Abstract: The affection of a two dimension inclination terrain mainly causes the distortion of the TM mode data,that decreases apparent resistivity curves of the TM mode. The affection could be ignored if the inclination angle is less than 10 degrees. The affection becomes more severe,as the inclination angle increases. The affection are also related with periods,the longer the period,the more severe the distortion causes,and remarkably affected periods become shorter as the inclination angle increases. In order to reduce these affections,two kinds of models which are homogenous half space with a flat surface and with a slope surface are respectively considered,magnetotelluric (MT) response functions have been computed and correction coefficients have been obtained.

Key words: Magnetotelluric (MT), Topographic correction, Inclination topography, TM-polarization mode

摘要： 二维倾斜地形影响,主要使TM极化模式的视电阻率降低。数值模拟结果证明,倾角小于10°时,地形影响可以忽略,随着倾角的增大,地形影响急剧加强。同时,倾斜地形影响与周期有关,周期愈长,影响愈甚,而且,当倾角增大时,开始出现显着影响的周期提前。利用带地形均匀半空间与水平均匀半空间的电磁响应,计算出校正系数,进而可以消除或降低地形影响。

关键词: 大地电磁, 地形校正, 倾斜地形, TM极化模式