Filters: Tags: resistivity (X)
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Shallow soil conductivity was mapped in the San Luis Valley, Colorado, using the DualEM421 electromagnetic sensor in March 2020. Data were acquired by towing the DualEM421 sensor on a wheeled cart behind an all-terrain vehicle, with the sensor at a height of 0.457 m above the ground surface. Approximately 62 line-kilometers of data were acquired over an area of nearly 1.5 square kilometers, with 20 m separation between survey lines. Data were manually edited for noise sources (powerlines, pipelines, or other buried structures), and averaged to regular output soundings every 1 m along survey lines. Data were corrected for offset between the recorded GPS location and data locations for each coil pair, but were not...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Alamosa County,
Colorado,
GGGSC,
Geology, Geophysics, and Geochemistry Science Center,
Mineral Resources,
Airborne electromagnetic (AEM) and magnetic survey data, a total of 3065 line-kilometers, were collected during October 2001 in two survey blocks and four repeated lines from an earlier survey. The largest area, Block 1 totaling 2692.2 line-kilometers was flown over Big Cypress Preserve, smaller Block 2 along 277.1 line-kilometers was flown near the town of Homestead, and four lines totaling 95.2 line-kilometers were flown over Everglades National Park. The lines over Everglades National Park repeated the path of four lines from an earlier AEM survey collected in December 1994 (released under USGS Open-File Report 02-101 downloadable at https://pubs.er.usgs.gov/publication/ofr02101). Electromagnetic data were acquired...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Big Cypress National Preserve,
City of Homestead,
Dade County,
Everglades National Park,
Florida Bay,
Note: There is an updated version of this data release, available here: https://doi.org/10.5066/P92R4OL2 A helicopter-borne electromagnetic/magnetic survey was flown over the Stillwater area, southwest Montana from May 5 to May 16, 2000. The survey was conducted over the Stillwater Igneous Complex, a Precambrian layered mafic-ultramafic intrusion which is characterized by igneous layering. Electromagnetic data were acquired using DIGHEM helicopter-borne electromagnetic system. Magnetic data were collected with optically pumped Cesium Vapor Geometrics G822 magnetometer. Sensor elevation above ground was measured with Honeywell/Sperry AA220 radar. The nominal elevation of the sensor was 60 meters. Survey coverage...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Geophysics,
Montana,
aeromagnetic surveying,
electromagnetic surveying,
geology,
This section of the data release includes core images in the format of photos (JPG) that have been compressed into a zipped file (2018LakePowellCoring_CorePhotos.zip). It is Part 4 (of four) in this data release and contains images of the cleaned archival half from split cores as they appeared immediately after splitting (late March and early April 2019). Each photo includes a ruler (in centimeters) and X-Rite ColorChecker Classic color correction card that may be used for corrections. Drillhole information, such as location and total recovery, are outlined in “Part 1 – Drillhole information from the 2018 coring project in Lake Powell, Utah” (2018LakePowellCoring_DrillholeInfo.csv) of this data release. Each drillhole...
This folder contains the raw and processed TEM data and inverted soundings showing resistivity (in ohm-m) with depth for all survey sites that were part of transect 11. In October and November 2016-2017, transient electromagnetic (TEM) data, also called time domain electromagnetic (TDEM) surveys, were acquired at 120 locations in the Genesee Valley, Livingston County, in New York, in order to characterize the subsurface resistivity structure in support of a U.S. Geological Survey groundwater investigation. The TEM data were collected as part of a project to evaluate geophysical methods to characterize the valley-fill sediments, underlying bedrock, and salinity of the subsurface. TEM data were collected using an...
Airborne electromagnetic (AEM) and magnetic survey data were collected during October 2016 over a total distance of 262 line kilometers in the southeastern San Joaquin Valley near Cawelo, California. These data were collected in support of groundwater salinity mapping and hydrogeologic framework development as part of the U.S. Geological Survey California Oil, Gas, and Groundwater program and the California State Water Resources Control Board’s Oil and Gas Regional Monitoring Program. Minimally processed binary AEM data received from SkyTEM ApS were imported into the Aarhus Workbench software (Aarhus Geosoftware, Aarhus, Denmark) and processed. Filters were applied to inclinometer and spatial positioning data to...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: CAWSC,
California,
California Water Science Center,
Cawelo,
GGGSC,
Airborne electromagnetic (AEM) and magnetic survey data were collected during January and February 2021 over a distance of 3,170 line kilometers in northeast Wisconsin. These data were collected in support of an effort to improve estimates of depth to bedrock through a collaborative project between the U.S. Geological Survey (USGS), Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP), and Wisconsin Geological and Natural History Survey (WGNHS). Data were acquired by SkyTEM Canada Inc. with the SkyTEM 304M time-domain helicopter-borne electromagnetic system together with a Geometrics G822A cesium vapor magnetometer. The survey was acquired at a nominal flight height of 30 - 40 m above terrain...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Brown County,
Calumet County,
Door County,
Fond du Lac County,
GGGSC,
Surface-based 2D electrical resistivity tomography (ERT) surveys were used to investigate the distribution of permafrost at wetland sites on the alluvial plain north of the Tanana River, 20 km southwest of Fairbanks, Alaska, in June and September 2014. The sites contained habitat types characteristic of interior Alaska, including thermokarst bog, forested permafrost plateau, and a rich fen. These habitats range from treed to open and vary in groundcover vegetation and peat thickness. Individual surveys used a cable with 56 electrodes at 2-m spacing. At a fen site, ERT surveys were performed across a mixed spruce forest area across a vegetation gradient into an open fen area. At a bog site,surveys were performed...
