大地电磁测深中用一维反演结果近似二维地电断面的效果

Effect of approximating 2-D geoelectric fault plane by using 1-D inversion result in magnetotelluric sounding

一维反演方法仍然是现今大地电磁测探资料解释中最常用的方法。但是利用一维庆演方法所得的等值线图很准确定二维地电断面的形态和大小，若配合截断电阻率，就能基本确定地电断面的形态和大小。文中利用有限元法计算了四种二维地电断面上的大地电磁TE极化和TM极化时的机电阻率测深曲线，反演分别采用Bostick法和最小二乘迭代法。

In nowadays, l-D inversion is still the most commonly-used method in interpre-tation of magnetotelluric sounding data. Unfortunately, the contour map derivedfrom the l-D inversion method can hardly display the shape and size of 2-D geoelec-tric fault plane. If we introduce cutoff resistivity,the shape and .ize of geoelectricfault plane can be known roughly. In the paper,finite element method is taken to ob-tain the apparent resistivity sounding curves relating to magnetotelluric TE and TMpolorizations over four kinds of 2-D geoelectric fault planes. The inversion involvesBostick method and least-square iterative method.