2020年1月19日新疆伽师MS6.4地震InSAR同震形变场特征及发震构造初步探讨  

PRELIMINARY DISCUSSION ON CHARACTERISTICS OF COSEISMIC DEFORMATION FIELD AND INSAR SEISMOGENIC STRUCTURE FOR XINJIANG JIASHI M S6.4 EARTHQUAKE ON JANUARY 19TH,2019

作　　者：温少妍[1] 李成龙 李金[1] WEN Shao-yan;LI Cheng-long;LI Jin(Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,Xinjiang,China;State Key Laboratory of Earthquake Dynamic,Institute of Geology,China Earthquake Administration,Beijing 100029,China)

机构地区：[1]新疆维吾尔自治区地震局,新疆乌鲁木齐830011 [2]中国地震局地质研究所,地震动力学国家重点实验室,北京100029

出　　处：《内陆地震》2020年第1期1-9,共9页Inland Earthquake

基　　金：国家自然科学基金(41974006,41874015);地震科技星火计划项目(XH19050Y,XH20067);新疆地震局局基金(201802).

摘　　要：基于Sentinel-1 SAR升、降影像,利用D-InSAR技术获取新疆伽师M S6.4地震的同震形变场,结果表明,本次地震引起的同震形变场整体呈近椭圆状分布,形变区东西长约66 km,南北宽约40 km,整个形变场由南部隆升区和北部沉降区组成,南部最大隆升量约7 cm,北部最大沉降量约3 cm。本次地震发生在块体俯冲界面处的低倾角逆冲推覆构造带上,隆升和沉降两个中心均位于逆冲推覆体的上盘,形变主要以隆升形变为主,符合低倾角逆断层中强震的变形特征。在沉降区与隆升区之间干涉条纹连续分布,未出现表征地表破裂位置的空间失相关带,表明地震未引起明显的地表破裂。结合震源机制、余震精定位及区域构造特征,初步推断认为伽师地震的发震构造可能为柯坪塔格推覆构造前缘的N倾的柯坪断裂。Jiashi M S6.4 earthquake struck Xinjiang Province,China,on 19th January 2020.Based on ascending and descending tracks of the Sentinel-1A satellite IW model,the co-seismic deformation field is obtained by D-InSAR.The result shows that the whole deformation field caused by this event looks like oval shape.Main deformation scope is about 66 km×40 km,long in east-west direction.The deformation field consists of a greater uplift area in the south and a weak subsidence area in the north,the maximum rising value reaches about 7 cm in LOS direction,and the maximum settlement displacement is about 3 cm in LOS The result implies that this event occurred on thrust nappe belt with the low dip at the block subduction interface.The two deformation centers of uplift and subsidence are located in the hanging wall of the thrust nappe,which is accord with the deformation feature of moderate earthquake caused by the low dip thrust.The fringes and unwrapped displacement between uplift and subsidence area are distributed continually,no incoherence belt can be found,which indicates that there is no obvious rupture on the surface.Combined with focal mechanism,precise location of aftershocks and regional structural features,it is preliminarily inferred that the N-dip Keping fault in the front of Kalpingtag thrust system could be the causative fault of Jiashi earthquake.

关 键 词：伽师MS6.4地震 哨兵卫星 D-INSAR 同震形变场 柯坪塔格推覆构造 

分 类 号：P315.7[天文地球—地震学]