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Note: this data release has been depecrated. Find the updated version here: https://doi.org/10.5066/P9X8RUBW. Electromagnetic (EM) geophysical methods provide information about the bulk electrical conductivity of the subsurface. EM data has been widely used to investigate aquifers and geologic structures. In the following study, the United States Geological Survey conducted a boat-towed, waterborne transient electromagnetic (FloaTEM) survey to examine conductivity within the subsurface of the Delaware River channel. These conductive zones determine the location of the groundwater freshwater/saltwater interface within the Delaware River, downstream from Wilmington, DE. The FloaTEM system transmits a primary electrical...
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...
Electrical resistivity tomography (ERT), downhole nuclear magnetic resonance (NMR), and manual permafrost-probe measurements were used to quantify permafrost characteristics along transects within several catchments in interior Alaska in late summer 2016 and 2017. Geophysical sites were chosen to coincide with additional soil, hydrologic, and geochemical measurements adjacent to various low-order streams and tributaries in a mix of burned and unburned watersheds in both silty and rocky environments. Data were collected in support of the Striegl-01 NASA ABoVE project, "Vulnerability of inland waters and the aquatic carbon cycle to changing permafrost and climate across boreal northwestern North America." Additional...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Active layer thickness,
Alaska,
Borehole nuclear magnetic resonance,
Disturbance,
Fire,
The West Fork of Dall Creek is located ~100km southwest of Coldfoot, AK along the Dalton Highway, south of the Brooks Range. The West Fork of Dall Creek is composed of unburned black spruce forest with a burn scar from the 2004 Dall City Fire. Multi-season, multi-method geophysical data were collected both within the burned and unburned areas. Geophysical techniques used include Nuculear Magnetic Resonance (NMR) and Ground Penetrating Radar (GPR) data. NMR data were collected with a down borehole Dart tool (Vista Clara Inc.). GPR data were collected with a Sensors and Software pulseEKKO pro unit and 100 mHz antennas and a high power (1000V) transmitter. Soil temperature data were collected from the unburned black...
As the climate warms and dry periods become more extreme, shallow groundwater discharge is generally becoming a less reliable source of streamflow while deep groundwater discharge remains a more resilient source. The implications of shifts in the relative balance of shallow and deep groundwater discharge sources are profound in gaining streams. These different sources exert critical controls on stream temperature and water quality as influenced by legacy groundwater contaminant transport. Groundwater discharge flux rates over time were used for the inference of source groundwater characteristics to prominent riverbank groundwater discharge faces along the mainstem Farmington River, CT USA. To estimate groundwater...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Connecticut,
Farmington River,
USGS Science Data Catalog (SDC),
groundwater,
groundwater and surface-water interaction,
Electromagnetic (EM) geophysical methods provide information about the bulk electrical conductivity of the subsurface. EM data has been widely used to investigate aquifers and geologic structures. In the following study, the United States Geological Survey conducted a boat-towed, waterborne transient electromagnetic (FloaTEM) survey to examine conductivity within the subsurface of the main Delaware River channel and the Leipsic River. The Leipsic River flows through an estuary into the Delaware Bay. Subsurface conductive zones, when viewed in the context of the regional conceptual model and other data, can help determine the likely groundwater location of the freshwater/saltwater interface within the Delaware River,...
Categories: Data;
Tags: Delaware River,
Geophysics,
Hydrology and Hydrogeology,
USGS Science Data Catalog (SDC),
geophysics,
This data release provides a recursive-estimation framework to infer groundwater/surface-water exchange based on temperature time series collected at different vertical depths below the sediment/water interface. A heat-transport problem was formulated as a state-space model (SSM), in which the spatial derivatives in the convection/conduction equation are approximated using finite differences. The SSM is calibrated to estimate time-varying specific discharge using the Extended Kalman Filter (EKF) and Extended Rauch-Tung-Striebel Smoother (ERTSS) algorithms. This data release contains both algorithms, synthetic and field-experimental data, as well as VFLUX model results (Neversink_obs.csv, VFLUX_results.csv) used...
Categories: Data;
Tags: Extended Kalman Filter,
Heat tracing,
Hydrology,
Rauch-Tung-Striebel Smoothing,
Sediment Water Interface,
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