青藏高原东南缘现今地壳运动速度场分析

利用“中国大陆构造环境监测网络”1999~2015年GPS观测数据，获得ITRF2014框架下青藏高原东南缘滇西菱形块体区域测站的水平速度场。结果表明，相对于欧亚板块固定，该区域现今地壳运动方向总体上呈现由东向到东南向、再到南西向的顺时针旋转分布；从运动速度大小分布来看，则呈现菱形块体中间大两侧小、由北向南逐渐减弱的态势。采用三角形法计算得到的区域最大剪应变率分布表明，最大剪应变率高值区基本上都集中在滇西菱形块体的东西边界上，主应变方向主要表现为东西向压缩和南北向拉伸。东侧断裂带主要呈现左旋运动，西侧断裂带主要呈现右旋运动，与基于地质调查的断层新生代构造运动基本一致。

Analysis of Current Crustal Movement Velocity Field of South-Eastern Tibetan Plateau

In this paper, using GPS observations of crustal movement observation network of China(CMONOC) from 1999 to 2015, we obtain the horizontal velocity field of the western Yunnan rhombic block, which is located in southeast of the Qinghai-Tibet plateau. It turns out that direction of the present-day crustal movement of this area, relative to the Eurasia plate, generally shows a clockwise rotation from east to southeast and from southeast to southwest. The magnitude of velocity in this research area shows that the value of velocity in the middle of rhombic block is greater than that on the sides, and the value shows a reducing tendency from north to south. The maximum shear strain rate of this area, calculated by triangle method, shows that higher valuesare concentrated in the east and west border of rhombic block. The direction of principal strain shows the state of east-west compression and north-south stretch. The fault zone on the east side of western Yunnan rhombic block presents sinistral movement and the fault zone on the west side presents right-lateral movement, which is identical to the results from geological survey.