断层构造对地震地电阻率异常的影响  

Influence of active faults on earthquake-related anomalies of geo-electric resistivity

作　　者：郑国磊[1,2] 杜学彬[1] 陈军营[1] 谭大成[1] 安张辉[1] 范莹莹[1] 刘君[1] 解滔[1] 

机构地区：[1]中国地震局兰州地震研究所,中国兰州730000 [2]天津市地球物理勘探中心,中国天津300181

出　　处：《地震学报》2011年第2期187-197,270,共11页Acta Seismologica Sinica

基　　金：国家科技支撑计划子专题(2006BAC01B02-04-03);国家科技支撑计划专题(2008BAC35B01-8)共同资助

摘　　要：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,模拟计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是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.We have studied the fault influence on the spatial distribution of geo-electric 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 geo-electric 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.

关 键 词：地震 地电阻率 不均匀性 断层 有限元 

分 类 号：P315.722[天文地球—地震学]