中文摘要：

以InSAR同震形变场为约束，采用各向同性弹性半空间位错模型，利用试错法对2008年西藏改则县扎西错Ms6．9地震断层几何形状进行格网搜索寻优模拟。观测值离散化得到1010个数据总集，并重采样80次得到80个数据子集，每个子集之间存在微小的噪声差异，采用Bootstrap方法进行80次搜索寻优。首先用单断裂矩形断层模型进行模拟，最大残差为30cm。然后用双断裂矩形断层模型进行模拟，最大残差为15cm。双断裂模型反映了观测形变场的基本特征，并与地震资料符合。根据80次搜索寻优得到主断裂倾滑量95％置信区间为1．6～2．4m。模拟表明，地表变形是主、余震两次破裂的结果。实际观测和数值模拟结果表明，InSAR可以作为监测青藏高原大陆动力学的有效技术。

英文摘要：

Taking the InSAR coseismic deformation field as the constraint and adopting the isotropic elastic half-space dislocation model we made the optimum simulation for the geometric form of the fault in which the Gaize Ms 6.9 earthquake oecured in 2008. First we using the model of one fault to model the InSAR coseismic deformation and get the residual deformation 30 cm. Secondly, using the model of two faults the residual deformation is 15 cm, so the model reflects the basic characteristics of the survey deformation field. At last, we obtained the dip-slip 95% interval is 1.6 - 2.4 m based on 20 repected observations. The results suggest that the eoseismic deformation is caused by two ruptures. The observations and simulatsed ruslts show that InSAR is the available tool dynamics to monitoring of the Tibtan plateau.