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New Zealand’s Alpine Fault (AF) ruptures quasi-periodically in large-magnitude earthquakes. Paleoseismological evidence suggests that about half of all recognized AF earthquakes terminated at the boundary between the Central and South Westland sections of the fault. There, fault geometry and the polarity of uplift change. The South Westland AF exhibits oblique-normal fault motion on a structure oriented 055/82SE that, for at least 35 km along strike, contains saponite-rich principal slip zone gouges. New hydrothermal friction experiments reveal that the saponite fault gouge is frictionally weak, exhibiting friction coefficients between =0.12 and =0.16 for a range of temperatures (T=25–210 C) and effective normal...
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Gravity data were collected from 2006 through 2015 to assist in mapping subsurface geology in the southern San Luis Basin, northern New Mexico. This data release provides principal facts for 566 new gravity stations that were acquired to fill in gaps in the existing public gravity data coverage.
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The U.S. Geological Survey (USGS) has been engaged in airborne electromagnetics (AEM) since the 1970s, playing a role in the development of early acquisition systems, developing calibration methods, refining standards for data acquisition, improving data processing, modeling, and interpretation methods, and expanding the range of AEM applications. However, USGS AEM survey visibility and data accessibility has not advanced as rapidly as our use of the technique. This data release catalogs AEM surveys in the United States that have contributed to studies under USGS programs including Water, Geologic Mapping, Minerals, Energy, Environmental Health, Ecosystems, Hazards, and Climate. This dataset contains locations for...
Categories: Data; Types: ArcGIS REST Map Service, ArcGIS Service Definition, Downloadable, Map Service; Tags: Alabama, Arizona, Arkansas, California, Colorado, All tags...
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Airborne geophysical surveys were conducted in the eastern Adirondacks from Dec. 7, 2015 - Dec. 21, 2015, by Goldak Airborne Surveys. The area was flown along a draped surface with a nominal survey height above ground of 200 meters. The flight line spacing was 250 meters for traverse lines and 2500 meters for control lines. Here we present downloadable magnetic and radiometric (gamma spectrometry) data from those surveys as image (Geotiff) and flight line data (csv format). Background The Eastern Adirondacks region was known for iron mining in the 1800's and 1900's but it also contains deposits of rare earth minerals. Rare earth minerals are used in advanced technology such as in cell phones, rechargeable batteries...
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Note: This data release has been superseded, available here: https://doi.org/10.5066/P9MYL7WJ This data release contains processed high-resolution multichannel sparker seismic-reflection (MCS) data that were collected aboard Humboldt State University’s R/V Coral Sea in October of 2018 on U.S. Geological Survey cruise 2018-658-FA on the shelf and slope between Cape Blanco, Oregon, and Cape Mendocino, California. MCS data were collected to characterize quaternary deformation and sediment dynamics along the southern Cascadia margin.
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In October and November 2016-2017, transient electromagnetic (TEM) data, also called time domain electromagnetic (TDEM) surveys, were acquired at 120 locations in the Genesee Valley, Livingston County, New York, in order to characterize the subsurface resistivity structure in support of a U.S. Geological Survey groundwater investigation. The TEM data were collected as part of a project to evaluate geophysical methods to characterize the valley-fill sediments, underlying bedrock, and salinity of the subsurface. TEM data were collected using an ABEM WalkTEM unit (acquisition software V 1.1.0 and newer) using two transmitter loop (Tx) sizes, 100 by 100 meter square and 40 by 40 meters square, a center-loop receiver...
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VS30, the time-averaged shear-wave velocity (VS) to a depth of 30 meters, is a key index adopted by the earthquake engineering community to account for seismic site conditions. VS30 is typically based on geophysical measurements of VS derived from invasive and noninvasive techniques at sites of interest. Owing to cost considerations, as well as logistical and environmental concerns, VS30 data are sparse or not readily available for most areas. Where data are available, VS30 values are often assembled in assorted formats that are accessible from disparate and (or) impermanent Websites. To help remedy this situation, we compiled VS30 measurements obtained by studies funded by the U.S. Geological Survey (USGS) and...
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More than 11,500 well records, such as geophysical logs, drilling descriptions, and published hydrogeologic framework information, were evaluated to help characterize the framework of hydrogeologic units in and near Gaines, Terry, and Yoakum Counties, Texas. Additional geophysical data were collected to improve the spatial coverage across the study area and to reduce uncertainty with regard to hydrogeologic unit extents. The evaluation of existing data plus the collection of new geophysical data provided that basis for developoing a refined understanding of how the saturated thickness of the Ogallala and Edwards-Trinity aquifers vary throughout the study area.
