composed of dominant CLVD and implosive isotropic components. The total scalar seismic moment is 2.12e22 dyne cm corresponding to a moment magnitude (Mw) of 4.2. The long-period records are very well matched by the model (Figure 2) with a variance reduction of 73.4%. An all dilational (down) first motion radiation pattern is predicted by the moment tensor solution, and observations of first motions are in agreement.« less

  19. Improvement of real-time seismic magnitude estimation by combining seismic and geodetic instrumentation

    NASA Astrophysics Data System (ADS)

    Goldberg, D.; Bock, Y.; Melgar, D.

    2017-12-01

    Rapid seismic magnitude assessment is a top priority for earthquake and tsunami early warning systems. For the largest earthquakes, seismic instrumentation tends to underestimate the magnitude, leading to an insufficient early warning, particularly in the case of tsunami evacuation orders. GPS instrumentation provides more accurate magnitude estimations using near-field stations, but isn't sensitive enough to detect the first seismic wave arrivals, thereby limiting solution speed. By optimally combining collocated seismic and GPS instruments, we demonstrate improved solution speed of earthquake magnitude for the largest seismic events. We present a real-time implementation of magnitude-scaling relations that adapts to consider the length of the recording, reflecting the observed evolution of ground motion with time.

  20. Superconductivity, Pairing Symmetry, and Disorder in the Doped Topological Insulator Sn 1-xIn xTe for x >= 0.10.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smylie, M. P.; Claus, H.; Kwok, W. -K.

    The temperature dependence of the London penetration depth Delta lambda(T) in the superconducting doped topological crystalline insulator Sn1-xInxTe was measured down to 450 mK for two different doping levels, x approximate to 0.45 (optimally doped) and x approximate to 0.10 (underdoped), bookending the range of cubic phase in the compound. The results indicate no deviation from fully gapped BCS-like behavior, eliminating several candidate unconventional gap structures. Critical field values below 1 K and other superconducting parameters are also presented. The introduction of disorder by repeated particle irradiation with 5 MeV protons does not enhance T-c, indicating that ferroelectric interactions domore » not compete with superconductivity.« less

  1. Seismic Reflection Methods

    EPA Pesticide Factsheets

    Seismic methods are the most commonly conducted geophysical surveys for engineering investigations. Seismic refraction provides engineers and geologists with the most basic of geologic data via simple procedures with common equipment.

  2. Transition métal—isolant dans V 1-xMn xO 2-2xF 2x (0 < x ≤ 0, 10)étude des propriétés structurales, magnétiques, etélectriques

    NASA Astrophysics Data System (ADS)

    Akroune, A.; Casalot, A.

    1987-05-01

    V 1- xMn xO 2-2 xF 2 x samples (0 < x ≤ 0, 10) have been prepared by solid state reaction in sealed platinium tubes. The metal ⇄ insulator transition occurs at a quickly decreasing temperatures as MnF 2 increases. The crystallographic, magnetic, transport properties, and DTA have been determined and discussed.

  3. Comparative statistical and spectral studies of seismic and non-seismic sub-ionospheric VLF anomalies

    NASA Astrophysics Data System (ADS)

    Wolbang, Daniel; Biernat, Helfried; Schwingenschuh, Konrad; Eichelberger, Hans; Prattes, Gustav; Besser, Bruno; Boudjada, Mohammed Y.; Rozhnoi, Alexander; Solovieva, Maria; Biagi, Pier Francesco; Friedrich, Martin

    2013-04-01

    We present a comparative study of seismic and non-seismic sub-ionospheric VLF anomalies. Our method is based on parameter variations of the sub-ionospheric VLF waveguide formed by the surface and the lower ionosphere. The used radio links working in the frequency range between 10 and 50 kHz, the receivers are part of the European and Russian networks. Various authors investigated the lithopsheric-atmospheric-ionospheric coupling and predicted the lowering of the ionosphere over earthquake preparation zones [1]. The received nighttime signal of a sub-ionospheric waveguide depends strongly on the height of the ionospheric E-layer, typically 80 to 85 km. This height is characterized by a typical gradient of the electron density near the atmospheric-ionospheric boundary [2]. In the last years it has been turned out that one of the major issues of sub-ionospheric seismo-electromagnetic VLF studies are the non-seismic influences on the links, which have to be carefully characterized. Among others this could be traveling ionospheric disturbances, geomagnetic storms as well as electron precipitation. Our emphasis is on the analysis of daily, monthly and annual variations of the VLF amplitude. To improve the statistics we investigate the behavior and typical variations of the VLF amplitude and phase over a period of more than 2 years. One important parameter considered is the rate how often the fluctuations are falling below a significant level derived from a mean value. The temporal variations and the amplitudes of these depressions are studied for several years for sub-ionospheric VLF radio links with the receivers in Graz and Kamchatka. In order to study the difference between seismic and non-seismic turbulences in the lower ionosphere a power spectrum analysis of the received signal is performed too. We are especially interested in variations T>6 min which are typical for atmospheric gravity waves causing the lithospheric-atmospheric-ionospheric coupling [3]. All

  4. 32 CFR 2003.10 - Approval, amendment, and publication of bylaws, rules, and procedures (Article X).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Approval, amendment, and publication of bylaws, rules, and procedures (Article X). 2003.10 Section 2003.10 National Defense Other Regulations Relating... Bylaws § 2003.10 Approval, amendment, and publication of bylaws, rules, and procedures (Article X...

  5. 32 CFR 2003.10 - Approval, amendment, and publication of bylaws, rules, and procedures (Article X).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Approval, amendment, and publication of bylaws, rules, and procedures (Article X). 2003.10 Section 2003.10 National Defense Other Regulations Relating... Bylaws § 2003.10 Approval, amendment, and publication of bylaws, rules, and procedures (Article X...

  6. SiSeRHMap v1.0: a simulator for mapped seismic response using a hybrid model

    NASA Astrophysics Data System (ADS)

    Grelle, Gerardo; Bonito, Laura; Lampasi, Alessandro; Revellino, Paola; Guerriero, Luigi; Sappa, Giuseppe; Guadagno, Francesco Maria

    2016-04-01

    The SiSeRHMap (simulator for mapped seismic response using a hybrid model) is a computerized methodology capable of elaborating prediction maps of seismic response in terms of acceleration spectra. It was realized on the basis of a hybrid model which combines different approaches and models in a new and non-conventional way. These approaches and models are organized in a code architecture composed of five interdependent modules. A GIS (geographic information system) cubic model (GCM), which is a layered computational structure based on the concept of lithodynamic units and zones, aims at reproducing a parameterized layered subsoil model. A meta-modelling process confers a hybrid nature to the methodology. In this process, the one-dimensional (1-D) linear equivalent analysis produces acceleration response spectra for a specified number of site profiles using one or more input motions. The shear wave velocity-thickness profiles, defined as trainers, are randomly selected in each zone. Subsequently, a numerical adaptive simulation model (Emul-spectra) is optimized on the above trainer acceleration response spectra by means of a dedicated evolutionary algorithm (EA) and the Levenberg-Marquardt algorithm (LMA) as the final optimizer. In the final step, the GCM maps executor module produces a serial map set of a stratigraphic seismic response at different periods, grid solving the calibrated Emul-spectra model. In addition, the spectra topographic amplification is also computed by means of a 3-D validated numerical prediction model. This model is built to match the results of the numerical simulations related to isolate reliefs using GIS morphometric data. In this way, different sets of seismic response maps are developed on which maps of design acceleration response spectra are also defined by means of an enveloping technique.

  7. Catalogs of micro-seismicity recorded at the Pechgraben landslide (Upper Austria)

    NASA Astrophysics Data System (ADS)

    Provost, Floriane; Hibert, Clément; Vouillamoz, Naomi; Malet, Jean-Philippe; Ottowitz, David; Jochum, Birgit

    2017-04-01

    The microseismicity activity of soft-rock landslides (i.e. developed in clays and clay-shales) present various types of seismic event associated with the slope deformation. They are assumed to be linked to the slip at the interface with the bedrock or at the boundaries of the landslide, to material failures, to fissure openings or to fluid transfers within the medium. It is currently necessary to document the microseismicity generated by soft-rock landslides on a larger amount of instrumented slopes in order to validate the current seismic typology and understand the source mechanisms in relation with the deformation. Previous studies have shown the interest of the Pechgraben (Upper Austria) clay-shale landslide for such documentation. This landslide was reactivated in summer 2013 after heavy rainfalls and is characterized by a shallow bedrock (<10m) and varying displacement rates in space and time (from mm.day-1 to cm.day-1). A short pilot seismic campaign (<9 days) was carried out in 2015 and micro-earthquakes as well as episodic tremor-like signals were recorded. A new passive seismic campaign was conducted during one month in November-December 2016. Two broadband three-component seismometers were installed facing each other on the two stable borders of the slope with one tripartite seismic array deployed in the center, on top of the most active area of the landslide. The deformation pattern of the slope was monitored remotely with a ground-based InSAR at a high frequency (10 min). This study aims to present the variety of seismic sources generated by the landslide, using supervised machine learning algorithms for event detection and classification, and to correlate the resulting micro-seismic catalog with the changes in time of the slope deformation.

  8. Seismicity of the St. Lawrence paleorift faults overprinted by a meteorite impact crater: Implications for crustal strength based on new earthquake relocations in the Charlevoix Seismic Zone, Eastern Canada

    NASA Astrophysics Data System (ADS)

    Yu, H.; Harrington, R. M.; Liu, Y.; Lamontagne, M.; Pang, M.

    2015-12-01

    The Charlevoix Seismic Zone (CSZ), located along the St. Lawrence River (SLR) ~100 km downstream from Quebec City, is the most active seismic zone in eastern Canada with five historic earthquakes of M 6-7 and ~ 200 events/year reported by the Canadian National Seismograph Network. Cataloged earthquake epicenters outline two broad linear zones along the SLR with little shallow seismicity in between. Earthquakes form diffuse clusters between major dipping faults rather than concentrating on fault planes. Detailed fault geometry in the CSZ is uncertain and the effect on local seismicity of a meteorite impact structure that overprints the paleorift faults remains ambiguous. Here we relocate 1639 earthquakes occurring in the CSZ between 01/1988 - 10/2010 using the double-difference relocation method HypoDD and waveforms primarily from 7 local permanent stations. We use the layered SLR north shore velocity model from Lamontagne (1999), and travel time differences based on both catalog and cross-correlated P and S-phase picks. Of the 1639 relocated earthquakes, 1236 (75.4%) satisfied selection criteria of horizontal and vertical errors less than 2 km and 1 km respectively. Cross-sections of relocated seismicity show hypocenters along distinct active fault segments. Earthquakes located beneath the north shore of the SLR are likely correlated with the NW Gouffre fault, forming a ~10 km wide seismic zone parallel to the river, with dip angle changing to near vertical at the northern edge of the impact zone. In contrast, seismicity beneath the SLR forms a diffuse cloud within the impact structure, likely representing a highly fractured volume. It further implies that faults could be locally weak and subject to high pore-fluid pressures. Seismicity outside the impact structure defines linear structures aligning with the Charlevoix fault. Relocated events of M > 4 all locate outside the impact structure, indicating they nucleated on the NE-SW-oriented paleorift faults.

  9. Seismic databases of The Caucasus

    NASA Astrophysics Data System (ADS)

    Gunia, I.; Sokhadze, G.; Mikava, D.; Tvaradze, N.; Godoladze, T.

    2012-12-01

    The Caucasus is one of the active segments of the Alpine-Himalayan collision belt. The region needs continues seismic monitoring systems for better understanding of tectonic processes going in the region. Seismic Monitoring Center of Georgia (Ilia State University) is operating the digital seismic network of the country and is also collecting and exchanging data with neighboring countries. The main focus of our study was to create seismic 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 seismic networks. The first analog seismic station in Georgia was installed in 1899 in the Caucasus in Tbilisi city. The number of analog seismic 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 seismic network was developed in Georgia since 2003. The number of digital seismic 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 seismic stations. Database is available online. That will make convenient interface for seismic data exchange data between Caucasus neighboring countries. It also makes easier both the seismic 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.

  10. A large silent earthquake and the future rupture of the Guerrero seismic

    NASA Astrophysics Data System (ADS)

    Kostoglodov, V.; Lowry, A.; Singh, S.; Larson, K.; Santiago, J.; Franco, S.; Bilham, R.

