Electrical survey

Electrical survey (or, prospection) is a preliminary and non-invasive technique of investigating features below the earth's surface which takes advantage of the fact that archaeological structures have a different degree of electrical conductibility than do naturally occurring objects. Electrical survey depends on a series of measurements taken at close intervals. If the values obtained are similar to each other, the subsoil does not contain archaeological structure. If, on the other hand, there are strong variations in the measurements, it is probable that there are archaeological remains. For more information, see the Archaeological Prospection page of Bradford University. See also magnetic survey.