基于GPS速度场采用RELSM模型分析青藏块体东北缘的形变—应变特征  

Analysis of deformation-strain characteristics of the northeast margin of Qinghai-Tibet Block using the RELSM model based on the GPS velocity field

作　　者：瞿伟[1] 张勤[1] 张冬菊[2] 刘忠 张显云[1] 管建安[1] 

机构地区：[1]长安大学地质工程与测绘学院,陕西710054 [2]湖南工程职业技术学院,湖南410000 [3]西安市勘测院,陕西710048

出　　处：《地球物理学进展》2009年第1期67-74,共8页Progress in Geophysics

基　　金：国家自然科学基金项目(40534021、40672173、40802075)联合资助

摘　　要：利用青藏块体东北缘地区1999~2001年GPS观测获得的地壳水平运动速率场,通过对该地区进行块体划分,将该地区划分为9个块体,应用块体的整体旋转线性应变模型（RELSM）估计了各个块体的旋转与应变参数,以及计算了该地区内143个GPS站点的应变参数,以此分析了该地区的应变场的基本特征.结果表明：①阿拉善块体s较稳定,其旋转角为0.630×10-8,运动速率为0.688 mm/a.②相比其他块体,共和块体旋转角最大达到了6.589×10-8,运动速率达到了7.296 mm/a.③应变高值区主要集中在祁连山断裂,海原断裂等,在这些地区最大剪应变率达到了7.5×10-8、面膨胀率达到了-2.5×10-8、主压应变达到了-6×10-8.The velocity of crustal horizontal movement in the northeast margin of the Qinghai-Tibet block is studied based on GPS data in 1999 and 2001.The area is divided into 9 blocks.The strain and rotation parameters of each block are estimated using the model with rotation in the entire block and linear strain.Then the strain parameters of 104 GPS sites in the area are calculated,and the basic characteristics of the strain field are analyzed.The results indicate that： ① The Alashan block is stable,the rotation reaches the highest value of 0.630×10-8,the velocity of movement reaches the highest value of 0.688 mm/a,②Compare with other blocks,the movement of the Gonghe block is fierce,the rotation reaches the value of 6.589×10-8,the velocity of movement reaches the value of 7.296mm/a.③The high strain zones are concentrated in the Qilianshan and Haiyuan faults,the maximum shear strain rate reaches the value of 7.5×10-8,the surface expansion rate reaches the value of-2.5×10-8,and the principal strain rate reaches the value of-6×10-8.

关 键 词：青藏块体东北缘 整体旋转 线性应变 应变特征 

分 类 号：P313[天文地球—固体地球物理学]