Abstract：The vertical crust deformation of northeast margin of QinghaiTibet block before and after Wenchuan \%M\%s8.0 earthquake has been analyzed with the regional leveling and faultcrossing leveling data. The results show that within 10 years before the earthquake the regional vertical deformation has a certain diversity with regional feature. In detail, that the tectogenesis for degressive Qilian mountain and anabatic aislebasin in Hexi area reflected by the vertical deformation is counterinheritance motion; that the tectogenesis in XijiHaiyuan Guyuan area reflected by the vertical deformation is balanced motion, and on the west to ZhangxianWudu of LanzhouTianshuiWudu area, Minshan’s rise is obviously increasing and accompanied with high gradient belt. It could be inferred that the pressure from the Tibetan plateau is relatively weakened in the north direction and clearly increased in the east direction. Monitoring data show that the vertical deformation of northeast margin of QinghaiTibet has an extensive inverted variation from Aug. to Oct. in 2008 after Wenchuan Ms8.0 earthquake. The Xiahe and Hezuo area of Minshan uplift shows rapid counterinheritance sinking relative to Linxia from 2006-2008. It could be inferred that the pressure eastward from the Tibetan plateau is weakened due to Wenchuan Ms8.0 earthquake.The monitoring data in 2010 show that the crustal vertical deformation of northeast margin of QinghaiTibet is decresing, and that Hezuo area is counterinheritance sinking relative to Linxia from 2008-2010, nevertheless, the differential morement between Hezuo and Linxia is decreasing. It could be inferred that regional tectogenesis reflected by the vertical deformation, including Minshan uplift, has been to stable state.
Zhang Sixin,Wang Shuangxu,and Liu Liwei. ANALYSIS OF VERTICAL CRUST DEFORMATION OFNORTHEAST MARGIN OF QINGHAI-TIBET BLOCK BEFORE AND AFTER WENCHUAN Ms8.0 EARTHQUAKE[J]. jgg, 2011, 31(6): 25-31.
