摘要
Based on the division of Sichuan-Yunnan area,using the horizontal crustal movement velocity field by GPS measurements during 1999 to 2007 and 2009 to 2011,we calculated the state of block strain,the homogeneous elastic deformation of the internal blocks and relative motion of the boundary between the adjacent blocks by the homogeneous elastic strain block model.Considering the impact of Wenchuan MS8.0 earthquake and Yushu MS7.1 earthquake on crustal movement of Sichuan-Yunnan area,the calculation analysis results showed that:(1) The calculation results reflected the better characteristics of tectonic movement in the region;(2) The movement of the east boundary on Sichuan-yunan block mainly was strike-slip.The intersections of An’ninghe and Zemuhe Faults showed that the left-lateral strike-slip movement was blocked apparently,and there were significant strain accumulation in the block on both sides of this site,which indicated it maybe the area of possible strong earthquakes preparation in the future;(3) The spatial differences of the blocks boundary movement were enhanced in 2009~2011 than that in 2007~2009,which reflects the impact of Wenchuan MS8.0 earthquake and Yushu MS7.1 earthquake on the regional crustal movement in the whole area.