The time-domain electromagnetic (TDEM) technique utilizes differences in the electrical properties of geologic materials to map subsurface conditions.
An electric current is induced into the ground by a loop of wire laid out on the ground surface. These induced currents propagate downward into the subsurface and are increasingly influenced by the electrical properties of deeper layers.
A series of measurements of the secondary magnetic field are used to model electrical resistivity as a function of depth. Changes in subsurface resistivity values can result from changes in lithology, water content, pore-water chemistry, and the presence of buried debris.
Mapping Groundwater Aquifers, boundaries, saltwater intrusions and fault zones
Geological Stratigraphy Mapping
Detecting buried debris
Archaeological Sites Investigation