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Surface and water-borne geophysical methods can provide information for the characterization of the subsurface structure of the earth for aquifer investigations. Floating and towed transient electromagnetic (FloaTEM and tTEM) surveys provide resistivity soundings of the subsurface, which can be related to lithology and hydrogeology. In the TEM method, a primary electrical current is cycled through a wire in a transmitter loop (Tx), which in turn produces a static primary magnetic field. When the current in the TX loop is abruptly terminated, secondary electrical currents are induced in the earth that move downward and outward decaying with time. The decay of the secondary electrical field is controlled by the subsurface...
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Shallow subsurface electrical conductivity was mapped at Goose Lake National Wildlife Refuge (NWR) in northeast Montana using the DUALEM421 electromagnetic sensor (Dualem, Inc., ON, Canada) in the winter of 2017. Data were acquired by towing the DUALEM421 sensor on a sled behind an all-terrain vehicle or snow machine, with the sensor at a nominal height of 0.3 meters (m) above ground surface. Approximately 15 line-kilometers (km) of data were acquired over an area of approximately 1 square-kilometer. Data were manually edited to remove sensor dropouts, lag corrected for apparent offsets between recorded GPS location and data locations for each coil pair, and averaged to a sounding distance of 1m along the survey...
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Surface electrical resistivity tomography, magnetic, and gravity surveys were conducted in July 2017 in the greater East River Watershed near Crested Butte Colorado with a focused effort in Redwell Basin as part of a broader study of the role of bedrock groundwater in the hydrogeology of mineralized mountain watersheds. Ten gravity stations were acquired with a LaCoste and Romberg G-model relative gravimeter to map density variations. This data release includes principal facts for the gravity stations provided as digital data. Data fields are defined in the data dictionary.
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Shallow subsurface electrical conductivity was mapped at Norman Lake National Wildlife Refuge (NWR) in northwest North Dakota using the DUALEM421 electromagnetic sensor (Dualem, Inc., ON, Canada) in the winter of 2018. Data were acquired by towing the DUALEM421 sensor on a sled behind an all-terrain vehicle or snow machine, with the sensor at a nominal height of 0.3 meters (m) above ground surface. Approximately 41 line-kilometers (km) of data were acquired over an area of approximately 2 square-kilometers. At this survey location, the 4m transmitter-receiver horizontal co-panar and perpendicular coil orientations did not function due to equipment malfunction. Data were manually edited to remove sensor dropouts,...
Airborne electromagnetic (AEM), magnetic, and radiometric data were acquired November 2018 to February 2019 along 16,816 line-kilometers (line-km) over the Mississippi Alluvial Plain (MAP). Data were acquired by CGG Canada Services, Ltd. with three different helicopter-borne sensors: the CGG Canada Services, Ltd. Resolve frequency-domain AEM instrument that is used to map subsurface geologic structure at depths up to 100 meters, depending on the subsurface resistivity; a Scintrex CS-3 cesium vapor magnetometer that detects changes in deep (hundreds of meters to kilometers) geologic structure based on variations in the magnetic properties of different formations; and a Radiation Solutions RS-500 spectrometer that...
Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Arkansas, Bayou Bartholomew, Bayou Meto, Boeuf River, Cache River, 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. 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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Airborne electromagnetic (AEM), magnetic, and radiometric data were acquired in late February to early March 2018 along 2,364 line-kilometers in the Shellmound, Mississippi study area. Data were acquired by CGG Canada Services, Ltd. with three different helicopter-borne sensors: the CGG Canada Services, Ltd. RESOLVE frequency-domain AEM instrument that is used to map subsurface geologic structure at depths up to 100 meters, depending on the subsurface resistivity; a Scintrex CS-3 cesium vapor magnetometer that detects changes in deep (hundreds of meters to kilometers) geologic structure based on variations in the magnetic properties of different formations; and a Radiation Solutions RS-500 spectrometer that detects...
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Airborne electromagnetic (AEM), magnetic, and radiometric data were acquired in late February to early March 2018 along 2,364 line-kilometers in the Shellmound, Mississippi study area. Data were acquired by CGG Canada Services, Ltd. with three different helicopter-borne sensors: the CGG Canada Services, Ltd. RESOLVE frequency-domain AEM instrument that is used to map subsurface geologic structure at depths up to 100 meters, depending on the subsurface resistivity; a Scintrex CS-3 cesium vapor magnetometer that detects changes in deep (hundreds of meters to kilometers) geologic structure based on variations in the magnetic properties of different formations; and a Radiation Solutions RS-500 spectrometer that detects...
