可控源音频大地电磁和微动资料的拟二维联合反演  

Quasi-two-dimensional joint inversion of the data from the controlled sourceaudio-frequency magnetotellurics and the microtremor survey

作　　者：张继伟 谭慧 ZHANG Ji-Wei;TAN Hui(Institute of Urban Underground Space and Energy Studies,The Chinese University of Hong Kong(Shenzhen),Shenzhen 518172,China)

机构地区：[1]香港中文大学(深圳)城市地下空间及能源研究院,广东深圳518172

出　　处：《物探与化探》2024年第4期1094-1102,共9页Geophysical and Geochemical Exploration

基　　金：云南省2023科技计划项目“云南省中深层地热能开发关键技术研究”(202302AF080001);可控源电磁和微动探测数据联合反演及其在北京市地热勘探中的应用(8192041)。

摘　　要：可控源音频大地电磁(CSAMT)和微动探测在城市强干扰条件下均有较好的应用前景,但单一的地球物理反演具有多解性。为了实现不同地球物理方法优势的互补,同时解决单点反演横向不连续性的问题,本文开展了CSAMT和微动探测数据的拟二维联合反演研究。作者将横向约束矩阵引入联合反演的目标函数中,同时采用有限内存拟牛顿反演算法(LBFGS),实现了两种方法的联合反演。通过理论模型合成数据反演算例,验证了联合反演的可靠性和有效性。结果表明,联合反演相比单一数据反演能有效地提高反演结果的准确度,其电阻率模型和横波速度结构更加趋于一致,同时,横向约束能有效地降低相邻测点物性参数的不连续性。通过加入横向约束的拟二维联合反演以单点反演的效率,获得了更合理的物性参数和地下结构的剖面结果,提高了反演的可靠性。Both the controlled source audio-frequency magnetotellurics(CSAMT)and the microtremor survey exhibit promising application prospectsunder strong urban interference.However,single geophysical inversion methods are challenged by a multiplicity of solutions.To achieve the complementary advantages of different geophysical methods,and address the lateral discontinuity of single-point inversion,this studyexplored the quasi-two-dimensional joint inversion of the CSAMTand microtremor survey data.It enabled the joint inversionby introducing a lateral constraint matrix into the objective function for joint inversion and employing the limited-memory Broyden-Fletcher-Goldfarb-Shanno(LBFGS)algorithm.The reliability and effectiveness of the joint inversion were verified using the inversion example of synthetic data from theoretical models.The results show that compared to single data inversion,the joint inversion can effectively improve the accuracy of inversion results,with the resistivity model more consistent with theshear-wave velocity structure.Moreover,lateral constraints can effectively reduce the discontinuity of the physical parameters of adjacentsurvey points.The quasi-two-dimensional joint inversion with lateral constraints enhances the inversion reliability by obtaining more reasonable profile results of physical parameters and structures with the efficiency of single-point inversion.

关 键 词：联合反演 可控源音频大地电磁法 微动探测 横向约束反演 

分 类 号：P631[天文地球—地质矿产勘探]