基于D-InSAR技术的玉树M_S7.1地震同震形变场提取与分析

Calculation and Analysis of the Coseismic Deformation of the 2010 Yushu M_S7.1 Earthquake Based on D-InSAR Technology

2010年4月14日青海玉树县发生了MS7.1地震。本文利用差分干涉合成孔径雷达(D-InSAR)测量技术,通过对日本先进陆地观测卫星搭载的ALOS PALSAR获得的雷达数据进行处理,提取了此次地震的同震干涉形变场。结果表明,形变场分布特征与其发震断层甘孜—玉树断裂带的左旋走滑特征一致;最大视线向形变量为-61.4 cm,如果全部换算成沿断裂方向的走滑形变量,为-129.3 cm,该点位置为33°03′29″N,90°50′56″E,与野外观测到的宏观震中位置(33°04′23″N,96°49′32″E)基本吻合;破裂带全长约60 km,破裂以宏观震中为起点,向西北方向经甘达村、措美村延伸至隆宝镇西南,向东南方向延伸至结古镇南,沿断层的走滑量也随着向两个方向递减或消亡;断层两侧的最大相对走滑量为182.3 cm,断层西南盘的形变量明显大于东北盘,这可能是由于主震之后大部分余震发生在西南盘引起的。

An MS7.1 earthquake happened on 14 April,2010 in Yushu County,Qinghai Province.This paper processed data from the ALOS/PALSAR satellite of Japan and analysed the coseismic deformation characteristics of the Yushu earthquake using the Differential Interferometric Synthetic Aperture Radar（D-InSAR） technology.The investigation indicates that the deformation characteristics of this earthquake are consistent with that of seismogenic fault.The maximum slant range displacement is about-61.4 cm,and the overall horizontal displacement along the fault direction reaches-129.3 cm.The location of the maximum displacement is at 96°51′26″E,33°03′11″N,which is very close to the location of macro-epicenter derived from field investigation.The surface rupture zone is about 60 km long,extending from southeast of the Jiegu town to southwest of Longbao town.The maximum relative dispalcement across the fault is 182.3 cm.The displacements of the southwest wall of the fault are obviously more than that of the northeast wall.This phenomenon may be caused by aftershocks mostly occurred in the southwest wall.