利用中国地壳运动观测网络1999~2006年的观测数据,计算出川滇地块及其邻区内中国地壳运动观测网络中151个监测站在欧亚参考框架下的水平速度,水平运动速度大小在3.44~19.74mm/a之间,平均为11.68mm/a。分析川滇地块及其邻区内测站运动方向的变化得出:川滇地块及其邻区在围绕喜马拉雅东结点作顺时针旋转,川滇地块南北方向上存在明显的挤压,东西方向上存在延伸现象。使用最小二乘法求得川滇地块整体运动速度的大小为13.36mm/a,运动方向为东偏南64.9°,川西北次级块体的运动速度的大小为15.66mm/a.运动的方向为东偏南52.1°。滇中次级块体的运动速度的大小为12.57mm/a,运动方向为东偏南72.4°。
We use the observational data during 1999 to 2006 of the Crustal Movement Observation Network of China (CMONC) to calculate the horizontal movement velocities in the Eurasian reference frame at CMONC 151 stations in the Chuan-Dian block and its adjacent areas. The velocity values range from 3.44 to 19.74 ram/a, and the average velocity is of the value 11.68 mm/a. Analysis of the directions of the velocities leads us to conclude that the Chuan-Dian block and its adjacent areas are in clockwise rotation centered on the eastern Himalayan node, and the Chuan-Dian block is obviously squeezed along the north-south direction, but is stretched along the east-west direction. Using least-squares fitting we obtain the collective velocity of the Chuan-Dian block as 13.36 mm/a in the direction of E 64.9° S, and those of the Northwest-Chuan subblock and Middle-Dian subblock as( 15.66 mm/a, E 52. 1° S)and( 12.57 mm/a, E 72.4°S) , respectively.