基于地磁垂直分量反相位现象的地下畸变电流正演计算

基于毕奥萨伐尔定理正演模拟不同深度和强度的电流感应磁场空间分布及其随时间的变化，并根据甘东南地区大地电磁测深反演的电性结构成果，定量计算2013年岷县漳县MS6.6地震前的畸变电流强度，发现其感应磁场在Z分量上的叠加效果与实测数据差异较小。该模型在一定程度上解释了此次地震前出现的大范围地磁低点位移现象，可应用于出现低点位移现象且电性结构比较清楚的地区。

Calculating the Distortion Current Based on the Anti-Phase Phenomena of the Geomagnetic Vertical Component

We simulate and calculate the spatial distribution and the time dependent characteristics of the induced geomagnetic under different depths, intensities and changes. In addition, the distortion current intensity and distribution depth before the Minxian-Zhangxian MS6.6 earthquake in 2013 are calculated based on the electrical structural results of magnetotelluric sounding in the southeast of Gansu province. The difference between the superposition effect on the Z component and the measured data is very small. The model explains the site of a large range low point displacement before the earthquake, and the method may also be used in other areas with low point displacement with clear electrical structure.