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The collection of borehole geophysical logs data was conducted by the U.S. Geological Survey South Atlantic Water Science Center in the vicinity of the Cristex Drum National Priorities List Superfund Site near Oxford, North Carolina, during January through March 2016. In an effort to assist the U.S. Environmental Protection Agency in the development of a conceptual groundwater model for the assessment of current contaminant distribution and future migration of contaminants, borehole geophysical log and image data collection, which included the delineation of more than 150 subsurface features (primarily fracture orientations) in 3 open borehole wells.
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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 northern Año Nuevo, California in 2012. SGFZ is a right-lateral fault system that is mainly offshore, and prior studies provide highly variable slip estimates, which indicates uncertainty about the seismic hazard it poses. Therefore, the primary goal of the seismic survey was to better understand the structure and geometry of the onshore section of the Frijoles Fault strand of the SGFZ. We deployed 118 geophones (channels) at 5-m spacing along a linear profile centered on the mapped surface trace of the Frijoles Fault and co-located active P- and S-wave sources...
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This dataset presents where, why, and how much probabilistic ground motions have changed with the 2018 update of the National Seismic Hazard Model (NSHM) for the conterminous U.S. (CONUS) vs. the 2014 NSHM. In the central and eastern U.S., hazard changes are the result of updated ground motion models (further broken down by median and epistemic uncertainty, aleatory variability, and site effects models) and gridded seismicity models. In the western U.S., hazard changes are the result of updated ground motion models in four urban areas with deep sedimentary basins and gridded seismicity models. Probabilistic ground motion changes (2% in 50 years probability of exceedance for a firm rock site, VS30 = 760 m/s, NEHRP...
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This data release consists of three geophysical data sets measured in the lower Guadalupe River channel, south-central Texas, and one supplementary geophysical data set measured in a laboratory. The lower Guadalupe River is incised into the outcrop of the Carrizo-Wilcox aquifer in south-central Texas. The river and the aquifer are hydraulically connected across the outcrop, although the connectivity is obscured by alluvium and surface-water and groundwater exchange dynamics are currently poorly understood. The data sets were therefore produced to investigate surface-water and groundwater exchange dynamics between the lower Guadalupe River and the Carrizo-Wilcox aquifer, and consist of (1) a 14.86 kilometer (km)...
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We present high-resolution (10-cm pixel) digital surface models (DSMs) generated for the northern 16 km of the surface rupture associated with the 1983 Mw 6.9 Borah Peak earthquake. These DSMs were generated using Agisoft Photoscan (and Metashape) image-based modeling software and low-altitude aerial photographs acquired from unmanned aircraft systems and a tethered balloon. DSM files consist of GeoTIFFs with georeferencing information stored in the file headers.
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The New Madrid Seismic Zone presents significant seismic hazard to the central and eastern United States. We mapped newly-identified coseismic ridge-spreading features, or sackungen, in the bluffs east of the Mississippi River in western Tennessee. We use this mapping dataset in an accompanying manuscript to show that sackungen form during earthquakes on the Reelfoot fault and may fail in preferred orientations. Ultimately, these data can be used to infer fault source and mechanism and improve the paleoseismic record used in hazard models.
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A 3D temperature model is constructed in order to support the estimation of physical parameters within the USGS National Crustal Model. The crustal model is defined by a geological framework consisting of various lithologies with distinct mineral compositions. A temperature model is needed to calculate mineral density and bulk and shear modulus as a function of position within the crust. These properties control seismic velocity and impedance, which are needed to accurately estimate earthquake travel times and seismic amplitudes in earthquake hazard analyses. The temperature model is constrained by observations of surface temperature, temperature gradient, and conductivity, inferred Moho temperature and depth, and...
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This publication provides digital flight line data for a high-resolution magnetic and radiometric survey over an area of northwest Arkansas. The airborne geophysical survey was jointly funded by the USGS National Cooperative Geologic Mapping Program and the Earth Mapping Resource Initiative and was designed to meet the complimentary needs related to geologic mapping and mineral resource research. The survey covers an irregular area 225 by 110 kilometer over the transition between the Ouachita and Ozarks Plateau physiographic provinces and includes 67,614 line-kilometers of magnetic and radiometric data. Data were collected from a fixed-wing aircraft flown at mean terrain clearance of 167 meters (m) above topography...
Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: AASG, Association of American State Geologists, Barry County, Baxter County, Boone County, All tags...
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This dataset includes the magnetotelluric (MT) sounding data collected in 2005 along an east-west profile north of Wells, Nevada. It is important to know whether major mining districts in the Northern Nevada Gold Province are underlain by rocks of the Archean Wyoming craton, which are known to contain orogenic gold deposits, or by accreted rocks of the Paleoproterozoic Mojave province. It is also important to know the location and orientation of the Archean/Proterozoic suture zone between these provinces as well as major basement structures within these terranes because they may influence subsequent patterns of sedimentation, deformation, magmatism, and hydrothermal activity. This study was funded by the U.S. Geological...
