摘要
目前,我国用于地震前兆监测的地电阻率观测系统大部分都是单一极距的,这种观测方法在实际观测中普遍存在着地电阻率季节性变化的现象,这种季节性变化与地震异常变化一起叠加在观测值中,给地震异常的识别和判定带来了一定困难。而解决这一问题的有效途径就是进行地电阻率的多极距观测。本文介绍了采用ZD8MI电阻率多极距观测系统在山丹地震台的试验观测情况,该系统是最新研制的、专用于地震前兆监测的地电阻率多极距观测系统。一年多的台站试验观测和反演结果表明,浅层电阻率的变化相对较大,而深层的相对变化较小,因此利用多极距观测系统进行不同层位的地电阻率观测,对排除干扰和识别地震前兆信息显得尤为重要,是地电阻率观测技术发展的一个趋势。
At present,symmetric four-electrode configuration are used in the measurement of the geo-electric resistivity in most geo-electric stations in China.Usually,there exists phenomenon of annual variation of apparent resistivity,so it is difficult to identify earthquake precursors from these variations.One of the effective ways to solve this problem is using multi-separation array observation system.This paper introduced the experimental observation and preliminary data analysis in Shandan earthquake station by using the latest developed multi-separation array observation system-ZD8MI,which is satisfied for the demand of earthquake precursor observation.After a year＇s observation,the result shows that resistivity variation of shallow layer is lager than those of deep layers.Variation of apparent resistivity is relatively large in the case of small power polar distance（AB≤300 m）,indicating that the shallow layer′s resistivity is greatly affected by the rain and human activity,while the deep layer is affected less.So the multi-separation array observation is important for the identification of earthquake precursors and the elimination of interferences.
出处
《地震》
CSCD
北大核心
2011年第1期20-31,共12页
Earthquake
基金
中国地震局行业科研专项(200808030)资助
关键词
地电阻率
多极距观测
电极控制器
地电阻率年变化
Geo-electrical resistivity
Multi-separation array observation
Annual Variation
