大地电磁倾子响应的异常规律及影响分析

The Characteristics and Effects of Anomalous Body on Magnetotelluric Tripper Responses

摘要: 在二维地电模型中，大地电磁测深的倾子响应依赖于TE极化模式的数值模拟问题，能很好地反映地电构造的水平非均匀性，可作为复杂构造的表征。低阻覆盖层对电磁波具有屏蔽效应，会降低大地电磁测深的探测能力。通过对存在低阻覆盖层模型与不存在低阻覆盖层模型进行了正演计算，低阻覆盖层对于定性分析大地电磁的倾子响应资料是不存在影响的，而对于定性分析视电阻率资料的影响较大。同时，对静位移模型的模拟计算，倾子响应的实部、虚部和振幅均能反映出不均匀体的横向分布情况，且能分辨出地表不均匀体的横向不均匀性。

Abstract: In the two-dimensional geo-electric model, the tipper responses of magnetotelluric (MT) depend on the numerical simulation of the TE mode, which can reflect the horizontal distribution of the body and can provide for qualitative interpretation of field data. Because of the shielding effect on electromagnetic waves, the low-resistivity cover can reduce the detability of magnetotelluric sounding method. The low hindrance cover model and the model without low resistance cover are calculated, and the low resistance cover layer has no influence on the qualitative analysis of the magnetotelluric response data, but it has a great influence on the qualitative analysis of the ap-parent resistivity data. At the same time, for the simulation calculation of the static displacement model, the lateral distribution of the inhomogeneous body can be reflected by the real part, the imaginary part and the amplitude of the tilting response, and the lateral in-homogeneity of the surface inhomogeneous body can be distinguished.