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This dataset includes the magnetotelluric (MT) sounding data collected in 2003 along a north-south profile west of Wendover, 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....
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This dataset includes the magnetotelluric (MT) sounding data collected in 2006 in the Southern San Luis Valley, Colorado. The U.S. Geological Survey conducted a series of multidisciplinary studies, including MT surveys, in the San Luis Valley to improve understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits comprising the principal groundwater aquifers of the Rio Grande rift. The shallow unconfined and the deeper confined Santa Fe Group aquifers in the San Luis Basin are the main sources of municipal water for the region. The population of the San Luis Valley region is growing rapidly and water shortfalls could have serious consequences. Future growth and land management...
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The 2002 U.S. Geological Survey (USGS) National Seismic Hazard Maps display earthquake ground motions for various probability levels across the United States and are applied in seismic provisions of building codes, insurance rate structures, risk assessments, and other public policy. This update of the maps incorporates new findings on earthquake ground shaking, faults, seismicity, and geodesy. The resulting maps are derived from seismic hazard curves calculated on a grid of sites across the United States that describe the frequency of exceeding a set of ground motions.
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This dataset includes the magnetotelluric (MT) sounding data collected in 2007 in and near the San Luis Valley, Colorado. The U.S. Geological Survey conducted a series of multidisciplinary studies, including MT surveys, in the San Luis Valley to improve understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits comprising the principal groundwater aquifers of the Rio Grande rift. The shallow unconfined and the deeper confined Santa Fe Group aquifers in the San Luis Basin are the main sources of municipal water for the region. The population of the San Luis Valley region is growing rapidly and water shortfalls could have serious consequences. Future growth and land management...
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This dataset includes the magnetotelluric (MT) sounding data collected in 2009 in and near the San Luis Basin, New Mexico. The U.S. Geological Survey conducted a series of multidisciplinary studies, including MT surveys, in the San Luis Basin to improve understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits comprising the principal groundwater aquifers of the Rio Grande rift. The shallow unconfined and the deeper confined Santa Fe Group aquifers in the San Luis Basin are the main sources of municipal water for the region. The population of the San Luis Basin region is growing rapidly and water shortfalls could have serious consequences. Future growth and land management...
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This dataset consists of 102 magnetotelluric (MT) stations collected in 2012-2014 in the Rio Grande Rift and southern Rocky Mountains. The U.S. Geological Survey acquired these data to improve regional conductivity models of the western United States. This work is in support of studies of the effect of lithospheric modification on electrical resistivity structure and tectonic evolution of the western United States.
Categories: Data; Types: Citation, Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Mora County, apparent resistivity, Mesa County, Rio Arriba County, tipper, All tags...
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The database contains uniformly processed ground motion intensity measurements (peak horizontal ground motions and 5-percent-damped pseudospectral accelerations for oscillator periods 0.1–10 s). The earthquake event set includes more than 3,800 M≥3 earthquakes in Oklahoma and Kansas from January 2009 to December 2016. Ground motion time series were collected out to 500 km. We also relocated the majority of the earthquake hypocenters using a multiple-event relocation algorithm to produce a set of near-uniformly processed hypocentral locations. Details about data processing are reported in the accompanying article. First posted - October 11, 2017 Revised - December 18, 2017, ver. 1.1
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Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system to changes in sediment supply. The U.S. Geological Survey (USGS) developed an integrated research program aimed at understanding the ecosystem responses following dam removal. The research program included repeated surveys of beach topography, nearshore bathymetry, and surface sediment grain size to quantify changes in delta morphology...
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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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High-resolution multichannel minisparker and chirp seismic-reflection data were collected in August of 2015 to explore marine geologic hazards of inland waterways of southeastern Alaska. Sub-bottom profiles were acquired in the inland waters between Glacier Bay and Juneau, including Cross Sound and Chatham Strait. High-resolution seismic-reflection profiles were acquired to assess evidence for active seabed faulting and submarine landslide hazards. The data were collected aboard the U.S. Geological Survey R/V Alaskan Gyre. Chirp data were acquired using a tow-fish Edgetech 512 chirp subbottom profiler, and multichannel (mcs) minisparker data were acquired using a 500-Joule minisparker source and a 48-channel Geometrics...
Categories: Data; Tags: Geophysics
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The Geologic Map Index of Alaska (Map Index) is an online, interactive web mapping application that provides access to an actively growing geographic index of geology-related maps of Alaska and adjacent areas. This online research tool provides the locations and outlines of most DGGS and U.S. Geological Survey (USGS) geologic and geophysical maps of Alaska in a single, interactive web map. It allows searches of the map database by geographic area of interest, keywords, themes, publishing agency, dates, and other criteria. The search results provide links to DGGS's comprehensive, multi-agency publications database, where users may view and download publications for free. No other geographic index of Alaska geologic...