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Airborne electromagnetic (AEM), magnetic, and radiometric data were acquired November 2018 to February 2019 along 16,816 line-kilometers (line-km) over the Mississippi Alluvial Plain (MAP). Data were acquired by CGG Canada Services, Ltd. with three different helicopter-borne sensors: the CGG Canada Services, Ltd. Resolve frequency-domain AEM instrument that is used to map subsurface geologic structure at depths up to 100 meters, depending on the subsurface resistivity; a Scintrex CS-3 cesium vapor magnetometer that detects changes in deep (hundreds of meters to kilometers) geologic structure based on variations in the magnetic properties of different formations; and a Radiation Solutions RS-500 spectrometer that...
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Airborne electromagnetic (AEM), magnetic, and radiometric data were acquired November 2019 to March 2020 along 24,030 line-kilometers (line-km) over the Mississippi Alluvial Plain (MAP). Data were acquired by CGG Canada Services, Ltd. with three different airborne sensors: the CGG Canada Services, Ltd. TEMPEST time-domain AEM instrument that is used to map subsurface geologic structure at depths up to 300 meters (m), depending on the subsurface resistivity; a Scintrex CS-3 cesium vapor magnetometer that detects changes in deep (hundreds of meters to kilometers) geologic structure based on variations in the magnetic properties of different formations; and a Radiation Solutions RS-500 spectrometer that detects the...
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Airborne electromagnetic (AEM), magnetic, and radiometric data were acquired September 2021 to January 2022 along 27,204 line-kilometers (line-km) over the Mississippi Alluvial Plain (MAP), Mississippi Embayment, and Gulf Coastal Plain. Data were acquired by Xcalibur Multiphysics (Canada), Ltd. with three different airborne sensors: the 30Hz TEMPEST time-domain AEM instrument that is used to map subsurface geologic structure at depths up to 300 meters (m) depending on the subsurface resistivity; a Scintrex CS-3 cesium vapor magnetometer that detects changes in deep (hundreds of meters to kilometers) geologic structure based on variations in the magnetic properties of different formations; and a Radiation Solutions...
Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Arkansas, Arkansas River, GGGSC, Geology, Geophysics, and Geochemistry Science Center, Illinois, All tags...
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Water-borne towed transient electromagnetic method, commonly referred to as FloaTEM, was acquired along a single survey track on the Ouachita River during October 2018. During the survey, 39.75 line-kilometers were collected near Blankston, Louisiana study area. Data were collected by members of the U.S. Geological Survey, Hydrogeophysics Branch, and Lower-Mississippi Gulf Science Center and the Aarhus University Hydrogeophysics Group. FloaTEM data acquired along the approximately 40 line kilometers of the Ouachita River in Caldwell County, in Louisiana,were collected to characterize the subsurface resistivity structure in support of a U.S. Geological Survey groundwater investigation of the Mississippi Alluvial...
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Electrical resistivity results from two regional airborne electromagnetic (AEM) surveys (Minsley et al. 2021 and Burton et al. 2021) over the Mississippi Alluvial Plain (MAP) were combined by the U.S. Geological Survey to produce three-dimensional (3D) gridded models and derivative hydrogeologic products. Grids were discretized in the horizontal dimension to align with the 1 kilometer (km) x 1 km National Hydrogeologic Grid (NHG; Clark et al. 2018), and vertically discretized into both 5 meter (m) depth slices and 5 m elevation slices. To support hydrogeologic and geologic studies within the MAP region and the Mississippi River Valley Alluvial aquifer (MRVA), derivative products were calculated from the 3D resistivity...
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Towed transient electromagnetic (tTEM) data were acquired at two field locations near Shellmound, Mississippi during March 2018. During the survey, approximately 34.7 line-kilometers were collected in the study area. Data were collected by members of the U.S. Geological Survey, Hydrogeophysics Branch, and the Aarhus University Hydrogeophysics Group. tTEM data acquired along the approximately 35-line kilometers in two agricultural fields near the banks of the Tallahatchie River in Leflore County, Mississippi. Data were collected to characterize the subsurface resistivity structure in support of a U.S. Geological Survey groundwater investigation of the Mississippi Alluvial Plain. tTEM data were collected using an...
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Water-borne towed transient electromagnetic method, commonly referred to as FloaTEM, was acquired along a single survey track on the Ouachita River during October 2018. During the survey, approximately 46.15 line-kilometers were collected near Monroe, Louisiana study area. Data were collected by members of the U.S. Geological Survey, Hydrogeophysics Branch, and Lower-Mississippi Gulf Science Center and the Aarhus University Hydrogeophysics Group. FloaTEM data acquired along the approximately 46.1 line kilometers of the Ouachita River in Ouachita Parish, in Louisiana,were collected to characterize the subsurface resistivity structure in support of a U.S. Geological Survey groundwater investigation of the Mississippi...