    2003-04-01

    The largest global earthquakes typically occur at subduction zones, at the seismogenic boundary between two colliding tectonic plates. These earthquakes release elastic strains accumulated over many decades of plate motion. Forecasts of these events have large errors resulting from poor knowledge of the seismic cycle. The discovery of slow slip events or "silent earthquakes" in Japan, Alaska, Cascadia and Mexico provides a new glimmer of hope. In these subduction zones, the seismogenic part of the plate interface is loading not steadily as hitherto believed, but incrementally, partitioning the stress buildup with the slow slip events. If slow aseismic slip is limited to the region downdip of the future rupture zone, slip events may increase the stress at the base of the seismogenic region, incrementing it closer to failure. However if some aseismic slip occurs on the future rupture zone, the partitioning may significantly reduce the stress buildup rate (SBR) and delay a future large earthquake. Here we report characteristics of the largest slow earthquake observed to date (Mw 7.5), and its implications for future failure of the Guerrero seismic gap, Mexico. The silent earthquake began in October 2001 and lasted for 6-7 months. Slow slip produced measurable displacements over an area of 550x250 km2. Average slip on the interface was about 10 cm and the equivalent magnitude, Mw, was 7.5. A shallow subhorizontal configuration of the plate interface in Guererro is a controlling factor for the physical conditions favorable for such extensive slow slip. The total coupled zone in Guerrero is 120-170 km wide while the seismogenic, shallowest portion is only 50 km. This future rupture zone may slip contemporaneously with the deeper aseismic sleep, thereby reducing SBR. The slip partitioning between seismogenic and transition coupled zones may diminish SBR up to 50%. These two factors are probably responsible for a long (at least since 1911) quiet on the Guerrero seismic gap

  11. Co-seismic slip, post-seismic slip, and largest aftershock associated with the 1994 Sanriku-haruka-oki, Japan, earthquake

    NASA Astrophysics Data System (ADS)

    Yagi, Yuji; Kikuchi, Masayuki; Nishimura, Takuya

    2003-11-01

    We analyzed continuous GPS data to investigate the spatio-temporal distribution of co-seismic slip, post-seismic slip, and largest aftershock associated with the 1994 Sanriku-haruka-oki, Japan, earthquake (Mw = 7.7). To get better resolution for co-seismic and post-seismic slip distribution, we imposed a weak constraint as a priori information of the co-seismic slip determined by seismic wave analyses. We found that the post-seismic slip during 100 days following the main-shock amount to as much moment release as the main-shock, and that the sites of co-seismic slip and post-seismic slip are partitioning on a plate boundary region in complimentary fashion. The major post-seismic slip was triggered by the mainshock in western side of the co-seismic slip, and the extent of the post-seismic slip is almost unchanged with time. It rapidly developed a shear stress concentration ahead of the slip area, and triggered the largest aftershock.

  12. Seismic vibration source

    NASA Technical Reports Server (NTRS)

    Dowler, W. L.; Varsi, G.; Yang, L. C. (Inventor)

    1979-01-01

    A system for vibrating the earth in a location where seismic mapping is to take place is described. A relatively shallow hole formed in the earth, such as a hole 10 feet deep, placing a solid propellant in the hole, sealing a portion of the hole above the solid propellant with a device that can rapidly open and close to allow a repeatedly interrupted escape of gas. The propellant is ignited so that high pressure gas is created which escapes in pulses to vibrate the earth.

  13. Small aperture seismic arrays for studying planetary interiors and seismicity

    NASA Astrophysics Data System (ADS)

    Schmerr, N. C.; Lekic, V.; Fouch, M. J.; Panning, M. P.; Siegler, M.; Weber, R. C.

    2017-12-01

    Seismic arrays are a powerful tool for understanding the interior structure and seismicity across objects in the Solar System. Given the operational constraints of ground-based lander investigations, a small aperture seismic array can provide many of the benefits of a larger-scale network, but does not necessitate a global deployment of instrumentation. Here we define a small aperture array as a deployment of multiple seismometers, with a separation between instruments of 1-1000 meters. For example, small aperture seismic arrays have been deployed on the Moon during the Apollo program, the Active Seismic Experiments of Apollo 14 and 16, and the Lunar Seismic Profiling Experiment deployed by the Apollo 17 astronauts. Both were high frequency geophone arrays with spacing of 50 meters that provided information on the layering and velocity structure of the uppermost kilometer of the lunar crust. Ideally such arrays would consist of instruments that are 3-axis short period or broadband seismometers. The instruments must have a sampling rate and frequency range sensitivity capable of distinguishing between waves arriving at each station in the array. Both terrestrial analogs and the data retrieved from the Apollo arrays demonstrate the efficacy of this approach. Future opportunities exist for deployment of seismic arrays on Europa, asteroids, and other objects throughout the Solar System. Here we will present both observational data and 3-D synthetic modeling results that reveal the sensing requirements and the primary advantages of a small aperture seismic array over single station approach. For example, at the smallest apertures of < 1 m, we constrain that sampling rates must exceed 500 Hz and instrument sensitivity must extend to 100 Hz or greater. Such advantages include the improved ability to resolve the location of the sources near the array through detection of backazimuth and differential timing between stations, determination of the small-scale structure

  14. First USGS urban seismic hazard maps predict the effects of soils

    USGS Publications Warehouse

    Cramer, C.H.; Gomberg, J.S.; Schweig, E.S.; Waldron, B.A.; Tucker, K.

    2006-01-01

    Probabilistic and scenario urban seismic hazard maps have been produced for Memphis, Shelby County, Tennessee covering a six-quadrangle area of the city. The nine probabilistic maps are for peak ground acceleration and 0.2 s and 1.0 s spectral acceleration and for 10%, 5%, and 2% probability of being exceeded in 50 years. Six scenario maps for these three ground motions have also been generated for both an M7.7 and M6.2 on the southwest arm of the New Madrid seismic zone ending at Marked Tree, Arkansas. All maps include the effect of local geology. Relative to the national seismic hazard maps, the effect of the thick sediments beneath Memphis is to decrease 0.2 s probabilistic ground motions by 0-30% and increase 1.0 s probabilistic ground motions by ???100%. Probabilistic peak ground accelerations remain at levels similar to the national maps, although the ground motion gradient across Shelby County is reduced and ground motions are more uniform within the county. The M7.7 scenario maps show ground motions similar to the 5%-in-50-year probabilistic maps. As an effect of local geology, both M7.7 and M6.2 scenario maps show a more uniform seismic ground-motion hazard across Shelby County than scenario maps with constant site conditions (i.e., NEHRP B/C boundary).

  15. Investigating the Evolution of Southern California Salt Marshes: A Facies Model to Understand the Influence of Seismic Events on Environmental Resiliency and Sustainability

    NASA Astrophysics Data System (ADS)

    Aranda, A. N.; Carlin, J. A.; Rhodes, B. P.; Kirby, M.

    2016-02-01

    Only 10-20% of the US Pacific coast is estimated to be suitable for marsh development. In southern California specifically, marshes are disappearing ecosystems due to high population and urbanization. The future environmental impacts from climate change on these ecosystems are complicated not only by anthropogenic influences, but also by seismic activity in the region. In general, marsh evolution and response to seismic activity has yet to be fully explored in southern California. This study aims to develop a sediment facies model for salt marsh evolution in southern California by utilizing the salt marshes of the Seal Beach Wetlands (SBW). The SBW is an ideal location to develop the facies model because it straddles the active Newport-Inglewood Fault Zone. We collected sediment cores from the SBW that underwent a variety of sedimentological and geochemical analyses including grain size, X-Ray Fluorescence core scanning, magnetic susceptibility, and loss-on-ignition.. The results show a facies model consisting of sequences of marsh accretion punctuated by seismic events. These seismic events caused the marsh to subside, effectively re-setting marsh development from peat generation at a vegetated marsh state, to subtidal to intertidal mud deposition. The model also allowed us to qualify and quantify marsh recovery as inferred from event intensity, where what we perceived as more intense events resulted in more significant ecosystem disturbances and longer recovery times. Understanding this interplay between seismic activity and marsh development highlights the fragile nature of these ecosystems to climate change and sea level rise, as these stresses will only become amplified by seismic events.

  16. Investigation of the presence of transverse anisotropy in the 3D baseline seismic data at Ketzin, Germany

    NASA Astrophysics Data System (ADS)

    Kruachanta, Mingkhwan; Ivandic, Monika; Juhlin, Christopher

    2015-04-01

    A 3D seismic baseline survey was acquired within the EU funded CO2SINK project at Ketzin, Germany in 2005. CO2 was injected at about 630-650 meters depth into the Stuttgart Formation. The formation is heterogeneous with lithological facies of channel sandstones interbedded with floodplain mudstones. It underlies an approximately 210 meters thick sequence of claystone, silty claystone and anhydrite of the Weser and Arnstadt Formations. Claystone is considered to be an intrinsic-type anisotropic medium due to the platy shape of clay minerals. A thick interval of claystone caprock may show seismic velocity variation with propagation angle or seismic anisotropy. In this study, the degree of anisotropy was assumed to be weak. The processing steps followed conventional seismic data processing, except for the velocity estimation used for the moveout correction. The velocity approximation used nonhyperbolic or 4th order moveout for transverse anisotropic (TI) media which was proposed by Alkhalifah (1997). The 4th order moveout velocity approximation used the zero-dip normal moveout velocity (V nmo) and eta (?) anisotropic parameter for the velocity correction as defined by the following equations. tx = √(t02+X2/Vnmo2-2? X4/vnmo2 / t2o[1+2?)X2/Vnmo2]) where ? = 12[ 2 ] VVh2- - 1 nmoand tx is the traveltime, to is traveltime at zero offset, X is the offset and V h is horizontal velocity. Preliminary results indicate the presence of anisotropy in the study area with an eta parameter ranging from -0.185 to +0.180. Moveout velocity corrected stacked sections show an improvement in the continuity of reflections in the shallow part of the survey (above 500 ms), whereas there is no significant difference in the deeper region.

  17. Geophysical Observatory in Kamchatka region for monitoring of phenomena connected with seismic activity

    NASA Astrophysics Data System (ADS)

    Uyeda, S.; Nagao, T.; Hattori, K.; Hayakawa, M.; Miyaki, K.; Molchanov, O.; Gladychev, V.; Baransky, L.; Chtchekotov, A.; Fedorov, E.; Pokhotelov, O.; Andreevsky, S.; Rozhnoi, A.; Khabazin, Y.; Gorbatikov, A.; Gordeev, E.; Chebrov, V.; Sinitzin, V.; Lutikov, A.; Yunga, S.; Kosarev, G.; Surkov, V.; Belyaev, G.

    Regular monitoring of some geophysical parameters in association with seismicity has been carried out since last year at the Japan-Russian Complex Geophysical Observatory in the Kamchatka region. This observatory was organized in connection with the ISTC project in Russia and was motivated by the results of the FRONTIER/RIKEN and FRONTIER/NASDA research projects in Japan. The main purpose of the observations is to investigate the electromagnetic and acoustic phenomena induced by the lithosphere processes (especially by seismic activity). The seismicity of the Kamchatka area is analyzed and a description of the observatory equipment is presented. At present, the activity of the observatory includes the seismic (frequency range ∆F = 0.5 - 40 Hz) and meteorological recordings, together with seismo-acoustic (∆F = 30 - 1000 Hz) and electromagnetic observations: three-component magnetic ULF variations ( ∆F = 0.003 - 30 Hz), three-component electric potential variations ( ∆F < 1.0 Hz), and VLF transmitter's signal perturbations ( ∆F ~ 10 - 40 kHz).

  18. Seismic Yield Estimates of UTTR Surface Explosions

    NASA Astrophysics Data System (ADS)

    Hayward, C.; Park, J.; Stump, B. W.

    2016-12-01

    Since 2007 the Utah Test and Training Range (UTTR) has used explosive demolition as a method to destroy excess solid rocket motors ranging in size from 19 tons to less than 2 tons. From 2007 to 2014, 20 high quality seismic stations within 180 km recorded most of the more than 200 demolitions. This provides an interesting dataset to examine seismic source scaling for surface explosions. Based upon observer records, shots were of 4 sizes, corresponding to the size of the rocket motors. Instrument corrections for the stations were quality controlled by examining the P-wave amplitudes of all magnitude 6.5-8 earthquakes from 30 to 90 degrees away. For each station recording, the instrument corrected RMS seismic amplitude in the first 10 seconds after the P-onset was calculated. Waveforms at any given station for all the observed explosions are nearly identical. The observed RMS amplitudes were fit to a model including a term for combined distance and station correction, a term for observed RMS amplitude, and an error term for the actual demolition size. The observed seismic yield relationship is RMS=k*Weight2/3 . Estimated yields for the largest shots vary by about 50% from the stated weights, with a nearly normal distribution.

  19. Avoidance of seismic survey activities by penguins.

    PubMed

    Pichegru, Lorien; Nyengera, Reason; McInnes, Alistair M; Pistorius, Pierre

    2017-11-24

    Seismic surveys in search for oil or gas under the seabed, produce the most intense man-made ocean noise with known impacts on invertebrates, fish and marine mammals. No evidence to date exists, however, about potential impacts on seabirds. Penguins may be expected to be particularly affected by loud underwater sounds, due to their largely aquatic existence. This study investigated the behavioural response of breeding endangered African Penguins Spheniscus demersus to seismic surveys within 100 km of their colony in South Africa, using a multi-year GPS tracking dataset. Penguins showed a strong avoidance of their preferred foraging areas during seismic activities, foraging significantly further from the survey vessel when in operation, while increasing their overall foraging effort. The birds reverted to normal behaviour when the operation ceased, although longer-term repercussions on hearing capacities cannot be precluded. The rapid industrialization of the oceans has increased levels of underwater anthropogenic noises globally, a growing concern for a wide range of taxa, now also including seabirds. African penguin numbers have decreased by 70% in the last 10 years, a strong motivation for precautionary management decisions, including the exclusion of seismic exploratory activities within at least 100 km of their breeding colonies.

