关键词: 大地电磁, MPI, 二维, 有限元, 正演

Abstract: Nowadays,the 2-D inversion of magnetotelluric data has been put into practice,however,the 3-D inversion is still in its infancy,not because of the backward inversion methods or theories from the real yield but the lag of the hardware development.It is the huge amount of time to calculate in 2-D and 3-D inversion processes that traditional single-computer calculation speed is unacceptable.The most time-consuming part of the inversion is forward calculation,so it is of great significance to take parallel processing technology to improve the efficiency of parallel calculation.The program for 2-D magnetotelluric forward problems presented in this paper is based on the classic finite element method put forward by Wannamaker.It combines FORTRAN and MPICH 2 on Linux system in compilation.The forward computing for two-dimensional magnetotellurics is done separately in each frequency,and the value of electromagnetic field in the corresponding frequency is independent,therefore it is fit for frequency-decomposing parallel computing.This paper presents the two-dimensional magnetotelluric forward parallel algorithm,based on the finite element.Using the development tools of Fortran and MPICH 2,we write a parallel program that combines the advantages of MPI,and adopt the master-slave parallel mode and the parallel program of frequency-decomposing parallel computing.In order to verify the program,we designed two models,and compared with the serial program to validate the feasibility and accuracy of this algorithm,the result provides a research base for the parallel computation for two-dimensional inversion and three-dimensional forward and inversion.

Key words: magnetotellurics, MPI, two-dimensional, finite element, forward computation