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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...
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Surface electrical resistivity tomography (ERT), electromagnetic induction (EMI), and self-potential (SP) data were acquired March 9 - 20, 2018 by the U.S. Geological Survey, in collaboration with the U.S. Army Corps of Engineers, at the Jim Woodruff Lock and Dam near Chattahoochee, Florida. Eleven ERT profiles were acquired along the right (west) abutment, and immediately downstream, of the concrete, fixed-crest spillway located west of the lock to map geologic structure at depths up to 50 meters (m) using the Advanced Geosciences, Inc. SuperSting R8 resistivity meter. This data release includes the raw and processed resistivity data as well as inverted resistivity models. All are provided as digital data, and...
Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Apalachicola River, Chattahoochee, Chattahoochee River, Decatur County, ERT surveying, All tags...
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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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Surface electrical resistivity tomography (ERT), electromagnetic induction (EMI), and self-potential (SP) data were acquired March 9 - 20, 2018 by the U.S. Geological Survey, in collaboration with the U.S. Army Corps of Engineers, at the Jim Woodruff Lock and Dam near Chattahoochee, Florida. Self-potential (SP) data were acquired at 384 unique stations with Borin Stelth 3 copper-copper sulfate porous-pot electrodes and Keysight U1253B high-impedance multimeter to identify variations in subsurface hydrologic flow. This data release includes the raw and processed self-potential data. They are provided as digital data, and data fields are defined in the data dictionary. Jim Woodruff Lock and Dam is located...
Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Apalachicola River, Chattahoochee, Chattahoochee River, Decatur County, ERT surveying, All tags...
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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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Surface electrical resistivity tomography (ERT), electromagnetic induction (EMI), and self-potential (SP) data were acquired March 9 - 20, 2018 by the U.S. Geological Survey, in collaboration with the U.S. Army Corps of Engineers, at the Jim Woodruff Lock and Dam near Chattahoochee, Florida. Frequency-domain electromagnetic induction data were acquired along approximately 9 line-kilometers with the Geophex GEM-2 system to map variations in structure up to about 10 m in depth. This data release includes the raw and processed frequency-dependent in-phase and quadrature data. They are provided as digital data, and data fields are defined in the data dictionary. Jim Woodruff Lock and Dam is located on the Apalachicola...
Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Apalachicola River, Chattahoochee, Chattahoochee River, Decatur County, ERT surveying, All tags...
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Surface electrical resistivity tomography (ERT), electromagnetic induction (EMI), and self-potential (SP) data were acquired March 9 - 20, 2018 by the U.S. Geological Survey, in collaboration with the U.S. Army Corps of Engineers, at the Jim Woodruff Lock and Dam near Chattahoochee, Florida. Eleven ERT profiles were acquired along the right (west) abutment, and immediately downstream, of the concrete, fixed-crest spillway located west of the lock to map geologic structure at depths up to 50 meters (m) using the Advanced Geosciences, Inc. SuperSting R8 resistivity meter. Frequency-domain electromagnetic induction data were acquired along approximately 9 line-kilometers with the Geophex GEM-2 system to map variations...
Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Apalachicola River, Chattahoochee, Chattahoochee River, Decatur County, ERT surveying, All tags...
Electromagnetic induction (EMI) instruments provide rapid, noninvasive, and spatially dense data for characterization of soil and groundwater properties. Data from multi-frequency EMI tools can be inverted to provide quantitative electrical conductivity estimates as a function of depth. In this study, multi-frequency EMI data collected across an abandoned uranium mill site near Naturita, Colorado, USA, are inverted to produce vertical distribution of electrical conductivity (EC) across the site. The relation between measured apparent electrical conductivity (ECa) and hydraulic conductivity (K) is weak (correlation coefficient of 0.20), whereas the correlation between the depth dependent EC obtained from the inversions,...


    map background search result map search result map Borehole, Surface and Water-Borne Geophysical Surveys at the Callahan Mine Superfund Site in Brooksville, Maine: October 2016 to July 2018 Water-Based Frequency Domain Electromagnetic Surveys at the Callahan Mine Superfund Site in Brooksville, Maine: October 2016 to May 2017 Land-Based Frequency Domain Electromagnetic Surveys at the Callahan Mine Superfund Site in Brooksville, Maine: October 2016 to May 2017 Electrical and electromagnetic geophysical surveys at Jim Woodruff Lock and Dam, Chattahoochee, Florida, March 2018 Electrical resistivity tomography (ERT) data Electromagnetic induction (EMI) data Self-potential (SP) data Electromagnetic induction (EMI) data Self-potential (SP) data Electrical and electromagnetic geophysical surveys at Jim Woodruff Lock and Dam, Chattahoochee, Florida, March 2018 Electrical resistivity tomography (ERT) data Borehole, Surface and Water-Borne Geophysical Surveys at the Callahan Mine Superfund Site in Brooksville, Maine: October 2016 to July 2018 Water-Based Frequency Domain Electromagnetic Surveys at the Callahan Mine Superfund Site in Brooksville, Maine: October 2016 to May 2017 Land-Based Frequency Domain Electromagnetic Surveys at the Callahan Mine Superfund Site in Brooksville, Maine: October 2016 to May 2017