OREO ERT

These are data from two electrical resistivity surveys that took place across the western lateral shear margin in the transport zone of Oak Ridge Earthflow. We conducted the first survey in June 2018 and then in November 2018 we reoccupied the same line. A SuperSting R8 system (Advanced Geosciences Inc. [AGI], Austin, TX, USA) was used for a survey line that spanned approximately 90 meters and used 45 electrodes spaced two meters apart. Each electrode was pinned to the underlying sediment with a 35-cm stainless steel spike. In an effort to minimize known potential errors, each electrode was tested to ensure a good and consistent connection to the ground. For each survey date, we repeated surveys to acquire data in both dipole-dipole and Schlumberger configurations. Apparent resistivity values were calculated based on the known value of current injected and the measured value of voltage at each electrode. We then inverted the results to obtain electrical resistivity tomography. During data processing, we used a topographic profile derived from 3-meter resolution LiDAR to account for influences from variable topography. The files presented below include the inverted data for the dipole-dipole and Schlumberger configurations on both survey dates, a terrain file for each survey data, and Matlab scripts that make the necessary topographic corrections and plot the inverted data.

Elevation data for terrain corrections come from the U.S. Geological Survey National Elevation Dataset referenced below.