??Ms8.0?????????????α???

????1951??????????????????1999-2007???GPS???????????????????α???????о???????????????岻????ε????α???????????α?????8.0??????????????????????????????8.0?????????????α?????????????α???????????????????????????????????????骲???????????й????λ?????????????????????????????????????γ????????????????????????????????????

BACKGROUND OF VERTICAL DEFORMATION BEFORE WENCHUAN Ms8.0 EARTHQUAKE

Based on the data obtained since 1951 and the crustal vertical deformation rate calculated from the GPS data obtained from 1999 to 2007, the vertical deformation characteristics in Qinghai??Tibet block and southern China block, and the relationship between the vertical deformation and both of the occurrence and the development of Wenchuan ??M??s8.0 earthquake was studied. The results show that Wenchuan ??M??s8.0 earthquake happened in the vertical deformation rate gradient zone that was the dramatic rising area.The accumulation of deformation strain energy was related with collisions of the Indian??Eurasian plates, and the vertical uplift of the Qinghai??Tibet block by strong squeeze in North??South direction at the front edge of the collision of the two plates with the substance movement to the East and South??East.