Filters: Tags: Geophysical Survey (X)
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New active-source shallow seismic (shear-wave and acoustic-wave) measurements were obtained at 18 prioritized seismic monitoring station locations in the north San Francisco Bay area to measure site-specific ground motion amplification effects, soil depth, depth to bedrock (Z1.0 Vs=1 km/s), calculate site specific velocity-depth profiles and Vs30, and develop NEHRP site classifications for each location. This study was led by Principal Investigators Jamey Turner, Cooper Brossy, and Daniel O’Connell and field data were acquired by Glendon Adams and Lincoln Steele. Seismic monitoring sites that recorded high PGA values during the M6.0 Napa earthquake, proximal to higher population densities, and sites recommended...
Categories: Data;
Types: Citation,
Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: California,
EHP,
Earthquake Hazards Program,
GHSC,
Geologic Hazards Science Center,
Lake Poinsett is a 260-hectare (640 acres) lake located on Crowley’s Ridge in northeastern Arkansas, approximately 6 km southeast of Harrisburg, Arkansas within Poinsett County. The lake was built for recreation by the Arkansas Highway Department in 1960 by constructing a roughly 800-meter dam across the southern boundary of the Distress Creek watershed. The dam is currently operated by the Arkansas Game and Fish Commission (AGFC). AGFC and Arkansas Natural Resources Commission (ANRC) plan to drain the lake to allow access for a series of bank stabilization and dam safety improvements. Because none of the original blueprints exist, AGFC asked the U.S. Geological Survey (USGS) to conduct a series of differential...
Categories: Data;
Tags: Arkansas,
Crowley's Ridge,
Electrical Resistivity,
Frequency Domain Electromagnetics,
GNSS Survey,
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),
Fortymile mining district electromagnetic and magnetic airborne geophysical survey, data compilation
The Fortymile electromagnetic and magnetic airborne geophysical survey data were acquired with a DIGHEM-V Electromagnetic (EM) system and a cesium magnetometer. The EM and magnetic sensors were flown at a height of 30 meters (m). In addition the survey recorded data from radar and laser altimeters, a GPS navigation system, 50/60 Hz monitors and a video camera. Flights were performed with an AS-350-B2 Squirrel helicopter at a mean terrain clearance of 60 m along N-S survey flight lines with a spacing of 400 m. Tie lines were flown perpendicular to the flight lines at intervals of approximately 4,800 m
Airborne geophysical data for the Tanacross area were acquired and processed by Goldak Airborne Surveys under contract with the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (DGGS). Project funded by the US Geological Survey, Mineral Resources Program. This high sensitivity aeromagnetic survey was carried out by Goldak Airborne Surveys (Goldak) on behalf of the Alaska Department of Geological and Geophysical Surveys (DGGS) between June 17th and July 31st, 2015. Aircraft equipment operated included three cesium vapor magnetometers, a GPS/GLONASS real-time and post-corrected differential positioning system, a flight path recovery camera, a digital video titling and...
Livengood mining district electromagnetic and magnetic airborne geophysical survey, data compilation
The Livengood electromagnetic and magnetic airborne geophysical survey data were acquired with a DIGHEM-V Electromagnetic (EM) system and a cesium magnetometer. The EM and magnetic sensors were flown at a height of 30 meters (m). In addition the survey recorded data from radar and laser altimeters, a GPS navigation system, 50/60 Hz monitors and a video camera. Flights were performed with an AS-350-B2 Squirrel helicopter at a mean terrain clearance of 60 m along N-S survey flight lines with a spacing of 400 m. Tie lines were flown perpendicular to the flight lines at intervals of approximately 4,800 m
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...
Merged grids of residual magnetic intensity, digital terrain model, and apparent resistivity compiled from the Black Mountain, Liscum, Goodpaster, SE extension of Salcha River - Pogo, and Salcha River Pogo geophysical surveys.
The hydrogeology of the Cannon Air Force Base (AFB) in Curry County, is being investigated to better understand the mechanics of groundwater flow in the area, including the identification of preferential groundwater flow paths. Mapping the top of the Dockum Group was done to help identify potential paleochannels that may have eroded the surface of the Dockum Group and subsequently filled in with coarse-grained sediments of the overlying Ogallala Formation. The Dockum Group is composed of sandstone, siltstone, mudstone, and shale that were originally deposited in fluvial and lacustrine environments (McGowen and others, 1979). The upper part of the Dockum Group is a thick layer of red clay referred to locally as the...
Merged grids of residual magnetic intensity, digital terrain model, and apparent resistivity compiled from the Tanacross, Ladue, Western Fortymile, and Fortymile geophysical surveys.
This data release consists of three different types of data: including direct current (DC) resistivity profiles, frequency domain electromagnetic (FDEM) survey data, and global navigation satellite system (GNSS) coordinate data of the geophysical measurement locations. A data dictionary is included along with the data and defines all of the table headings, definitions, and units. Earthen dams are common on lakes and ponds, but characteristics of these structures such as construction history, composition, and integrity are often unknown for older dams. Geophysical surveying techniques provide a non-invasive method of mapping their lithology and structure. In particular, DC resistivity and FDEM methods can,...
