川滇块体东边界主要断裂带现今运动特征分析
Current Movement Characteristics of Major Faults in the East Boundary of Sichuan-Yunnan Block

基于2009年以来的GPS观测数据，利用块体模型和GPS剖面方法分别计算川滇块体东边界主要断裂带的滑动速度，并结合跨断裂带的区域应变时间序列分析断裂带现今的运动特征。结果表明：从速度场变化来看，2013-2015期的速度场在川滇块体东北部有东向增加的微弱变化；从滑动速率结果来看，鲜水河北段的左旋走滑运动有所增强，拉张运动有所增加；小江断裂带的左旋走滑运动普遍有微弱的增强；从去掉线性的区域应变时间序列结果来看，小江断裂带南段主张应变在2014年底出现了趋势性转折，值得进一步关注。
The Sichuan-Yunnan region located on the southeast margin of the Qinghai-Tibet plateau and east of the stable south China block, has a very complex tectonic setting. A lot of experience was accumulated by using GPS observation data in order to analyze the movement characteristics of the main faults. Based on the GPS observation data in east boundary of the Sichuan-Yunnan block during 2009-2015 and the slip rates of the major faults in the study area were calculated by using the block model and GPS profile method, respectively. Additionally, the recent movement characteristics of the faults were analyzed by combining them with the time series of the regional strain across the fault zone. The results show that, from the GPS perspective of velocity change, the velocity field during the period 2013-2015 in the north-east part of the Sichuan-Yunnan block exhibited an eastbound increase with a very slight change. From the perspective of the slip rate, the sinistral strike-slip movement and the tensile movement in the northern part of the Xianshuihe fault increased. The left-lateral strike-slip movement in the Xiaojiang fault was, in general, slightly enhanced. From the perspective of the regional strain time series after removing the linear trend, the principal tension strain of the southern section of the Xiaojiang fault exhibited a trend reversal at the end of 2014, and this should be investigated further in future work.