唐山M 4.8地震地磁谐波振幅比变化  

Variation of the geomagnetic harmonic wave amplitude ratio before the Tangshan M 4.8 earthquake

作　　者：贾立峰[1] 乔子云[1] 张国苓[1] 寇海川 Jia Lifeng;Qiao Ziyun;Zhang Guoling;Kou Haichuan(Hebei Earthquake Agency,Shijiazhuang 050021,China）Abstract)

机构地区：[1]河北省地震局,中国石家庄050021

出　　处：《地震地磁观测与研究》2018年第5期39-47,共9页Seismological and Geomagnetic Observation and Research

基　　金：国家自然科学基金项目(批准号:41274079);河北省地震局地震科技星火项目(项目编号:DZ20170511073)

摘　　要：针对2012年5月28日河北唐山M 4.8地震,采用地磁谐波振幅比方法,分析昌黎、静海、红山及承德地磁台2007年1月至2015年12月地磁观测数据,结果显示:各台站10 min周期的计算结果波动性明显,其他周期形态较为一致;距震中最近的昌黎地磁台Y_(ZHx)(NS)测向的10—40min周期地磁谐波在下降至极低值后,开始转折时发生地震,而Y_(ZHy)(EW)测向未出现明显转折现象;位于河北平原地震带中部的静海地磁台对此次地震反应显著,2个测向在震前均出现下降—转折—上升的变化特征。通过对比位于不同地区的4个地磁台站地磁谐波振幅比变化,发现受大范围整体构造应力场作用的影响,计算结果具有相似的趋势性变化特征,具体到局部地区或断裂带内部,各台站之间显示出一定差异。In the past decades, numerous geomagnetic observation stations were built in Hebei Province and surrounding, and accomplished digital upgrade in ten years ago. These stations have produced a large amount of geomagnetic data so far. In this paper, the Tangshan M 4.8 earthquake was analyzed by the geomagnetic harmonic wave amplitude ratio method based on the geomagnetic data of observation stations such as Changli, Chengde, Jinghai and Hongshan. It was found that the volatility of 10 min period is more obvious, other periods were similar to each other and slightly dull. Changli station was the nearest to the earthquake, and the 10-40 min periods of YZHx（NS） turn up when they down to the low, and then earthquake occurred. But in the same time YZHy（EW） have no similar changes. Jinghai station was located in the central of Hebei seismic belt, and the response of the result is more obvious, YZHx（NS） and YZHy（EW） both appeared decline-twist-rise up characteristics. These four observation stations were located in different regions, the trend of each results was similar because of the tectonic stress feld as a whole. But because they were located in different regions indeed, some differences will be displayed slightly.

关 键 词：唐山M4.8地震 地磁谐波振幅比 深部电导率 地磁异常 

分 类 号：P315.7[天文地球—地震学]