京西盆岭构造区积累库仑破裂应力变化对强震的影响

Cumulative Coulomb Stress Changes in the Basin-range Region of West Bejing and Their Effects on Strong Earthquakes

以拉张正断层作用为主的京西盆岭活动构造区（112°~116.2°N,38.3°~41.5°E）自BC231年以来共记载和记录15次M6~7.5地震。本研究计算每一次强震产生的以及逐次积累的库仑破裂静应力变化,并分析强震之间的应力触发关系。结果显示在14次后发的强震中,有10次发生在先发强震产生的积累库仑破裂静应力变化为正的触发区,触发率为71%。所有15次历史强震作用共同引起研究区积累库仑破裂静应力变化的正值区,主要分布于六棱山北麓断裂中段、怀涿盆地北缘断裂、新保安沙城断裂、桑干河断裂以及蔚县盆地南缘断裂,并使得这些断裂（段）的强震危险性有所增加,这可为分析研究区的未来强震危险性提供参考。

Since 231 BC,a total of 15 M6~7.5earthquakes were recorded in the basinrange of west Beijing（38.3°~41.5°E,112°~116.2°N）,where tensional forces dominate.In this paper,we calculate Coulomb stress changes of each earthquake and the cumulated stress changes.On this basis,we analyze stress triggering of strong earthquakes.The results show that there are 10 of 14earthquake occurred in triggered zones,in which the Coulomb stress change is positive,triggering rate is 71%.The positive areas of cumulative Coulomb stress change caused by these 15 earthquakes are：the middle section of the northern Liulengshan fault,northern Huaizhu basin fault,Xinbaoan-Shacheng fault,Sangganhe fault and southern Yuxian basin fault.These Coulomb stress changes increase seismic risk on these faults,and the resultsit can be a reference for future seismic risk analysis in this area.