  20. Seismic hazards in Thailand: a compilation and updated probabilistic analysis

    NASA Astrophysics Data System (ADS)

    Pailoplee, Santi; Charusiri, Punya

    2016-06-01

    A probabilistic seismic hazard analysis (PSHA) for Thailand was performed and compared to those of previous works. This PSHA was based upon (1) the most up-to-date paleoseismological data (slip rates), (2) the seismic source zones, (3) the seismicity parameters ( a and b values), and (4) the strong ground-motion attenuation models suggested as being suitable models for Thailand. For the PSHA mapping, both the ground shaking and probability of exceedance (POE) were analyzed and mapped using various methods of presentation. In addition, site-specific PSHAs were demonstrated for ten major provinces within Thailand. For instance, a 2 and 10 % POE in the next 50 years of a 0.1-0.4 g and 0.1-0.2 g ground shaking, respectively, was found for western Thailand, defining this area as the most earthquake-prone region evaluated in Thailand. In a comparison between the ten selected specific provinces within Thailand, the Kanchanaburi and Tak provinces had comparatively high seismic hazards, and therefore, effective mitigation plans for these areas should be made. Although Bangkok was defined as being within a low seismic hazard in this PSHA, a further study of seismic wave amplification due to the soft soil beneath Bangkok is required.

  1. Geographic deaggregation of seismic hazard in the United States

    USGS Publications Warehouse

    Harmsen, S.; Frankel, A.

    2001-01-01

    The seismic hazard calculations for the 1996 national seismic hazard maps have been geographically deaggregated to assist in the understanding of the relative contributions of sources. These deaggregations are exhibited as maps with vertical bars whose heights are proportional to the contribution that each geographical cell makes to the ground-motion exceedance hazard. Bar colors correspond to average source magnitudes. We also extend the deaggregation analysis reported in Harmsen et al. (1999) to the western conterminous United States. In contrast to the central and eastern United States (CEUS); the influence of specific faults or characteristic events can be clearly identified. Geographic deaggregation for 0.2-sec and 1.0-sec pseudo spectral acceleration (SA) is performed for 10% probability of exceedance (PE) in 50 yr (475-yr mean return period) and 2% PE in 50 yr (2475-yr mean return period) for four western U.S. cities, Los Angeles, Salt Lake City, San Francisco, and Seattle, and for three central and eastern U.S. cities, Atlanta, Boston, and Saint Louis. In general, as the PE is lowered, the sources of hazard closer to the site dominate. Larger, more distant earthquakes contribute more significantly to hazard for 1.0-sec SA than for 0.2-sec SA. Additional maps of geographically deaggregated seismic hazard are available on the Internet for 120 cities in the conterminous United States (http://geohazards. cr.usgs.gov/eq/) for 1-sec SA and for 0.2-sec SA with a 2% PE in 50 yr. Examination of these maps of hazard contributions enables the investigator to determine the distance and azimuth to predominant sources, and their magnitudes. This information can be used to generate scenario earthquakes and corresponding time histories for seismic design and retrofit. Where fault density is lower than deaggregation cell dimensions, we can identify specific faults that contribute significantly to the seismic hazard at a given site. Detailed fault information enables

  2. Seismic Linear Noise Attenuation with Use of Radial Transform

    NASA Astrophysics Data System (ADS)

    Szymańska-Małysa, Żaneta

    2018-03-01

    One of the goals of seismic data processing is to attenuate the recorded noise in order to enable correct interpretation of the image. Radial transform has been used as a very effective tool in the attenuation of various types of linear noise, both numerical and real (such as ground roll, direct waves, head waves, guided waves etc). The result of transformation from offset - time (X - T) domain into apparent velocity - time (R - T) domain is frequency separation between reflections and linear events. In this article synthetic and real seismic shot gathers were examined. One example was targeted at far offset area of dataset where reflections and noise had similar apparent velocities and frequency bands. Another example was a result of elastic modelling where linear artefacts were produced. Bandpass filtering and scaling operation executed in radial domain attenuated all discussed types of linear noise very effectively. After noise reduction all further processing steps reveal better results, especially velocity analysis, migration and stacking. In all presented cases signal-to-noise ratio was significantly increased and reflections covered previously by noise were revealed. Power spectra of filtered seismic records preserved real dynamics of reflections.

  3. An Optical and Infrared Time-domain Study of the Supergiant Fast X-Ray Transient Candidate IC 10 X-2

    NASA Astrophysics Data System (ADS)

    Kwan, Stephanie; Lau, Ryan M.; Jencson, Jacob; Kasliwal, Mansi M.; Boyer, Martha L.; Ofek, Eran; Masci, Frank; Laher, Russ

    2018-03-01

    We present an optical and infrared (IR) study of IC 10 X-2, a high-mass X-ray binary in the galaxy IC 10. Previous optical and X-ray studies suggest that X-2 is a Supergiant Fast X-ray Transient: a large-amplitude (factor of ∼100), short-duration (hours to weeks) X-ray outburst on 2010 May 21. We analyze R- and g-band light curves of X-2 from the intermediate Palomar Transient Factory taken between 2013 July 15 and 2017 February 14 that show high-amplitude (≳1 mag), short-duration (≲8 days) flares and dips (≳0.5 mag). Near-IR spectroscopy of X-2 from Palomar/TripleSpec show He I, Paschen-γ, and Paschen-β emission lines with similar shapes and amplitudes as those of luminous blue variables (LBVs) and LBV candidates (LBVc). Mid-IR colors and magnitudes from Spitzer/Infrared Array Camera photometry of X-2 resemble those of known LBV/LBVcs. We suggest that the stellar companion in X-2 is an LBV/LBVc and discuss possible origins of the optical flares. Dips in the optical light curve are indicative of eclipses from optically thick clumps formed in the winds of the stellar counterpart. Given the constraints on the flare duration (0.02–0.8 days) and the time between flares (15.1 ± 7.8 days), we estimate the clump volume filling factor in the stellar winds, f V , to be 0.01< {f}V< 0.71, which overlaps with values measured from massive star winds. In X-2, we interpret the origin of the optical flares as the accretion of clumps formed in the winds of an LBV/LBVc onto the compact object.

  4. Structure and magnetic properties of Sm1-xZrx Fe10Si2 (x=0.2-0.6) alloys

    NASA Astrophysics Data System (ADS)

    Gjoka, M.; Sarafidis, C.; Psycharis, V.; Devlin, E.; Niarchos, D.; Hadjipanayis, G.

    2017-10-01

    Structure and magnetic properties of Sm1-xZrxFe10Si2 (0.1 ≤ x ≤ 0.6) alloys have been characterized using X-ray diffraction, thermomagnetic analysis and Mössbauer spectroscopy. The formation of the tetragonal ThMn12 -type structure was been observed in all alloys, without further annealing. The Curie temperature decreases linearly with Zr substitution from 322 °C for x=0.1 to 395 °C for x=0.6. Mössbauer spectroscopy showed the iron hyperfine field values decrease with increasing Zr content, and also confirmed changes to the magnetic anisotropy with increasing Zr content observed by XRD on oriented samples.

  5. The 2017 Maple Creek Seismic Swarm in Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Pang, G.; Hale, J. M.; Farrell, J.; Burlacu, R.; Koper, K. D.; Smith, R. B.

    2017-12-01

    The University of Utah Seismograph Stations (UUSS) performs near-real-time monitoring of seismicity in the region around Yellowstone National Park in partnership with the United States Geological Survey and the National Park Service. UUSS operates and maintains 29 seismic stations with network code WY (short-period, strong-motion, and broadband) and records data from five other seismic networks—IW, MB, PB, TA, and US—to enhance the location capabilities in the Yellowstone region. A seismic catalog is produced using a conventional STA/LTA detector and single-event location techniques (Hypoinverse). On June 12, 2017, a seismic swarm began in Yellowstone National Park about 5 km east of Hebgen Lake. The swarm is adjacent to the source region of the 1959 MW 7.3 Hebgen Lake earthquake, in an area corresponding to positive Coulumb stress change from that event. As of Aug. 1, 2017, the swarm consists of 1481 earthquakes with 1 earthquake above magnitude 4, 8 earthquakes in the magnitude 3 range, 115 earthquakes in the magnitude 2 range, 469 earthquakes in the magnitude 1 range, 856 earthquakes in the magnitude 0 range, 22 earthquakes with negative magnitudes, and 10 earthquakes with no magnitude. Earthquake depths are mostly between 3 and 10 km and earthquake depth increases toward the northwest. Moment tensors for the 2 largest events (3.6 MW and 4.4. MW) show strike-slip faulting with T axes oriented NE-SW, consistent with the regional stress field. We are currently using waveform cross-correlation methods to measure differential travel times that are being used with the GrowClust program to generate high-accuracy relative relocations. Those locations will be used to identify structures in the seismicity and make inferences about the tectonic and magmatic processes causing the swarm.

  6. X-38 Experimental Aeroheating at Mach 10

    NASA Technical Reports Server (NTRS)

    Berry, Scott A.; Horvath, Thomas J.; Weilmuenster, K. James; Alter, Stephan J.; Merski, N. Ronald

    2001-01-01

    This report provides an update of the hypersonic aerothermodynamic wind tunnel test program conducted at the NASA Langley Research Center in support of the X-38 program. Global surface heat transfer distributions were measured on 0.0177 and 0.0236 scale models of the proposed X-38 configuration at Mach 10 in air. The parametrics that were investigated primarily include freestream unit Reynolds numbers of 0.6 to 2.2 million per foot and body flap deflections of 15, 20, and 25 deg for an angle-of-attack of 40 deg. The model-scale variance was tested to obtain laminar, transitional, and turbulent heating levels on the defected bodyflaps. In addition, a limited investigation of forced boundary layer transition through the use of discrete roughness elements was performed. Comparisons of the present experimental results to computational predictions and previous experimental data were conducted Laminar, transitional, and turbulent heating levels were observed on the deflected body flap, which compared favorably to the computational results and to the predicted heating based on the flight aerothermodynamic database.

  7. Seismic imaging of the oil and geothermal reservoirs using the induced seismicity

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Toksoz, M. N.; Fehler, M.

    2011-12-01

    It is known that microseismicity can be induced in the oil field due to the stress change caused by oil/gas production. Similarly, injection of high-pressure fluids into the reservoir can also induce microseismicity. Due to the proximity of induced seismicity to the reservoir, in some cases, it may be advantageous to use induced seismicity to image the reservoir. The seismic stations for monitoring the induced seismicity are usually sparse. Conventional travel time tomography using travel times from seismic events to stations may not be applicable because of poor ray coverage outside the source region. In comparison, the double-difference tomography method of Zhang and Thurber (2003) that uses the differential travel times is able to image the reservoir by avoiding determining the velocity structure outside the source region. In this study, we present two case studies of applying double-difference tomography to induced seismicity monitored by borehole stations. In the case of an oil field in Oman, five closely spaced monitoring wells are used to monitor microseismicity induced by gas production. In each well, multiple seismic sensors are positioned from depths 750 m - 1250 m and about 2000 events are selected for tomography. Reservoir imaging shows encouraging results in identifying structures and velocity changes within reservoir layers. Clear velocity contrast was seen across the major northeast-southwest faults. Low Vp, low Vs and low Vp/Vs anomalies are mainly associated with the gas production layer. For the case of the Soultz Enhanced Geothermal System at Soultz-sous-Forets, France, we used travel time data from the September and October 1993 hydraulic stimulations, where only four borehole stations are available. The results showed that the S-wave velocity structure correlated well with seismicity and showed low velocity zones at depths between 2900 and 3300 meters, where fluid was believed to have infiltrated the reservoir. We also attempt time

  8. Archaeological Graves Revealing By Means of Seismic-electric Effect

    NASA Astrophysics Data System (ADS)

    Boulytchov, A.

    [a4paper,12pt]article english Seismic-electric effect was applied in field to forecast subsurface archaeological cul- tural objects. A source of seismic waves were repeated blows of a heavy hammer or powerful signals of magnetostrictive installation. Main frequency used was 500 Hz. Passed a soil layer and reached a second boundary between upper clayey-sand sedi- ments and archaeological object, the seismic wave caused electromagnetic fields on the both boundaries what in general is due to dipole charge separation owe to an im- balance of streaming currents induced by the seismic wave on opposite sides of a boundary interface. According to theoretical works of Pride the electromagnetic field appears on a boundary between two layers with different physical properties in the time of seismic wave propagation. Electric responses of electromagnetic fields were measured on a surface by pair of grounded dipole antennas or by one pivot and a long wire antenna acting as a capacitive pickup. The arrival times of first series of responses correspond to the time of seismic wave propagation from a source to a boundary between soil and clayey-sand layers. The arrival times of second row of responses correspond to the time of seismic wave way from a source to a boundary of clayey-sand layer with the archaeological object. The method depths successfully investigated were between 0.5-10 m. Similar electromagnetic field on another type of geological structure was also revealed by Mikhailov et al., Massachusetts, but their signals registered from two frontiers were too faint and not evident in comparing with ours ones that occurred to be perfect and clear. Seismic-electric method field experi- ments were successfully provided for the first time on archaeological objects.

  9. Effects of Regulation on Induced Seismicity in Southern Kansas

    NASA Astrophysics Data System (ADS)

    Rubinstein, J. L.; Ellsworth, W. L.; Dougherty, S. L.

