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Staff from Alaska Earthquake Center, Geophysical Institute and Alaska Division of Geological & Geophysical Surveys evaluated potential tsunami hazards for the city of Sand Point, on Popof Island in the Shumagin Islands archipelago. We numerically modeled the extent of inundation from tsunami waves generated by local and distant earthquake sources. We considered the results in light of historical observations. The worst-case scenarios are defined by analyzing results of the sensitivity study of the tsunami dynamics with respect to different slip distributions along the Aleutian megathrust. For the Sand Point area, the worst-case scenarios are thought to be thrust earthquakes in the Shumagin Islands region with magnitudes...
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The data set consists of time, depth, reflection coefficient synthetic, sonic velocity, density, and amplitude used to create synthetic seismogram - City of Hollywood Utility, G-2961, (HOL-IW1), Broward County, Florida.
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ShakeMap is a product of the USGS Earthquake Hazards Program in conjunction with the regional seismic networks. ShakeMaps provide near-real-time maps of ground motion and shaking intensity following significant earthquakes. These maps are used by federal, state, and local organizations, both public and private, for post-earthquake response and recovery, public and scientific information, as well as for preparedness exercises and disaster planning.
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A scenario represents one realization of a potential future earthquake by assuming a particular magnitude, location, and fault-rupture geometry and estimating shaking using a variety of strategies. In planning and coordinating emergency response, utilities, local government, and other organizations are best served by conducting training exercises based on realistic earthquake situations—ones similar to those they are most likely to face. ShakeMap Scenario earthquakes can fill this role. They can also be used to examine exposure of structures, lifelines, utilities, and transportation corridors to specified potential earthquakes. A ShakeMap earthquake scenario is a predictive ShakeMap with an assumed magnitude and...
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Compressional- (P-) wave seismic refraction data were acquired in December 2018 and July 2019 along fourteen profiles within the spillway of Success Dam in Porterville, California. A new concrete ogee weir is planned for construction within the existing spillway, and the P-wave seismic velocity models will be used to inform further geotechnical investigations, including siting new geologic borings, and the advanced engineering design phases in terms of rock rippability and relative rock hardness/competency. Data acquisition, processing, and modeling were conducted collaboratively between the U.S. Geological Survey (USGS) and U.S. Army Corps of Engineers (USACE) Sacramento District. Data were acquired with Geometrics...
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New active-source shallow seismic (shear-wave and acoustic-wave) measurements were obtained at 18 prioritized seismic monitoring station locations in the north San Francisco Bay area to measure site-specific ground motion amplification effects, soil depth, depth to bedrock (Z1.0 Vs=1 km/s), calculate site specific velocity-depth profiles and Vs30, and develop NEHRP site classifications for each location. This study was led by Principal Investigators Jamey Turner, Cooper Brossy, and Daniel O’Connell and field data were acquired by Glendon Adams and Lincoln Steele. Seismic monitoring sites that recorded high PGA values during the M6.0 Napa earthquake, proximal to higher population densities, and sites recommended...
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This data release provides access to a low-altitude, aeromagnetic survey of a part of south-central Washington and north-central Oregon. The survey extends from the Blue Mountains westward to the Cascade Range and covers the Oregon cities of The Dalles, Hermiston, and Milton Freewater and the Washington cities of Richland, Pasco, Kennewick, and Walla Walla. Data were acquired during the summer of 2010 by Goldak Airborne Surveys working under contract to the U.S. Geological Survey. Total magnetic field values were acquired using a fixed-wing aircraft flown at a target elevation of 150 m above terrain (305 m over urban areas) and along flight lines and tie lines spaced 400 m and 4000 m apart, respectively. Flight...
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Here we present an inventory of remotely and field-observed landslides triggered by 2019-2020 Puerto Rico earthquake sequence. The inventory was mapped using pre- and post-event satellite imagery (PR_landslide_inventory_imagery.csv), an extensive collection of field observations (https://doi.org/10.5066/P96QNFMB) and using pre-earthquake lidar as guidance for mapping polygons with more precise locations and geometries (2015 - 2017 USGS Lidar DEM: Puerto Rico dataset). The inventory consists of a shapefile of 309 polygons (PR_landslide_inventory_pts.shp) outlining the source area and deposits together. It also includes a point inventory (PR_landslide_inventory_pts.shp) marking 170 individual displaced boulders that...
