Abstract: The magnetotelluric response to the two dimension structures has been numerically modeled by use of the finite element method.Itcan be concluded that in the two dimension structure area in the North China Plain,rather than the lateral ones,one dimension inversion of longitudinal apparent resistivity plot can provide accurate information on real distribution of deep earth conductivity.The principle of two dimension forward magnetotelluric sounding has been presented,and then derived expression as well as the two profile models following two profiles obtained from magnetotelluric sounding along with other relevant data.The calculation has been carried out for two curves of apparent resistivity corresponding to polarized orientationas well.The two measuring profiles are across the Tangshan seismic zone (Malanyu-Bege-zuang) and NNE-trending tectonic zone partly passing the Beijing area,respectively.

摘要： 本文阐述在大地电磁测深工作中,用有限单元法,模拟计算京津唐地区二维地质构造的大地电磁响应。 文章前部分,论述了用有限单元法正演二维大地电磁测深曲线的原理及其数学公式推导。文章后部分,根据两条测线实测的大地电磁测深结果并结合其它地球物理探测资料,给出了两个二维剖面模型,并计算了两种极化的视电阻率曲线。两条实测剖面分别是横切唐山地震带的马兰峪—柏各庄剖面及横过北京地区北北东构造走向的文化营—王辛庄剖面。