Abstract
The purpose of this research was to establish a three-dimensional (3D) numerical modeling method for electromagnetic (EM) exploration problems, such as the magnetotelluric (MT) method, and to determine the iterative solver and preconditioner suitable for a system of linear equations of the 3D EM modeling. We developed a new numerical calculation code for solving Maxwell's equations based on EM potentials by a finite difference method incorporating the Lis (Library of iterative solvers for linear systems). The accuracy of the developed code was confirmed by comparing its results with those of the integral equation method using two synthetic geoelectrical models, which are typical for electromagnetic exploration. Thereafter, we used various Lis'iterative solvers and preconditioners to solve the system of linear equations. Calculation results indicate that a combination of FGMRES and ILU(0) is the best for the 3D finite difference modeling of the MT method.
