汶川地震对芦山地震及周边断层发震概率的影响  

Effect of Wenchuan earthquake on probabilities of earthquake occurrence of Lushan and surrounding faults

作　　者：刘博研[1] 史保平[2] 雷建设[1] 

机构地区：[1]中国地震局地壳应力研究所地壳动力学重点实验室,中国北京100085 [2]中国科学院大学地球科学学院,中国北京100049

出　　处：《地震学报》2013年第5期642-651,1,共10页Acta Seismologica Sinica

基　　金：中国地震局地壳应力研究所中央级公益性科研院所基本科研业务专项(ZDJ2013-13)资助

摘　　要：大震后区域静态库仑应力变化常常被用于解释区域地震活动性速率的变化、主震断层外余震的发生以及即将失稳断层的地震发生概率的变化.2013年4月20日芦山MS7.0地震的发生重新引起了对2008年5月12日汶川MS8.0大地震的热议.利用含(滑移)速率和状态的摩擦定律,结合汶川大地震前后的地震活动性水平,定量化计算了汶川地震后雅安地区发震概率的变化,并着重解释了芦山地震发震的可能根源.此外,还对库仑应力明显增加的鲜水河断层和熊坡断层进行了发震概率的定量化计算,计算结果与中国地震台网中心的地震目录基本符合.鲜水河断层从汶川地震后至今近5年来未发生M>6.0地震,而M>6.0的发震概率已约为60%;熊坡断层自汶川地震以来尚未发生M>4.0地震,芦山地震后M>4.0的发震概率已接近90%.所以,我们认为鲜水河断层附近将成为M>6.0地震的重点防范地区,熊坡地区将来仍旧存在发生中强地震的危险性.Abstract： Static stress changes have been proposed to explain variations of seis- micity rates, off-fault aftershocks and probability changes for the occurrence of impending earthquakes. The occurrence of Lushan Ms7.0 earthquake re-arouses the hot discussion about the Wenchuan Ms8. 0 earthquake. Based on the rate- and-state dependent frictional law, combined with the seismicity analysis before and after Wenchuan earthquake, we have quantitatively calculated the probability of earthquake occurrences in Ya＇an area, and explained the probable causes of Lushan Ms7.0 earthquake. In addition, we have also computed the earthquake probabilities of Xianshuihe and Xiongpo faults, where the Coulomb stress also increased after Wenchuan earthquake. The results are in accordance with the earthquake catalog of the China Earthquake Networks Center. No earthquake of M〉6.0 happened on the Xianshuihe fault since the Wenchuan earthquake five years ago, but the probability of M〉6.0 earthquake is about 60% at present. There is no earthquake of M〉4.0 occurred on Xiongpo fault in the past five years, but the probabilities of earthquake occurrence of M〉4.0 is nearly 90% after the Lushan earthquake. Therefore, we propose that Xianshuihe area will become the key area to monitoring M〉6. quakes are still likely to occur in Xiongpo 0 earthquakes, and destructive earth area.

关 键 词：含（滑移）速率和状态的摩擦定律 地震发生概率 库仑应力变化 

分 类 号：P315.7[天文地球—地震学]