THE INVERSE PROBLEM OF MAGNETOTELLURIC SOUNDING

Abstract

Based on the model of a flat layered earth, a nonlinear, least‐squares method is used to invert magnetotelluric sounding curves to obtain the layer resistivities and thicknesses. Partial derivatives of the apparent resistivity with respect to layer parameters show the manner in which the layer parameters are contrbuting to the apparent resistivities. Uniqueness of the inversion is not guaranteed, but when the partial derivatives are linearly independent and the relative magnitudes of the layer resistivities of the initial guess are not too far from the correct ones, the convergence of the method to the correct values seems to be ensured.