安宁河、则木河构造区近期强震危险性的概率估计  

Probabilistic Estimate of Strong Earthquake Risk in the Anninghe-Zemuhe Tectonic Zone

作　　者：路鹏[1] 袁一凡[1] 袁洪克[2] 刘学领[3] 于晓辉[1] 段玉石[1] 

机构地区：[1]防灾科技学院,河北燕郊065201 [2]中国地震局地球物理勘探中心,河南郑州450002 [3]天津市地震局,天津300201

出　　处：《地震》2012年第4期62-72,共11页Earthquake

基　　金：中国地震局教师基金

摘　　要：2008年5月12日汶川8.0级地震发生后,作为历史强震多发地段——南北地震带中南段的安宁河、则木河构造区强地震危险性受到广泛关注。本文在分析安宁河、则木河构造区强震活动特点的基础上,利用地震危险性韦布尔概率估计方法,对该区未来10年内发生6.5级以上强震的累计概率和条件概率进行了计算,并结合前人针对汶川地震破裂对周边断层产生的库仑应力变化及潜在震源区判定等研究结果,对该区强地震危险性进行了综合判断。结果表明,汶川8.0级地震发生后,安宁河、则木河构造区5级以上中强地震似有逐步活跃的趋势;根据韦布尔概率模型计算得出的该区2021年前发生6.5级以上强地震的概率高达0.93,条件概率为0.32。因此,该构造区,尤其是区内的冕宁—西昌一带未来10年发生强地震的可能性相对较高。After the 2008 Wenchuan magnitude 8.0 earthquake,Anninghe-Zemuhe fracture region,which has been a frequent strong earthquake zone in history,located in the middle south of the South-North Seismic Zone,has received extensive attention.Based on analyzing the unique characters of strong earthquake activity in Anninghe-Zemuhe tectonic zone,this paper calculated the cumulative probability and conditional probability of strong earthquake above magnitude 6.5 in the next decade in this area,by using the Weibull probability seismic risk estimation method.Moreover,by integrating previous studies on the Coulomb stress changes in peripheral faults and the potential focal zone caused by the Wenchuan earthquake rupture,we proposed a comprehensive judgment on the strong earthquake risk in Anninghe-Zemuhe tectonic zone.The results show that the 2008 Wenchuan earthquake would inevitably lead to middle and strong earthquakes above magnitude 5.0 earthquake activates gradually in Anninghe-Zemuhe tectonic zone.According to the Weibull probability model,the probability of occurring strong earthquake above magnitude 6.5 before 2021 in this area is as high as 0.93,and the conditional probability is 0.32.Therefore,in this tectonic zone,especially in the Mianning-Xichang region within this zone,the possibility of strong earthquake in the next decade is relatively high.

关 键 词：安宁河、则木河构造区 强震危险性 韦布尔概率分布 概率预测 

分 类 号：P315.7[天文地球—地震学]