一维大地电磁和地震数据联合反演方法研究

针对江汉盆地海相地层的地电结构特点，对区内５口探井的物性数据作了统计，给出了一维层状介质模型。大地电磁数据是采和一维层状介质递推关系式模拟，差商法求其偏导数，地震数据是以水平界面为基础进行快速射线追踪正演，运用解析法求偏导数，理论数据采用典型ＨＡＫ型曲线５层地球物理模型试算。

Research on joint inversion of 1-D magnetotelluric and seismic data

1-D layered medium model has been designed by analysing both the actual geo-electric structure of marine sediments in Jianghan basin and the statistical physicaldata taken from 5 boreholes there. The magnetotelluric data are simulated by usingrecursion formula for 1-D layered medium, and partial derivatives are computed bytaking difference quotient method. The forward computation of seismic data isachieved by doing fast ray tracing on horizontal interface, and the partial deriva-tives are estimated by adopting analytic method- The theoretical data are derivedfrom typical HAK curve and 5-layer geophysical model.Then, the joint inversion of magnetotelluric and seismic data is described in de-talil. The inversion involves the following steps: Introducing the space vector of model, whose parameters consist of velocity,resistivity and thickness of each layer.. Offering the response function of the model.. Determining the mapping relation between the response function and datavector.Different data sets have different physical spaces and magnitudes, so that wemust do normalization, for which we introduce relative prediction error vector thatinvolves the use of the method for solving an ill-posed problem.Theoretical model and joint inversion of real data show that it is better than theinversion of any single kind of geophysical data.