选取河南范县及邻区2008年1月~2015年9月M_L ≥ 2.0地震78个，用双差定位法进行重新定位。结果显示，重定位的震中主要沿聊城-兰考断裂带呈NE向分布，较此前更集中。重定位后的震源深度82%位于7~8km，也比此前更集中。在此基础上，用CAP方法研究了该地区2008年以来M_L ≥ 3.0地震的震源机制解。结果显示，节面Ⅰ的14个地震中有11个地震震中分布呈NE向，这与用双差法重新定位后的震中分布方向一致。此外，这14个地震中有9个地震的P轴方位在50°~100°，均值为75°，这与华北地区主压应力方向基本一致。综合分析认为，该区域的地震活动与聊城-兰考断裂有关。

78 digital seismic events(M_L ≥ 2.0)recorded by the Henan Digital Seismic Network in Fanxian County and its adjacent regions from January 2008 to September 2015 were screened out through the double difference earthquake location method for precise relocating. Compared to previous location,which is showed in the results,the relocated relative position of seismic source is more concentrated. The earthquakes which are closely associated with fault distributed along Liaocheng-Lankao fault zone in NE direction. In addition,82% earthquakes are concentrated at 7~8km,which are more concentrated than before. On this basis,the CAP method is used to study the focal mechanism solution of M_L ≥ 3.0 earthquake in the region since 2008. The results are as follows:11 of 14 earthquakes' strike,which is along NE in pitch surface one,is in accordance with precisely positioned distribution direction of the epicenter. 9 of 14 earthquakes' azimuth of P axis are between 50 and 100 degree and its average value is about 75 degree,which is accordance with the direction of compressional stress in North China. It is therefore concluded that there is a certain correlation between Liaocheng-Lankao fault and the earthquake activities in this region.

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河南省地震局科研基金资助