断层构造对地震地电阻率异常的影响

摘要

We have studied the fault influence on the spatial distribution of geoelectric resistivity anomalies through analyzing typical cases of earthquake.Then, the strain distribution in a geologic body model with a fault is calculated using the elasto-plastic 2-D finite element method, and the strain values are converted into the relative changes of geo-electric resistivity. This paper proposed a well explanation for the spatially non-uniform distribution of changes of geoelectric resistivity before an earthquakes. According to the research result of this paper, the spatially non-uniform distribution of the moderate-term and imminent geo-electric resistivity anomalies around an earthquake source region is mainly caused by spatially non-uniform distribution of the underground medium deformations due to the active faults and different focal mechanisms.%分析了典型震例,研究了断层构造对地电阻率异常空间分布的影响;应用弹-塑性二维有限元方法,模拟汁算了含断层的地质体中介质应变的空间不均匀分布.换算为视电阻率变化,解释了震前地电阻率异常空间不均匀分布的现象.研究表明,震源区周围地电阻率中期,短临异常空间不均匀分布的根本原因足断层构造以及不同震源机制引起的地下介质变形的不均匀性.