摘要
柴北缘断裂带是青藏高原东北缘的重要地质边界,几何形态复杂。目前少有针对区域整体断层现今闭锁程度与滑动亏损的研究。本文收集并融合得到了较为密集的区域GPS数据,建立了包括赛什腾-绿梁山断裂段、锡铁山-阿木尼克山-牦牛山断裂段、北鄂拉山断裂段、南鄂拉山断裂段及阿克塞-德令哈块体、柴达木块体、鄂拉山块体的几何模型,采用负位错模型反演研究了柴北缘断裂带的现今闭锁程度与滑动亏损。结果表明:赛什腾-绿梁山断裂段闭锁程度和滑动亏损从中部(15 km深度内平均闭锁系数约0.7)向两端逐渐减小;锡铁山-阿木尼克山-牦牛山断裂段闭锁程度和滑动亏损从西北向东南均逐渐增大,中部和东南端15 km深度内平均闭锁系数约0.99,平均滑动亏损约3.34 mm/a和3.80 mm/a;北鄂拉山断裂段最北端闭锁深度较浅,中部和南端闭锁深度较深(约19 km),中部滑动亏损较大;南鄂拉山断裂段两端闭锁深度达20 km(15 km深度内平均闭锁系数约0.9和0.99),中部闭锁深度较浅,北端滑动亏损较大。综合反演结果与历史地震分布分析,锡铁山-阿木尼克山-牦牛山断裂段中部和东南端、北鄂拉山断裂段中部、南鄂拉山断裂段北端地震危险性可能较高,须加以关注。
The fault zone in northern Qaidam Basin is an essential geological boundary of the northeastern margin of the Qinghai-Tibet Plateau,and its geometry is complex.At present,there are few studies on the current locking degree and slip deficit of regional integral faults.In this paper,a dense regional GPS data is collected and fused,and a geometric model including the Saishiteng-Lüliangshan fault section,Xitieshan-Amunikeshan-Maoniushan fault section,the northern Elashan fault section,the southern Elashan fault section,and the Akesai-Delingha block,the Qaidam block and the Elashan block is established.The negative dislocation model is used to invert the current locking degree and slip deficit of the fault zone in northern Qaidam Basin.The results show that the locking degree and slip deficit of the Saishiteng-Lüliangshan fault section gradually decrease from the central(the average locking coefficient within 15 km depth is about 0.7)to both ends.The locking degree and slip deficit of Xitieshan-Amunikeshan-Maoniushan fault section increase gradually from northwest to southeast.The average locking coefficient within 15 km depth in the central and southeast parts is about 0.99,and the average slip deficits are about 3.34 mm/a and 3.80 mm/a,respectively.The locking depth of the northern most part of the northern Elashan fault section is shallow,the locking depth of the central and southern parts is deep(about 19 km),and the slip deficit of central part is enormous.The locking depth at both ends of the southern Elashan fault section is up to 20 km(the average locking coefficients within 15 km depth are about 0.9 and 0.99,respectively),the locking depth of central part is shallow,and the slip deficit of northern part is enormous.Based on the comprehensive inversion results and the analysis of historical seismic distribution,the seismic risk of central and southeastern parts of Xitieshan-Amunikeshan-Maoniushan fault section,the central part of northern Elashan fault section,and the northern part of southern Elashan fault section may be high,which should be paid attention to.
作者
刘洋
邱雨轩
王君毅
李航昊
张宇
温扬茂
许才军
LIU Yang;QIU Yuxuan;WANG Junyi;LI Hanghao;ZHANG Yu;WEN Yangmao;XU Caijun(School of Geodesy and Geomatics,Wuhan University,Wuhan 430079,China;Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,Wuhan University,Wuhan 430079,China;Key Laboratory of Geophysical Geodesy,Ministry of Natural Resources,Wuhan 430079,China)
出处
《测绘学报》
EI
CSCD
北大核心
2023年第12期2015-2027,共13页
Acta Geodaetica et Cartographica Sinica
基金
国家自然科学基金(41874011,41974004)
中央高校基本科研业务费专项资金(2042023kfyq01)。
关键词
柴北缘断裂带
GPS
负位错模型
闭锁程度
滑动亏损
the fault zone in northern Qaidam Basin
GPS
negative dislocation model
locking degree
slip deficit
作者简介
第一作者:刘洋(1984-),男,博士,副教授,主要研究方向为大地测量与地壳变形。E-mail:Yang.Liu@sgg.whu.edu.cn。
