松山台地电场的自然电位异常  

A selt-potentail anomaly of geoelectric field at Tianzhu station

作　　者：安海静[1] 赵家骝[2] 赵和云[1] 刘宝勤[1] 

机构地区：[1]中国地震局兰州地震研究所,甘肃兰州730000 [2]中国地震局分析预报中心,北京100036

出　　处：《地震》2004年第3期115-120,共6页Earthquake

基　　金：中国地震局中法电磁合作项目(LC2003062)

摘　　要：根据对中法合作天祝松山电磁台运行6年的全部资料(变化周期≥1d)的分析,从中可看出,我国西部某些中强以上地震前,天祝地电场出现了缓变信息异常,也就是通常所指的自然电位异常。异常有2种形式,先增大后降低的趋势性背景变化和大幅度的单向加速变化。除此之外,震前还有短临的大地电场阶跃性异常。文中讨论了几种异常的可能机理,认为大幅度的单向加速异常与磁暴有关;而趋势性背景变化是过滤电场的冲流电位在震前明显改变所致,主要出现在2001年昆仑山口西8.1级大震之前。All geoelectric and geomagnetic data observed for 6 years at Tianzhu Sino-France cooperative station have been put on display (sampling period one day). We can see from them that before some moderately strong earthquakes occurred in western region of China, Tianzhu geoelectric field appeared a slow abnormal variation, and also a self-potential anomaly. There are 2 kinds of forms: a) at first showing increase, then decrease tendency variation, b) acceleration variation with large amplitude and single direction. In addition, before earthquake there is still short-term step anomaly in telluric field. A possible mechanism of several kinds of anomalies is roughly discussed in this paper. It is considered that among them the large amplitude acceleration variation belongs to magnetic storm, the obvious change of streaming potential before earthquakes results in tendency background variation, which only emerges before Kunlun Mountain earthquake with M_S=8.1 in 2001.

关 键 词：地电场 自然电位 异常 地震 电磁台 

分 类 号：P315.722[天文地球—地震学]