Skip to main content
Advanced Search

Filters: Tags: Seismology (X) > Date Range: {"choice":"year"} (X)

75 results (19ms)   

View Results as: JSON ATOM CSV
thumbnail
In August 2017, the U.S. Geological Survey acquired high-resolution P- and S-wave seismic data near six Southern California Seismic Network (SCSN) recording stations in southern California: CI.OLI Olinda; CI.SRN Serrano; CI.MUR Murrieta; CI.LCG La Cienega; CI.RUS Rush; and CI.STC Santa Clara (Figure 1). These strong-motion recording stations are located inside Southern California Edison electrical substations, critical infrastructures that provide essential services to millions of customers. The primary goals of the seismic survey were to understand the potential for amplified ground shaking and to evaluate lateral variability in shear-wave velocity at these sites. We deployed up to 88 geophones at 2-m or 4-m...
thumbnail
This geologic map database is comprised of new geologic mapping, at a 1:24,000 scale, along the southern Bartlett Springs fault in the northern California Coast Ranges. The map covers an area of 258 square miles in Lake, Napa, Colusa, and Yolo counties, work was undertaken between 2016 and 2021, and supported by the USGS National Cooperative Geologic Map Program. This geodatabase contains the most up-to-date and highest resolution mapping in the region. Results and observations reported here help elucidate the geologic deformational history, as well as relationships between active older and active structures. Please consult the map pamphlet and description of map units for a detailed presentation and interpretation...
thumbnail
The 2014 update of the U.S. Geological Survey (USGS) National Seismic Hazard Model (NSHM) for the conterminous United States (2014 NSHM; Petersen and others, 2014; https://pubs.usgs.gov/of/2008/1128/) included probabilistic ground motion maps for 2 percent and 10 percent probabilities of exceedance in 50 years, derived from seismic hazard curves for peak ground acceleration (PGA) and 0.2 and 1.0 second spectral accelerations (SAs) with 5 percent damping for the National Earthquake Hazards Reduction Program (NEHRP) site class boundary B/C (time-averaged shear wave velocity in the upper 30 meters [VS30]=760 meters per second [m/s]). This data release provides 0.1 degree by 0.1 degree gridded seismic hazard curves,...
thumbnail
This publication releases swath bathymetry and backscatter datasets derived from multibeam bathymetric data acquired by the U.S. Geological Survey (USGS) on the R/V Marcus G. Langseth legs MGL1108 (transit) and MGL1109 in the Gulf of Alaska, and MGL1111 in the Bering Sea. Leg MGL1108 data were combined with leg MGL1109 data during processing. These data were acquired with a Kongsberg Simrad EM-122 multibeam echosounder and Seafloor Information System (SIS) acquisition software. This dataset includes 100-m bathymetry grids generated from processed bathymetry soundings, 100-m backscatter grids generated from coregistered processed backscatter values, extracted center beam bathymetry soundings, and associated metadata....
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]).
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 digital map database provides an areally continuous representation of the Quaternary surficial deposits of the San Francisco Bay region merged from the database files from Knudsen and others (2000) and Witter and others (2006). The more detailed mapping by Witter and others (2006) of the inner part of the region (compiled at a scale of 1:24,000), is given precedence over the less detailed mapping by Knudsen and others (2000) of the outer part of the area (compiled at a scale of 1:100,000). The Quaternary map database is accompanied by a list of the map-unit names represented by polygon identities, a digital map index of the 1:24,000-scale topographic quadrangles of the region, and a figure illustrating the...
Between October 12, 2019 and December 13, 2019, the U.S. Geological Survey deployed 30 nodal seismometers in Humboldt county CA for the purpose of recording seismicity in the subducting Gorda plate. 20 instruments were deployed at the McBride ranch, around NCSN station KCT, and 10 were deployed at the Bureau of Land Management’s Lost Coast Headlands property. The nodes were replaced in mid-November after one month of recording due to battery life.
thumbnail
The U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the Frijoles Fault strand of the San Gregorio Fault Zone (SGFZ) at Año Nuevo, California in 2012. The SGFZ is a Holocene-active, dominantly right-lateral fault system that trends more than 200 km along the California coastline. The Frijoles Fault is one of several onshore strands of the SGF system, and together the strands represent a 3- to 4-km wide fault zone at Año Nuevo. Prior paleoseismology studies indicate highly variable slip-rate estimates, indicating considerable uncertainty about the slip history of the SGFZ and the seismic hazard it poses. Amongst the onshore strands of the SGFZ at Año Nuevo, the Frijoles Fault presented...
