利用GPS资料分析天山现今地壳缩短速率

PRESENT CRUSTAL SHORTENING RATE OF TIANSHAN MOUNTAIN WITH GPS DATA

基于中国地壳运动观测网络1999-2013年的GPS区域网资料,并结合中国大陆构造环境监测网络2009--2013年的GPS资料以及境外天山、帕米尔等地区公开发布的最新速度场结果,获取整个天山及邻区较为完整的地壳运动图像,以此研究天山及邻区的现今地壳缩短速率及其空间变化。初步结果表明,自西向东分别横跨帕米尔北缘逆冲断裂带、柯坪塔格逆断裂-褶皱带、库车逆断裂-褶皱带、玛纳斯逆断裂-褶皱带和吐鲁番中央隆起逆断裂-褶皱带的5条GPS速度剖面显示,整个天山南北向的缩短速率由西向东逐渐减小,且剖面内的地壳缩短与变形并非线性分布,其现今地壳缩短速率分别为26、20、12、9和4 mm/a。

GPS data of Crustal Movement Observation Network of China 1999 -2013 ,data of Continental Tec- tonic Environment Monitoring Network of China and other published GPS results were used to calculate a more com- plete horizontal velocity field covering the Tianshan mountain. Present crustal shortening rates and its spatial varia- tion were analyzed using 5 GPS profiles across the Northern-Pamir Thrust Zone, Kepingtage Fold-and-Thrust Belt, Kuche Fold-and-Thrust Belt, Manas Fold-and-Thrust Belt and Turpan Fold-and-Thrust Belt, respectively. Prelimina- ry results demonstrate that the current shortening rates across the entire Tianshan mountain decrease from west to east with nonlinear features, and the current shortening rates in these profiles are about 26 mm/a,20 mm/a, 12 mm/ a,9 mm/a and 4 mm/a, respectively.