Abstract: We have developed a new two-dimensional inversion method for magnetotelluric data inversion. This method is based on one-dimensional magnetotelluric curve comparison method with phase information, using resistivity and impedance phase data set from 1D inversion as the initial model, and then modeling with 2D finite element method(FEM). In successive iteration, model resitivity is modified by the 1D inversion procedure at depth and by 2D FEM in survey line. We can obtain a data set approximately approached real resitivity distribution after inversion process. The result shows that inversion process is feasible, and has the advantages of simplity, rapidity and avoiding the caculation of partial derivative matrix.

Key words: 2D MT, Finite element method, Inversion

摘要： 最近开发了一种针对二维大地电磁野外数据进行处理解释的新反演方法。该方法以加入阻抗相位信息的一维大地电磁连续介质曲线对比法为基础,把一维反演得到的电阻率和相位的数据集作为二维反演的初始模型,使用二维有限单元法做正演模拟。在程序的后继迭代中,深度方向上用一维反演修改模型的电阻率和深度值,沿测线方向由二维有限元作修改,反演结束可得到一个接近真实电性分布的电阻率数据集,并绘制成电阻率断面图。对模型的反演实验结果显示,该反演方法能够较真实地反映地下电性分布,而且避免了偏导数矩阵的计算,其原理简单,计算速度快,表明该反演方案是可行的。

关键词: 二维大地电磁, 有限元法, 反演