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In February 2016 the University of Washington in cooperation with the U.S. Geological Survey, Pacific Coastal and Marine Science Center (USGS, PCMSC) collected multibeam bathymetry and acoustic-backscatter data in and near the Catalina Basin, southern California aboard the University of Washington's Research Vessel Thomas G. Thompson. Data was collected using a Kongsberg EM300 multibeam echosounder hull-mounted to the 274-foot R/V Thomas G. Thompson. The USGS, PCMSC processed these data and produced a series of bathymetric surfaces and acoustic-backscatter images for scientific research purposes. This data release provides a 10-m resolution bathymetry surface and a 10-m resolution acoustic backscatter image. In...
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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,...
map background search result map search result map Airborne Geophysical Surveys over the Eastern Adirondacks, New York State Principal facts of gravity data in the southern San Luis Basin, northern New Mexico Geophysical Logging at the Cristex Drum National Priorities List Superfund Site near Oxford, North Carolina Multibeam bathymetry and acoustic-backscatter data collected in 2016 in Catalina Basin, southern California and merged multibeam bathymetry datasets of the northern portion of the Southern California Continental Borderland 14.86 km Profiles of the Electric and Self-potential Fields Measured in the Lower Guadalupe River Channel, Texas Interior Gulf Coastal Plain, September 2016 Magnetotelluric sounding data, stations 26 to 36, north of Wells, Nevada, 2005 Data Used to Assess the Hydrogeologic Framework with Emphasis on the Ogallala and Edwards-Trinity Aquifers, in and Near Gaines, Terry, and Yoakum Counties, Texas, 2018 Data Release for Additional Period and Site Class Maps for the 2014 National Seismic Hazard Model for the Conterminous United States Data for Frictional Properties and 3-D Stress Analysis of the Southern Alpine Fault, New Zealand (2013) Data Set S1 for "Coseismic Sackungen in the New Madrid Seismic Zone, USA" Airborne Electromagnetic (AEM) Survey Inventory Digital Surface Models for the northern 16 km of the 1983 Borah Peak earthquake rupture, northern Lost River fault zone (Idaho, USA) Grids in support of the U.S. Geological Survey Thermal Model for Seismic Hazard Studies Multichannel sparker seismic reflection data of USGS field activity 2018-658-FA collected between Cape Blanco and Cape Mendocino from 2018-10-04 to 2018-10-18 Time-domain electromagnetic soundings to delineate saline groundwater in the Genesee valley-fill aquifer system, New York (2016-2017) Data Release for the 2018 Update of the U.S. National Seismic Hazard Model: Where, Why, and How Much Probabilistic Ground Motion Maps Changed Airborne magnetic and radiometric survey over northwest Arkansas, 2019-2020 Updated Compilation of VS30 Data for the United States High-resolution seismic data acquired at northern Año Nuevo, California High-resolution seismic data acquired at northern Año Nuevo, California 14.86 km Profiles of the Electric and Self-potential Fields Measured in the Lower Guadalupe River Channel, Texas Interior Gulf Coastal Plain, September 2016 Geophysical Logging at the Cristex Drum National Priorities List Superfund Site near Oxford, North Carolina Time-domain electromagnetic soundings to delineate saline groundwater in the Genesee valley-fill aquifer system, New York (2016-2017) Data for Frictional Properties and 3-D Stress Analysis of the Southern Alpine Fault, New Zealand (2013) Digital Surface Models for the northern 16 km of the 1983 Borah Peak earthquake rupture, northern Lost River fault zone (Idaho, USA) Data Set S1 for "Coseismic Sackungen in the New Madrid Seismic Zone, USA" Principal facts of gravity data in the southern San Luis Basin, northern New Mexico Multibeam bathymetry and acoustic-backscatter data collected in 2016 in Catalina Basin, southern California and merged multibeam bathymetry datasets of the northern portion of the Southern California Continental Borderland Data Used to Assess the Hydrogeologic Framework with Emphasis on the Ogallala and Edwards-Trinity Aquifers, in and Near Gaines, Terry, and Yoakum Counties, Texas, 2018 Airborne magnetic and radiometric survey over northwest Arkansas, 2019-2020 Multichannel sparker seismic reflection data of USGS field activity 2018-658-FA collected between Cape Blanco and Cape Mendocino from 2018-10-04 to 2018-10-18 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 2018 Update of the U.S. National Seismic Hazard Model: Where, Why, and How Much Probabilistic Ground Motion Maps Changed Grids in support of the U.S. Geological Survey Thermal Model for Seismic Hazard Studies Airborne Electromagnetic (AEM) Survey Inventory Updated Compilation of VS30 Data for the United States