以1999-2011年西藏、青海地区GPS区域站观测结果为基础,利用欧拉模型、多核函数法和球面应变模型,计算了青藏高原中南部地区区域整体无旋转基准下的运动场和应变场,对汶川地震前后两个时段的结果进行了对比分析.结果显示:青藏高原中南部地区多年来的总体运动特征未发生较大改变,整体以东西向拉张运动为主,中部以南北向的压缩变形为主,并且由南向北逐渐向两侧分异.北向运动主要集中在喜马拉雅块体和拉萨块体的中部,在拉萨块体的北部,北向运动已明显减弱.而在拉萨块体与羌塘块体分界处,区域运动方向已经明显转为东西向运动.汶川地震以后研究区东向运动有一定加强.%Based on the GPS regional station observations from 1999-2011 in the Tibet and Qinghai areas,using Euler model,multi-kernel function method and the spherical strain model,the regional No-Net-Rotation frame motion field and strains are calculated in the central and southern Qinghai-Tibet Plateau,and compares and analyses the results before and after the Wenchuan earthquake.The results show:The general movement features of the study area did not change greatly over the years.The crust motion is generally the East-West tensive movement on the whole.In the central area,the crust motion is primarily the North-South compressive movement,and disparts from south to north gradually.The north movement is mainly concentrated in the central Himalaya block and Lhasa block,and obviously weakened in the north Lhasa block.While in boundary of the Lhasa block and Qiangtang block,the motion changes obviously as the East-West movement.The eastward motion is strengthened in the study area after the Wenchuan earthquake.
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