    2016-12-01

    The appearance of seismicity concurrent with the expansion of oil and gas activities in southern Kansas since September 2012 suggests that industrial operations are inducing earthquakes there. Much of the seismicity can be related to high-rate injection wells within 5 km of the earthquakes. There is significant complexity to the situation, though. Some of the seismicity, including the 2014 M4.8 Milan earthquake, the largest earthquake to occur in the area, lies at least 10km from high-rate injection wells. Additionally, the presence of high-rate wells does not guarantee that there will be nearby seismicity. Many of the highest-rate injection wells are located to the southwest of our study area, where there is minimal seismicity. We have also seen changes in earthquake rates shortly following the March 2015 enactment of new limits on the rate of wastewater disposal in five areas in southern Kansas. Overall, the earthquake rate has decreased significantly since these rules went into place. In more detail, however, earthquake rates within the five areas decreased, but the rate outside the five zones increased. It is likely that fluid-pressure diffusion is responsible for the migration of seismicity outside the areas of reduced injection because there is little injection in the areas unaffected by the new injection rules. This increase is also a reminder that seismicity can persist long after the reduction or cessation of injection. In addition to the effect of the new injection rules, it is possible that the reduction in injection may be partially caused by economic factors that have resulted in a decrease in the production of oil and gas. We have yet to disentangle the effects of the new injection rules and the low prices of oil and gas on the induced seismicity in southern Kansas.

  10. P-Cable: New High-Resolution 3D Seismic Acquisition Technology

    NASA Astrophysics Data System (ADS)

    Planke, Sverre; Berndt, Christian; Mienert, Jürgen; Bünz, Stefan; Eriksen, Frode N.; Eriksen, Ola K.

    2010-05-01

    We have developed a new cost-efficient technology for acquisition of high-resolution 3D seismic data: the P-Cable system. This technology is very well suited for deep water exploration, site surveys, and studies of shallow gas and fluid migration associated with gas hydrates or leaking reservoirs. It delivers unparalleled 3D seismic images of subsurface sediment architectures. The P-Cable system consists of a seismic cable towed perpendicular to a vessel's steaming direction. This configuration allows us to image an up to 150 m wide swath of the sub-surface for each sail line. Conventional 3D seismic technology relies on several very long streamers (up to 10 km long streamers are common), large sources, and costly operations. In contrast, the P-Cable system is light-weight and fast to deploy from small vessels. Only a small source is required as the system is made for relatively shallow imaging, typically above the first water-bottom multiple. The P-Cable system is particularly useful for acquisition of small 3D cubes, 10-50 km2, in focus areas, rather than extensive mapping of large regions. The rapid deployment and recovery of the system makes it possible to acquire several small cubes (10 to 30 km2) with high-resolution (50-250 Hz) seismic data in during one cruise. The first development of the P-Cable system was a cooperative project achieved by Volcanic Basin Petroleum Research (VBPR), University of Tromsø, National Oceanography Centre, Southampton, and industry partners. Field trials using a 12-streamer system were conducted on sites with active fluid-leakage systems on the Norwegian-Barents-Svalbard margin, the Gulf of Cadiz, and the Mediterranean. The second phase of the development introduced digital streamers. The new P-Cable2 system also includes integrated tow and cross cables for power and data transmission and improved doors to spread the larger cross cable. This digital system has been successfully used during six cruises by the University of Troms

  11. Overview With Results and Lessons Learned of the X-43A Mach 10 Flight

    NASA Technical Reports Server (NTRS)

    Marshall, Laurie A.; Bahm, Catherine; Corpening, Griffin P.; Sherrill, Robert

    2005-01-01

    This paper provides an overview of the final flight of the NASA X-43A project. The project consisted of three flights, two planned for Mach 7 and one for Mach 10. The third and final flight, November 16, 2004, was the first Mach 10 flight demonstration of an airframe-integrated, scramjet-powered, hypersonic vehicle. The goals and objectives for the project as well as those for the third flight are presented. The configuration of the Hyper-X stack including the X-43A, Hyper-X launch vehicle, and Hyper-X research vehicle adapter is discussed. The second flight of the X-43A was successfully conducted on March 27, 2004. Mission differences, vehicle modifications and lessons learned from the second flight as they applied to the third flight are also discussed. An overview of flight 3 results is presented.

  12. Development of Towed Marine Seismic Vibrator as an Alternative Seismic Source

    NASA Astrophysics Data System (ADS)

    Ozasa, H.; Mikada, H.; Murakami, F.; Jamali Hondori, E.; Takekawa, J.; Asakawa, E.; Sato, F.

    2015-12-01

    The principal issue with respect to marine impulsive sources to acquire seismic data is if the emission of acoustic energy inflicts harm on marine mammals or not, since the volume of the source signal being released into the marine environment could be so large compared to the sound range of the mammals. We propose a marine seismic vibrator as an alternative to the impulsive sources to mitigate a risk of the impact to the marine environment while satisfying the necessary conditions of seismic surveys. These conditions include the repeatability and the controllability of source signals both in amplitude and phase for high-quality measurements. We, therefore, designed a towed marine seismic vibrator (MSV) as a new type marine vibratory seismic source that employed the hydraulic servo system for the controllability condition in phase and in amplitude that assures the repeatability as well. After fabricating a downsized MSV that requires the power of 30 kVA at a depth of about 250 m in water, several sea trials were conducted to test the source characteristics of the downsized MSV in terms of amplitude, frequency, horizontal and vertical directivities of the generated field. The maximum sound level satisfied the designed specification in the frequencies ranging from 3 to 300 Hz almost omnidirectionally. After checking the source characteristics, we then conducted a trial seismic survey, using both the downsized MSV and an airgun of 480 cubic-inches for comparison, with a streamer cable of 2,000m long right above a cabled earthquake observatory in the Japan Sea. The result showed that the penetration of seismic signals generated by the downsized MSV was comparable to that by the airgun, although there was a slight difference in the signal-to-noise ratio. The MSV could become a versatile source that will not harm living marine mammals as an alternative to the existing impulsive seismic sources such as airgun.

  13. Structure of pseudotachylyte vein systems as a key to co-seismic rupture dynamics: the case of Gavilgarh-Tan Shear Zone, central India

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, A.; Bhattacharjee, D.; Mukherjee, S.

    2014-04-01

    The secondary fractures associated with a major pseudotachylyte-bearing fault vein in the sheared aplitic granitoid of the Proterozoic Gavilgarh-Tan Shear Zone in central India are mapped at the outcrop scale. The fracture maps help to identify at least three different types of co-seismic ruptures, e.g., X-X', T1 and T2, which characterize sinistral-sense shearing of rocks, confined between two sinistral strike-slip faults slipping at seismic rate. From the asymmetric distribution of tensile fractures around the sinistral-sense fault vein, the direction of seismic rupture propagation is predicted to have occurred from west-southwest to east-northeast, during an ancient (Ordovician?) earthquake. Calculations of approximate co-seismic displacement on the faults and seismic moment ( M 0) of the earthquake are attempted, following the methods proposed by earlier workers. These estimates broadly agree to the findings from other studied fault zones (e.g., Gole Larghe Fault zone, Italian Alps). This study supports the proposition by some researchers that important seismological information can be extracted from tectonic pseudotachylytes of all ages, provided they are not reworked by subsequent tectonic activity.

  14. Probabilistic properties of injection induced seismicity - implications for the seismic hazard analysis

    NASA Astrophysics Data System (ADS)

    Lasocki, Stanislaw; Urban, Pawel; Kwiatek, Grzegorz; Martinez-Garzón, Particia

    2017-04-01

    Injection induced seismicity (IIS) is an undesired dynamic rockmass response to massive fluid injections. This includes reactions, among others, to hydro-fracturing for shale gas exploitation. Complexity and changeability of technological factors that induce IIS, may result in significant deviations of the observed distributions of seismic process parameters from the models, which perform well in natural, tectonic seismic processes. Classic formulations of probabilistic seismic hazard analysis in natural seismicity assume the seismic marked point process to be a stationary Poisson process, whose marks - magnitudes are governed by a Gutenberg-Richter born exponential distribution. It is well known that the use of an inappropriate earthquake occurrence model and/or an inappropriate of magnitude distribution model leads to significant systematic errors of hazard estimates. It is therefore of paramount importance to check whether the mentioned, commonly used in natural seismicity assumptions on the seismic process, can be safely used in IIS hazard problems or not. Seismicity accompanying shale gas operations is widely studied in the framework of the project "Shale Gas Exploration and Exploitation Induced Risks" (SHEER). Here we present results of SHEER project investigations of such seismicity from Oklahoma and of a proxy of such seismicity - IIS data from The Geysers geothermal field. We attempt to answer to the following questions: • Do IIS earthquakes follow the Gutenberg-Richter distribution law, so that the magnitude distribution can be modelled by an exponential distribution? • Is the occurrence process of IIS earthquakes Poissonian? Is it segmentally Poissonian? If yes, how are these segments linked to cycles of technological operations? Statistical tests indicate that the Gutenberg-Richter relation born exponential distribution model for magnitude is, in general, inappropriate. The magnitude distribution can be complex, multimodal, with no ready

  15. Improved synthesis of ADAM10 inhibitor GI254023X.

    PubMed

    Hoettecke, Nicole; Ludwig, Andreas; Foro, Sabine; Schmidt, Boris

    2010-01-01

    The metalloproteinases ADAM10 and ADAM17 are involved in various diseases: neurodegeneration, cancer and inflammation. The inhibition of these proteases is a promising target in the treatment of inflammation and cancer. In this study, we present an improved synthesis of the ADAM10 reference inhibitor GI254023X with a higher overall yield, enhanced detection ability and increased acid stability, providing easier handling. This upscaled synthesis, free of diastereomeric intermediates, ensures single-batch identity, thus warranting its reproducibility in further biological investigations. 2010 S. Karger AG, Basel.

  16. Anatomy of an Active Seismic Source: the Interplay between Present-Day Seismic Activity and Inherited Fault Zone Architecture (Central Apennines, Italy)

    NASA Astrophysics Data System (ADS)

    Fondriest, M.; Demurtas, M.; Bistacchi, A.; Fabrizio, B.; Storti, F.; Valoroso, L.; Di Toro, G.

    2017-12-01

    The mechanics and seismogenic behaviour of fault zones are strongly influenced by their internal structure, in terms of both fault geometry and fault rock constitutive properties. In recent years high-resolution seismological techniques yielded new constraints on the geometry and velocity structure of seismogenic faults down to 10s meters length scales. This reduced the gap between geophysical imaging of active seismic sources and field observations of exhumed fault zones. Nevertheless fundamental questions such as the origin of geometrical and kinematic complexities associated to seismic faulting remain open. We addressed these topics by characterizing the internal structure of the Vado di Corno Fault Zone, an active seismogenic normal fault cutting carbonates in the Central Apennines of Italy and comparing it with the present-day seismicity of the area. The fault footwall block, which was exhumed from < 2 km depth, was mapped with high detail (< 1 m spatial resolution) for 2 km of exposure along strike, combining field structural data and photogrammetric surveys in a three dimensional structural model. Three main structural units separated by principal fault strands were recognized: (i) cataclastic unit (20-100 m thick), (ii) damage zone (≤ 300 m thick), (iii) breccia unit ( 20 thick). The cataclastic unit lines the master fault and represents the core of the normal fault zone. In-situ shattering together with evidence of extreme (possibly coseismic) shear strain localization (e.g., mirror-like faults with truncated clasts, ultrafine-grained sheared veins) was recognized. The breccia unit is an inherited thrust zone affected by pervasive veining and secondary dolomitization. It strikes subparallel to the active normal fault and is characterized by a non-cylindrical geometry with 10-100 m long frontal and lateral ramps. The cataclastic unit cuts through thrust flats within the breccia unit, whereas normal to oblique inversion occur on frontal and lateral ramps

  17. Detection capability of the IMS seismic network based on ambient seismic noise measurements

    NASA Astrophysics Data System (ADS)

    Gaebler, Peter J.; Ceranna, Lars

    2016-04-01

    All nuclear explosions - on the Earth's surface, underground, underwater or in the atmosphere - are banned by the Comprehensive Nuclear-Test-Ban Treaty (CTBT). As part of this treaty, a verification regime was put into place to detect, locate and characterize nuclear explosion testings at any time, by anyone and everywhere on the Earth. The International Monitoring System (IMS) plays a key role in the verification regime of the CTBT. Out of the different monitoring techniques used in the IMS, the seismic waveform approach is the most effective technology for monitoring nuclear underground testing and to identify and characterize potential nuclear events. This study introduces a method of seismic threshold monitoring to assess an upper magnitude limit of a potential seismic event in a certain given geographical region. The method is based on ambient seismic background noise measurements at the individual IMS seismic stations as well as on global distance correction terms for body wave magnitudes, which are calculated using the seismic reflectivity method. From our investigations we conclude that a global detection threshold of around mb 4.0 can be achieved using only stations from the primary seismic network, a clear latitudinal dependence for the detection threshold can be observed between northern and southern hemisphere. Including the seismic stations being part of the auxiliary seismic IMS network results in a slight improvement of global detection capability. However, including wave arrivals from distances greater than 120 degrees, mainly PKP-wave arrivals, leads to a significant improvement in average global detection capability. In special this leads to an improvement of the detection threshold on the southern hemisphere. We further investigate the dependence of the detection capability on spatial (latitude and longitude) and temporal (time) parameters, as well as on parameters such as source type and percentage of operational IMS stations.

