利用Chebyshev谱方法模拟一维大地电磁响应  

Modeling of One-dimensional Magnetotelluric Responses Using Chebyshev Spectral Method

作　　者：童孝忠[1,2] 何婷 赵理芳[3] 李爱勇[3] Tong Xiaozhong;He Ting;Zhao Lifang;Li Aiyong(School of Geosciences and Info-physics,Central South University,Changsha Hunan 410083,China;Key Laboratory of Non-ferrous Resource and Geological of Hunan Province,Central South University,Changsha Hunan 410083,China;Team 814 of East China Non-ferrous Metals Geological Exploration Bureau of Jiangsu Province,Zhenjiang Jiangsu 212005,China)

机构地区：[1]中南大学地球科学与信息物理学院,湖南长沙410083 [2]中南大学有色资源与地质灾害探查湖南省重点实验室,湖南长沙410083 [3]江苏省有色金属华东地质勘查局八一四队,江苏镇江212005

出　　处：《工程地球物理学报》2020年第6期752-758,共7页Chinese Journal of Engineering Geophysics

基　　金：湖南省自然科学基金(编号:2020JJ4697);大学生创新创业训练计划项目(编号:202010533279)。

摘　　要：为了计算一维地电模型的大地电磁响应,采用高精度的Chebyshev谱方法进行了数值模拟。首先,从磁场满足的微分方程出发,利用Chebyshev求导矩阵导出了一维大地电磁正演计算的线性方程组;其次,利用Matlab工具编写了一维大地电磁响应的Chebyshev谱方法计算程序,同时通过计算均匀半空间模型的数值解,并与理论解析结果对比,验证了正演算法的正确性;最后,通过对二层D型地电模型的大地电磁响应模拟,说明了Chebyshev谱算法的有效性,并总结了近地表单元剖分间距对大地电磁响应的影响。In order to compute the one-dimensional magnetotelluric responses,high-accuracy Chebyshev spectral method is adopted for numerical results.Firstly,from the magnetic field based on the differential equation,the linear equation for magnetotelluric numerical modeling is derived by non-uniform grids finite difference method.Secondly,the numerical program for one-dimensional magnetotelluric responses is programmed by using MATLAB tool.Meanwhile,the computed results and analytical results of homogeneous half-space model are compared.Lastly,the effectiveness of Chebyshev spectrum algorithm is illustrated by simulating the magnetotelluric response of the two-layer D-type geoelectric model,and the influence of near surface cell division spacing on magnetotelluric response is summarized,and the accuracy can be affected by grid size near the ground surface.

关 键 词：大地电磁测深 一维模型 正演模拟 Chebyshev谱方法 

分 类 号：P631.3[天文地球—地质矿产勘探]