【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。更多还原

【Abstract】 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-twistrise up characteristics. These four observation stations were located in different regions, the trend of each results was similar because of the tectonic stress field as a whole. But because they were located in different regions indeed, some differences will be displayed slightly.更多还原