  18. Hydrologically-driven crustal stresses and seismicity in the New Madrid Seismic Zone.

    PubMed

    Craig, Timothy J; Chanard, Kristel; Calais, Eric

    2017-12-15

    The degree to which short-term non-tectonic processes, either natural and anthropogenic, influence the occurrence of earthquakes in active tectonic settings or 'stable' plate interiors, remains a subject of debate. Recent work in plate-boundary regions demonstrates the capacity for long-wavelength changes in continental water storage to produce observable surface deformation, induce crustal stresses and modulate seismicity rates. Here we show that a significant variation in the rate of microearthquakes in the intraplate New Madrid Seismic Zone at annual and multi-annual timescales coincides with hydrological loading in the upper Mississippi embayment. We demonstrate that this loading, which results in geodetically observed surface deformation, induces stresses within the lithosphere that, although of small amplitude, modulate the ongoing seismicity of the New Madrid region. Correspondence between surface deformation, hydrological loading and seismicity rates at both annual and multi-annual timescales indicates that seismicity variations are the direct result of elastic stresses induced by the water load.

  19. Seismic imaging of a fractured gas hydrate system in the Krishna-Godavari Basin offshore India

    USGS Publications Warehouse

    Riedel, M.; Collett, T.S.; Kumar, P.; Sathe, A.V.; Cook, A.

    2010-01-01

    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 system. 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) seismic data were subsequently used to image the fractured system and explain the occurrence of gas hydrate associated with the fractures. A system 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 seismic data and was mapped using seismic coherency attributes. The fractured system around Site NGHP-01-10 extends over a triangular-shaped area of ~2.5 km2 defined using seismic attributes of the seafloor reflection, as well as " seismic 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 seismic data ~6 km NW of Site NGHP-01-10. ?? 2010.

  20. The assessment of seismic hazard for Gori, (Georgia) and preliminary studies of seismic microzonation

    NASA Astrophysics Data System (ADS)

    Gogoladze, Z.; Moscatelli, M.; Giallini, S.; Avalle, A.; Gventsadze, A.; Kvavadze, N.; Tsereteli, N.

    2016-12-01

    Seismic risk is a crucial issue for South Caucasus, which is the main gateway between Asia and Europe. The goal of this work is to propose new methods and criteria for defining an overall approach aimed at assessing and mitigating seismic risk in Georgia. In this reguard seismic microzonation represents a highly useful tool for seismic risk assessmentin land management, for design of buildings or structures and for emergency planning.Seismic microzonation assessment of local seismic hazard,which is a component of seismicity resulting from specific local characteristics which cause local amplification and soil instability, through identification of zones with seismically homogeneous behavior. This paper presents the results of preliminary study of seismic microzonation of Gori, Georgia. Gori is and is located in the Shida Kartli region and on both sides of Liachvi and Mtkvari rivers, with area of about 135 km2around the Gori fortress. Gori is located in Achara-Trialeti fold-thrust belt, that is tectonically unstable. Half of all earthquakes in Gori area with magnitude M≥3.5 have happened along this fault zone and on basis of damage caused by previous earthquakes, this territory show the highest level of risk (the maximum value of direct losses) in central part of the town. The seismic microzonation map of level 1 for Gori was carried out using: 1) Already available data (i.e., topographic map and boreholes data), 2) Results of new geological surveys and 3) Geophysical measurements (i.e., MASW and noise measurements processed with HVSR technique). Our preliminary results highlight the presence of both stable zones susceptible to local amplifications and unstable zones susceptible to geological instability. Our results are directed to establish set of actions aimed at risk mitigation before initial onset of emergency, and to management of the emergency once the seismic event has occurred. The products obtained, will contain the basic elements of an integrated system

  1. Toward Building a New Seismic Hazard Model for Mainland China

    NASA Astrophysics Data System (ADS)

    Rong, Y.; Xu, X.; Chen, G.; Cheng, J.; Magistrale, H.; Shen, Z.

    2015-12-01

    At present, the only publicly available seismic hazard model for mainland China was generated by Global Seismic Hazard Assessment Program in 1999. We are building a new seismic hazard model by integrating historical earthquake catalogs, geological faults, geodetic GPS data, and geology maps. To build the model, we construct an Mw-based homogeneous historical earthquake catalog spanning from 780 B.C. to present, create fault models from active fault data using the methodology recommended by Global Earthquake Model (GEM), and derive a strain rate map based on the most complete GPS measurements and a new strain derivation algorithm. We divide China and the surrounding regions into about 20 large seismic source zones based on seismotectonics. For each zone, we use the tapered Gutenberg-Richter (TGR) relationship to model the seismicity rates. We estimate the TGR a- and b-values from the historical earthquake data, and constrain corner magnitude using the seismic moment rate derived from the strain rate. From the TGR distributions, 10,000 to 100,000 years of synthetic earthquakes are simulated. Then, we distribute small and medium earthquakes according to locations and magnitudes of historical earthquakes. Some large earthquakes are distributed on active faults based on characteristics of the faults, including slip rate, fault length and width, and paleoseismic data, and the rest to the background based on the distributions of historical earthquakes and strain rate. We evaluate available ground motion prediction equations (GMPE) by comparison to observed ground motions. To apply appropriate GMPEs, we divide the region into active and stable tectonics. The seismic hazard will be calculated using the OpenQuake software developed by GEM. To account for site amplifications, we construct a site condition map based on geology maps. The resulting new seismic hazard map can be used for seismic risk analysis and management, and business and land-use planning.

  2. Field test investigation of high sensitivity fiber optic seismic geophone

    NASA Astrophysics Data System (ADS)

    Wang, Meng; Min, Li; Zhang, Xiaolei; Zhang, Faxiang; Sun, Zhihui; Li, Shujuan; Wang, Chang; Zhao, Zhong; Hao, Guanghu

    2017-10-01

    Seismic reflection, whose measured signal is the artificial seismic waves ,is the most effective method and widely used in the geophysical prospecting. And this method can be used for exploration of oil, gas and coal. When a seismic wave travelling through the Earth encounters an interface between two materials with different acoustic impedances, some of the wave energy will reflect off the interface and some will refract through the interface. At its most basic, the seismic reflection technique consists of generating seismic waves and measuring the time taken for the waves to travel from the source, reflect off an interface and be detected by an array of geophones at the surface. Compared to traditional geophones such as electric, magnetic, mechanical and gas geophone, optical fiber geophones have many advantages. Optical fiber geophones can achieve sensing and signal transmission simultaneously. With the development of fiber grating sensor technology, fiber bragg grating (FBG) is being applied in seismic exploration and draws more and more attention to its advantage of anti-electromagnetic interference, high sensitivity and insensitivity to meteorological conditions. In this paper, we designed a high sensitivity geophone and tested its sensitivity, based on the theory of FBG sensing. The frequency response range is from 10 Hz to 100 Hz and the acceleration of the fiber optic seismic geophone is over 1000pm/g. sixteen-element fiber optic seismic geophone array system is presented and the field test is performed in Shengli oilfield of China. The field test shows that: (1) the fiber optic seismic geophone has a higher sensitivity than the traditional geophone between 1-100 Hz;(2) The low frequency reflection wave continuity of fiber Bragg grating geophone is better.

  3. Georgia-Armenia Transboarder seismicity studies

    NASA Astrophysics Data System (ADS)

    Godoladze, T.; Tvaradze, N.; Javakishvili, Z.; Elashvili, M.; Durgaryan, R.; Arakelyan, A.; Gevorgyan, M.

    2012-12-01

    In the presented study we performed Comprehensive seismic analyses for the Armenian-Georgian transboarder active seismic fault starting on Armenian territory, cutting the state boarder and having possibly northern termination on Adjara-Triealeti frontal structure in Georgia. In the scope of International projects: ISTC A-1418 "Open network of scientific Centers for mitigation risk of natural hazards in the Southern Caucasus and Central Asia" and NATO SfP- 983284 Project "Caucasus Seismic Emergency Response" in Akhalkalaki (Georgia) seismic center, Regional Summer school trainings and intensive filed investigations were conducted. Main goal was multidisciplinary study of the Javakheti fault structure and better understanding seismicity of the area. Young scientists from Turkey, Armenia, Azerbaijan and Georgia were participated in the deployment of temporal seismic network in order to monitor seisimity on the Javakheti highland and particularly delineate fault scarf and identify active seismic structures. In the scope of international collaboration the common seismic database has been created in the southern Caucasus and collected data from the field works is available now online. Javakheti highland, which is located in the central part of the Caucasus, belongs to the structure of the lesser Caucasus and represents a history of neotectonic volcanism existed in the area. Jasvakheti highland is seismicalu active region devastating from several severe earthquakes(1088, 1283, 1899…). Hypocenters located during analogue network were highly scattered and did not describe real pattern of seismicity of the highland. We relocated hypocenters of the region and improved local velocity model. The hypocenters derived from recently deployed local seismic network in the Javakheti highland, clearly identified seismically active structures. Fault plane solutions of analogue data of the Soviet times have been carefully analyzed and examined. Moment tensor inversion were preformed

  4. Apex-4 for SpaceX CRS-10

    NASA Image and Video Library

    2017-02-16

    APEX-04, or Advanced Plant EXperiments-04, is being prepared in a cold room in the Kennedy Space Center Processing Facility for SpaceX-10. Dr. Anna Lisa Paul of the University of Florida is the principal investigator for APEX-04. Apex-04 is an experiment involving Arabidopsis in petri plates inside the Veggie facility aboard the International Space Station. Since Arabidopsis is the genetic model of the plant world, it is a perfect sample organism for performing genetic studies in spaceflight. The experiment is the result of a grant from NASA’s Space Life and Physical Sciences division.

  5. Kinetics and thermal stability of the Ni62Nb38- x Ta x ( x=5, 10, 15, 20 and 25) bulk metallic glasses

    NASA Astrophysics Data System (ADS)

    He, MengKe; Zhang, Yi; Xia, Lei; Yu, Peng

    2017-07-01

    We studied thermal stability and its relationship to the glass-forming ability (GFA) of the Ni62Nb38- x Ta x ( x=5, 10, 15, 20, 25) bulk metallic glasses (BMG) from a kinetic point of view. By fitting the heating-rate dependence of glass transition temperature ( T g onset) and crystallization temperatures ( T x onset and T x peak) of the Ni62Nb38- x Ta x BMG using the Vogel-Fulcher-Tammann (VFT) equation, we obtained the ideal glass transition and crystallization temperatures ( T g 0 and T x 0) and the fragility parameter ( m), and also constructed continuous heating transition (CHT) diagrams for crystallization of the BMG. The CHT diagrams of the BMG indicate enhanced thermal stability by Ta addition; the T g 0 as well as the T x 0 also illustrates this improved stability limit. The compositional dependence of m, which agrees well with that of the reduced glass-transition temperature, indicates a strong correlation between liquid fragility and glass-forming ability in the present alloy system. These results provide new evidence for understanding thermal stability, liquid fragility, and GFA in BMG.

  6. Seismic footprints of shallow dyke propagation at Etna, Italy.

    PubMed

    Falsaperla, Susanna; Neri, Marco

    2015-07-15

    One of the key issues in forecasting volcanic eruptions is to detect signals that can track the propagation of dykes towards the surface. Continuous monitoring of active volcanoes helps significantly in achieving this goal. The seismic data presented here are unique, as they document surface faulting processes close (tens to a few hundred meters) to their source, namely the dyke tip. They originated nearby - and under - a seismic station that was subsequently destroyed by lava flows during eruptive activity at Etna volcano, Italy, in 2013. On February 20, a ~600 m-long and ~120 m wide NW-SE fracture field opened at an altitude between 2750 and 2900 m. The consequent rock dislocation caused the station to tilt and offset the seismic signal temporarily. Data acquisition continued until the arrival of the lava flow that led to the breakdown of the transmission system. Shallow ground fracturing and repeated low-frequency oscillations occurred during two stages in which the seismic signal underwent a maximum offset ~2.57 × 10(4) nm/s. Bridging instrumental recordings, fieldwork and conceptual modelling, these data are interpreted as the seismic footprints of a magmatic dyke intrusion that moved at speed ~0.02 m/s (first stage) and 0.46 m/s (second stage).

  7. Seismic Hazard Assessment of Tehran Based on Arias Intensity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Amiri, G. Ghodrati; Mahmoodi, H.; Amrei, S. A. Razavian

    2008-07-08

    In this paper probabilistic seismic hazard assessment of Tehran for Arias intensity parameter is done. Tehran is capital and most populated city of Iran. From economical, political and social points of view, Tehran is the most significant city of Iran. Since in the previous centuries, catastrophic earthquakes have occurred in Tehran and its vicinity, probabilistic seismic hazard assessment of this city for Arias intensity parameter is useful. Iso-intensity contour lines maps of Tehran on the basis of different attenuation relationships for different earthquake periods are plotted. Maps of iso-intensity points in the Tehran region are presented using proportional attenuation relationshipsmore » for rock and soil beds for 2 hazard levels of 10% and 2% in 50 years. Seismicity parameters on the basis of historical and instrumental earthquakes for a time period that initiate from 4th century BC and ends in the present time are calculated using Tow methods. For calculation of seismicity parameters, the earthquake catalogue with a radius of 200 km around Tehran has been used. SEISRISKIII Software has been employed. Effects of different parameters such as seismicity parameters, length of fault rupture relationships and attenuation relationships are considered using Logic Tree.« less

  8. Probabilistic seismic hazard assessment of southern part of Ghana

    NASA Astrophysics Data System (ADS)

    Ahulu, Sylvanus T.; Danuor, Sylvester Kojo; Asiedu, Daniel K.