Shallow subsurface electrical conductivity was mapped at selected U.S. Fish and Wildlife Service managed lands in northeast Montana and northwest North Dakota using the DUALEM421 electromagnetic sensor (Dualem, Inc., ON, Canada) in the winters of 2017 and 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 427 line-kilometers (km) of data were acquired over an area of nearly 26 square-kilometers. 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...
Categories: Data;
Types: ArcGIS REST Map Service,
ArcGIS Service Definition,
Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Anderson,
Beaver Lake,
Bigslough,
Divide County, ND,
Dog Leg,
Shallow subsurface electrical conductivity was mapped at Ward 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 .5 square-kilometers. 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;...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: GGGSC,
Geology, Geophysics, and Geochemistry Science Center,
Montana,
NOROCK,
National Wildlife Refuge,
This publication, GPR 2017-1, provides geophysical data produced from an airborne geophysical survey conducted in 2001 and released in 2002 for 276 sq miles of the Liberty Bell area, western Bonnifield mining district, central Alaska. Aeromagnetic and electromagnetic data were acquired during the survey. During 2016, the same digital data were reformatted for ease of use with modern processing tools; vector shapefiles and the analytic signal and calculated first vertical derivative grids were added. Other than the creation of calculated grids, no new processing was done. Data provided in GPR 2017-1 include processed (1) linedata ASCII databases, (2) gridded files of magnetic and resistivity data, (3) vector files...
Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability and resilience of different landscapes to permafrost degradation are needed. Geophysical and other field observations reveal details of both near-surface (less than 1 m) and deeper (greater than 1 m) impacts of fire on permafrost along 14 transects that span burned-unburned boundaries in different landscape settings within interior...
Categories: Data;
Types: Citation,
Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Active layer thickness,
Alaska,
Borehole nuclear magnetic resonance,
Chatanika,
City of Fairbanks,
Airborne electromagnetic (AEM) and magnetic survey data were collected during February 2016 along 300 line kilometers in the western Yukon Flats near Stevens Village, Alaska. Data were acquired with the CGG RESOLVE frequency-domain helicopter-borne electromagnetic systems together with a Scintrex Cesium Vapour CS-3 magnetometer. The AEM average depth of investigation is about 100 m. The survey was flown at a nominal flight height of 30 m above terrain along widely spaced reconnaissance lines. This data release includes raw and processed AEM data and laterally-constrained inverted resistivity depth sections along all flight lines. This release also includes unprocessed and processed magnetic data that has been drift...
This release contains plant species cover measured along transects in Alaska, 2015. Site condition information in terms of wildfire burns is also included.
Categories: Data;
Types: Citation;
Tags: Active layer,
Active layer thickness,
Alaska,
Borehole nuclear magnetic resonance,
Chatanika,
Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability and resilience of different landscapes to permafrost degradation are needed. Geophysical and other field observations reveal details of both near-surface (less than 1 m) and deeper (greater than 1 m) impacts of fire on permafrost along 14 transects that span burned-unburned boundaries in different landscape settings within interior...
Categories: Data;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Active layer thickness,
Alaska,
Borehole nuclear magnetic resonance,
Chatanika,
City of Fairbanks,
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...
Airborne electromagnetic (AEM) and magnetic survey data were collected during October 2016 along 1,443 line kilometers in the southwestern San Joaquin Valley near Lost Hills, California. These data were collected in support of groundwater salinity mapping and hydrogeologic framework development as part of the U.S. Geological Survey California Oil, Gas, and Groundwater program and the California State Water Resources Control Board’s Program of Regional Monitoring of Water Quality in Areas of Oil and Gas Production. Minimally processed binary AEM data received from the contractor were imported into the Aarhus Workbench software (Aarhus Geosoftware, Aarhus, Denmark) and processed. Filters were applied to inclinometer...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: CAWSC,
California,
California Water Science Center,
GGGSC,
Geology, Geophysics, and Geochemistry Science Center,
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...
This section of the data release includes drillhole information in the format of a comma-separated value (CSV) file (2018LakePowellCoring_DrillholeInfo.csv). It is Part 1 (of four) in this data release and represents the broadest hierarchical information on the dataset including the drillhole name, location, water depth, sediments top and bottom, drillhole depth, and recovery for each coring location. Each drillhole comprises multiple cores which are outlined in “Part 2 – Core and core section information from the 2018 coring project in Lake Powell, Utah” (2018LakePowellCoring_CoreSectionInfo.csv) of this data release. Core logs and spectrophotometry data are available in “Part 3 – Multi-Sensor Core Logger and spectrophotometry...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Animas River,
Antelope Canyon,
Bears Ears National Monument,
Bullfrog,
Bullfrog Bay,
Airborne electromagnetic (AEM) and magnetic survey data were collected during March 2018 along 1,637 line line-kilometers over the western Hualapai Indian Reservation and surrounding areas. The survey was conducted as part of a study of the groundwater resources of the Truxton basin and Hualapai Plateau. The survey was designed to improve the understanding of the geometry of the major hydrostratigraphic contacts of the study area. Data were acquired by SkyTEM ApS with the SkyTEM 312 time-domain helicopter-borne electromagnetic system together with a Geometrics G822A cesium vapor magnetometer. The survey was flown at a nominal flight height of 30 meters (m) above terrain along block-style lines with a nominal spacing...
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