【摘要】 2006年7月4日河北文安县发生了M_?5.1地震,有6个地电场观测台布设在北京周围.本文阐述了地电场多极距观测系统的噪音识别原理及其在地电场数据分析中的应用方法.通过对首都圈6个地电场台观测资料的研究分析,在所选出的众多震前地电场异常信号中逐一排除,最后选定的5组地电场异常信号基本上被认为是震前地电场前兆异常信号.结果表明:①文安M_?5.1地震前存在着地电场异常前兆信号;②文安地震前地电场异常前兆信号的出现存在着"敏感点"效应;③地电场异常前兆信号在不同的台站存在着不同步出现的现象,并且异常结束至发震时间间隔也不同;④离震中区较近的宝坻台记录到的震前地电场异常幅度较小,而离震中区较远的昌黎台记录到的震前地电场异常幅度则较大.更多还原

【Abstract】 On July 4,2006,an M_?5.1 earthquake occurred in Wen’an county of Hebei Province,near Beijing.Six geoelectric field monitoring stations have been in operation for several years around the Beijing area to examine the rela- tionship between electric field changes and earthquakes.This paper firstly ex- plains the principle of the eliminating noise method by using multi-dipole obser- vation system of the geoelectric field.Then the data observed at the stations are studied and a lot of abnormal signals preceding the Wen’an earthquake are se- lected,of which five abnormal signals of the geoelectric field are finally recog- nized as the precursory signals.The result shows that:①there probably exists the precursory signals of the geoelectric field preceding the Wen’an earthquake;②there are sensitive sites in the spatial distribution of the abnormal variation of the geoelectric field before the quack;③the anomalous signals do not appear synchronously,and their durations are not same at different stations;④the amplitudes of the abnormal signals recorded at Baodi station are small,but large at Changli station,while the latter is farther from the epicentral area than the former.更多还原