    2018-05-01

    This paper presents a seismic hazard map for the southern part of Ghana prepared using the probabilistic approach, and seismic hazard assessment results for six cities. The seismic hazard map was prepared for 10% probability of exceedance for peak ground acceleration in 50 years. The input parameters used for the computations of hazard were obtained using data from a catalogue that was compiled and homogenised to moment magnitude (Mw). The catalogue covered a period of over a century (1615-2009). The hazard assessment is based on the Poisson model for earthquake occurrence, and hence, dependent events were identified and removed from the catalogue. The following attenuation relations were adopted and used in this study—Allen (for south and eastern Australia), Silva et al. (for Central and eastern North America), Campbell and Bozorgnia (for worldwide active-shallow-crust regions) and Chiou and Youngs (for worldwide active-shallow-crust regions). Logic-tree formalism was used to account for possible uncertainties associated with the attenuation relationships. OpenQuake software package was used for the hazard calculation. The highest level of seismic hazard is found in the Accra and Tema seismic zones, with estimated peak ground acceleration close to 0.2 g. The level of the seismic hazard in the southern part of Ghana diminishes with distance away from the Accra/Tema region to a value of 0.05 g at a distance of about 140 km.

  9. [Immobilization of pectawamorine G10x by gel entrapment].

    PubMed

    Bogatskiĭ, A V; Davidenko, T I; Areshidze, I V; Gren', T A; Sevast'ianov, O V

    1979-01-01

    Polyacrylamide gel immobilization of pectawamorine G10x was investigated. Its pectinesterase and polygalacturonase activity and stability in storage were measured. The degree of pectawamorine binding during gel immobilization was 80--90%, 55% of initial activity being retained. Thermal stability of the immobilized and native preparations was equal. Pectinesterase activity of the gel immobilized enzyme increased during storage.

  10. Rockfall induced seismic signals: case study in Montserrat, Catalonia

    NASA Astrophysics Data System (ADS)

    Vilajosana, I.; Suriñach, E.; Abellán, A.; Khazaradze, G.; Garcia, D.; Llosa, J.

    2008-08-01

    After a rockfall event, a usual post event survey includes qualitative volume estimation, trajectory mapping and determination of departing zones. However, quantitative measurements are not usually made. Additional relevant quantitative information could be useful in determining the spatial occurrence of rockfall events and help us in quantifying their size. Seismic measurements could be suitable for detection purposes since they are non invasive methods and are relatively inexpensive. Moreover, seismic techniques could provide important information on rockfall size and location of impacts. On 14 February 2007 the Avalanche Group of the University of Barcelona obtained the seismic data generated by an artificially triggered rockfall event at the Montserrat massif (near Barcelona, Spain) carried out in order to purge a slope. Two 3 component seismic stations were deployed in the area about 200 m from the explosion point that triggered the rockfall. Seismic signals and video images were simultaneously obtained. The initial volume of the rockfall was estimated to be 75 m3 by laser scanner data analysis. After the explosion, dozens of boulders ranging from 10-4 to 5 m3 in volume impacted on the ground at different locations. The blocks fell down onto a terrace, 120 m below the release zone. The impact generated a small continuous mass movement composed of a mixture of rocks, sand and dust that ran down the slope and impacted on the road 60 m below. Time, time-frequency evolution and particle motion analysis of the seismic records and seismic energy estimation were performed. The results are as follows: 1 A rockfall event generates seismic signals with specific characteristics in the time domain; 2 the seismic signals generated by the mass movement show a time-frequency evolution different from that of other seismogenic sources (e.g. earthquakes, explosions or a single rock impact). This feature could be used for detection purposes; 3 particle motion plot analysis shows

  11. Seismological investigation of earthquakes in the New Madrid Seismic Zone. Final report, September 1986--December 1992

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Herrmann, R.B.; Nguyen, B.

    Earthquake activity in the New Madrid Seismic Zone had been monitored by regional seismic networks since 1975. During this time period, over 3,700 earthquakes have been located within the region bounded by latitudes 35{degrees}--39{degrees}N and longitudes 87{degrees}--92{degrees}W. Most of these earthquakes occur within a 1.5{degrees} x 2{degrees} zone centered on the Missouri Bootheel. Source parameters of larger earthquakes in the zone and in eastern North America are determined using surface-wave spectral amplitudes and broadband waveforms for the purpose of determining the focal mechanism, source depth and seismic moment. Waveform modeling of broadband data is shown to be a powerful toolmore » in defining these source parameters when used complementary with regional seismic network data, and in addition, in verifying the correctness of previously published focal mechanism solutions.« less

  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. Characteristics of Helicopter-Generated and Volcano-Related Seismic Tremor Signals

    NASA Astrophysics Data System (ADS)

    Eibl, Eva P. S.; Lokmer, Ivan; Bean, Christopher J.; Akerlie, Eggert; Vogfjörd, Kristin S.

    2017-04-01

    In volcanic environments it is crucial to distinguish between man-made seismic signals and signals created by the volcano. We compare volcanic, seismic signals with helicopter generated, seismic signals recorded in the last 2.5 years in Iceland. In both cases a long-lasting, emergent seismic signal, that can be referred to as seismic tremor, was generated. In the case of a helicopter, the rotating blades generate pressure pulses that travel through the air and excite Rayleigh waves at up to 40 km distance depending on wind speed, wind direction and topographic features. The longest helicopter related seismic signal we recorded was at the order of 40 minutes long. The tremor usually has a fundamental frequency of more than 10 Hz and overtones at integers of the fundamental frequency. Changes in distance lead to either increases or decreases of the frequency due to the Doppler Effect and are strongest for small source-receiver distances. The volcanic tremor signal was recorded during the Bardarbunga eruption at Holuhraun in 2014/15. For volcano-related seismic signals it is usually more difficult to determine the source process that generated the tremor. The pre-eruptive tremor persists for 2 weeks, while the co-eruptive tremor lasted for 6 months. We observed no frequency changes, most energy between 1 and 2 Hz and no or very little energy above 5 Hz. We compare the different characteristics of helicopter-related and volcano-related seismic signals and discuss how they can be distinguished. In addition we discuss how we can determine if a frequency change is related to a moving source or change in repeat time or a change in the geometry of the resonating body.

  14. Fault Mechanics and Post-seismic Deformation at Bam, SE Iran

    NASA Astrophysics Data System (ADS)

    Wimpenny, S. E.; Copley, A.

    2017-12-01

    The extent to which aseismic deformation relaxes co-seismic stress changes on a fault zone is fundamental to assessing the future seismic hazard following any earthquake, and in understanding the mechanical behaviour of faults. We used models of stress-driven afterslip and visco-elastic relaxation, in conjunction with a dense time series of post-seismic InSAR measurements, to show that there has been minimal release of co-seismic stress changes through post-seismic deformation following the 2003 Mw 6.6 Bam earthquake. Our modelling indicates that the faults at Bam may remain predominantly locked, and that the co- plus inter-seismically accumulated elastic strain stored down-dip of the 2003 rupture patch may be released in a future Mw 6 earthquake. Modelling also suggests parts of the fault that experienced post-seismic creep between 2003-2009 overlapped with areas that also slipped co-seismically. Our observations and models also provide an opportunity to probe how aseismic fault slip leads to the growth of topography at Bam. We find that, for our modelled afterslip distribution to be consistent with forming the sharp step in the local topography at Bam over repeated earthquake cycles, and also to be consistent with the geodetic observations, requires either (1) far-field tectonic loading equivalent to a 2-10 MPa deviatoric stress acting across the fault system, which suggests it supports stresses 60-100 times less than classical views of static fault strength, or (2) that the fault surface has some form of mechanical anisotropy, potentially related to corrugations on the fault plane, that controls the sense of slip.

  15. Photocopy of photograph (this photograph is an 8x10 enlargement from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph (this photograph is an 8x10 enlargement from a 4x5 negative); United State Army Corps of Engineers, Savannah District, photographer unknown, November 1968: Aerial (alt 4000') view to south with complex in lower left - Fort Bragg, Noncommissioned Officers' Service Club, South of Butner Road, Fayetteville, Cumberland County, NC

  16. Seismic Analysis Capability in NASTRAN

    NASA Technical Reports Server (NTRS)

    Butler, T. G.; Strang, R. F.

    1984-01-01

    Seismic analysis is a technique which pertains to loading described in terms of boundary accelerations. Earthquake shocks to buildings is the type of excitation which usually comes to mind when one hears the word seismic, 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 seismic analysis. They are: Direct Seismic Frequency Response, Direct Seismic Transient Response, Modal Seismic Frequency Response, and Modal Seismic 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.

  17. Evaluating the Use of Declustering for Induced Seismicity Hazard Assessment

    NASA Astrophysics Data System (ADS)

    Llenos, A. L.; Michael, A. J.

    2016-12-01

    The recent dramatic seismicity rate increase in the central and eastern US (CEUS) has motivated the development of seismic hazard assessments for induced seismicity (e.g., Petersen et al., 2016). Standard probabilistic seismic hazard assessment (PSHA) relies fundamentally on the assumption that seismicity is Poissonian (Cornell, BSSA, 1968); therefore, the earthquake catalogs used in PSHA are typically declustered (e.g., Petersen et al., 2014) even though this may remove earthquakes that may cause damage or concern (Petersen et al., 2015; 2016). In some induced earthquake sequences in the CEUS, the standard declustering can remove up to 90% of the sequence, reducing the estimated seismicity rate by a factor of 10 compared to estimates from the complete catalog. In tectonic regions the reduction is often only about a factor of 2. We investigate how three declustering methods treat induced seismicity: the window-based Gardner-Knopoff (GK) algorithm, often used for PSHA (Gardner and Knopoff, BSSA, 1974); the link-based Reasenberg algorithm (Reasenberg, JGR,1985); and a stochastic declustering method based on a space-time Epidemic-Type Aftershock Sequence model (Ogata, JASA, 1988; Zhuang et al., JASA, 2002). We apply these methods to three catalogs that likely contain some induced seismicity. For the Guy-Greenbrier, AR earthquake swarm from 2010-2013, declustering reduces the seismicity rate by factors of 6-14, depending on the algorithm. In northern Oklahoma and southern Kansas from 2010-2015, the reduction varies from factors of 1.5-20. In the Salton Trough of southern California from 1975-2013, the rate is reduced by factors of 3-20. Stochastic declustering tends to remove the most events, followed by the GK method, while the Reasenberg method removes the fewest. Given that declustering and choice of algorithm have such a large impact on the resulting seismicity rate estimates, we suggest that more accurate hazard assessments may be found using the complete catalog.

  18. High-Resolution Seismic Reflection Imaging of the Reelfoot Fault, New Madrid, Missouri

    NASA Astrophysics Data System (ADS)

    Rosandich, B.; Harris, J. B.; Woolery, E. W.

    2017-12-01

    Earthquakes in the Lower Mississippi Valley are mainly concentrated in the New Madrid Seismic Zone and are associated with reactivated faults of the Reelfoot Rift. Determining the relationship between the seismogenic faults (in crystalline basement rocks) and deformation at the Earth's surface and in the shallow subsurface has remained an active research topic for decades. An integrated seismic data set, including compressional (P-) wave and shear (S-) wave seismic reflection profiles, was collected in New Madrid, Missouri, across the "New Madrid" segment of the Reelfoot Fault, whose most significant rupture produced the M 7.5, February 7, 1812, New Madrid earthquake. The seismic reflection profiles (215 m long) were centered on the updip projection of the fault, which is associated with a surface drainage feature (Des Cyprie Slough) located at the base of a prominent east-facing escarpment. The seismic reflection profiles were collected using 48-channel (P-wave) and 24-channel (S-wave) towable landsteamer acquisition equipment. Seismic energy was generated by five vertical impacts of a 1.8-kg sledgehammer on a small aluminum plate for the P-wave data and five horizontal impacts of the sledgehammer on a 10-kg steel I-beam for the S-wave data. Interpretation of the profiles shows a west-dipping reverse fault (Reelfoot Fault) that propagates upward from Paleozoic sedimentary rocks (>500 m deep) to near-surface Quaternary sediments (<10 m deep). The hanging wall of the fault is anticlinally folded, a structural setting almost identical to that imaged on the Kentucky Bend and Reelfoot Lake segments (of the Reelfoot Fault) to the south.

  19. Location Performance and Detection Threshold of the Spanish National Seismic Network

    NASA Astrophysics Data System (ADS)

    D'Alessandro, Antonino; Badal, José; D'Anna, Giuseppe; Papanastassiou, Dimitris; Baskoutas, Ioannis; Özel, Nurcan M.

