2008年汶川大地震造成了惨重的损失，而随后的中强余震又进一步加重了损失，妨碍救援和灾后重建。虽然汶川主震的发震机理得到了深入系统的研究，但汶川地震的中强余震发震断层、震源破裂模型、断层滑移量时空分布、发震机理等方面的研究还有待进一步深入。而龙门山断裂带地区结构横向不均匀性和地形起伏十分剧烈，传统基于一维速度结构的地震学方法难以获得这些中强余震的破裂模型，本项目拟通过引入三维应变格林张量（Strain Green's Tensor，SGT)数据库方法，实现三维速度模型中可靠反演中强地震震源破裂模型，包括6级左右中等余震平均破裂模型的反演，获取与地震破裂方向性效应相关的有限源平均或整体特征；以及三维速度模型中反演6.5级左右强余震滑移量时空分布模型，了解强震发生的破裂过程；探讨汶川地震中强余震发震断层，破裂特性，发震机理，为准确进行强地面运动预测、地震灾害评估、强震触发机理研究提供重要参数。

The 2008 great Wenchuan earthquake caused colossal damages, which were further aggravated by the following moderate and strong aftershocks. While rupture processes and seismotectonics of the mainshock have been well studied, the causative faults and rupture models of these aftershocks are still not known. The drastic topography variation and 3D velocity contrast across the Longmenshan fault makes it difficult to resolve the rupture parameters with 1D Greens’function. We propose to determine rupture parameters of ~M6 aftershocks and rupture processes of ~M6.5 afterschosk with Strain Green’s Tensor computed with 3D velocity models, and then resolve causative faults of these aftershocks. These parameters will be helpful for understanding for occurrence of damaging aftershocks after large earthquakes.