Categories: Data;
Tags: Arkansas,
Bob Kidd Lake,
Direct current resistivity,
Earthen dam,
Earthen structure,
This digital publication, GPR 2011-4, contains Fugro Airborne Surveys' analysis and interpretation of data produced from airborne geophysical surveys published by DGGS in 2011 (GPR 2011-2) of the Iditarod survey area. Fugro Airborne Surveys' frequency-domain DIGHEM V system was used for the EM data. GPR 2011-4 includes (1) Fugro's project report with interpretation and detailed EM Anomalies in tabular format, (2) Multi-channel stacked profiles in pdf format, and (3) interpretation and em anomalies are each provided as Geotiffs and maps. The document gpr2011_004_readme (.txt and .pdf) lists all files included in this publication. Other supporting files include gpr2011-4_browsegraphic.pdf, gpr2011-4_emanomaly_readme.pdf....
Frequency domain electromagnetic data and magnetic geophysical data were collected below a helicopter using a 30 meter (m) long line and a towed bird for the 1997 Iron Creek survey. The geophysical data were acquired with a DIGHEM-V Electromagnetic (EM) system, a Scintrex cesium magnetometer, and a Herz VLF system installed in on AS350B-2 Squirrel helicopter. In addition, the survey recorded data from a radar altimeter, GPS navigation system, 50/60 Hz monitors and video camera. Many of the files for this release were published on paper and available by mail order beginning in 1998. This updated data release provides a compilation of the previously published paper files (in PDF format) and the originating data files...
This publication, GPR 2015-3, contains geophysical data produced from airborne surveys conducted in 1996 and released in 1997 for 415 sq miles of the Petersville mining district, Alaska by the Alaska Division of Geological & Geophysical Surveys (DGGS). Aeromagnetic and electromagnetic data were acquired during the helicopter-based surveys. During 2004, the same digital data were reformatted for ease of use with modern processing tools, vector files and the 56,000 Hz resistivity grid, were added, and new color maps were produced. Except for leveling of the 56,000 Hz coplanar resistivity grid, no reprocessing of the geophysical data was done. The files represent the end part of the 2004 process. A few maps produced...
Karst environments present many challenges to agencies and engineers attempting to work in these landscapes, particularly towards building infrastructure. The interconnectivity of karst hydrologic systems means that activities occurring on the surface of a karst landscape can have an impact on water quality and quantity. Additionally, soil thickness in karst landscape is often highly variable due to the presence of solutionally-enlarged fractures, joints, and openings at the soil-bedrock interface. Therefore, when planning infrastructure in karst terrains it is critical to do a thorough assessment to ensure that planned activities will not negatively impact the sensitive environment. In October 2020 Electric Resistivity...
Merged grids of residual magnetic intensity, digital terrain model, and apparent resistivity compiled from the Tok, Ladue, Slate Creek - Slana River, Alaska Highway Corridor, and Fortymile geophysical surveys.
This data release consists of two .csv files of inverted models of electrical resistivity created from the processed resistivity data in the accompanying two data releases: (Miller and Others, 2018) and (2018 Raw and Processed, in progress). During 2016, 17, and 18, the U.S. Geological Survey conducted continuous resistivity profiling along 15 rivers or lakes in the Mississippi Alluvial Plain of Mississippi, Arkansas, Louisiana, and Missouri to characterize streambed hydraulic conductivity values. These techniques characterize the near surface geomorphology of the streambed that controls the recharge to the alluvial aquifer. These data can be used to map changes in the lithology of the streambed and identify areas...
Categories: Data;
Types: ArcGIS REST Map Service,
ArcGIS Service Definition,
Downloadable,
Map Service;
Tags: Arkansas,
Black River,
Bogue Phalia,
Cache River,
Continuous Resistivity Profiling,
The Tonsina electromagnetic and magnetic airborne geophysical survey data were acquired with a DIGHEMv Electromagnetic (EM) system and a CGG D1344 cesium magnetometer with a Scintrex CS3 cesium sensor. The EM and magnetic sensors were flown at a height of 30 meters (m). In addition the survey recorded data from radar and laser altimeters, GPS navigation system, 50/60 Hz monitors and video camera. Flights were performed with an AS-350-B3 Squirrel helicopter at a mean terrain clearance of 60 m along NW-SE (345 degrees) survey flight lines with a spacing of 400 m. Tie lines were flown perpendicular to the flight lines at intervals of approximately 4,800 m. These data were produced under contract between the State of...
The Tok electromagnetic and magnetic airborne geophysical survey data were acquired with a DIGHEMv Electromagnetic (EM) system and a CGG D1344 cesium magnetometer with a Scintrex CS3 cesium sensor. The EM and magnetic sensors were flown at a height of 30 meters (m). In addition the survey recorded data from radar and laser altimeters, a GPS navigation system, 50/60 Hz monitors and a video camera. Flights were performed with an AS-350-B3 Squirrel helicopter at a mean terrain clearance of 60 m along NE-SW (12 degrees) survey flight lines with a spacing of 400 m. Tie lines were flown perpendicular to the flight lines at intervals of approximately 4,800 m. These data were produced under contract between the State of...
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