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This dataset consists of 122 magnetotelluric (MT) soundings collected in 2016 in the northern Harrat Rahat, located near the holy city of Al-Madinah Al-Munawarah in Saudi Arabia. These data were collected as part of a joint project between the U.S. Geological Survey and the Saudi Geological Survey examining the volcanic hazard associated with the harrat. Imaging the 3-D electrical resistivity structure of the crust and upper mantle beneath the harrat will help in understanding the magmatic system at depth.
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This data release provides access to a low-altitude aeromagnetic survey flown over a part of the Cascade Range of the US Pacific Northwest, approximately centered over the town of Cascade Locks, Oregon. The Cascade Locks magnetic survey encompasses two large stratovolcanoes of the Cascade Range: Mt. Hood (3426 m) in Oregon and Mt. Adams (3742 m) in Washington. Data were acquired between October 17, 2021, and February 26, 2022, by KBM Resources Group, Thunder Bay, Ontario, Canada, working under contract to the U.S. Geological Survey. The survey is underlain by a diverse magnetic terrane, including Miocene flood basalts of the Columbia River Basalt Group and Tertiary to Quaternary volcanic and intrusive rocks of the...
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Sonic velocity and density well logs in the Central Coast Ranges in California were digitized by hand. These logs are available as scanned files (pdfs and tiffs) on the California Division of Oil, Gas, and Geothermal Resources website and the data consist of interval transit times and bulk density measured downhole in oil and gas wells in the region. Sonic velocity data were also compiled from a number of sources. A summary table provides basic information of these wells, available on the California Division of Oil, Gas, and Geothermal Resources website.
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This dataset of the elevation of basement and thickness of sediment above the syn- and post-rift unconformity (sediments above being generally Late Cretaceous and younger) was constructed for application to site response models in earthquake hazard analyses. Sediment thickness in meters is provided in zipped csv format on a 0.01-degree grid, and sediment thickness and basement elevation in meters relative to mean sea level are provided in GeoTIFF format on a 1-km grid.
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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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The U.S. Geological Survey (USGS) collected rock magnetic susceptibility and density measurements to understand the causative sources of airborne magnetic and ground gravity survey anomalies in the Wet Mountains, Colorado. A total of 609 magnetic susceptibility and 86 density measurements were collected from outcrops and hand samples, respectively, from July 2022 to June 2023. These measurements aid the interpretation of newly collected geophysical data to identify concealed Ediacaran-Ordovician alkaline igneous features and potential rare earth element deposits. On average, 16 magnetic susceptibility and 4 density measurements were taken from each outcrop/hand sample to best represent the lithology. Outcrop/sample...
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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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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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This data release presents beach topography and nearshore bathymetry data from repeated surveys in northern Monterey Bay, California to document changes in shoreline position and coastal morphology as they relate to episodic (storms), seasonal, and interannual and longer (e.g. El Niño) processes. The ongoing monitoring program was initiated in October 2014 with semi-annual surveys performed in late summer (September or October) and Spring (March). Nearshore bathymetry and topography data were collected along a series of shore-perpendicular transects spaced primarily at 50-250 m intervals between Santa Cruz and Moss Landing, California (fig. 1). The transects were located along sandy stretches of the coastline...
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Multichannel minisparker and boomer seismic-reflection and chirp sub bottom data were collected by the U.S. Geological Survey in September of 2013 in Port Valdez, Alaska. Data were collected aboard the USGS R/V Alaskan Gyre during field activity G-01-13-GA. Sub-bottom acoustic penetration spans several hundreds of meters and is variable by location. High-resolution multichannel seismic-reflection data were acquired to support the U.S. Geological Survey Alaska coastal and marine hazards project to explore the sedimentary structure of tsunamigenic landslide deposits around an IODP drill site in Port Valdez. These data and information are intended for science researchers, students from elementary through college, policy...
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High-resolution single-channel Chirp and minisparker seismic-reflection data were collected by the U.S. Geological Survey in September and October 2006, offshore Bolinas to San Francisco, California. Data were collected aboard the R/V Lakota, during field activity L-1-06-SF. Chirp data were collected using an EdgeTech 512 chirp subbottom system and were recorded with a Triton SB-Logger. Minisparker data were collected using a SIG 2-mille minisparker sound source combined with a single-channel streamer, and both were recorded with a Triton SB-Logger.
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High-resolution acoustic backscatter data, bathymetry data, single channel minisparker seismic-reflection data were collected by the U.S. Geological Survey (USGS) and the Alaska Department of Fish and Game in May of 2014 southwest of Chenega Island and southwest of Montague Island, Alaska. Data were collected aboard the Alaska Department of Fish and Game vessel, R/V Solstice, during USGS field activity 2014-622-FA, using a pole mounted 100-kHz Reson 7111 multibeam echosounder, a 500 Joule SIG 2-mille minisparker sound source and a single channel streamer.
This data release includes approximately 1,032 km of marine single-channel seismic-reflection data collected by the U.S. Geological Survey on a research cruise (USGS survey 2014-632-FA) in July and August, 2014, between Point Sal and Refugio State Beach. The dataset includes 168 profiles, most of which were collected on tracklines roughly perpendicular to the coast at 1 km line spacing; additional profiles were collected on coast-parallel tie lines. These data were acquired to support the California Seafloor Mapping Program and USGS Geologic Hazards projects. Seismic-reflection data were collected using a minisparker system that creates an acoustic signal by discharging an electrical pulse between electrodes and...
