基于D-InSAR技术的西藏改则地震同震形变场特征分析  

Characteristics of Coseismic Deformation of the 2008 Gaize,Tibet Earthquake Based on D-InSAR Technology

作　　者：洪顺英[1,2] 申旭辉[2] 单新建[1] 刘智荣[3] 戴娅琼[2] 荆凤[2,4] 

机构地区：[1]中国地震局地质研究所,北京100029 [2]中国地震局地震预测研究所,北京100036 [3]防灾科技学院,北京东燕郊101601 [4]中国科学院遥感应用研究所,北京100101

出　　处：《地震》2009年第4期23-31,共9页Earthquake

基　　金：国家科技支撑计划课题(2008BAC35B04-4);中国地震局地震预测研究所基本科研项目(0207690224;0207690207);中国地震局地震科学联合基金(C07007)联合资助

摘　　要：2008年1月9日在西藏改则地区发生6.9级地震,接着1月16日又发生6.0级余震,表现为双震型。本文利用差分干涉测量技术(D-INSAR),通过对欧空局ASAR数据进行处理获取了其同震干涉形变场。通过分析表明:改则地震干涉形变场呈双贝壳状,影响范围约33 km×30 km,以北东向地震破裂带为分界线分为西北视线向沉降盘与东南视线向隆升盘,最大视线向沉降形变量约53.2 cm,最大视线向隆升形变量约11.3 cm。西北沉降盘又存在东、西两个形变中心,推测西部形变中心受6.0级余震的控制,东部形变中心受6.9级主震的控制。宏观震中位置应位于左旋走滑改则—洞错断裂与依布茶卡—日干配错断裂的分阶部位(左阶),构造应力场以张性拉伸为主,导致地震破裂为典型的正断层破裂,与此次地震的干涉形变场特征及哈佛大学震源机制解吻合。On 9 January, 2008, an Ms6. 9 earthquake happened in Gaize region（Tibet）, with an Ms6.0 aftershock on 16 January, it is a typical double-earthquake. This paper uses the ESA ASAR SLC data to analyse the coseismic deformation characteristics of the Gaize earthquake by the Differential Interferometric Synthetic Aperture Radar（D-InSAR）. The analysis indicate that the interferogram is dual-shell shape, about 33 km×30 km in extension. And it is divided into two parts by the NE-direction earthquake rupture, the northwest slant range subsides and the southeast slant range ascends. The max slant range change subsides about 53.2 cm, the max slant range change ascends about 11.3 cm. There are two deformation centers at the northwest subside part. It is speculated that the west deformation center is controlled by the Ms6.0 aftershock, and the east deformation center is controlled by the Ms6.9 earthquake. The macroscopical seismic center is located at the apart position（left step） of Laevo strike slip fault of Gaize-Dongeuo fault and Yibuchaka- Riganpeicuo fault, the tensile stress of this apart position leads to the typical normal fault L fracture of the Gaize earthquake, and this accords with the interferogram characteristics and the Harvard mechanism.

关 键 词：改则地震 D-INSAR 同震形变 视线向形变 断层 

分 类 号：P315.7[天文地球—地震学]