Electromagnetic surveys are a simple solution for shallow underground imaging, with applications from archaeological and environmental to highway infrastructure conditions.
Electromagnetic conductivity is a method to locate buried materials having a high conductance. During a survey, alternating electromagnetic waves generated at the surface are induced into the ground. When the waves pass through a conducting body, they induce an alternating electrical current in the conductive materials. These currents become the source of secondary magnetic fields which can be detected at the surface. The strength of the field is directly proportional to the average conductivity of the subsurface materials. Typical electromagnetic applications include location of buried pipes, tanks, drums and metallic objects, as well as sludge wastes, leachate plumes, saltwater intrusions, acid mine drainage and other groundwater contamination problems. Other applications include quick and economical site evaluation of areas with variable bedrock topography such as those found in karst terrain, clay layer mapping, fault detection, and mine or quarry location assessment.