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The U.S. Geological Survey (USGS) collected high-resolution multichannel sparker, minisparker and chirp seismic-reflection data in November 2014, from offshore Catalina and Santa Cruz basins. The survey was designed to image faults and folds associated with movement on the faults in offshore southern California, including the Catalina, Catalina Ridge, San Clemente, and San Diego Trough faults. Data were collected aboard the Scripps Institution of Oceanography R/V Robert Gordon Sproul. Subbottom acoustic penetration spans several hundred meters and is variable by location. This data release contains processed digital SEG-Y. The seismic-reflection profiles of bedrock, sediment deposits and tectonic structure provide...
Categories: Data, Data Release - Revised; Tags: Geophysics
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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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An irrigation monitoring experiment was performed in Haddam Meadows State Park, Connecticut, on July 16, 2019. Prior to this experiment, ground penetrating radar (GPR), frequency domain electromagnetics (FDEM), and electrical resistivity tomography (ERT) geophysical data were collected over a 20 meter by 10-meter grid to provide baseline information. A vertical soil moisture probe was installed in the center of this area that recorded volumetric water content, temperature, and electrical conductivity at 9 discrete depths down to 1 meter below land surface. Over the next 8 hours, 5,300 liters of irrigation water (with specific conductance of 1,000 microSiemens per centimeter) was sprayed as evenly as practical over...
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A model of the lower seismogenic depth distribution of earthquakes in the western United States was developed to support models for seismic hazard assessment that will be included in the 2023 USGS National Seismic Hazard Model. This data release presents a recalibration using the hypocentral depths of events M>1 from the Advanced National Seismic System Comprehensive Earthquake Catalog from 1980 to 2021. For higher precision and better resolution in the model, the data were supplemented with seismicity from southern California that was relocated by Hauksson and others (2012). Along the San Andreas Fault, the deepest seismogenic depths are located at 23 km around the Cholame segment, whereas the shallowest depths...
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Seismicity catalogs, GIS shapefiles, gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2014 National Seismic Hazard Model for the Conterminous U.S. Probabilistic seismic hazard data and maps of the conterminous U.S. 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. Hazard was calculated on a 0.05 degree by 0.05 degree grid, defined by a bounding box encompassing the conterminous U.S. (-125 to -65 degrees longitude...
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Seismicity catalogs, gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2002 National Seismic Hazard Model for the Conterminous U.S. Seismicity catalogs are available for the western U.S. (in Mw) and central and eastern U.S. (in mb). Probabilistic seismic hazard data and maps of the conterminous U.S. for peak ground acceleration (PGA) and 0.1, 0.2, 0.3, 0.5, 1.0 and 2.0 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. Hazard was calculated on a 0.1 degree by 0.1...
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Gridded ground motion data and mapped gridded ground motion values are available for the 1999 Alaska Seismic Hazard Model. Probabilistic seismic hazard data and maps of Alaska and the Aleutians 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 (annual probability of 0.000404) and 10 percent in 50 years (annual probably of 0.0021), assuming firm rock soil conditions at 760 m/s, are available. Development of the 1999 Alaska Seismic Hazard Model is documented in the USGS Open-File Report 99-36 (https://doi.org/10.3133/ofr9936). This dataset is considered a legacy dataset. The original dataset was released at the time of publication...
map background search result map search result map Airborne Geophysical Surveys over the Eastern Adirondacks, New York State Bathymetry and topography data from the Elwha River delta, Washington, May 2011 Beach topography and nearshore bathymetry of northern Monterey Bay, California Magnetotelluric data from northern Harrat Rahat, Saudi Arabia, 2016 Chirp and minisparker seismic-reflection data of field activity L-1-06-SF collected offshore Bolinas to San Francisco, California from 2006-09-25 to 2006-10-03 Data Release for the 2002 National Seismic Hazard Model for the Conterminous U.S. Data Release for the 2014 National Seismic Hazard Model for the Conterminous U.S. 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 Chirp, multichannel minisparker, and boomer seismic-reflection data from USGS field activity G-01-13-GA collected in Port Valdez, Alaska, in September 2013 Geophysical and Other Data From an Irrigation Monitoring Experiment at Haddam Meadows, CT, July 2019 Data release for the lower seismogenic depth model of western U.S. earthquakes Atlantic and Gulf Coastal Plains Sediment Thickness (v220517) Digitized sonic velocity and density log data of Central Coast Ranges, California Magnetic susceptibility and density measurements in the Wet Mountains, Colorado, 2022 to 2023 High-Resolution Aeromagnetic Survey Over Cascade Locks, Oregon, and Surrounding Areas Geophysical and Other Data From an Irrigation Monitoring Experiment at Haddam Meadows, CT, July 2019 Bathymetry and topography data from the Elwha River delta, Washington, May 2011 Beach topography and nearshore bathymetry of northern Monterey Bay, California Chirp and minisparker seismic-reflection data of field activity L-1-06-SF collected offshore Bolinas to San Francisco, California from 2006-09-25 to 2006-10-03 Magnetic susceptibility and density measurements in the Wet Mountains, Colorado, 2022 to 2023 Chirp, multichannel minisparker, and boomer seismic-reflection data from USGS field activity G-01-13-GA collected in Port Valdez, Alaska, in September 2013 Airborne Geophysical Surveys over the Eastern Adirondacks, New York State High-Resolution Aeromagnetic Survey Over Cascade Locks, Oregon, and Surrounding Areas Magnetotelluric data from northern Harrat Rahat, Saudi Arabia, 2016 Digitized sonic velocity and density log data of Central Coast Ranges, California 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 the lower seismogenic depth model of western U.S. earthquakes Atlantic and Gulf Coastal Plains Sediment Thickness (v220517) Data Release for the 2002 National Seismic Hazard Model for the Conterminous U.S. Data Release for the 2014 National Seismic Hazard Model for the Conterminous U.S.