用GPS资料揭示现今中国大陆构造运动

TECTONIC MOVEMENT OF CHINESE MAINLAND REVEALED FROM GPS DATA

利用GIPSY软件计算分析了1999年、2001年以及2004年中国地壳运动观测网络1 000多个台站的GPS数据(包括区域网、基本网和基准网数据),得到了中国大陆地壳运动速度场(其中绝大多数测站速度分量的估值精度优于2 mm/a,基准站精度较高,优于1.5 mm/a)。同时结合蒙古、缅甸、印度、尼泊尔和喜马拉雅等周边地区多年的GPS观测资料,采用连续介质假设条件下的数值模拟方法,得到了中国大陆的整体水平位移速度,模拟结果还显示出中国大陆构造运动的分区特征,揭示了现阶段青藏高原向东挤出运动及其内部变形在调节印度-欧亚板块汇聚中发挥的主导作用。

We have analyzed GPS observations in 1999,2001 and 2004 from more than one thousand stations in the Crustal Movement Observation Network of China including fiducial network, basis networks, regional network by GIPSY software ,and calculated the crustal movement velocity field of Chinese mainland with the accuracy better than 2 mm/a of most sites and better than 1.5 mm/a at fiducial sites. Assuming that the contemporary tectonic activity can be treated as continuous, we have combined the GPS observations of areas around China, including Mongolia, Myanmar, India, Nepal and Himalayas, using a bicubic spline interpolation function to simulate the integral horizontal velocity, which shows the regional characteristics of tectonic movement of Chinese mainland,and reveal that the eastwards extrusion and inte- rior deformation of Qinghai-Tibet plateau play dominant action in accommodating the collision of India Plate with Eurasia Plate at present day.