magnetotelluric sounding

views updated

magnetotelluric sounding The use of changing components of the geomagnetic field to study the electrical conductivity of the rocks within the Earth. The geomagnetic-field changes induce eddy currents within the Earth that are in proportion to the electrical conductivity of the rocks concerned, but they can readily be separated from the inducing currents because of their phase difference. It is generally applied to studies of the lower crust and upper mantle.