thumbnail
This dataset contains the supplemental information for the article "Oklahoma experiences largest earthquake during ongoing regional wastewater injection hazard mitigation efforts" published in Geophysical Research Letters (Yeck and others, 2017). Included is a table of relocated earthquake hypocenters and the velocity model used in the event relocations. These locations form the basis of the analysis presented in the article.
thumbnail
In May of 2020, the U.S. Geological Survey responded to the M6.5 Monte Cristo Range Earthquake, occurring near Tonopah, Nevada: https://www.usgs.gov/news/featured-story/m65-monte-cristo-range-earthquake. 60 DTCC SmartSolo 3-component nodal seismograph systems ("nodes") were deployed in the area and continuously recorded seismic data for about a month. Nodes were deployed in various arrays including a square grid, circular grid, linear array, and near 2 permanent strong-motion instruments. This report provides the metadata needed to analyze the seismic data.
thumbnail
This Data Release consists of broadband ground motion simulations for 12 California region earthquakes. The ground motion simulations were done as part of a validation study that is described in more detail in Graves (2022). These simulations were computed using a hybrid simulation methodology (hereafter referred to as GP). The GP approach is a hybrid in that separate responses are computed for the low- and high-frequency components, which are then summed together to produce the full broadband response. The 12 earthquakes considered in Graves, R.W. (2022). Using a Grid-Search Approach to Validate the Graves-Pitarka Broadband Simulation Method, Earth, Planets and Space, 74:186, doi: 10.1186/s40623-022-01742-y, are...
thumbnail
Earthquake stress drop is a critical parameter for estimating seismic hazard. This parameter can have a strong effect on ground motion amplitudes above ~1Hz and is especially important in Oklahoma and Kansas where earthquake rates have increased sharply since 2008. We estimate stress drops for 1121 earthquakes greater than ~M3 in and near the conterminous United States using spectral ratios between collocated events at given stations. We find that the average stress drop for the few eastern United States (EUS, 26–340 Bars) tectonic main shocks studied, which tend to be deeper thrusting events with few foreshocks and aftershocks, is about three times greater than tectonic main shocks in the western United States...
thumbnail
Gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2003 Puerto Rico and U.S. Virgin Islands Seismic Hazard Model. Probabilistic seismic hazard data and maps are available for peak ground acceleration (PGA) and 0.2, 0.3, and 1.0 second spectral acceleration at probability levels of 2 percent in 50 years and 10 percent in 50 years, assuming firm rock soil conditions at 760 m/s. Development of the 2003 Puerto Rico and U.S. Virgin Islands Seismic Hazard Model is documented at https://doi.org/10.1193/1.3277667 and https://pubs.usgs.gov/of/2003/ofr-03-379/ofr-03-379.html. This dataset is considered a legacy dataset. The original dataset was uploaded...
thumbnail
Gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2012 Guam and Northern Mariana Islands Seismic Hazard Model. Probabilistic seismic hazard data and maps of Guam and the Northern Mariana Islands for peak ground acceleration (PGA) and 0.2 and 1.0 second spectral acceleration at probability levels of 2 percent in 50 years (annual probability of 0.000404) and 10 percent in 50 years (annual probability of 0.0021), assuming firm rock soil conditions at 760 m/s, are available. Development of the 2012 Guam and Northern Mariana Islands Seismic Hazard Model is documented in the USGS Open-File Report 2012-1015 (https://pubs.usgs.gov/of/2012/1015/)....
thumbnail
Gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2007 Afghanistan Seismic Hazard Model. Probabilistic seismic hazard data and maps of Afghanistan for peak ground acceleration (PGA) and 0.2 and 1.0 second spectral acceleration at probability levels of 2 percent in 50 years (annual probability of 0.000404), 5 percent in 50 years (annual probability of 0.001026), and 10 percent in 50 years (annual probability of 0.0021), assuming firm rock soil conditions at 760 m/s, are available. Development of the 2007 Afghanistan Seismic Hazard Model is documented in the USGS Open-File Report 2007-1137 (https://pubs.usgs.gov/of/2007/1137/index.html). This...
