Filters: Types: OGC WMS Layer (X) > partyWithName: U.S. Geological Survey (X) > Types: Map Service (X) > partyWithName: Eric A White (X)
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This data release includes raw and processed (inverted) data for three different geophysical methods, continuous resistivity profiles (CRP), direct current electrical resistivity tomography (ERT), and frequency domain electromagnetic induction (FDEM) data. These surface geophysical methods were used as a proxy for groundwater salinity in the Paradox Valley in western Colorado to investigate temporal and spatial variations in the position of brine-rich groundwater under the Dolores River. Continuous resistivity profile surveys along a 8-10 km reach of the Dolores River were conducted on March 7, May 16, and September 13 of 2017. The ERT surveys were conducted along 3 lines crossing the river and 1 line parallel to...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Bedrock, Colorado,
Dolores River,
Montrose County,
Paradox Valley,
USGS Science Data Catalog (SDC),
The Air Force Research Laboratory (AFRL) is about 7 kilometers southwest of Boron, California, and covers 320 square kilometers of Edwards Air Force Base. The AFRL consists of 12 facilities for testing full-size rocket engines, engine components, and liquid and solid propellants. The historical release of contaminants from rocket test stands, evaporation ponds, burn pits, catch basins, and leaking waste-collection tanks has contaminated groundwater in the AFRL. Groundwater aquifers near the AFRL are mostly restricted to fractured granitic bedrock, but previous studies indicate that groundwater and associated contaminants have moved into alluvium to the north and northwest. The U.S. Geological Survey (USGS) and the...
Time-domain electromagnetic (TEM) surveys were done northwest of the Air Force Research Laboratory (AFRL) at Edwards Air Force Base. TEM surveys were done at 33 locations between May and October 2018 to refine the understanding of the bedrock-alluvial aquifer transition zone downgradient from the AFRL. TEM surveys (also called transient electromagnetic surveys) provide 1D resistivity soundings of the subsurface, which can be related to lithology and hydrogeology. In the TEM method, electrical current is cycled through a transmitter loop (Tx) wire, which in turn produces a primary magnetic field. When the current is abruptly terminated, a secondary magnetic field is induced in the earth, and it moves downward and...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service,
Shapefile;
Tags: Antelope-Fremont Valleys,
Boron,
California,
Edwards Air Force Base,
Kern County,
A suite of geophysical methods was used along the Cedar River in Cedar Rapids, Iowa to support the hydrogeologic characterization of the alluvial aquifer associated with the river and to assess the area for suitability for larger-scale airborne geophysics. The aquifer is comprised of sand and gravel, interbedded with finer sediments, and underlain by carbonate-dominated bedrock. The aquifer is the principal source of municipal drinking water for the City of Cedar Rapids. The raw data provided here includes waterborne continuous resistivity profiling (CRP) and continuous seismic profiling (CSP) data (collected at the same time), electrical resistivity tomography (ERT) profiles, and horizontal-to-vertical spectral...
From October 2016 to July 2018, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers and Maine Department of Transportation, collected surface, marine and borehole geophysical surveys to characterize the subsurface materials on land and under the water at a former mine facility in Brooksville, Maine. Three water-based geophysical methods were used to evaluate the geometry and composition of subsurface materials. Continuous seismic profiling (CSP) methods provide the depth to water bottom, and, when sufficient signal penetration can be achieved, delineate the depth to bedrock and subbottom materials. Continuous resistivity profiling (CRP) and frequency domain electromagnetics (FDEM) methods...
In July 2016, July 2019, and March 2020, 318 seismic recordings were acquired at locations within Shenandoah National Park, Virginia, using MOHO Tromino Model TEP-3C three-component seismometers to assess depth to bedrock using the HVSR method. This method requires a measurement of estimate of shear wave velocity, which depends on the regolith sediment composition and density, for the conversion of measured resonance frequency to a depth to bedrock. Shear wave velocities were calculated for sediment in Shenandoah NP at locations where regolith thickness is known (e.g. at documented boreholes). The locations in this study were generally selected to characterize the depths to bedrock adjacent to streams monitored...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: HVSR,
Headwater Streams,
Hydrogeology,
Regolith Thickness,
Shenandoah National Park,
In June 2018, the U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency (EPA) collected geophysical measurements to help evaluate the suitability of a proposed landfill site for disposing mine-waste materials in Fredericktown, Missouri. Geophysical methods were used to evaluate and characterize the unconsolidated sediment (i.e., regolith) above the crystalline bedrock as well as determine depth bedrock. Land-based geophysical methods included frequency domain electromagnetic induction (FDEM), electrical resistivity tomography (ERT), horizontal-to-vertical spectral ratio passive seismic (HVSR), and shear-wave seismic refraction. Water-borne methods included FDEM surveys to characterize...
In March 2016, the U.S. Geological Survey drilled a borehole, MA-FSW-750-0100, through the unconsolidated sediments and 1.5 m into the bedrock in East Falmouth, Massachusetts, to improve understanding of the glacial history and hydrologic properties of the Cape Cod aquifer. Prior to drilling, candidate sites were investigated using surface geophysical methods. Passive seismic horizontal-to-vertical spectral ratio (HVSR) methods were used to estimate the depth of the unconsolidated deposits over bedrock. Transient electromagnetic (TEM) surveys were conducted to characterize the lithology and salinity of formation water in the subsurface, which was used to plan the borehole completion. The specific conductance of...
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