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More than 11,500 well records, such as geophysical logs, drilling descriptions, and published hydrogeologic framework information, were evaluated to help characterize the framework of hydrogeologic units in and near Gaines, Terry, and Yoakum Counties, Texas. Additional geophysical data were collected to improve the spatial coverage across the study area and to reduce uncertainty with regard to hydrogeologic unit extents. The evaluation of existing data plus the collection of new geophysical data provided that basis for developoing a refined understanding of how the saturated thickness of the Ogallala and Edwards-Trinity aquifers vary throughout the study area.
The transboundary Mesilla Basin/Conejos-Médanos aquifer system was identified as one of the priority transboundary aquifer systems for additional study by the United States and Mexico U.S.-Mexico Transboundary Aquifer Assessment Act of 2006 (United States-Mexico Transboundary Aquifer Act, Public Law 109-448). As one of the largest rechargeable groundwater systems by total available volume in the Rio Grande/Rio Bravo del Norte Basin region of the United States and Mexico, the Mesilla Basin/Conejos-Médanos aquifer system supplies water for irrigation as well as municipal use in El Paso, Texas; Las Cruces, New Mexico; and Ciudad Juárez, Chihuahua, Mexico (Alley, 2013). The U.S. Geological Survey in cooperation with...
Declining groundwater levels in and near Gaines, Yoakum, and Terry Counties in the Texas Panhandle have raised concerns about the amount of available groundwater and the potential for water-quality changes resulting from dewatering and increased vertical groundwater movement between adjacent water-bearing hydrogeologic units. More than 9,800 well records, such as geophysical logs, drilling descriptions, and published hydrogeologic framework information, were evaluated to help characterize the framework of hydrogeologic units in the study area. Additional geophysical data were collected to improve the spatial coverage across the study area and to reduce uncertainty with regard to hydrogeologic unit extents. Of greatest...
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...
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...
In 2022, the U.S. Geological Survey (USGS) New England Water Science Center, in cooperation with the New Hampshire Department of Transportation (NHDOT), surveyed four transportation infrastructure sites with frequency-domain electromagnetic induction (EMI) instruments and one site with ground-penetrating radar (GPR) to aid traditional geotechnical site characterizations performed by NHDOT. Information about subsurface physical properties is typically obtained through the use of borings during geotechnical site characterizations. Geotechnical site investigations that also include geophysical surveys (such as the EMI and GPR methods) between borings help provide more thorough characterizations. Integrated analysis...
Categories: Data;
Tags: Canterbury, NH,
Geophysics,
Geophysics,
Ground penetrating radar (GPR),
Groundwater,
Declining groundwater levels in the Hueco Bolson have raised concerns about the amount of available groundwater and the potential for water-quality changes. Fresh groundwater stored in the aquifer is bordered by regions of brackish-to-saline groundwater, and as the water levels in the Hueco Bolson have declined the local and regional hydraulic gradients have been altered such that the brackish-to-saline groundwater regions have encroached upon and degraded the quality of the freshwater zones (Hibbs 1999; Heywood and Yager, 2003). To help delineate the freshwater and saline groundwater transition zone, 20 time-domain electromagnetic soundings were collected to provide resistivity structure data in the area. This...
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