thumbnail
Memphis has a dense urban population near faults capable of producing major earthquakes. A high probability of a moderate earthquake in the near future (e.g., a 25-40% probability of a magnitude 6.0 or greater in the next 50 years) from the New Madrid seismic zone, and relatively low regional attenuation (in other words, seismic waves do damage over a greater area in this region than for the same magnitude earthquake in the west) necessitates being prepared for earthquake hazards. This dataset provides maps of probabilistic and deterministic earthquake ground motions and liquefaction hazard for the Memphis area. Deterministic ground motion maps show different types of motions for a single specific hypothetical earthquake...
The earthquake catalog was generated in August 2018 using the standard National Seismic Hazard Model methodology (Mueller, 2019) for the central and eastern United States. Pre-existing catalogs were merged, duplicate records were removed, the catalog was declustered, and induced earthquakes were removed. The final catalog contains 6802 records, M2.5–7.8, and extends from 1568 through July 2018.


map background search result map search result map Influence of Lithostatic Stress on Earthquake Stress Drops in North America Catalog of relocated earthquake hypocenters and local velocity model for the 2016 Mw 5.8 Pawnee, Oklahoma, sequence Data Release for Additional Period and Site Class Maps for the 2014 National Seismic Hazard Model for the Conterminous United States Data Release for the 2003 Puerto Rico and U.S. Virgin Islands Seismic Hazard Model Data Release for the 2007 Afghanistan Seismic Hazard Model Data Release for the 2012 Guam and Northern Mariana Islands Seismic Hazard Model Nodal Seismic Deployment at KCT and Lost Coast Headlands High-resolution seismic data acquired at six Southern California Seismic Network (SCSN) recording stations in 2017 Three-component nodal recordings of aftershocks from the 15 May 2020 Mw 6.5 Monte Cristo, Nevada earthquake High-resolution seismic data from the Frijoles Fault of the San Gregorio Fault zone, Año Nuevo, California Memphis Urban Seismic Hazard Maps, v2008 Broadband Ground Motion Simulations for 12 California Region Earthquakes Earthquake catalog (1568 to 2018) for the USGS National Seismic Hazard Model and Nuclear Regulatory Commission 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) Digital database for the geologic map along the southern Bartlett Springs fault zone and adjacent area between Cache Creek and Lake Berryessa, Northern Coast Ranges, California Quaternary deposits of the 9-county San Francisco Bay Region: an areally continuous digital map database prepared from Knudsen and others (2000) and Witter and others (2006) 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 High-resolution seismic data from the Frijoles Fault of the San Gregorio Fault zone, Año Nuevo, California Field evidence noted in 2008 to 2023 that pertains to sea floods of the past millennium on Anegada, British Virgin Islands Nodal Seismic Deployment at KCT and Lost Coast Headlands Sediment properties, charcoal counts, and radiocarbon dates from the Pallett Creek paleoseismic site, San Gabriel Mountains, California (ver. 2.0, February 2024) Memphis Urban Seismic Hazard Maps, v2008 Catalog of relocated earthquake hypocenters and local velocity model for the 2016 Mw 5.8 Pawnee, Oklahoma, sequence Digital database for the geologic map along the southern Bartlett Springs fault zone and adjacent area between Cache Creek and Lake Berryessa, Northern Coast Ranges, California Three-component nodal recordings of aftershocks from the 15 May 2020 Mw 6.5 Monte Cristo, Nevada earthquake 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 Quaternary deposits of the 9-county San Francisco Bay Region: an areally continuous digital map database prepared from Knudsen and others (2000) and Witter and others (2006) Data Release for the 2003 Puerto Rico and U.S. Virgin Islands Seismic Hazard Model Broadband Ground Motion Simulations for 12 California Region Earthquakes Data Release for the 2012 Guam and Northern Mariana Islands Seismic Hazard Model Data Release for the 2007 Afghanistan Seismic Hazard Model Data Release for Additional Period and Site Class Maps for the 2014 National Seismic Hazard Model for the Conterminous United States Earthquake catalog (1568 to 2018) for the USGS National Seismic Hazard Model and Nuclear Regulatory Commission Influence of Lithostatic Stress on Earthquake Stress Drops in North America