The electrical conductivity of the earth is used to help infer lithological and pore fluid properties. Various geophysical methods can provide estimates of the distribution of below ground electrical conductivity, with each method having certain limitations. This data release presents raw and processed results from land-based and water-based frequency domain electromagnetic induction imaging (EMI) data collected from March 31 to April 2, 2015. Data were primarily collected by walking throughout the wetland and riparian zones with the GEM-2 instrument (Geophex, Ltd.) at approximately 1 m off the ground in horizontal coplanar (ski flat) mode. A survey along a section of the Colorado River in a kayak was also collected (with approximate 0.3 m of elevation above the water surface).

Quantitative evaluation of groundwater/surface water exchange dynamics is universally challenging in large river systems, because existing physical methodology often does not yield spatially-distributed data and is difficult to utilize in deeper water. Here we apply combined frequency domain electromagnetic induction (EMI) and direct contact vertical electrical sounding (VES) measurements to identify shallow, fresh groundwater discharge estimates to the Colorado River through a 4 km2 wetland that borders the town of Moab, Utah, USA. EMI data were collected by a mobile tool that was hand carried or floated on the back of a kayak, providing extensive spatial coverage for the upper approximate 5 m of river channel/sediments. The VES measurements are made by installing electrodes directly into the ground around a common point and are therefore much less-mobile than the EMI approach, but can yield information about deeper (e.g., up to 25 m) saturated sediment electrical conductivity transitions. This data release contains (2) child items, one that contains and describes the EMI data, and another that contains and describes the VES data.

Quantitative evaluation of groundwater/surface water exchange dynamics is universally challenging in large river systems, because existing physical methodology often does not yield spatially-distributed data and is difficult to utilize in deeper water. Here we apply combined frequency domain electromagnetic induction (EMI) and direct contact vertical electrical sounding (VES) measurements to identify shallow, fresh groundwater discharge estimates to the Colorado River through a 4 km2 wetland that borders the town of Moab, Utah, USA. EMI data were collected by a mobile tool that was hand carried or floated on the back of a kayak, providing extensive spatial coverage for the upper approximate 5 m of river channel/sediments. The VES measurements are made by installing electrodes directly into the ground around a common point and are therefore much less-mobile than the EMI approach, but can yield information about deeper (e.g., up to 25 m) saturated sediment electrical conductivity transitions. This data release contains (2) child items, one that contains and describes the EMI data, and another that contains and describes the VES data.

Vertical electrical soundings (VES) are used to develop depth-resolved models of aquifer resistivity by making electrical potential measurements at increasingly larger electrode spacing, with the array centered around a common point. Variations in modeled electrical resistivity with depth can be used to infer groundwater salinity and preferential fresh groundwater flow zones. Each of the 4 VES measurement integrates approximately 11 individual electrical soundings with 4 electrodes driven into the soil in a linear Wenner array with electrode spacings ranging from 1 to 40 m. Data were collected manually with a SuperSting electrical resistivity meter (AGI - Advanced Geosciences, Inc) and recorded by hand in a field book.

Vertical electrical soundings (VES) are used to develop depth-resolved models of aquifer resistivity by making electrical potential measurements at increasingly larger electrode spacing, with the array centered around a common point. Variations in modeled electrical resistivity with depth can be used to infer groundwater salinity and preferential fresh groundwater flow zones. Each of the 4 VES measurement integrates approximately 11 individual electrical soundings with 4 electrodes driven into the soil in a linear Wenner array with electrode spacings ranging from 1 to 40 m. Data were collected manually with a SuperSting electrical resistivity meter (AGI - Advanced Geosciences, Inc) and recorded by hand in a field book.

Shallow soil characteristics were mapped near Shellmound, Mississippi, using the DualEM 421 electromagnetic sensor in October 2018. Data were acquired by towing the DualEM sensor on a wheeled cart behind an ATV, with the sensor at a height of 0.432 meters (m) above the ground surface. Approximately 175 line-kilometers of data were acquired over an area of nearly four square kilometers, with 25 m separation between survey lines. Data were manually edited for noise sources such as powerlines or other buried structures, and averaged to regular output soundings every 5 m along survey lines. This data release contains the processed data that have been averaged and culled to produce final resistivity models. Digital data of the processed soundings are provided and fields are defined in the data dictionary.

The electrical conductivity of the earth is used to help infer lithological and pore fluid properties. Various geophysical methods can provide estimates of the distribution of below ground electrical conductivity, with each method having certain limitations. This data release presents raw and processed results from hand-caried frequency domain electromagnetic induction imaging (EMI) data collected from June 27-28 along Blacktail Creek near Williston, North Dakota. Data were primarily collected by walking in the creek or along the riparian zones with the GEM-2 instrument (Geophex, Ltd.) at approximately 0.5 m off the ground in horizontal coplanar (ski flat) mode.

The electrical conductivity of the earth is used to help infer lithological and pore fluid properties. Various geophysical methods can provide estimates of the distribution of below ground electrical conductivity, with each method having certain limitations. This data release presents raw and processed results from hand-caried frequency domain electromagnetic induction imaging (EMI) data collected from June 27-28 along Blacktail Creek near Williston, North Dakota. Data were primarily collected by walking in the creek or along the riparian zones with the GEM-2 instrument (Geophex, Ltd.) at approximately 0.5 m off the ground in horizontal coplanar (ski flat) mode.

Shallow soil characteristics were mapped near Shellmound, Mississippi, using the DualEM 421 electromagnetic sensor in October 2018. Data were acquired by towing the DualEM sensor on a wheeled cart behind an ATV, with the sensor at a height of 0.432 meters (m) above the ground surface. Approximately 175 line-kilometers of data were acquired over an area of nearly four square kilometers, with 25 m separation between survey lines. Raw data are provided here.

Shallow soil characteristics were mapped near Shellmound, Mississippi, using the DualEM 421 electromagnetic sensor in October 2018. Data were acquired by towing the DualEM sensor on a wheeled cart behind an ATV, with the sensor at a height of 0.432 meters (m) above the ground surface. Approximately 175 line-kilometers of data were acquired over an area of nearly four square kilometers, with 25 m separation between survey lines. Raw data are provided here.