鲁西南聊考断裂带地震危险性评价与活动性分布

摘要

Based on the earthquake catalogues of the Liaocheng-Lankao fault zone and the 50 km surrounding areas since 1970,combined with historical earthquake and seismic background data,we calculate the b-values and point out the highest stress accumulation areas.We use the maximum likelihood and the least square methods,then utilize probability of seismic potential method on north and south segments to calculate the time-dependent seismic potential probability and the background seismicity.We make following conclusions:(1) Fanxian,Qingfeng,Puyang and Juancheng are in high stress accumulation areas,with stable b-values ranging 0.6～0.7.(2) Depending on the time-dependent seismic potential probability,the south of Liaocheng-Lankao fault zone will be more dangerous in the next 50 years and all fault zones will have higher probability of M5.0～6.0 earthquakes occurringin 100 years.(3) The earthquakes in the study areas are mainly concentrated in 115.2°to 115.6°E,34.9°to 36°N,and the seismicity made greater change more since 2000.%利用1970年以来沿聊考断裂带及周边50 km范围内的地震数据,结合历史强震与现今地震活动背景,分别运用最大似然法和最小二乘法对研究区进行b值计算,圈出高应力累积区,并借助时间相依的地震潜势概率评估方法以及地震活动性分布,得出以下结论:1)南段的范县、清丰、濮阳以及鄄城地区的b值维持在0.6～0.7之间,属于高应力积累区;2)未来50 a内南段危险性较高,100 a内整条断裂发生M5.0～6.0地震的可能性较大;3)地震活动主要集中在115.2°～115.6°E、34.9°～36°N区域内,且自2000年后地震活动性变强.