摘要
利用时序InSAR技术提取川滇菱形块体东缘安宁河-则木河断裂区域震间地表形变场,反演安宁河-则木河断裂的震间运动速率与闭锁深度。结果表明,安宁河断裂由北向南跨断裂InSAR形变速度差异由约2 mm/a逐步增加至约2.5 mm/a,则木河断裂跨断裂形变速率差异相对较小,约1.8 mm/a。安宁河断裂最北段石棉段滑动速率约2.8 mm/a,中段冕宁段滑动速率约4.0 mm/a,最南段西昌段滑动速率约3.2 mm/a;则木河断裂北段滑动速率最大约3.1 mm/a,向南至宁南段逐渐衰减至约2.6 mm/a。西昌段闭锁深度最深,约37.8 km,其向南、向北方向延伸均逐渐减小,其中最北段石棉段闭锁深度最浅约5.0 km,而在最南段宁南段闭锁深度约13.2 km。整体而言,西昌段具有相对更大的断裂滑动速率和更深的闭锁深度,表明其孕震潜能更强,而这也与该区段更为密集的地震活动形成相互验证关系。
This study employs time-series InSAR technology to extract the interseismic surface deformation field along the Anninghe-Zemuhe fault zone on the eastern margin of the Sichuan-Yunnan rhombic block.We further invert the interseismic slip rates and locking depths of the fault system.Key findings include:the cross-fault InSAR deformation velocity gradient along the Anninghe fault increases progressively from~2 mm/a in the northern segment to~2.5 mm/a in the southern segment,whereas the Zemuhe fault exhibits a relatively smaller gradient of~1.8 mm/a.Slip rates along the Anninghe fault vary spatially:~2.8 mm/a at the northern Shimian segment,~4.0 mm/a at the central Mianning segment,and~3.2 mm/a at the southern Xichang segment.The Zemuhe fault shows a decreasing slip rate from~3.1 mm/a in the northern segment to~2.6 mm/a in the southern Ningnan segment.Locking depth analysis reveals maximum values(~37.8 km)beneath the Xichang segment,gradually shallowing northward to~5.0 km at Shimian and southward to~13.2 km at Ningnan.These results demonstrate that the Xichang segment,characterized by higher slip rates and deeper locking depths,exhibits enhanced seismic potential,consistent with its historically dense seismicity.This spatial correlation between geodetic deformation patterns and seismic activity provides critical insights into strain accumulation processes within this active tectonic boundary.
作者
谢丽媛
杨莹辉
许强
李小云
陈强
谭莎莎
XIE Liyuan;YANG Yinghui;XU Qiang;LI Xiaoyun;CHEN Qiang;TAN Shasha(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,1 Dongshan Road,Chengdu 610059,China;Faculty of Geosciences and Engineering,Southwest Jiaotong University,111 North-Section 1 of Erhuan Road,Chengdu 610031,China)
出处
《大地测量与地球动力学》
北大核心
2025年第9期972-982,共11页
Journal of Geodesy and Geodynamics
基金
国家自然科学基金(42474041,42471485)
地质灾害防治与地质环境保护国家重点实验室科研课题(SKLGP2020K019,SKLGP2021Z016)。