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In March 2015, the U.S. Geological Survey acquired seismic reflection and refraction data along an approximately 2.8-km-long profile across northwest-trending San Andreas Fault splays located at the Dos Palmas Preserve east of Salton Sea. To acquire the reflection and refraction data, we collocated shots and geophones, spaced every 3 m along the profile. We used 933 SercelTM L40A P-wave (40-Hz vertical-component) geophones with a sensitivity of 22.34 volts/meter/second to record 925 P-wave shots. We generated P-wave data using one of two active sources: 400-grain Betsy-SeisgunTM shots at approximately every 90 m and a 3.5-kg sledgehammer and steel plate combination at every 3 m between the seisgun shots. All data...
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The 2018 KÄ«lauea eruption and caldera collapse generated intense cycles of seismicity tied to repeated large seismic (Mw ~5) collapse events associated with magma withdrawal from beneath the summit. To gain insight into the underlying dynamics and aid eruption response, we applied waveform-based earthquake detection and double-difference location as the eruption unfolded. Here, we augment these rapid results by grouping events based on patterns of correlation-derived phase polarities across the network. From April 29 to August 6, bracketing the eruption, we used ~2800 events cataloged by the Hawaiian Volcano Observatory to detect and precisely locate 44,000+ earthquakes. Resulting hypocentroids resolve complex,...
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Subduction zones are home to the most seismically active faults on the planet. The shallow megathrust interface of subduction zones host our largest earthquakes, and are the only faults capable of M9+ ruptures. Despite these facts, our knowledge of subduction zone geometry - which likely plays a key role in determining the spatial extent and ultimately the size of subduction zone earthquakes - is incomplete. Here we calculate the three- dimensional geometries of all active global subduction zones. The resulting model - Slab2 - provides for the first time a comprehensive geometrical analysis of all known slabs in unprecedented detail. ##### This distribution includes models of three-dimensional slab geometry under...
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I use template matching and precise relative relocation techniques to develop a high-resolution earthquake catalog for the initial portion of the 2019 Ridgecrest earthquake sequence, from July 4-16, encompassing the foreshock sequence and the first 10+ days of aftershocks following the Mw 7.1 mainshock. Using 13,525 routinely cataloged events as waveform templates, I detect and precisely locate a total of 34,091 events. Precisely located earthquakes reveal numerous cross-cutting fault structures with dominantly perpendicular SW- and NW-strikes. Foreshocks of the Mw 6.4 event appear to align on a NW-striking fault. Aftershocks of the Mw 6.4 event suggest that it further ruptured this NW-striking fault, as well as...
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In October 2016, we acquired an approximately 15-km-long seismic profile along a linear transect across the East Bay region of the San Francisco Bay area. Our goal was to image previously unknown strands of the Hayward Fault zone and to better delineate the structure and geometry of the main trace of the Hayward Fault. Our profile started near the southern border of San Leandro, California at the San Francisco Bay shoreline, trended ENE through the northern edge of Castro Valley, California, and ended approximately 5 km WSW of San Ramon, California. The data were analyzed using refraction tomography modeling, reflection processing, and guided-wave analysis. The analyzed data are presented in separate reports by...
This dataset consists of an inventory of the locations of liquefaction-related phenomena triggered by the 7 January 2020 M6.4 Puerto Rico earthquake. The inventory is primarily based on field observations collected during post-earthquake reconnaissance conducted by the USGS and partners (Allstadt and others, 2020, Interactive Dashboard). Some additional locations were added based on reconnaissance reports by other groups (Miranda and others, 2020; Morales-Velez and others, 2020). We delineated 43 polygons of liquefaction areas and lateral spreading where we had sufficient evidence to do so (liquefaction_polygons_20210913.zip), but all outlines are approximate because liquefaction is primarily a subsurface process...
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These data are a series of telecommunications voice and data restoration percentages for 17 counties affected by the HayWired earthquake scenario, a magnitude 7.0 earthquake occurring on the Hayward Fault on April 18, 2018, with an epicenter in the city of Oakland, CA. These data for telecommunications demand served are derived from residual network capacity based on potential hazard information (for example, ground shaking and liquefaction), assumptions about dependence on electric power restoration, and assumptions about network congestion caused by demand surge. Various resilience cases pertain to assumptions about the presence of backup power (for example, batteries or generators), ability to truck in fuel and...
