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Passive seismic data collection was done northwest of the Air Force Research Laboratory (AFRL) at Edwards Air Force Base using the horizontal-to-vertical spectral ratio (HVSR) technique. HVSR surveys were done at 43 locations between May and September 2018 to refine the understanding of the bedrock-alluvial aquifer transition zone downgradient from the AFRL. Specifically, the data were collected to help determine the depth to bedrock. The HVSR method is a passive seismic technique that uses a three-component seismometer to measure the vertical and horizontal components of ambient seismic noise. Seismic noise in the range of ~0.1 to 1 Hertz (Hz) is caused by ocean waves, large regional storms, and tectonic sources....
Categories: Data;
Tags: Antelope-Fremont Valleys,
Boron,
California,
Edwards Air Force Base,
Kern County,
In June 2018, 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, MO. Frequency domain electromagnetic (FDEM) induction data were collected along the edge of the water. The antenna was placed on a plastic frame and held approximately 1 m above the water surface. The antenna was mounted on a raft that was towed behind a canoe. All unprocessed and processed data including the in-phase and quadrature components in parts per million, electrical conductivity (EC) in milliSiemens per meter (mS/m), and magnetic susceptibility in...
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...
In June 2018, U.S. Geological Survey 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, MO. Shear-wave (Vs) refraction surveys were collected to measure the shear-wave velocity of the subsurface, which can be used for estimating the depth to rock with the horizontal-to-vertical spectral ratio (HVSR) passive seismic reconnaissance method. A secondary objective was to determine the depth of interfaces for comparison to the resistivity surveys and frequency domain electromagnetic profiles.
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...
Water levels in Goose Pond were collected while collecting geophysical surveys in May 2017. Three transducers were set to monitor the change in water level associated with tidal changes.
On June 5, 2015, transient electromagnetic (TEM) data were acquired on the baseball field at the East Falmouth, Massachusetts Elementary School approximately 30 m north the well MA-FWS-750. Transient electromagnetic induction (TEM) surveys provide resistivity soundings of the subsurface, which can be related to lithology and hydrogeology. Electrical current is cycled through a wire placed on the land surface in a transmitter loop (Tx), which in turn produces a static magnetic field. When the current is abruptly terminated, an instantaneous current is induced in the earth, and it moves downward and outward as the induced current decays with time. The decay is controlled by the resistivity of the earth. One or more...
In June 2017, the U.S. Geological Survey (USGS)collected borehole geophysical logs to characterize the shallow alluvial aquifer in and near Cedar Rapids, Iowa. Borehole geophysical logs were collected from nine shallow boreholes to identify geophysical properties of the aquifer in the area surrounding the boreholes. Electromagnetic induction logs were used to determine the electrical properties of the fluid and formation surrounding the borehole. A natural gamma tool was used to identify the naturally occurring gamma radiation that is emitted from the earth materials. Nuclear magnetic resonance (NMR) tools were used to measure the water content and estimate the pore-size distribution and hydraulic conductivity (K)...
On May 10, 2017 an electrical resistivity tomography (ERT) profile was collected on the land along the gravel path between the water and the slime impoundment associated with the former mine activities. A total of 56 electrodes, spaced 1 m apart, extended along the base of the slope. Electrode 1 was near monitoring well MW-701 and electrode 56 was near MW-702. In the ERT measurement current is injected through two current electrodes and voltage is measured sequentially across multiple pairs of potential electrodes, which is used to determine the apparent resistivity of the subsurface. In addition, induced polarization (IP) was measured to assess the presence of chargeable layers. Two surveys were collected in dipole-dipole...
The horizontal-to-vertical spectral ratio (HVSR) method is a passive seismic technique that uses a three-component seismometer to measure the vertical and horizontal components of ambient seismic noise. Seismic noise in the range of ~0.1 to 1 Hertz (Hz) is caused by ocean waves, large regional storms, and tectonic sources. A resonance frequency (f0) is induced in the unconsolidated when there is a substantial contrast (greater than 2:1) in shear-wave acoustic impedance between the overburden and the bedrock. The f0 is determined from the analysis of the spectral ratio of the horizontal and vertical components of the seismic data. The thickness of the overburden can be related to the f0. In general, lower f0 relates...
