A study on Parallel Computation Based on Finite Element Forward Modeling of 2D Magnetotelluric

Mao Wang, Handong Tan, Changhong Lin, Xiao Liu, Zhiyong Zhang

School of Geophysics and Geoinformation Technology, China University of Geosciences, Beijing, China.

DOI: 10.4236/ijg.2015.68070                

Abstract

Magnetotelluric sounding method based on the difference of the rock’s resistivity is an exploration method about doing research in earth’s resistivity and phase using the native electromagnetic field. The paper adopts 2D finite element method as the magnetotelluric forward method and calculates the total field by primary field (also named background field) plus secondary field. We can get more accurate forward result through the finite element method and we can get the result effected by the dense degree of grid slightly by the total field. But the method is not effective enough when the model is divided into relative big grid. When the frequency changes, program solves relevant equation separately. According to the feature of the algorithm, we apply MPI parallel method in the algorithm. Every process solves relevant equation. The account of frequency that a process needs to solve in parallel computation is less than the account that the process needs to solve in serial algorithm. We can see that the forward result is the same with the serial algorithm and proves the correctness of algorithm. We do statistics about the efficiency of the parallel algorithm. When the account of processes is from 2 to 8, the speedup is from 1.63 to 2.64. It proves the effectiveness of the parallel algorithm.

Keywords

Magnetotelluric, 2D Forward Modeling, Finite Element, Parallel Algorithm, Total Field

Conflicts of Interest

The authors declare no conflicts of interest.

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