川滇区域活动块体运动与应变特征地震影响分析

本文利用川滇1999—2007、2009—2015年GNSS实测速度场，通过引入平移-旋转-应变模型，构建该区域地震前后的活动块体运动和应变模型，有效对块体运动和块体的应变特征进行了分离，并据此分析了该区域地震前后块体运动和应变特征。结果表明，巴颜喀拉和羌塘块体东向运动有明显增大趋势；汶川地震后川滇块体与羌塘块体边界带相对挤压运动明显增大，巴颜喀拉-华南块体边界带南段形成了较大的挤压应变，川滇块体与华南块体相对运动没有明显变化。

Block Movement and Strain Characteristics Effected by Earthquake in Sichuan-Yunnan Region

In this paper,we studied the active blocks movement and deformation in the Sichuan-Yunnan region before and after the Wenchuan earthquake by using the measured velocity field of GNSS during the period from 1999 to 2007 and from 2009 to 2015.We established movement and strain model of active blocks before and after earthquake by introducing the translation-rotation-strain model,and effective to separate the blocks movement and blocks strain characteristics.According to this,the characteristics of the motion and strain of the block before and after the earthquake are analyzed.The results show that the Qiangtang block and Bayankala block to the East movement increases significantly,and after the Wenchuan earthquake is the biggest change in the boundary zone between Qiangtang block and South-China block, the compressive strain larger boundary section,and after the Wenchuan earthquake the relative extrusion movement increased significantly between Sichuan-Yunnan block and Qiangtang block,and South-China block and Bayankala block,but the relative motion between the South-China block and Sichuan-Yunnan block did not change significantly.