    2013-11-01

    Spain is a low-to-moderate seismicity area with relatively low seismic hazard. However, several strong shallow earthquakes have shaken the country causing casualties and extensive damage. Regional seismicity is monitored and surveyed by means of the Spanish National Seismic Network, maintenance and control of which are entrusted to the Instituto Geográfico Nacional. This array currently comprises 120 seismic stations distributed throughout Spanish territory (mainland and islands). Basically, we are interested in checking the noise conditions, reliability, and seismic detection capability of the Spanish network by analyzing the background noise level affecting the array stations, errors in hypocentral location, and detection threshold, which provides knowledge about network performance. It also enables testing of the suitability of the velocity model used in the routine process of earthquake location. To perform this study we use a method that relies on P and S wave travel times, which are computed by simulation of seismic rays from virtual seismic sources placed at the nodes of a regular grid covering the study area. Given the characteristics of the seismicity of Spain, we drew maps for M L magnitudes 2.0, 2.5, and 3.0, at a focal depth of 10 km and a confidence level 95 %. The results relate to the number of stations involved in the hypocentral location process, how these stations are distributed spatially, and the uncertainties of focal data (errors in origin time, longitude, latitude, and depth). To assess the extent to which principal seismogenic areas are well monitored by the network, we estimated the average error in the location of a seismic source from the semiaxes of the ellipsoid of confidence by calculating the radius of the equivalent sphere. Finally, the detection threshold was determined as the magnitude of the smallest seismic event detected at least by four stations. The northwest of the peninsula, the Pyrenees, especially the westernmost segment

  20. SpaceX CRS-10 at Pad 39A

    NASA Image and Video Library

    2017-02-16

    A Falcon 9 rocket stands ready for liftoff at the Kennedy Space Center's Launch Complex 39A. The historic launch site now is operated by SpaceX under a property agreement signed with NASA. The rocket will boost a Dragon resupply spacecraft to the International Space Station. Liftoff is scheduled for 10:01 a.m. EST on Feb. 18. On its 10th commercial resupply services mission to the space station, Dragon will bring up 5,000 pounds of supplies, such as the Stratospheric Aerosol and Gas Experiment (SAGE) III instrument to further study ozone in the atmosphere. Once mounted on the space station, SAGE III will measure the Earth’s sunscreen, or ozone, along with other gases and aerosols, or tiny particles in the atmosphere.

  1. Seismic hazard assessment of Syria using seismicity, DEM, slope, active tectonic and GIS

    NASA Astrophysics Data System (ADS)

    Ahmad, Raed; Adris, Ahmad; Singh, Ramesh

    2016-07-01

    In the present work, we discuss the use of an integrated remote sensing and Geographical Information System (GIS) techniques for evaluation of seismic hazard areas in Syria. The present study is the first time effort to create seismic hazard map with the help of GIS. In the proposed approach, we have used Aster satellite data, digital elevation data (30 m resolution), earthquake data, and active tectonic maps. Many important factors for evaluation of seismic hazard were identified and corresponding thematic data layers (past earthquake epicenters, active faults, digital elevation model, and slope) were generated. A numerical rating scheme has been developed for spatial data analysis using GIS to identify ranking of parameters to be included in the evaluation of seismic hazard. The resulting earthquake potential map delineates the area into different relative susceptibility classes: high, moderate, low and very low. The potential earthquake map was validated by correlating the obtained different classes with the local probability that produced using conventional analysis of observed earthquakes. Using earthquake data of Syria and the peak ground acceleration (PGA) data is introduced to the model to develop final seismic hazard map based on Gutenberg-Richter (a and b values) parameters and using the concepts of local probability and recurrence time. The application of the proposed technique in Syrian region indicates that this method provides good estimate of seismic hazard map compared to those developed from traditional techniques (Deterministic (DSHA) and probabilistic seismic hazard (PSHA). For the first time we have used numerous parameters using remote sensing and GIS in preparation of seismic hazard map which is found to be very realistic.

  2. The Seismicity of Two Hyperextended Margins

    NASA Astrophysics Data System (ADS)

    Redfield, Tim; Terje Osmundsen, Per

    2013-04-01

    A seismic belt marks the outermost edge of Scandinavia's proximal margin, inboard of and roughly parallel to the Taper Break. A similar near- to onshore seismic belt runs along its inner edge, roughly parallel to and outboard of the asymmetric, seaward-facing escarpment. The belts converge at both the northern and southern ends of Scandinavia, where crustal taper is sharp and the proximal margin is narrow. Very few seismic events have been recorded on the intervening, gently-tapering Trøndelag Platform. Norway's distribution of seismicity is systematically ordered with respect to 1) the structural templates of high-beta extension that shaped the thinning gradient during Late Jurassic or Early Cretaceous time, and 2) the topographically resurgent Cretaceous-Cenozoic "accommodation phase" family of escarpments that approximate the innermost limit of crustal thinning [See Redfield and Osmundsen (2012) for diagrams, definitions, discussion, and supporting citations.] Landwards from the belt of earthquake epicenters that mark the Taper Break the crust consistently thickens, and large fault arrays tend to sole out at mid crustal levels. Towards the sea the crystalline continental crust is hyperextended, pervasively faulted, and generally very thin. Also, faulting and serpentinization may have affected the uppermost parts of the distal margin's lithospheric mantle. Such contrasting structural conditions may generate a contrasting stiffness: for a given stress, more strain can be accommodated in the distal margin than in the less faulted proximal margin. By way of comparison, inboard of the Taper Break on the gently-tapered Trøndelag Platform, faulting was not penetrative. There, similar structural conditions prevail and proximal margin seismicity is negligible. Because stress concentration can occur where material properties undergo significant contrast, the necking zone may constitute a natural localization point for post-thinning phase earthquakes. In Scandinavia

  3. Seismic Wave Propagation

    NASA Astrophysics Data System (ADS)

    Wu, Xianyun; Wu, Ru-Shan

    A seismic wave is a mechanical disturbance or energy packet that can propagate from point to point in the Earth. Seismic waves can be generated by a sudden release of energy such as an earthquake, volcanic eruption, or chemical explosion. There are several types of seismic waves, often classified as body waves, which propagate through the volume of the Earth, and surface waves, which travel along the surface of the Earth. Compressional and shear waves are the two main types of body wave and Rayleigh and Love waves are the most common forms of surface wave.

  4. Hf 3 Fe 4 Sn 4 and Hf 9 Fe 4-x Sn 10+x : Two stannide intermetallics with low-dimensional iron sublattices

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Calta, Nicholas P.; Kanatzidis, Mercouri G.

    2016-04-01

    This article reports two new Hf-rich intermetallics synthesized using Sn flux: Hf 3Fe 4Sn 4 and Hf 9Fe 4-xSn 10+x. Hf 3Fe 4Sn 4 adopts an ordered variant the Hf 3Cu 8 structure type in orthorhombic space group Pnma with unit cell edges of a=8.1143(5) Å, b=8.8466(5) Å, and c=10.6069(6) Å. Hf 9Fe 4-xSn 10+x, on the other hand, adopts a new structure type in Cmc21 with unit cell edges of a=5.6458(3) Å, b=35.796(2) Å, and c=8.88725(9) Å for x=0. It exhibits a small amount of phase width in which Sn substitutes on one of the Fe sites. Both structuresmore » are fully three-dimensional and are characterized by pseudo one- and two-dimensional networks of Fe–Fe homoatomic bonding. Hf 9Fe 4-xSn 10+x exhibits antiferromagnetic order at TN=46(2) K and its electrical transport behavior indicates that it is a normal metal with phonon-dictated resistivity. Hf 3Fe 4Sn 4 is also an antiferromagnet with a rather high ordering temperature of TN=373(5) K. Single crystal resistivity measurements indicate that Hf 3Fe 4Sn 4 behaves as a Fermi liquid at low temperatures, indicating strong electron correlation.« less

  5. Seismic seiches

    USGS Publications Warehouse

    McGarr, Arthur; Gupta, Harsh K.

    2011-01-01

    Seismic 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 seismic waves from an earthquake.

  6. Landslide seismic magnitude

    NASA Astrophysics Data System (ADS)

    Lin, C. H.; Jan, J. C.; Pu, H. C.; Tu, Y.; Chen, C. C.; Wu, Y. M.

    2015-11-01

    Landslides have become one of the most deadly natural disasters on earth, not only due to a significant increase in extreme climate change caused by global warming, but also rapid economic development in topographic relief areas. How to detect landslides using a real-time system has become an important question for reducing possible landslide impacts on human society. However, traditional detection of landslides, either through direct surveys in the field or remote sensing images obtained via aircraft or satellites, is highly time consuming. Here we analyze very long period seismic signals (20-50 s) generated by large landslides such as Typhoon Morakot, which passed though Taiwan in August 2009. In addition to successfully locating 109 large landslides, we define landslide seismic magnitude based on an empirical formula: Lm = log ⁡ (A) + 0.55 log ⁡ (Δ) + 2.44, where A is the maximum displacement (μm) recorded at one seismic station and Δ is its distance (km) from the landslide. We conclude that both the location and seismic magnitude of large landslides can be rapidly estimated from broadband seismic networks for both academic and applied purposes, similar to earthquake monitoring. We suggest a real-time algorithm be set up for routine monitoring of landslides in places where they pose a frequent threat.

  7. Comparison of Amplitudes and Frequencies of Explosive vs. Hammer Seismic Sources for a 1-km Seismic Line in West Texas

    NASA Astrophysics Data System (ADS)

    Kaip, G.; Harder, S. H.; Karplus, M. S.; Vennemann, A.

    2016-12-01

    In May 2016, the National Seismic Source Facility (NSSF) located at the University of Texas at El Paso (UTEP) Department of Geological Sciences collected seismic data at the Indio Ranch located 30 km southwest of Van Horn, Texas. Both hammer on an aluminum plate and explosive sources were used. The project objective was to image subsurface structures at the ranch, owned by UTEP. Selecting the appropriate seismic source is important to reach project objectives. We compare seismic sources between explosions and hammer on plate, focusing on amplitude and frequency. The seismic line was 1 km long, trending WSW to ENE, with 200 4.5 Hz geophones at 5m spacing and shot locations at 10m spacing. Clay slurry was used in shot holes to increase shot coupling around booster. Trojan Spartan cast boosters (150g) were used in explosive sources in each shot hole (1 hole per station). The end of line shots had 5 shot holes instead of 1 (750g total). The hammer source utilized a 5.5 kg hammer and an aluminum plate. Five hammer blows were stacked at each location to improve signal-to-noise ratio. Explosive sources yield higher amplitude, but lower frequency content. The explosions exhibit a higher signal-to-noise ratio, allowing us to recognize seismic energy deeper and farther from the source. Hammer sources yield higher frequencies, allowing better resolution at shallower depths but have a lower signal-to-noise ratio and lower amplitudes, even with source stacking. We analyze the details of the shot spectra from the different types of sources. A combination of source types can improve data resolution and amplitude, thereby improving imaging potential. However, cost, logistics, and complexities also have a large influence on source selection.

  8. X-38 flies free from NASA's B-52 mothership, July 10, 2001

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The second free-flight test of an evolving series of X-38 prototypes took place July 10, 2001 when the X-38 was released from NASA's B-52 mothership over the Edwards Air Force Base range in California's Mojave Desert. Shortly after the photo was taken, a sequenced deployment of a drogue parachute followed by a large parafoil fabric wing slowed the X-38 to enable it to land safely on Rogers Dry Lake at Edwards. NASA engineers from the Dryden Flight Research Center at Edwards, and the Johnson Space Center, Houston, Texas, are developing a 'lifeboat' for the International Space Station based on X-38 research.

  9. X-38 flies free from NASA's B-52 mothership, July 10, 2001

    NASA Image and Video Library

    2001-07-10

    The second free-flight test of an evolving series of X-38 prototypes took place July 10, 2001 when the X-38 was released from NASA's B-52 mothership over the Edwards Air Force Base range in California's Mojave Desert. Shortly after the photo was taken, a sequenced deployment of a drogue parachute followed by a large parafoil fabric wing slowed the X-38 to enable it to land safely on Rogers Dry Lake at Edwards. NASA engineers from the Dryden Flight Research Center at Edwards, and the Johnson Space Center, Houston, Texas, are developing a "lifeboat" for the International Space Station based on X-38 research.

  10. New data of the Gakkel Ridge seismicity

    NASA Astrophysics Data System (ADS)

    Antonovskaya, Galina; Basakina, Irina; Kremenetskaya, Elena

    2016-04-01

    250 earthquakes were recorded in the Gakkel Ridge during the period 2012-2014 by Arkhangelsk seismic network. The magnitude Ml of these earthquakes is 1.5 - 5.7, 70% of them have Ml up to 3.0. Seismic events are arranged along to a narrow center line of the Mid-Arctic Ridge, most of the earthquakes are confined to the southern board of the Ridge. Presumably it's connected with the reflection of spreading processes. The high seismic activity zones, which we associate with the volcano-tectonic processes, have been identified. Have been recorded 13 events per day in the Western Volcanic Zone. The largest number of events (75%) is confined to the Sparsely Magmatic Zone. About 30% of all recorded earthquakes with magnitudes above 2.9 have a T-phase. We divided the Gakkel Ridge's earthquakes into two groups by using spectral-time analysis. The first group: maximum energy of the earthquake is observed from 1.5 to 10 Hz, values of magnitudes Ml 2.50-5.29. Earthquakes are distributed along the Gakkel Ridge. The second group: maximum energy of the earthquake is observed from 1.5 to 20 Hz, clearly expressed a high-frequency component, values of magnitudes Ml 2.3-3.4. Earthquakes 2 groups focused only in the Sparsely Magmatic Zone. The new seismic data shows an unique information about geodynamic processes of the Gakkel Ridge.

