Skip to main content
Advanced Search

Filters: Tags: seismology (X)

249 results (16ms)   

Filters
View Results as: JSON ATOM CSV
Enhanced reservoir connectivity generally requires maximizing the intersection between hydraulic fracture (HF) and preexisting underground natural fractures (NF), while having the hydraulic fracture continue to propagate across the natural fractures. Observations of downhole core samples suggest that these natural fractures are in fact veins filled with minerals such as calcite (Mighani et al., 2016). We study this interaction during the approach of a hydraulic fracture to a smooth saw-cut fracture under triaxial stress conditions. The specimen is Solnhofen limestone, a fine-grained (<5 µm grain), low permeability (<10 nD) carbonate. The differential stress (1-20 MPa) and inclination of the fault which determines...
thumbnail
The dataset contains the catalog of 5446 events and arrival times resulting from subspace detection processing and relocation in the for the 2011 Prague, Oklahoma, aftershock sequence. Lines beginning with "E" contain event information in the following order: event ID, origin year, origin month, origin day, origin hour, origin minute, origin second, latitude, longitude, depth, and magnitude. Lines beginning with "P" contain phase information in the following order: event ID, network, station, phase, phase arrival year, phase arrival month, phase arrival day, phase arrival hour, phase arrival minute, phase arrival second.
These maps show the potential of widespread slope failures, in terms of landslide probabilities and displacement, triggered by a M7.0 scenario earthquake on the Hayward Fault in the 10-county area surrounding the San Francisco Bay region, California. The likelihood of landsliding was evaluated using an equation developed by Jibson and others (2000) that estimates landslide probability as a function of predicted Newmark displacement. Based on this equation, four landslide probability categories are established with their corresponding percent likelihood and displacement ranges: Low (0-2%; 0-1 cm), Moderate (2-15%; 1-5 cm), High (15-32%; 5-15 cm), and Very High (>32%; >15 cm).The seismic-landslide probability map...
thumbnail
The data set consists of time, depth, reflection coefficient synthetic, sonic velocity, density, and amplitude used to create synthetic seismogram - City of Plantation Utility, PLT-I1, Broward County, Florida.
thumbnail
This dataset represents the spatial locations of all modeled aftershocks magnitude 2.5 and greater resulting from the HayWired M7.0 mainshock occurring on April 18, 2018 along the Hayward Fault. The date/time, horizontal and vertical location, and sequence position is provided for each aftershock. The spatial extent covers 24 counties in whole or in part, corresponding to the modeled shaking extent for the HayWired mainshock ShakeMap (available at https://earthquake.usgs.gov/scenarios/eventpage/ushaywiredm7.05_se#shakemap). The sequence is simulated based on several known statistical relationships and generated using an epidemic type aftershock sequence (ETAS) model, resulting in one possible aftershock sequence....
thumbnail
The Consortium of Organizations for Strong Motion Observation Systems (COSMOS) supported blind trials using passive microtremor array data for shear-wave velocity site characterization. The trials included data from four sites in order to consider limitations imposed by differing geologies, differing sparse array geometries, and differing interpretation methodologies. The trials used a four-phase approach in order to evaluate changes in blind interpretation as each phase introduced additional array data. The microtremor array data were incrementally released to approximately a dozen analysts in four phases: (1) 2-station linear arrays; (2) sparse triangular arrays; (3) complex nested triangular or circular arrays;...
thumbnail
EXPO-CAT is a catalog of human exposure to discrete levels of shaking intensity, obtained by correlating Atlas ShakeMaps with a global population database. Combining this population exposure dataset with historical earthquake loss data provides a useful resource for calibrating loss methodologies against a systematically-derived set of ShakeMap hazard outputs. EXPO-CAT is derived from two key datasets: the PAGER-CAT earthquake catalog and the Atlas of ShakeMaps. PAGER-CAT provides accurate earthquake source information necessary to compute reliable ShakeMaps in the Atlas. It also contributes loss information (i.e., number of deaths and injuries) from historical events. Using historical earthquakes in the Atlas and...
thumbnail
The U.S. Geological Survey National Crustal Model (NCM) is being developed to include spatially varying estimates of site response in seismic hazard assessments. Primary outputs of the NCM are continuous velocity and density profiles from the Earth’s surface to the mantle transition zone at 410 km depth for each location on a 1-kilometer grid across the conterminous United States. Datasets used to produce the NCM may have a resolution of better than 1 km near the Earth’s surface in some regions, but, with increasing depth, NCM resolution decreases to 10’s to 100’s of km in the mantle. Basic subsurface information is provided by the NCM geologic framework (NCMGF), thermal model, and petrologic and mineral physics...
thumbnail
These data are damage and loss estimates obtained from various Hazus outputs covering all census tracts in 17 counties in and around the San Francisco Bay region in California, for the HayWired earthquake scenario and sixteen M5 or greater aftershocks occurring in the region during the two years following the HayWired mainshock. The HayWired earthquake scenario is a magnitude 7.0 earthquake hypothesized to occur on the Hayward Fault on April 18, 2018, with an epicenter in the city of Oakland, CA. The estimates contained in this dataset are a subset of the many results products generated by FEMA's Hazus-MH 2.1 application, and reflect potential damage due to the HayWired earthquake scenario mainshock and its aftershocks....
