河北省流动地磁观测异常特征分析

Anomaly Characteristics of Mobile Geomagnetic Observation in Hebei Province

运用1986—2009年河北省流动地磁观测资料,分析其地磁总场强度测值时间变化与空间分布特征,找出流磁异常特征。结果表明:流动地磁变化与该区的地震活动存在一定关系,且震前异常多在震前1—2年出现,δ_F值存在"连续大幅上升—临震大幅转折下降"的异常变化特征。

In this study, the netic total intensity in mobi netic observation data from temporal variation and spatial distribution characteristics of geomag le H geomagnetic observation were analyzed using the mobile geomag ebei province between 1986 and 2009; in addition, the characteris tics of mobile geomagnetic anomalies were discussed. The results show that there is a certain rela tion between the mobile geomagnetic changes and earthquakes in the area. The precursory anoma lies usually appear 1-2 years before the earthquake. The δF value has the variation characteristic of ＂continuous sharp rise impending sharp decline.＂ The bigger the magnitude the larger is the geomagnetic anomaly. In this study, only ML≥4.0 earthquakes occurring in the monitoring area can reveal seismic change information that can better predict the earthquake.