基于GPS观测数据的云南地区地壳形变特征研究

Research on crustal deformation characteristics in Yunnan area based on GPS observation data

利用1999~2013年间多期GPS观测数据,将云南地区分为5个活动块体,研究区域现今水平运动特征、应变特征以及各块体的运动特征,反演主要活动断裂带的走滑速率。结果表明,区域水平运动具有北强南弱的特征,小江断裂带、红河断裂带对云南地区构造活动具有明显控制作用,改变了断裂带两侧的运动特征;区域应变具有明显的差异,西部以拉张应变为主,东部小江断裂带周边地区拉张和挤压应变均衡且为强应变区,滇东地区应变较小;各块体运动方向与速率存在差异,滇东块体为逆时针旋转,其余块体顺时针旋转;基于块体模型反演的主要断裂带的走滑速率与地质方法获取的走滑速率具有较好的一致性。

Yunnan area are divided into five active blocks based on GPS velocity field during 1999~2013. Horizontal motion characteristics of the Yunnan region, the vectors of five active blocks, the strain field of area are calculated and analyzed and the slip velocities of main faults are presented. The result indicates that the regional horizontal movement has the characteristics of north strong south. The Red River fault and Xiaojiang fault have obvious control effect on Yunnan region activities, changing the movement characteristics of the fault both sides. The regional strain is obviously different. The west is dominated by tensile strain. The tension and compress strain is equilibrium and strong of the eastern Xiaojiang fault zone. The minimum strain is located in east area of Yunnan. The calculation of each block motion direction and velocity has been inconsistent. Yunnan east area goes by anti-clockwise rotation and other blocks clockwise rotation. The slip rate of the main fault zone based on block model inversion is consistent with the geological method.