ERT

Resistivity geophysical surveys measure variations in the electrical resistivity of the ground, the idea of ERT technique is to pass a current of known voltage into the subsurface to be imaged through two current electrodes, and then using a second pair of potential electrodes, measure the potential drop induced by the differential response of earth materials to the penetrating current. The survey data will be processed to produce graphics depth sections of the thickness and resistivity of subsurface electrical layers. The resistivity sections are correlated with ground interfaces such as soil and fill layers or soil-bedrock interfaces, to provide engineers with detailed information on subsurface ground conditions.

Applications:

 Measures bedrock & water table depth
 Detects solution features, cavities & voids
 Locates buried alluvial channels
 Profiling landslip geometry
 Identifies weathered\fractured bedrock
 Maps leachate contamination
 Defines saline groundwater incursions
 Finds abandoned mineshafts & workings