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Hydrothermally altered rocks, particularly if water saturated, can weaken stratovolcanoes, thereby increasing the potential for catastrophic sector collapses that can lead to far-traveled, destructive debris flows, which are the largest volcanic hazards for Mount Adams and Mount Baker. Evaluating the hazards associated with such alteration is difficult because much of the alteration is obscured by ice and its depth extent is unknown. Intense hydrothermal alteration significantly reduces the resistivity and magnetization of volcanic rock and therefore hydrothermally altered rocks are identified with helicopter electromagnetic and magnetic measurements at Mount Baker and Mount Adams. High resolution magnetic and electromagnetic...
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The files consist of two types: tabulated data files and graphical map files. Data files consist of six .csv files, representing six experiment dates (2016_06_14, 2016_16_15, 2016_18_15, 2016_16_21, 2016_16_22, 2016_16_23). Each of these files contains multiple columns of data, with each column representing either a time measurement or the value of a physical quantity measured at that time (e.g., flow depth, pore pressure, normal stress, etc.). Map files consist of six .pdf files, each representing an experiment date listed above. The maps show the thickness of the sediment deposited onto the runout pad after each experiment. Sediment thickness was determined using photogrammetery software from Adam Technology.
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This digital publication, GPR 2008-1, contains geophysical data and a digital elevation model that were produced from airborne geophysical surveys conducted in 2007 for part of the western Fortymile mining district, east-central Alaska. Aeromagnetic and electromagnetic data were acquired for 250 sq miles during the helicopter-based survey. Data provided in GPR 2008-1 include processed (1) linedata ASCII database, (2) gridded files of magnetic data, a calculated vertical magnetic gradient (first vertical derivative), apparent resistivity data, and a digital elevation model, (3) vector files of data contours and flight lines, and (4) the Contractor's descriptive project report. Data are described in more detail in...
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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.
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The temperature and surface geophysical data contained in this release have primarily been collected to support groundwater/surface water methods development, and to characterize the hydrogeological controls on native brook trout habitat. All data have been collected since 2010 along the Quashnet River corridor located on Cape Cod, MA, USA. Cape Cod is a peninsula in southeastern coastal Massachusetts, USA, composed primarily of highly permeable unconsolidated glacial moraine and outwash deposits. The largest of the Cape Cod sole-source aquifers occupies a western (landward) section of the peninsula, and is incised by several linear valleys that drain groundwater south to the Atlantic Ocean via baseflow-dominated...
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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...
The USGS uses an integrated geologic, hydrologic, and geophysical approach to characterize the unconsolidated and bedrock aquifers in the State. Hydrogeologic framework characterization is the backbone of most groundwater-related studies, including those involving aquifer mapping, saltwater-intrusion delineation, groundwater flow and transport modeling, geologic-hazards evaluation, water-tunnel construction and repair, geothermal assessments, and groundwater-quality sampling. The NYWSC uses state-of-the-art geophysical equipment for training and methods development for geophysics that include borehole-wall imagers, gamma spectral, induction, and full waveform sonic tools, and electromagnetic and heat-pulse flowmeters....
Tags: Geophysics
Geomechanical modeling of induced seismicity source parameters and implications for seismic hazard assessment, credited to Goertz-Allmann, BP, published in 2012. Published in Geophysics, volume 78, issue 1, in 2012.
Categories: Publication; Types: Citation, Journal Citation; Tags: Geophysics


map background search result map search result map De Soto Area, Magnetic Profiles - Fig. 5 Magnetotelluric data, Southern San Luis Valley, Colorado, 2006: Station 2 A database of instrumentally recorded ground motion intensity measurements from induced earthquakes in Oklahoma and Kansas Magnetotelluric sounding data, station 46, San Luis Valley, Colorado, 2007 Bathymetry and topography data from the Elwha River delta, Washington, May 2011 Sensor data from debris-flow experiments conducted in June, 2016, at the USGS debris-flow flume, HJ Andrews Experimental Forest, Blue River, Oregon Magnetotelluric sounding data, station 1, Taos Plateau Volcanic Field, New Mexico, 2009 Mount Adams Electromagnetic and Magnetic Data Regional scale magnetotelluric data from the Rio Grande Rift and southern Rocky Mountains Magnetotelluric sounding data, station 21, north eastern Nevada, 2003 Geologic Map Index of Alaska Line, grid, and vector data, plot files, and descriptive project report for the airborne geophysical survey of part of the western Fortymile mining district, east-central Alaska Temperature and geophysical data collected along the Quashnet River, Mashpee/Falmouth MA Data for Frictional Properties and 3-D Stress Analysis of the Southern Alpine Fault, New Zealand (2013) Sensor data from debris-flow experiments conducted in June, 2016, at the USGS debris-flow flume, HJ Andrews Experimental Forest, Blue River, Oregon Bathymetry and topography data from the Elwha River delta, Washington, May 2011 Temperature and geophysical data collected along the Quashnet River, Mashpee/Falmouth MA Data for Frictional Properties and 3-D Stress Analysis of the Southern Alpine Fault, New Zealand (2013) Mount Adams Electromagnetic and Magnetic Data A database of instrumentally recorded ground motion intensity measurements from induced earthquakes in Oklahoma and Kansas Regional scale magnetotelluric data from the Rio Grande Rift and southern Rocky Mountains Geologic Map Index of Alaska