中文摘要：

利用3景Envisat雷达遥感图像，获取了2008年10月6日西藏当雄Ms6．6地震的震前及同震形变场，结果表明，震前4个多月震中区未出现显著的地壳形变，只是地震造成震中区（20km×20km范围）最大近0．3m的明显变形。形变场近南北轴向对称分布，西部沉降，东部隆升。利用均匀弹性半无限位错模型和约束非线性优化算法，对断层的位错量及分布的估算表明，地震以正断破裂为主，断面最大位错达3m，震中位于90．374°E，29．745°N，震级Mw6．35；地震发生在走向189°、倾角60°的念青唐古拉山南东麓断裂带南段的次级断层上，发震断层长12km，宽11km，深度9．5km，以东西向拉伸运动为主。较浅的震源深度与断层附近的地壳热状态有关。

英文摘要：

Three scenes Envisat-1 images from ESA were used to derive the pre-seismic and coseismis deformation interfereograms caused by the Damxung Ms6.6 earthquake on Oct. 6, 2008, constrained by InSAR. The results indicate that InSAR could not detect notable crustal motion more than 4 months before the event which caused distinct displacement in an area of 20 km × 20 km with a maximum LOS change about 0.3 m. The deformation field was symmetrically distributed and separated by a NS axis, where the west subsided and the east rose. We used a linear elastic dislocation model in half space and nonlinear constraint optimized algorithm to estimate the dislocation value and distribution of the fault. The results indicate that the epicenter locates at E90.374°, N29. 745° with a seismic moment tensor Mw6.35. The earthquake is dominated by a normal fault fracture with the maximum slip of 3m on the 12 km × 11 km rupture surface striking S189°W, dipping 60°to NW at the bottom of 9.5 km, located at a sub - fault of the southeastern piedmout of the Nyainqentanglha Mountains. The seismic fault extensionally moves along EW. The shallow depth of epicenter is related to crust thermal status of seismic region.