以“中国地壳运动观测网络”工程1999—2001年GPS观测数据以及“大陆强震机理与预测”国家基础研究项目青藏块体东北缘GPS网1999,2001,2003年的观测资料为基础。应用GAMIT/GLOBK软件对数据进行精密解算,获得了青藏块体东北缘1999—2001年相对于鼎新基准站以及欧亚板块的水平运动速度场。结合板块构造以及大地动力学理论,对青藏块体进行了块体的划分,分析了块体间的相互作用,并进一步分析了该地区的地壳水平运动特征,得出了以下结论:(1)GPS技术用于地壳运动的监测是可行的;(2)1999—2001年期间,祁连一海原断裂带GPS运动位移与地质结果十分吻合;(3)印度板块与欧亚板块的碰撞以碰撞后印度大陆继续以50mm/a的速度向北推进是青藏块体东北缘的运动动力;(4)甘青块体西部子块体以北东向挤压运动为主;东部子块体主要表现为以海原断裂带为北边界的顺时针旋转为主;(5)鄂尔多斯块体存在逆时针旋转运动,其旋转速度在块体西南侧的六盘山断裂带一带最大,向北至块体西北部明显减小。
Northeastern margin of Qinghai-Tibet block is an important tectonic movement boundary, and is also a window to research on crustal movement of Qinghai-Tibet Plateau. Through studying the geology structure and tectonic-dynamic characteristics of the test areas, it is of great significance not only for Qinghai-Tibet Plateau itself, but also for correctly realizing and analyzing present-day tectonic deformation and dynamic mechanism in northwest China. Based on the GPS observation data of "the National Natural Science Foundation of China" from 1999 to 2001 and the data of "the Mechanism and Forecast of the Mainland Strong Shock"in 1999,2001,2003 ,on the basis of GAMIT/GLOBK, the horizontal movement rate-field in northeastern margin of Qinghai-Tibet block is obtained, which is relative to the stable Eurasian continent and the Dingxin reference station from 1999 to 2001. Combined with the mechanism of tectonic movement and geodynamics, the main conclusion shows that: ( 1 ) GPS technique is feasible to the survey of the earth's crust movement; (2) the movement displacement of GPS stations in Qilian-Haiyuan repture zone is suitable to geological results; (3)after the collision between the India continent and Eurasian continent, the India continent still keeps on pushing towards north by 50 mm/a; (4)the west part of Gansu- Qinghai block' crustal movement characteristics is dominated by N-S compression and crustal shortening, but the east part rotates clock-wisely as an integral rigid body; (4)the Erdos block may take anti-clockwise rotation driven by Gansu-Qinghai rotating block, and the velocity reaches the maximum in the northwest part of Liupan mountain fault.