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 May 2017 and July 2018, continuous seismic profiling (CSP) surveys were collected in Goose Pond at the Callahan Mine site. The chirp frequency CSP tool was used in the deep water. A tuned transducer (dual-echo sounder) was used in the shallow water, and the data are served separately but within this data release (See CSP-DSO). CSP methods use an acoustic sound source that travels through the water column, reflects off the bottom and sub-bottom layers and is received at the transducer. Using a water column velocity, the two-way travel time can be converted to distance. CSP methods provide the depth to water bottom, and when sufficient signal penetration can be achieved, CSP can be used to delineate the depth and...
In April 2015, approximately 19 miles of continuous resistivity profiling (CRP) surveys were collected on the Cedar River in Cedar Rapids, Iowa. The CRP method was used to characterize the resistivity of the water column and subbottom materials. Five CRP profiles were collected concurrently with the continuous seismic methods. For this investigation, 11 electrodes spaced 10 m apart and mounted in a streamer were towed behind the boat and data were collected using the dipole-dipole array type. The first two electrodes, closest to the boat, were used to inject current into the water and subbottom materials, and eight electrical potential measurements were made using the remaining nine electrodes. With this system,...
In June 2018, 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, MO. Forward Looking Infrared (FLIR) images were acquired at two locations to characterize the temperature of the water and the embankment along the shoreline of City Lake to evaluate potential groundwater discharge locations. The images were collected in the evening dusk to avoid reflections off the water surface while pointing at the shoreline. Visual true-color photographs and FLIR thermal images were collocated to help identify the location of potential...
In May 2017 a dual-frequency echo sounder was used in Goose Pond at the former Callahan Mine site to obtain seismic profiles in very shallow water. The method uses two fixed transducers mounted in the same housing. One transducer was 24 kHz and the other was 200 kHz. The CSP-DSO data were collected concurrently with continuous resistivity profiling data, and the water bottom was determined with the 200 kHz transducer. The seismic traces on the low frequency transducer were used to analyze the subbottom materials. In some places the signal penetrated the subsurface, but in many places the signal reflected off of a shallow subsurface layer. The data quality was not as good as the swept frequency (chirp) CSP data,...
In October 2016 and May 2017 frequency domain electromagnetic (FDEM) methods were used to image the electrical conductivity of the shallow subsurface. Electrical conductivity can be caused by changes in the soil, overburden, saturation, and water quality. Two multi-frequency tools were used at the site. One of the tools has a 1.6-m long antenna that was used in the vertical-dipole mode to collect data in stepped-frequency mode at seven user-selected frequencies ranging from 1530 to 47,970 Hz. The second tool has an antenna that is 2.1 m long, and it was used in vertical dipole mode with five stepped frequencies ranging from 90 to 24,000 Hz. In general, the lower frequencies penetrate to deeper depths, but the data...
In June 2018, 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, MO. Two survey profiles were collected, each including dipole-dipole and Wenner-Schlumberger configurations. For each survey a total of 28 electrodes spaced 1.0 meter (m) apart were used. During the ERT measurement, current is injected through two current electrodes and voltage is measured sequentially across multiple pairs of potential electrodes; the known current and the measured voltages are used to determine the apparent resistivity of the subsurface....
In October 2016 and May 2017 frequency domain electromagnetic (FDEM) methods were used to image the electrical conductivity of the shallow subsurface. Electrical conductivity can be caused by changes in the soil, overburden, saturation, and water quality. Two multi-frequency tools were used at the site. One of the tools has a 1.6-m long antenna that was used in the vertical-dipole mode to collect data in stepped-frequency mode at seven user-selected frequencies ranging from 1530 to 47,970 Hz. The second tool has an antenna that is 2.1 m long, and it was used in vertical dipole mode with five stepped frequencies ranging from 90 to 24,000 Hz. In general, the lower frequencies penetrate to deeper depths, but the data...
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