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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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Shallow subsurface electrical conductivity was mapped at Medwell National Wildlife Refuge (NWR) in northeast Montana using the DUALEM421 electromagnetic sensor (Dualem, Inc., ON, Canada) in the winter of 2017. Data were acquired by towing the DUALEM421 sensor on a sled behind an all-terrain vehicle or snow machine, with the sensor at a nominal height of 0.3 meters (m) above ground surface. Approximately 9 line-kilometers (km) of data were acquired over an area of approximately 1 square-kilometer. Data were manually edited to remove sensor dropouts, lag corrected for apparent offsets between recorded GPS location and data locations for each coil pair, and averaged to a sounding distance of 1m along the survey path;...
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Shallow subsurface electrical conductivity was mapped at Anderson National Wildlife Refuge (NWR) in northeast Montana using the DUALEM421 electromagnetic sensor (Dualem, Inc., ON, Canada) in the winter of 2017. Data were acquired by towing the DUALEM421 sensor on a sled behind an all-terrain vehicle or snow machine, with the sensor at a nominal height of 0.3 meters (m) above ground surface. Approximately 25 line-kilometers (km) of data were acquired over an area of approximately 1 square-kilometer. Data were manually edited to remove sensor dropouts, lag corrected for apparent offsets between recorded GPS location and data locations for each coil pair, and averaged to a sounding distance of 1m along the survey path;...
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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...
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Shallow subsurface electrical conductivity was mapped at Rabenberg National Wildlife Refuge (NWR) in northeast Montana using the DUALEM421 electromagnetic sensor (Dualem, Inc., ON, Canada) in the winter of 2017. Data were acquired by towing the DUALEM421 sensor on a sled behind an all-terrain vehicle or snow machine, with the sensor at a nominal height of 0.3 meters (m) above ground surface. Approximately 32 line-kilometers (km) of data were acquired over an area of approximately 1 square-kilometer. Data were manually edited to remove sensor dropouts, lag corrected for apparent offsets between recorded GPS location and data locations for each coil pair, and averaged to a sounding distance of 1m along the survey...


map background search result map search result map Processed airborne magnetic and radiometric grids AEM processed survey data Airborne electromagnetic, magnetic, and radiometric survey of the Mississippi Alluvial Plain, November 2018 - February 2019 AEM processed survey data Gravity Data Electrical and electromagnetic geophysical surveys at Jim Woodruff Lock and Dam, Chattahoochee, Florida, March 2018 Electromagnetic induction (EMI) data Self-potential (SP) data Anderson NWR, Montana, 2017 Goose Lake NWR, Montana, 2017 Rabenberg NWR, Montana, 2017 Norman Lake NWR, North Dakota, 2018 Medwell NWR, Montana, 2017 Floating and Towed Transient Electromagnetic Surveys used to Characterize Hydrogeology underlying Rivers and Estuaries: March - December 2018 Combined results and derivative products of hydrogeologic structure and properties from airborne electromagnetic surveys in the Mississippi Alluvial Plain Airborne EM, magnetic, and radiometric survey data tTEM processed survey data, Shellmound, Mississippi, March 2018 Water-borne towed-transient electromagnetic survey data, along the Ouachita River near Monroe, Louisiana, October 2018 Water-borne towed-transient electromagnetic survey data, along the Ouachita River near Blankston, Louisiana, October 2018 Airborne electromagnetic, magnetic, and radiometric survey of the Mississippi Alluvial Plain, Mississippi Embayment, and Gulf Coastal Plain, September 2021 - January 2022 Medwell NWR, Montana, 2017 Gravity Data Electromagnetic induction (EMI) data Self-potential (SP) data Electrical and electromagnetic geophysical surveys at Jim Woodruff Lock and Dam, Chattahoochee, Florida, March 2018 Rabenberg NWR, Montana, 2017 Anderson NWR, Montana, 2017 Goose Lake NWR, Montana, 2017 Norman Lake NWR, North Dakota, 2018 tTEM processed survey data, Shellmound, Mississippi, March 2018 Processed airborne magnetic and radiometric grids AEM processed survey data AEM processed survey data Airborne electromagnetic, magnetic, and radiometric survey of the Mississippi Alluvial Plain, November 2018 - February 2019 Airborne EM, magnetic, and radiometric survey data Airborne electromagnetic, magnetic, and radiometric survey of the Mississippi Alluvial Plain, Mississippi Embayment, and Gulf Coastal Plain, September 2021 - January 2022 Combined results and derivative products of hydrogeologic structure and properties from airborne electromagnetic surveys in the Mississippi Alluvial Plain Floating and Towed Transient Electromagnetic Surveys used to Characterize Hydrogeology underlying Rivers and Estuaries: March - December 2018