thumbnail
The datasets for this investigation consist of microtremor array data collected at: 1) 18 sites in Salt Lake and Utah valleys, Utah, and 2) two sites as part of the Frontier Observatory for Research in Geothermal Energy (FORGE) near Milford, Utah. Each of the 18 sites in the Salt Lake and Utah valleys were acquired with four-sensor arrays with three-component (3C) sensors having flat response from 0.033 Hz to 50 Hz. The data acquired as part of the FORGE investigation used both 3C broadband and 5-Hz geophone sensors. Additional information on these datasets can be found in the supporting documentation provided in this data release as well as in the paper by Zhang and others (2019) that utilized these data.
thumbnail
The “Database of Central and Eastern North American Seismic Velocity Structure” involves the compilation of one-dimensional (1D) seismic velocity-depth functions for central and eastern North America (CENA). The present database is an update of the report by Chulick and Mooney (2002) who present a compilation and statistical analysis of 1D seismic velocity-depth functions for North America and its margins. All seismic velocity-depth functions are extracted from peer-reviewed journal articles, with 86% derived from active-source seismic refraction profiles and the remaining 14% from receiver functions or local earthquake tomography models. No reanalysis of the original seismic field data was undertaken. The database...
thumbnail
The dataset is consisted of travel-time records (SWM_DATA.zip) in SEG2 format recorded using multi-station MASW and AM arrays near 10 seismographic stations located in California. A table in the spreadsheet (SWM_deployment_record.xlsx) summarizes the data collection, with multiple sheets providing further details about array configurations at each station. Stations included in the dataset are CE.25091, CE.25392, CI.MAG, CI.NEE2, CI.SNR, GF.99, NC.JECB, NC.JPSB, NP.1797, and JP.1865.
thumbnail
In May 2019, the U.S. Geological Survey acquired high resolution P- and S-wave seismic data near six seismic network recording stations in San Bernardino County, California: Southern California Seismic Network CI.CLT Calelectic, CI.MLS Mira Loma, CI.CJM Cajon Mountain and CI.HLN Highland; California Strong Motion Instrumentation Program station CE.23542; and US National Strong-Motion Network station NP.5326 (Figure 1). The primary goals of the seismic survey were to better understand the potential for amplified ground shaking, to evaluate lateral variability in shear-wave velocity, and to calculate Vs30 at these sites. We deployed up to 67 DTCC SmartSolo 3-component seismometer systems ("nodes") at 2-m spacing...
This dataset provides supporting evidence for a method of generating geometrically accurate orthophoto mosaics of paleoseismic trenches using physical scale bars printed with coded targets. These data accompany a forthcoming study by Delano et al., 2021, Quick and dirty (and accurate) 3D paleoseismic trench models using coded scale bars. The data constrain three-dimensional models of a 46-m long, narrow trench excavation across the Teton fault (Wyoming, USA). Files include: BB_photos_nwall.zip: Photographs (n= 234) in .jpg format of the north wall of the Buffalo Bowl trench used to construct models. totalstation_control_modelpointcloud.laz: Structure-from-motion model point cloud of the Buffalo Bowl north wall,...
thumbnail
The Bureau of Reclamation's Scoggins Dam lies within the Gales Creek fault zone southwest of Hillsboro, Oregon. Recent geologic mapping shows the dam to overlie a potentially active strand of the fault. This report describes the geology of the dam in detail and confirms that the dam overlies a strand of the Gales Creek fault. The report documents small faults in the reservoir and off the north end of the dam along the Parsons Creek strand of the fault. The report further documents the geology of an alternative dam site downstream of the existing dam.
thumbnail
Data are time series of clay shearing tests presented in 'Friction in clay-bearing faults increases with the ionic radius of interlayer cations' by Sakuma et al. in Communications Earth & Environment, 2022. Data were used for Figure 1 and Supplementary Figure 8 in that paper. Files contain shear strength as a function of fault slip in laboratory tests for brine-saturated montmorillonite clay.
thumbnail
This data release provides geochemical, sedimentological, and geochronological data from interbedded fluvial and marsh deposits and radiocarbon dates of the section spanning the last 1500 years from the Pallett Creek paleoseismic site, California. The samples were collected to support paleoenvironmental reconstruction of the site and refine several previous investigations of paleoearthquakes along the San Andreas Fault (Sieh, 1978; Sieh, 1984; Sieh et al., 1989; Biasi and Weldon, 1994; Scharer et al., 2011). Geochemical and sedimentological data include grain size, magnetic susceptibility, dry bulk density, percent total organic matter, and percent total carbonate at contiguous 1 cm spacing and carbon (total C)...
