青藏高原现今高分辨率地壳运动特征

High-Resolution Characteristics of Recent Crustal Movement in Qinghai-Tibet Plateau

利用GPS资料,采用最小二乘配置和小波技术分析了青藏高原的地壳运动特征,对该区地壳运动强度和涡旋运动进行了定量分析.结果显示,青藏高原地壳运动强度沿喀喇昆仑断裂、玛尼-玉树-鲜水河-小江的弧型构造带,自西向东递减.川滇菱形块体显示出北强南弱、西强东弱的特点,东边界形成明显的分界线,而西边界并不明显;青藏高原存在3个涡旋分区:顺时针旋转的拉萨、羌塘及川滇中西部地区,亚东-谷露断裂以东的区域为其涡旋高值区;逆时针旋转的柴达木地块及其以北的地区,西昆仑断裂与阿尔金断裂之间为其高值区;逆时针旋转的青藏高原与华南地块的边界带,龙门山与安宁河的拐角处为其高值区.

Characteristics of current crustal movement in Qinghai-Tibet Plateau were analyzed with least square collusion and wavelet using GPS data, and crustal movement strength and vortex movement were analyzed quantitatively. The conclusions are drawn as follows： The crustal movement strength in Qinghai-Tibet Plateau decreases from west to east along arc tectonic ruptures formed by Kala-Kunlun, Mani, Yushu, Xianshuihe and Xiaojiang faults. The crustal movement strengths in north and west are stronger than those of south and east in the Sichuan-Yunnan block, of which east boundaries are obvious, and west boundaries are not. There are three vortex zones in Qinghai-Tibet Plateau. Firstly, Lhasa, Qiangtang, and mid-west of Sichuan-Yunnan region clockwisely rotate, and areas to east of Yadong-Gulu are high-value areas. Secondly, Qaidam block and that to its north counterclockwisely rotate, and high-value areas are between West Kunlun and AlturL Thirdly, the boundaries of Qinghai-Tibet Plateau and southern China block counterclockwisely rotate, and high-value areas are in the corner of Longmenshan and Anninghe.