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This dataset accompanies planned publication 'Determining fault geometry through the transport-parallel distribution of thermochronometer cooling ages'. The Ar/Ar data is for samples that record the thermal history of the area. The geochronology provides time constraints for the thermal histories studied in the manuscript. Samples were collected from Nepal, overseen by Nadine McQuarrie (University of Pittsburgh), who sent them to the USGS Denver Argon Geochronology Laboratory for Ar/Ar analysis.
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Near-surface site characteristics are critical for accurately modeling ground motion, which in turn influences seismic hazard analysis and design of critical infrastructure. Currently, there are many strong motion accelerometers within the Advanced National Seismic System (ANSS) that are missing this information. We use a Geographic Information Systems (GIS) based framework to intersect the site coordinates of approximately 5,500 ANSS accelerometers located throughout the United States and its territories with geology and velocity information. We consider: (1) surficial geology from digitized geologic maps (Horton, 2017; Wilson et al., 2015; Sherrod et al., 2007; Bawiec, 1999; Saucedo, 2005; Bedrossian et al., 2012;...
Categories: Data; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: ANSS, Alabama, American Samoa, Arizona, Arkansas, All tags...
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The NEIC global earthquake bulletin is called the Preliminary Determination of Epicenters or PDE, and is one of many discrete products in the ANSS Comprehensive Catalog (ComCat). We use the word "Preliminary" for our final bulletin because the Bulletin of the International Seismological Centre is considered to be the final global archive of parametric earthquake data, in other words phase arrival (“pick”) times and amplitudes.


map background search result map search result map G-2946 : Synthetic Seismogram Data for Correlation Between Seismic-Reflection Profiles and Well Data, Broward County, Florida G-2961 (HOL-IW1) : Synthetic Seismogram Data for Correlation Between Seismic-Reflection Profiles and Well Data, Broward County, Florida Tsunami inundation maps for the city of Sand Point, Alaska LiDAR and paleoseismology solve 140-yr old earthquake mystery in the Pacific Northwest USA - source tabular data and images for 1872 Chelan earthquake fault scarp study 2015 high resolution seismic acquisition at Dos Palmas Preserve, Mecca, California Velocity models and first break picks, Success Dam spillway seismic refraction survey, Porterville, California Voice and data telecommunications restoration curves for 17 counties affected by the April 18, 2018, M7.0 HayWired earthquake scenario mainshock High resolution earthquake catalogs from the 2018 Kilauea eruption sequence High-Resolution Aeromagnetic Survey of the Pasco Area, Washington and Oregon Argon data for Nepal Inventory of landslides triggered by the 2020 Puerto Rico earthquake sequence Data Release for the 2016 East Bay Seismic Imaging Investigation of the Hayward Fault Zone Compilation of Geologic and Seismic Velocity Characteristics at Advanced National Seismic System Strong Motion Accelerometer Sites Velocity models and first break picks, Success Dam spillway seismic refraction survey, Porterville, California 2015 high resolution seismic acquisition at Dos Palmas Preserve, Mecca, California High resolution earthquake catalogs from the 2018 Kilauea eruption sequence Tsunami inundation maps for the city of Sand Point, Alaska Data Release for the 2016 East Bay Seismic Imaging Investigation of the Hayward Fault Zone LiDAR and paleoseismology solve 140-yr old earthquake mystery in the Pacific Northwest USA - source tabular data and images for 1872 Chelan earthquake fault scarp study Inventory of landslides triggered by the 2020 Puerto Rico earthquake sequence G-2946 : Synthetic Seismogram Data for Correlation Between Seismic-Reflection Profiles and Well Data, Broward County, Florida G-2961 (HOL-IW1) : Synthetic Seismogram Data for Correlation Between Seismic-Reflection Profiles and Well Data, Broward County, Florida Argon data for Nepal High-Resolution Aeromagnetic Survey of the Pasco Area, Washington and Oregon Voice and data telecommunications restoration curves for 17 counties affected by the April 18, 2018, M7.0 HayWired earthquake scenario mainshock Compilation of Geologic and Seismic Velocity Characteristics at Advanced National Seismic System Strong Motion Accelerometer Sites