【摘要】 为深入了解2010年玉树地震引起的地表位移及发震断层的细节情况,对玉树地震震前、震后的PALSAR数据进行干涉处理,并针对轨道不精确引起的相位残差问题,采用最小二乘多项式模型拟合的方法对其进行去除,得到玉树地震地表的同震形变场。结果显示,形变最大地区发生在33.06°N、96.83°E附近,雷达视线方向形变最大值为-0.442 m。通过地质调查结果及合成孔径雷达干涉测量(InSAR)形变场的分析,对断层进行分段,基于弹性半空间位错模型对分段后的断层进行了同震滑动分布反演,并对反演结果的可靠性进行分析。结果表明,断层的最大位移为2.084 m,位于隆宝滩地表以下14 km处,反演结果对应的矩震级为MW7.0,与地震学和地质调查的情况较吻合,且反演的结果较可靠。更多还原

【Abstract】 To understand the surface deformation caused by 2010 Yushu earthquake and the situation of the causative fault,pre-and post-seismic PALSAR data were processed by the synthetic aperture radar interferometry(InSAR) method.The least squares fitting method was introduced in eliminating the phase caused by inaccurate orbital information.The coseismic deformation shows that the main deformation area is located in the N33.06°,E96.83°,and the maximal deformation in radar line-of-sight(LOS) is about-0.442 m.With the analysis of geological survey and InSAR deformation field,the fault was divided into five small segments.After determining the geometric parameters of the segmented faults,the inversion of the slip distribution becomes a linear problem under the elastic half-space dislocation model.Then it was carried out using least squares method.The fault slip distribution result shows that there exist two slip peak zones,and the two segmented faults located in Longbaotan and Yushu are outcropping.The maximal slip on the fault is 2.084 m,located in the depth of 14 km of Longbaotan area,but the biggest outcropped slip is located in the Yushu area.This is the main reason that the earthquake caused severe damage in Yushu county.The calculated moment magnitude is MW7.0,which is well consistent with the seismological solution and geological survey.更多还原