Combined results and derivative products of hydrogeologic structure and properties from airborne electromagnetic surveys in the Mississippi Alluvial Plain (ver. 2.0, July 2024)

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 grids to refine system-scale detail of MRVA properties, the degree of confinement or connectivity in surface material, shallow streambed properties, and the hydrologic connection potential across the base of the MRVA. The 3D gridded models were exported in NetCDF format with accompanying XML NetCDF Markdown Language metadata files. All other products are provided as raster images in Georeferenced Tagged Image File Format (GeoTIFF) files. Burton, B.L., Minsley, B.J., Bloss, B.R., and Kress, W.H., 2021, Airborne electromagnetic, magnetic, and radiometric survey of the Mississippi Alluvial Plain, November 2018 - February 2019: U.S. Geological Survey data release, https://doi.org/10.5066/P9XBBBUU. Clark, B.R., Barlow, P.M., Peterson, S.M., Hughes, J.D., Reeves, H.W., and Viger, R.J., 2018, National-scale grid to support regional groundwater availability studies and a national hydrogeologic database: U.S. Geological Survey data release, https://doi.org/10.5066/F7P84B24. Minsley, B.J., James, S.R., Bedrosian, P.A., Pace, M.D., Hoogenboom, B.E., and Burton, B.L., 2021, Airborne electromagnetic, magnetic, and radiometric survey of the Mississippi Alluvial Plain, November 2019 - March 2020: U.S. Geological Survey data release, https://doi.org/10.5066/P9E44CTQ.