Electrical Resistivity Surveying

ATS International, Inc. is proficient in the application of surface electrical resistivity imaging. Electrical resistivity is a versatile tool that offers the ability to obtain high-density subsurface data quickly and cost-effectively.

Geologic information obtainable by electrical resistivity include:

• Water Table Surface
• Preferential Flow Paths
• Lithology Changes
• Geologic Structures
• Contaminant Plumes

Electrical resistivity is measured by inducing a current between two electrodes and measuring the resulting potential at other electrodes. The more widely spaced the electrodes, the deeper the sampling depth.

The raw data collected from a resistivity profile are the apparent resistivities in a cross-section of the earth. Apparent resistivities are different than the actual resistivities of the profile because of changes in the electric current that result from its pathway through various earth materials. Therefore, the apparent resistivities often require inversion modeling to convert the raw data to actual resistivities.

After the resistivity profiles are interpreted in cross-section, multiple resistivity profile data can be laterally interpolated to provide three-dimensional geologic models.