  11. Improvements on the seismic catalog previous to the 2011 El Hierro eruption.

    NASA Astrophysics Data System (ADS)

    Domínguez Cerdeña, Itahiza; del Fresno, Carmen

    2017-04-01

    Precursors from the submarine eruption of El Hierro (Canary Islands) in 2011 included 10,000 low magnitude earthquakes and 5 cm crustal deformation within 81 days previous to the eruption onset on the 10th October. Seismicity revealed a 20 km horizontal migration from the North to the South of the island and depths ranging from 10 and 17 km with deeper events occurring further South. The earthquakes of the seismic catalog were manually picked by the IGN almost in real time, but there has not been a subsequent revision to check for new non located events jet and the completeness magnitude for the seismic catalog have strong changes during the entire swarm due to the variable number of events per day. In this work we used different techniques to improve the quality of the seismic catalog. First we applied different automatic algorithms to detect new events including the LTA-STA method. Then, we performed a semiautomatic system to correlate the new P and S detections with known phases from the original catalog. The new detected earthquakes were also located using Hypoellipse algorithm. The resulting new catalog included 15,000 new events mainly concentrated in the last weeks of the swarm and we assure a completeness magnitude of 1.2 during the whole series. As the seismicity from the original catalog was already relocated using hypoDD algorithm, we improved the location of the new events using a master-cluster relocation. This method consists in relocating earthquakes towards a cluster of well located events instead of a single event as the master-event method. In our case this cluster correspond to the relocated earthquakes from the original catalog. Finally, we obtained a new equation for the local magnitude estimation which allow us to include corrections for each seismic station in order to avoid local effects. The resulting magnitude catalog has a better fit with the moment magnitude catalog obtained for the strong earthquakes of this series in previous studies

  12. Bighorns Arch Seismic Experiment (BASE): Amplitude Response to Different Seismic Charge Configurations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Harder, S. H., Killer, K. C., Worthington, L. L., Snelson, C. M.

    2010-09-02

    Contrary to popular belief, charge weight is not the most important engineering parameter determining the seismic amplitudes generated by a shot. The scientific literature has long claimed that the relationship, A ~R2L1/2, where A is the seismic amplitude generated by a shot, R is the radius of the seismic charge and L is the length of that charge, holds. Assuming the coupling to the formation and the pressure generated by the explosive are constants, this relationship implies that the one should be able to increase the charge radius while decreasing the charge length and obtain more seismic amplitude with lessmore » charge weight. This has significant implications for the economics of lithospheric seismic shots, because shallower holes and small charge sizes decrease cost. During the Bighorns Array Seismic Experiment (BASE) conducted in the summer of 2010, 24 shots with charge sizes ranging from 110 to 900 kg and drill hole diameters of 300 and 450 mm were detonated and recorded by an array of up to 2000 single-channel Texan seismographs. Maximum source-receiver offset of 300 km. Five of these shots were located within a one-acre square in an effort to eliminate coupling effects due to differing geological formations. We present a quantitative comparison of the data from these five shots to experimentally test the equation above.« less

  13. Continuous Seismic Threshold Monitoring

    DTIC Science & Technology

    1992-05-31

    Continuous threshold monitoring is a technique for using a seismic network to monitor a geographical area continuously in time. The method provides...area. Two approaches are presented. Site-specific monitoring: By focusing a seismic network on a specific target site, continuous threshold monitoring...recorded events at the site. We define the threshold trace for the network as the continuous time trace of computed upper magnitude limits of seismic

  14. Evaluation Seismicity west of block-lut for Deterministic Seismic Hazard Assessment of Shahdad ,Iran

    NASA Astrophysics Data System (ADS)

    Ney, B.; Askari, M.

    2009-04-01

    Evaluation Seismicity west of block-lut for Deterministic Seismic Hazard Assessment of Shahdad ,Iran Behnoosh Neyestani , Mina Askari Students of Science and Research University,Iran. Seismic Hazard Assessment has been done for Shahdad city in this study , and four maps (Kerman-Bam-Nakhil Ab-Allah Abad) has been prepared to indicate the Deterministic estimate of Peak Ground Acceleration (PGA) in this area. Deterministic Seismic Hazard Assessment has been preformed for a region in eastern Iran (Shahdad) based on the available geological, seismological and geophysical information and seismic zoning map of region has been constructed. For this assessment first Seimotectonic map of study region in a radius of 100km is prepared using geological maps, distribution of historical and instrumental earthquake data and focal mechanism solutions it is used as the base map for delineation of potential seismic sources. After that minimum distance, for every seismic sources until site (Shahdad) and maximum magnitude for each source have been determined. In Shahdad ,according to results, peak ground acceleration using the Yoshimitsu Fukushima &Teiji Tanaka'1990 attenuation relationship is estimated to be 0.58 g, that is related to the movement of nayband fault with distance 2.4km of the site and maximum magnitude Ms=7.5.

  15. TexNet seismic network performance and reported seismicity in West Texas

    NASA Astrophysics Data System (ADS)

    Savvaidis, A.; Lomax, A.; Aiken, C.; Young, B.; Huang, D.; Hennings, P.

    2017-12-01

    In 2015, the Texas State Legislature began funding the Texas Seismological Network (TexNet). Since then, 22 new permanent broadband three-component seismic stations have been added to 17 existing stations operated by various networks [US, N4, IM]. These stations together with 4 auxiliary stations, i.e. long term deployments of 20 sec portable stations, were deployed to provide a baseline of Texas seismicity. As soon as the deployment of the new permanent stations took place in West Texas, TexNet was able to detect and characterize smaller magnitude events than was possible before, i.e. M < 2.5. As a consequence, additional portable stations were installed in the area in order to better map the current seismicity level. During the different stages of station deployment, we monitored the seismic network performance and its ability to detect earthquake activity. We found that a key limitation to the network performance is industrial noise in West Texas. For example, during daytime, phase picking and event detection rates are much lower than during nighttime at noisy sites. Regarding seismicity, the high density portable station deployment close to the earthquake activity minimizes hypocentral location uncertainties. In addition, we examined the effects of different crustal velocity models in the area of study on hypocentral location using the local network first arrivals. Considerable differences in location were obtained, which shows the importance of local networks and/or reliable crustal velocity models for West Texas. Given the levels of seismicity in West Texas, a plan to continuously monitor the study area is under development.

  16. Historical seismicity, palaeoseismicity and seismic risk in Western Macedonia, Northern Greece

    NASA Astrophysics Data System (ADS)

    Stiros, Stathis C.

    Western Macedonia, Northern Greece, was a seismically quiescent region for one or more centuries, and was regarded as a nearly aseismic, rigid block inside a broad zone of distributed continental deformation and faulting, and a region of minimum seismic risk. Consequently, the May 13, 1995 destructive earthquake ( M = 6.6) which hit this assumed aseismic zone was a surprise for scientists, government and population. However, historical and archaeoseismic evidence, as well as coastal change data indicate that the assumed aseismic region of Western Macedonia has been affected in the last 2,000 years by at least seven, and possibly nine destructive earthquakes. One of these earthquakes occurred in circa 1700, and probably had the same epicentre with, but higher magnitude than the 1995 shock. The earthquake in circa 1700 is deduced from historical data and is modelled on the base of a swarm of church repairs which is explained as post-seismic recovery of the broader Kozani area: except for certain well known cases of towns or areas in which religious privileges were granted, large scale repairs or reconstruction of churches during the Ottoman period were possible only after Sultan's permissions, usually following earthquakes and other calamities. It can hence be concluded that some, at least, of the apparently aseismic regions inside broad zones of distributed seismicity are hit by stronger shocks, but with longer (200 years or more) recurrence intervals than their adjacent zones. Consequently, the seismic risk of the apparently aseismic regions is certainly not low, especially since relatively long periods of seismic quiescence lead to constructions vulnerable to earthquakes.

  17. Apex-4 for SpaceX CRS-10

    NASA Image and Video Library

    2017-02-16

    APEX-04, or Advanced Plant EXperiments-04, is being prepared in a cold room in the Kennedy Space Center Processing Facility for SpaceX-10. The three science kits are weighed prior to flight. Dr. Anna Lisa Paul of the University of Florida is the principal investigator for APEX-04. Apex-04 is an experiment involving Arabidopsis in petri plates inside the Veggie facility aboard the International Space Station. Since Arabidopsis is the genetic model of the plant world, it is a perfect sample organism for performing genetic studies in spaceflight. The experiment is the result of a grant from NASA’s Space Life and Physical Sciences division.

  18. Seismogenic structures of the central Apennines and its implication for seismic hazard

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Riaz, M. S.; Shan, B.

    2017-12-01

    The central Apennines belt is formed during the Miocene-to-Pliocene epoch under the environment where the Adriatic Plate collides with and plunges beneath the Eurasian Plate, eventually formed a fold and thrust belt. This active fold and thrust belt has experienced relatively frequent moderate-magnitude earthquakesover, as well as strong destructive earthquakes such as the 1997 Umbira-Marche sequence, the 2009 Mw 6.3 L'Aquila earthquake sequence, and three strong earthquakes occurred in 2016. Such high seismicity makes it one of the most active tectonic zones in the world. Moreover, most of these earthquakes are normal fault events with shallow depths, and most earthquakes occurred in the central Apennines are of lower seismic energy to moment ratio. What seismogenic structure causes such kind of seismic features? and how about the potential seismic hazard in the study region? In order to make in-depth understanding about the seismogenic structures in this reion, we collected seismic data from the INGV, Italy, to model the crustal structure, and to relocate the earthquakes. To improve the spatial resolution of the tomographic images, we collected travel times from 27627 earthquakes with M>1.7 recorded at 387 seismic stations. Double Difference Tomography (hereafter as DDT) is applied to build velocity structures and earthquake locations. Checkerboard test confirms that the spatial resolution between the depths range from 5 20km is better than 10km. The travel time residual is significantly decreased from 1208 ms to 70 ms after the inversion. Horizontal Vp images show that mostly earthquakes occurred in high anomalies zones, especially between 5 10km, whereas at the deeper depths, some of the earthquakes occurred in the low Vp anomalies. For Vs images, shallow earthquakes mainly occurred in low anomalies zone, at depths range of 10 15km, earthquakes are mainly concentrated in normal velocity or relatively lower anomalies zones. Moreover, mostly earthquakes occurred

  19. A Flexible Sensing Unit Manufacturing Method of Electrochemical Seismic Sensor

    PubMed Central

    Li, Guanglei; Sun, Zhenyuan; Wang, Junbo; Chen, Deyong; Chen, Lianhong; Xu, Chao; Qi, Wenjie; Zheng, Yu

    2018-01-01

    This paper presents an electrochemical seismic sensor in which paraylene was used as a substrate and insulating layer of micro-fabricated electrodes, enabling the detection of seismic signals with enhanced sensitivities in comparison to silicon-based counterparts. Based on microfabrication, paralene-based electrochemical seismic sensors were fabricated in which the thickness of the insulating spacer was 6.7 μm. Compared to silicon-based counterparts with ~100 μm insulating layers, the parylene-based devices produced higher sensitivities of 490.3 ± 6.1 V/(m/s) vs. 192.2 ± 1.9 V/(m/s) at 0.1 Hz, 4764.4 ± 18 V/(m/s) vs. 318.9 ± 6.5 V/(m/s) at 1 Hz, and 4128.1 ± 38.3 V/(m/s) vs. 254.5 ± 4.2 V/(m/s) at 10 Hz. In addition, the outputs of the parylene vs. silicon devices in response to two transit inputs were compared, producing peak responses of 2.97 V vs. 0.22 V and 2.41 V vs. 0.19 V, respectively. Furthermore, the self-noises of parylene vs. silicon-based devices were compared as follows: −82.3 ± 3.9 dB vs. −90.4 ± 9.4 dB at 0.1 Hz, −75.7 ± 7.3 dB vs. −98.2 ± 9.9 dB at 1 Hz, and −62.4 ± 7.7 dB vs. −91.1 ± 8.1 dB at 10 Hz. The developed parylene-based electrochemical seismic sensors may function as an enabling technique for further detection of seismic motions in various applications. PMID:29641455

  20. Apollo 14 and 16 Active Seismic Experiments, and Apollo 17 Lunar Seismic Profiling

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Seismic refraction experiments were conducted on the moon by Apollo astronauts during missions 14, 16, and 17. Seismic velocities of 104, 108, 92, 114 and 100 m/sec were inferred for the lunar regolith at the Apollo 12, 14, 15, 16, and 17 landing sites, respectively. These data indicate that fragmentation and comminution caused by meteoroid impacts has produced a layer of remarkably uniform seismic properties moonwide. Brecciation and high porosity are the probable causes of the very low velocities observed in the lunar regolith. Apollo 17 seismic data revealed that the seismic velocity increases very rapidly with depth to 4.7 km/sec at a depth of 1.4 km. Such a large velocity change is suggestive of compositional and textural changes and is compatible with a model of fractured basaltic flows overlying anorthositic breccias. 'Thermal' moonquakes were also detected at the Apollo 17 site, becoming increasingly frequent after sunrise and reaching a maximum at sunset. The source of these quakes could possibly be landsliding.