高可扩展三维大地电磁电阻率各向异性、磁导率正演  

Efficient scalable three-dimensional magnetotelluric forward modeling method considering resistive anisotropy and magnetic resistivity

作　　者：程旭 龚春叶[1,2,6,7] 王光杰[3,4] 肖调杰 杨博[1,2,7] 刘杰 王赟 CHENG Xu;GONG ChunYe;WANG GuangJie;XIAO TiaoJie;YANG Bo;LIU Jie;WANG Yun(College of Computing,National University of Defense Technology,Changsha 410073,China;Laboratory of Digitizing Software for Frontier Equipment,National University of Defense Technology,Changsha 410073,China;Institute of Geology and Geophysics,Chinese Academy of Sciences,Institute of Earth Science,Chinese Academy of Science,Beijing 100029,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Geophysics and Information Technology,China University of Geosciences,Beijing 100083,China;National Supercomputer Center in Tianjin,Tianjin 300457,China;National Key Laboratory of Parallel and Distributed Computing,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学计算机学院,长沙410073 [2]高端装备数字化软件湖南省重点实验室,长沙410073 [3]中国科学院地质与地球物理研究所,中国科学院地球科学研究院,北京100029 [4]中国科学院大学,北京100049 [5]中国地质大学(北京)地球物理与信息技术学院,北京100083 [6]国家超级计算天津中心,天津300457 [7]国防科技大学并行与分布计算全国重点实验室,长沙410073

出　　处：《地球物理学进展》2024年第5期1963-1978,共16页Progress in Geophysics

基　　金：国家重点研发计划“天河高性能计算机系统优化与升级项目”(2021YFBO300101);国家自然科学基金项目(62032023,42104078,61902411)联合资助。

摘　　要：大地电磁测深(Magnetotelluric sounding,MT)是一种重要的地球物理方法,被广泛应用于矿产资源勘探、地球深部结构探测等领域.当前,MT进一步朝着精细化方向发展,电阻率和磁导率是影响MT响应特征的两个重要物性参数,且电阻率各向异性现象客观存在,而目前成熟的MT三维资料解释技术通常仅考虑电阻率各向同性单一参数,且可扩展性较差.因此,本文同时考虑电阻率各向异性、磁导率双参数,基于C语言、MPI并行编程模型,实现了一种高效的频率间并行计算、阻抗矩阵并行填充、第一类边界条件并行添加和方程组并行求解的大规模多层级MT三维并行正演算法,并在此基础上研究了磁导率对MT响应的影响.结果表明电阻率各向异性、磁导率双参数使得MT响应变得更为复杂,当低阻异常体与围岩电阻率差异较小时,较大的磁导率甚至可以反转视电阻率和相位的形态.该算法具有较好的可扩展性,对于文中测试模型16个频率时,串行计算耗时117.58 h,而2048个进程计算耗时仅12.95 min,加速547.24倍.本文研究成果可为实际资料解释提供高效快速的正演方案,有助于进一步认识三维电阻率各向异性、磁导率异常体的MT响应特征.Magnetotelluric sounding(MT)is an important geophysical method which has been widely used in mineral resource exploration,deep structure exploration,and other fields.Currently,MT is further developing towards refinement,and resistivity and magnetic permeability are two important physical parameters that affect the response of MT,and the phenomenon of resistive anisotropy objectively exists.However,mature MT 3D data interpretation techniques usually only consider a single parameter of resistivity and have poor scalability.Therefore,this article considers both resistive anisotropy and magnetic permeability parameters,and based on C language and MPI parallel programming model,implements an efficient large-scale multi-layer MT 3D parallel forward algorithm with parallel calculation between frequencies,parallel filling of impedance matrix,parallel addition of first type boundary conditions,and parallel solution of equation sets.On this basis,the influence of magnetic permeability on MT response was deeply studied.The experimental results show that the resistive anisotropy and the magnetic permeability make the MT response more complex.When the difference in resistivity between the anomalous body and the surrounding rock is small,larger magnetic permeability can even reverse the morphology of apparent resistivity and phase.This algorithm has a good scalability.For the test model;the 16 frequency serial computation takes 117.58 hours,while the 2048 process computation only takes 12.95 minutes,with an acceleration ratio of 547.24.The research results of this article contribute to further understanding the MT response characteristics of three-dimensional resistive and magnetic permeability anomalies,and provide efficient and fast forward modeling solutions for practical data interpretation.

关 键 词：大地电磁测深 数值模拟 电阻率各向异性 磁导率 并行计算 

分 类 号：P631[天文地球—地质矿产勘探]