地震工程学报Issue(1)：175-180,6.DOI:10.3969/j.issn.1000-0844.2015.01.0175
东昆仑断裂带玛曲-玛沁段大震危险性分析和探讨
Analysis and Discussion of Large Earthquake Risk along the Maqu-Maqin Segment of the East Kunlun Fault Zone
摘要
Abstract
In this paper,based on the seismicity and seismic structural analysis of the margin of the Bayan Har block,we discuss the risk of large earthquakes in the Maqu-Maqin seismic gap with regard to spatial seismicity patterns and temporal evolution of event sequences.According to paleo-earthquake and historical earthquake seismicities,there was an initial seismic gap at Maqu-Maqin along the east Kunlun fault,and therefore,large earthquakes will recur in this area.A second seismic gap,the seismic quiescence of no ML ≥5.0 earthquakes,has been detected in the same area since 2008.A comparison with previous earthquake cases showed that a similar period of seismic quiescence formed in the region of Gansu-Qinghai-Sichuan provinces before the 1 990 Gonghe M 7.0 earthquake.The distribution of ML ≥4.0 earthquakes in the current seismic quies-cence is also similar to that of the Gonghe M 7.0 case;hence,we think there is a risk of a large earthquake in the current gap.From the temporal sequences evolution analysis (M-T relations), we found that seismicity in the Gonghe gap had undergone strong-weak-strong stages prior to the Gonghe M 7.0 earthquake.However,the seismicity in the current seismic gap in the region of Gansu-Qinghai - Sichuan provinces has also undergone the first two stages,and therefore,we conclude that it will soon reach the strong seismicity stage.We scanned the b-value distribution in this region,which showed that the b-values are very low around the east Kunlun fault and that there is locking in this area.We also calculated the spatial correlation lengths (SCL)and multiple fractal dimensions from the earthquake catalog of the Bayan Har block using GeoTaos.All the sta-tistical seismicity parameters indicate that the risk of a large earthquake on the Maqu - Maqin segment of the east Kunlun fault is increasing,and therefore,researchers should monitor and study this area.关键词
东昆仑断裂带/玛曲-玛沁空区/地震活动时空演化/大震危险性Key words
east Kunlun fault zone/Maqu-Maqin seismic gap/temporal and spatial evolution of seismicity/large earthquake risk分类
天文与地球科学引用本文复制引用
温燕林,宋治平,赵文舟,朱佳苗,马钦忠..东昆仑断裂带玛曲-玛沁段大震危险性分析和探讨[J].地震工程学报,2015,(1):175-180,6.基金项目
上海市地震局科技专项(2012专10) （2012专10）
上海市科委科研计划(12231202700) （12231202700）
中国地震局地震科技星火计划(XH12016) （XH12016）
