【摘要】 基于1999～2007年和2007～2009年的GPS站点观测数据计算的速度场,分析了青藏亚板块的运动特征.利用块体(旋转与线性应变)弹性运动公式计算可可西里—巴颜喀拉块体和羌唐块体的应变率、可可西里—玉树断裂带的运动速度和应变率,研究了玉树7.1级地震前的形变应变特征.结果表明:可可西里—巴颜喀拉块体处于青藏亚板块运动场的差异变化较大的地带;1999～2007年可可西里—玉树断裂带左旋走滑运动为主;2007～2009年可可西里—玉树断裂带在玉树以西压应变率显著增强,利于应力积累,以东为右旋为主,玉树附近地段成为不同应变应力状态的转换地带——不稳定地段.可可西里—玉树断裂带的活动为7.1级地震孕育提供了能量积累和发震条件.更多还原

【Abstract】 Base on the velocity field calculated from the GPS data from 1999 to 2007 and from 2007 to 2009,the movement characteristics of Qinghai-Tibet subplates were studied.The strain rate of Hoh Xil-Bayan Har block and the Qiangtang block,the velocity and the strain rate of Hoh Xil-Yushu fault zone were calculated by the block(rotation and linear stain)elastic movement formula.The deformation strain before M_S7.1 Yushu earthquake has been studied.The result shows that between 1999 and 2007 the activity in Yushu fault zone was mostly left-lateral strike slip.Between 2007 and 2009,the strain rate of Hoh Xil-Yushu fault zone in the western part of Yushu has increased remarkably,which is favorable to stress accumulation.The Hoh Xil-Yushu fault zone in the eastern part of Yushu showed mainly right-lateral strike slip activity.Yushu was a transitional area between different kinds of active strain and became an unstable zone.The activity in Hoh Xil-Yushu fault zone became a condition of the M_S7.1 earthquake,in the meantime,accumulated energy for the earthquake.更多还原