利用重复地震观测滦县地区的地壳介质变化

OBSERVING CRUSTAL MEDIA VARIATION IN LUANXIAN AREA BY USING REPEATED EARTHQUAKES

摘要: 运用双差定位法对滦县地区2002年1月至2010年8月M_L≥2.0级地震进行精定位,利用射线追踪方法对滦县地区的重复地震进行位置归一处理,计算了滦县地区重复地震序列经过射线追踪方法校正后得到的P波走时差变化。研究发现,2004年1月20日滦县M_L5.0级和2010年3月6日滦县M_L4.7级2次中等地震前所选取的测震台站均记录到P波走时差的低值异常变化。

Abstract: The earthquakes with M_L≥2.0 from January 2002 to August 2010 occurred in Luanxian area are relocated using the method of double difference, the locations of the repeated earthquakes in the study area are normalize by using ray-tracing method, and the P-wave travel time difference change of the repeated earthquakes are calculated after corrected with ray tracing method.The results show that before the Luanxian M_L5.0 earthquake in the January 20, 2004 and Luanxian M_L4.7 earthquake in the March 6, 2010, the low value abnormal change of P-wave travel time difference is found at selected seismic stations.