Geomagnetic induction in eccentrically nested spheres

Abstract We present an analytic solution for a class of multidimensional forward problems of electromagnetic induction in a heterogeneous sphere. A variety of numerical methods for 3-D global electromagnetic modeling have been introduced recently, including this sheet, perturbation expansion, and finite element/finite difference schemes. The present analytic approach provides a model response against which the accuracy of more general numerical algorithms can be tested. We solve the electromagnetic induction problem in an azimuthally symmetric system of two eccentrically nested spheres and compute the surface magnetic vector potential A Φ and polar magnetic field B θ as functions of several of the model parameters.