2015年塔吉克斯坦M_S7.4地震的InSAR观测及其构造意义  

InSAR Observation Results of the 2015 Tajikistan M_S7.4 Earthquake and Its Tectonic Significance

作　　者：李宁[1] 赵强[1] 孙赫[1] 

机构地区：[1]中国地震局第二监测中心,西安市西影路316号710054

出　　处：《大地测量与地球动力学》2018年第1期43-47,110,共6页Journal of Geodesy and Geodynamics

基　　金：国家自然科学基金(41604015);中国地震局地震科技星火计划(XH17059);中国地震局青年震情跟踪课题(2017010207)~~

摘　　要：利用欧空局提供的Sentinel-1A卫星差分干涉数据为约束,对2015-12-07塔吉克斯坦MS7.4地震的震源机制进行反演。首先运用两轨法对卫星雷达影像进行差分干涉处理,获取覆盖塔吉克斯坦地震震区的同震形变场,然后运用分布式滑动模型反演获取较精细的断层滑动分布。结果显示,分布式滑动模型与观测结果有很高的拟合度。反演结果表明,发震断层以左旋走滑运动为主,此次地震断层的最大滑移量为4.42m,同震的地震矩为73.71×1018 Nm,矩震级为MW7.19,与震后USGS、GCMT、IPGP等机构给出的震源机制解结果一致,是在具有左旋走滑运动特征的显著构造背景下的一次正常、必然的破裂事件。In this paper, we use InSAR data from the Sentinel-lA satellite to invert the focal mecha- nism solutions of the Ms7. 4 earthquake,which occurred in Tajikistan on 7 December 2015. First,two- pass interferometry technique is utilized to obtain the coseismic deformation of the region, covering the whole epicenter o{ the Tajikistan earthquake. Second, we utilize the distributed slip model inversion method to obtain a more precise distribution of fault slip by means of down-sampling the original ob- servation data. The results indicates that inversion results are consistent with the observation data. In addition, the inversion results show that the seismogenic fault is dominated by sinistral strike-slip movement. The maximum slip of the earthquake fault is 4.42 m, and the coseismic seismic moment is about 73.71 × 10TM Nm （MwT. 19）, which is consistent with the seismic research results available from USGS, GCMT, IPGP after this event. It also shows that this earthquake is a normal and inevitable rupture event in the significant tectonic setting with left-lateral strike-slip motion.

关 键 词：塔吉克斯坦Ms7.4地震 雷达干涉测量 同震形变 滑动分布 位错反演 

分 类 号：P315[天文地球—地震学]