基于GPS的青藏块体东北缘运动特征分析

Analysis of Movement Characteristics in Northeastern Margin of QinghaiTibet Block Based on GPS

利用2010年、2012年、2014年3期GPS大地测量数据和通过加权平均生成的2010～2014年平均速度场数据,探讨了青藏块体东北缘地区的地壳运动以及形变变化特征。结果表明:①青海省内部呈NE向运动的地壳变化特征,西南最快,约为25.0 mm/a,由西南至西北逐渐减低;②在阿拉善与鄂尔多斯块体的阻挡下,河西走廊与甘东南地区地壳运动接近正E方向,且运动速率随"2010—2012—2014"的时间线依次降低,表明其地壳内部发生了应力积累现象;③青海内部西南至西宁东北方向,主要呈NE向挤压、NW向拉张的变化特征。

In this paper,we used the GPS geodetic data in 2010,2012,2014 and the average velocity field data generated by the weighted average from 2010 to 2014,to discuss the crustal movement and deformation characteristics of the northeastern margin of Qinghai-Tibet block.The results show that①the interior of Qinghai Province presents the crustal change characteristic of NE movement.The southwest is the fastest,about 25.0 mm/a,and decreases gradually from southwest to northwest.②Under the block of Alashan and Ordos block,the direction of crustal movement in Hexi Corridor and southeast of Gansu Province is close to E direction.The movement rate is attenuated with the“2010-2012-2014”time line,which indicating the occurrence of stress accumulation within the crust.③From the interior southwest of Qinghai Province to northeast of Xining,it mainly shows the characteristics of NE extrusion and NW stretching.