Towed transient electromagnetic (tTEM) surveys adjacent to the Tallahatchie River near Shellmound, Mississippi

Towed transient electromagnetic (tTEM) data were acquired adjacent to the Tallahatchie River during March 2018. During the survey, approximately 35 line-kilometers were collected in the Shellmound, Mississippi study area. Data were collected by members of the U.S. Geological Survey, Hydrogeophysics Branch, and the Aarhus University HydroGeophysics Group. FloaTEM data acquired near the Tallahatchie River in Leflore County, in Mississippi, were collected to characterize the subsurface resistivity structure in support of a U.S. Geological Survey groundwater investigation of the Mississippi Alluvial Plain. tTEM data were collected using an Aarhus University HydroGeophysics Group tTEM unit using a transmitter loop (Tx) size, 4 by 2 meter square (m^2), in an offset-loop receiver (Rx) configuration utilizing a receiver coil that is 0.5 by 0.5 m^2 in size (with an effective area of 35 m^2) towed about 7 meters behind the Tx loop. The Tx loop was towed about 2.8m behind the all-terrain vehicle (ATV) The Tx outputs dual currents of about 3 and 30 amperes (A) for dual-moment transmission. The measurement cycles take approximately 0.5 seconds to complete and are comprised of several hundred individual transients that are averaged into 1D soundings along the profile. This data release includes the averaged, culled, and inverted tTEM data along the survey line that were used to produce the final resistivity models. Digital data of the processed soundings are provided, and fields are defined in a data dictionary. (1) Files with *AVERAGED.xyz and *AVERAGED.csv are space- and comma-delimited ASCII files that contain the least processed data where transients were averaged together and most coupled data were removed. Data locations are provided as UTM Zone 15 N projection and datum of WGS-84. (2) Files with *CULLED.xyz and *CULLED.csv are space- and comma- delimited ASCII files containing the processed data where negatively-impacted transients and coupled data were removed using a combination of automated and manual processing. Data locations are provided as UTM Zone 15 N projection and datum of WGS-84. (3) Files with *INVERTED.xyz and *INVERTED.csv are space- and comma-delimited ASCII files containing the inversion model results. Model locations are provided as UTM Zone 15 N projection and datum of WGS-84. (4) Files with *INVERTED_image.png and *INVERTED_image.pdf are the inverted model output as a 2D profile of electrical resistivity distribution in the subsurface.

[
  "010:12"
]

[
  "geospatial"
]