This publication is a preliminary map and geodatabase of the coseismic surface rupture and other coseismic features generated from the August 9, 2020, Mw 5.1 earthquake near Sparta, North Carolina. Geologic mapping facilitated by analysis of post-earthquake quality level 0 to 1 lidar, document the coseismic surface rupture, named the Little River fault, and other coseismic features. The Little River fault is traced for approximately 4 kilometers and cuts the regional Paleozoic fabric (mean foliation, 063°/57°), and the dominant strike of joint sets are 0°–10°, 130°–150° and 320°–340°. Individual fault strands occur in an en echelon pattern within an approximately 10-meter-wide zone. Trenches across the Little River...
thumbnail
This release provides inventories of georeferenced evidence pertaining to extreme waves on Anegada, a low Caribbean island perched south of the Puerto Rico Trench: CORAL BOULDERS AND COBBLES -- Derived offshore, found inland. Boulder star coral Orbicella franksii (37 localities), brain coral Pseudodiploria strigosa (171), elkhorn coral Acropora palmata (36), mustard hill coral Porites astreoides (29). LIMESTONE BOULDERS AND COBBLES -- Derived and found onshore (633). MOLLUSCAN SHELLS -- Queen conch Aliger gigas, discarded by precolonial fishers (12 onshore heaps) and by modern fishers (40 offshore heaps); individual conch shells deposited inland by precolonial sea flood (59); tiger lucine Codakia orbicularis, also...
thumbnail
This is a conversion of Wentworth and others (2023)[DAS1] to the Geologic Map Schema (GeMS) for inclusion in the National Geologic Map Database. The original publication was in the Alacarte schema commonly used for geologic map databases prior to the release of the now mandatory GeMS. The GIS layers in this release have the same scientific content as the source data release. The source data release lacks description of map units, however, so those have been copied verbatim from the two principal sources for that work (Witter and others, 2006 [DAS2]; Knudsen and others, 2000 [DAS3]).


map background search result map search result map PLT-I1 : Synthetic Seismogram Data for Correlation Between Seismic-Reflection Profiles and Well Data, Broward County, Florida Point locations for earthquakes M2.5 and greater in a two-year aftershock sequence resulting from the HayWired scenario earthquake mainshock (4/18/2018) in the San Francisco Bay area, California Aftershock Catalog for the November 2011 Prague, Oklahoma, Earthquake Sequence A Bayesian Monte-Carlo Inversion of Spatial Auto-Correlation (SPAC) for Near-Surface Vs Structure Applied to Both Broadband and Geophone Data - Data Release Selected products of the scenario HayWired earthquake sequence Hazus analyses for 17 counties in the San Francisco Bay region, California Calibration Coefficients for the U.S. Geological Survey National Crustal Model and Depth to Water Table Data release for: An assessment of uncertainties attributed by analysts, array types and processing algorithms for microtremor observations, using the phased 2018 COSMOS Blind Trials Data to accompany the study "Quick and dirty (and accurate) 3D paleoseismic trench models using coded scale bars" Database of Central and Eastern North American Seismic Velocity Structure Data from the manuscript: Friction in clay-bearing faults increases with the ionic radius of interlayer cations High-resolution seismic data acquired at six seismic network recording stations in San Bernardino County, California in 2019 Array-based Surface-wave Active- or Passive-source Recordings at 10 Seismic Station Sites in California Data Release for Luminescence: Geologic map of Scoggins Dam, Henry Hagg Lake, and the Scoggins Valley area, Washington County, Oregon Field evidence noted in 2008 to 2023 that pertains to sea floods of the past millennium on Anegada, British Virgin Islands Sediment properties, charcoal counts, and radiocarbon dates from the Pallett Creek paleoseismic site, San Gabriel Mountains, California (ver. 2.0, February 2024) Geologic Map Schema (GeMS) version of Wentworth, C.M., Knudsen, K.L., and Witter, R.C., 2023, Quaternary deposits of the 9-county San Francisco Bay Region Data to accompany the study "Quick and dirty (and accurate) 3D paleoseismic trench models using coded scale bars" Field evidence noted in 2008 to 2023 that pertains to sea floods of the past millennium on Anegada, British Virgin Islands Aftershock Catalog for the November 2011 Prague, Oklahoma, Earthquake Sequence High-resolution seismic data acquired at six seismic network recording stations in San Bernardino County, California in 2019 PLT-I1 : Synthetic Seismogram Data for Correlation Between Seismic-Reflection Profiles and Well Data, Broward County, Florida Geologic Map Schema (GeMS) version of Wentworth, C.M., Knudsen, K.L., and Witter, R.C., 2023, Quaternary deposits of the 9-county San Francisco Bay Region A Bayesian Monte-Carlo Inversion of Spatial Auto-Correlation (SPAC) for Near-Surface Vs Structure Applied to Both Broadband and Geophone Data - Data Release Point locations for earthquakes M2.5 and greater in a two-year aftershock sequence resulting from the HayWired scenario earthquake mainshock (4/18/2018) in the San Francisco Bay area, California Selected products of the scenario HayWired earthquake sequence Hazus analyses for 17 counties in the San Francisco Bay region, California Array-based Surface-wave Active- or Passive-source Recordings at 10 Seismic Station Sites in California Database of Central and Eastern North American Seismic Velocity Structure Calibration Coefficients for the U.S. Geological Survey National Crustal Model and Depth to Water Table