【摘要】 2007年5月5日,西藏阿里地区发生了Mw6.1级地震。本文采用Envisat卫星的升、降轨SAR数据获取地震的精确同震地表位移,然后基于弹性半空间位错模型,分别采用MPSO非线性和最小二乘线性反演算法确定了断层几何参数和滑动分布模型。结果表明,分布式滑动分布模型能较好地解释观测到的InSAR地表形变场。地震发震断层为走向158°、倾角43°的西南倾断层,主要的滑动量集中在7~12km的深度,最大滑动量约0.3m,位于9km的深度。反演给出的地震矩为1.24×1018 Nm,与地震学结果相一致。更多还原

【Abstract】 On 5th May,2007,aMw6.1earthquake occurred in the Ali region,China.In this study,ascending and descending tracks of ASAR images collected by Envisat satellite are employed to derive the precise coseismic surface displacements,then nonlinear MPSO algorithm and linear least-square method with elastic half-space dislocation model are used to estimate the fault geometry and coseismic slip distribution.Our model suggests that the distributed slip mode can fit the observations very well.The earthquake fault is a normal fault with a strike of158°,a dip of 43°and dipping to southwest.The slip mainly occurs within 7~12km along the orientation,with a maximum slip of 0.3mat a depth of 9km.The determined geodetic moment is 1.24×1018 Nm,which is consistent with seismological results.更多还原