摘要
文中收集了1999—2015年天山地震带及其周边地区的GNSS数据,计算得到了速度场结果,并利用弹性块体模型计算了研究区域内各块体的闭锁深度和主要断层的滑动速率。研究结果表明:南天山断裂带西段的迈丹断裂的缩短速率处于高值状态,达(-6.3±1.9) mm/a,高于南天山东段;北天山断裂带西段的缩短速率同样高于东段。利用主要断裂带的滑动速率计算出各地震带的地震矩积累变化及1900年以来的地震矩释放变化量,以分析地震矩亏损分布,结果显示北天山山前断裂、迈丹断裂、额尔齐斯断裂带北段和喀什河断裂西段存在较大的地震矩亏损,具有孕育7级以上地震的潜能,而北轮台断裂、柯坪断裂带中段则呈现地震矩盈余状态,在未来的一段时间内不具备发生强震的可能。
Late Cenozoic and modern tectonic deformation in China's Mainland is mainly characterized by active block movement,and the average slip rate of faults in the fault zone at the block boundary is an important indicator for quantitatively measuring the intensity of fault activity.The Tianshan Mountains,as the largest revival orogenic belt within Eurasia,with crustal movement basically manifesting as near north-south deformation and a large number of strong seismic surface ruptures,is one of the regions with strong tectonic movement and one of the key seismic hazard zones in China.Many experts have conducted relevant studies on the Tianshan region using GPS technology and have obtained some useful conclusions.These studies have not divided and analyzed the fault zone in detail,but only divided the Tianshan seismic zone into several major fault zones,such as the eastern and western sections of the northern Tianshan,and the eastern and western sections of the southern Tianshan.In order to analyze the activity characteristics of the major faults in the Tianshan region more clearly,this paper refines the major faults and selects 14 major active faults in combination with the distribution of active faults in China proposed by Xu Xi-wei et al.18 blocks are divided into secondary blocks in Tianshan region,with the major active blocks in the Tianshan region taken as the boundary;The GNSS data of the surrounding areas of 1999—2015 in the Tianshan seismic zone are collected in this paper and used to calculate the velocity field results,and the block locking depth and the slip rate of major faults are calculated using the elastic block model to quantify the seismogenic capacity of major faults.Because the fault closure will produce obvious elastic deformation gradient around the fault,the greater the depth of fault closure is,the greater the influence will be.The fault locking depth can be constrained by the method of GPS data fitting of this model,and the influence of fault locking depth is verified by the method of GPS mini
作者
朱爽
梁洪宝
魏文薪
李经纬
ZHU Shuang;LIANG Hong-bao;WEI Wen-xin;LI Jing-wei(The First Monitoring and Application Center,China Earthquake Administration,Tianjin 300180,China;Institute of Earthquake Forecasting,China Earthquake Administration,Beijing 100036,China)
出处
《地震地质》
EI
CSCD
北大核心
2021年第1期249-261,共13页
Seismology and Geology
基金
国家重点研发计划项目(2018YFC1503606)
中国大陆地震重点监视防御区任务和震情跟踪青年课题(2020010229)共同资助。
