electromagnetic surveying

electromagnetic surveying

[i¦lek·trō·mag′ned·ik sər′vā·iŋ] (engineering) Underground surveying carried out by generating electromagnetic waves at the surface of the earth; the waves penetrate the earth and induce currents in conducting ore bodies, thereby generating new waves that are detected by instruments at the surface or by a receiving coil lowered into a borehole. Also known as electromagnetic prospecting.