九江—瑞昌M_S5.7地震地磁异常的观测与分析  

OBSERVATION AND ANALYSIS OF GEOMAGNETIC ABNOR-MITY ASSOCIATED WITH THE M_S=5.7 JIUJIANG-RUICHANG EARTHQUAKE

作　　者：顾左文[1] 张毅[2] 姚同起[1] 高金田[1] 刘欣[2] 陈斌[1] 詹志佳[1] 顾春雷[2] 

机构地区：[1]中国地震局地球物理研究所,中国北京100081 [2]安徽省地震局,中国合肥230031

出　　处：《地震学报》2006年第6期611-621,共11页Acta Seismologica Sinica

基　　金：中国地震局项目资助

摘　　要：2005年11月26日九江—瑞昌MS5.7地震发生前,震中及其周围地区的地磁基本场测量和相应的“2005.0中国地磁基本场曲面样条模型”显示,震中周围100km范围内存在显著的“2005.0九江—瑞昌地磁基本场水平分量异常”.而该异常在“1970.0中国地磁基本场曲面样条模型”中并不存在.2005年12月在震中及其周围地区的21个测点上进行了地磁重复测量,并建立了“局部修订2005.0中国地磁基本场曲面样条模型”.该模型显示,震后“2005.0九江—瑞昌地磁基本场水平分量异常”明显减弱.因此认为,“2005.0九江—瑞昌地磁基本场水平分量异常”是地震地磁前兆异常现象.A three-component geomagnetic survey was carried out during the period from 2002 to 2004 in China including Jiujiang-Ruichang region. Comparing the ＂2005.0 surface spline model of China geomagnetic field＂ created on the basis of the survey data with the ＂1970.0 surface spline model of China geomagnetic field＂, we can see an obvious abnormity in the geomagnetic horizontal component within a range of about 100 km around the epicenter of the Ms = 5.7 Jiujiang-Ruichang earthquake occurred on November 26, 2005. After the earthquake, we carried out a repeated geomagnetic survey at 21 stations in the Jiujiang-Ruichang region and created a corresponding ＂2005.0 partially revised surface spline model of China geomagnetic field＂. By comparing the above three models, analyzing the geomagnetic horizontal component at the profile in the Jiujiang-Ruichang region and quantitatively studying the geomagnetic data of each station around the Ms =5.7 earthquake,we have obtained the geomagnetic abnormity associated with this earthquake. Then the geomagnetic abnormity and its relation with seismic activity arc discussed in this paper.

关 键 词：地磁测量 曲面样条模型 地磁异常 九江-瑞昌Ms5.7地震 

分 类 号：P318.21[天文地球—固体地球物理学]