Characteristics Of Crustal Motion And Deformation From GPS Monitoring In The Eastern Qinghai-Tibet Plateau And Adjacent Areas

The eastern Qinghai-Tibet plateau and adjacent areas is the most typical mainland lithosphere distortion zone. The long-term tectonic activity formed a series of great scale active faults that divided plateau crust into blocks in different size and shape. Thus, blocks and faults constitute the main tectonics frame in this zone. The region possessing the complex and variety particularly geological tectonics is key zone to study the deformation of crust, formation and evolution of Qinghai-Tibet plateau.By way of Synthetically computation to the GPS measurement data in GAMIT/GLOBK software, the velocity field on different reference framework has been obtained. According to the velocity field varying in different reference framework and sections, the characteristics of crustal motion has been discussed. At the same time, on the basis of velocity field on the Eurasia reference framework, velocity vector about motion and rotation of blocks as well as active character of faults was gained by means of least squares fitting under the hypotheses of rigid mass. As a result, the mechanism of kinematics, dynamics in Qinghai-Tibet plateau had been discussed.GPS measurement shows that: from east to west, the GPS stations velocities gradually become smaller. In the northern region of Xianshuihe faults, GPS stations velocity is biggest and gradually become smaller toward south and north. The directions of stations movement gradually transfer from NE to SE indicating clockwise vortex feature.Studying to motion of blocks indicates that: The modern velocities of Qaidam, Chuan-Qing, South China, Chuan-Dian, Indian China block movement are 11.95±2.89, 11.86±2.32, 7.83±2.08, 13.18±2.43, 6.45±1.95 mm/a, respectively;Movement directions of blocks are 61.1°, 93.8°, 113.1°, 134.8°, 141.6°,respectively;Rotation velocities of blocks are 2.91, 6.91, 0.38, 2.15,1.45 (×10^-9 rad/a), respectively. Every block rotates clockwise around the Eastern Himalayan syntaxis.Studying to velocities and nature of faults also indicates that: The Longmen...