Towed transient electromagnetic survey data, Historic Jamestowne Island, Virginia, August 2021

Towed transient electromagnetic (tTEM) data were acquired during August 2021 in Historic Jamestowne, which is part of Colonial National Historic Park of Virginia. Members of the U.S. Geological Survey, Hydrogeophysics Branch, and the Virginia-West Virginia Water Science Center collected approxximately 15.7 line kilometers of tTEM data along the the Tour Road in James City County, Virginia to characterize the subsurface earth resistivity structure in support of a U.S. Geological Survey groundwater investigation of the effect of sea level rise on the historic island. tTEM data were collected using a transmitter loop (Tx) with size of, 4 by 2 square-meters, in an offset-loop receiver (Rx) configuration utilizing a receiver coil that is 0.5 by 0.5 square-meters in size (with an effective area of 35 m^2) towed about 7 meters behind the transmitter loop. The transmitter outputs dual currents of about 2.8 and 30 amperes (A) for dual-moment transmission. The Tx measurement cycles require approximately 0.5 seconds to complete and are comprised of several hundred individual transients. This data release includes the raw and averaged tTEM data along the Tour Road. Export of the digital data from the towed-TEM soundings were produced by a Windows 10 operating system running Aarhus GeoSoftware's Workbench version 6.6.0.2 and data fields contained in the files are defined in the entity and attributes section of the XML file.