基于块体模型的青藏高原及邻区地壳三维构造形变分析

Analysis on 3D crustal deformation of Qinghai-Tibet Plateau and its surrounding areas based on block model

2020珠峰高程测量,获得了丰富的青藏高原及邻区的GNSS监测数据。本文收集了陆态网、尼泊尔CORS网GNSS长期观测数据,计算了该地区20多年GNSS三维速度场,利用GRACE模型精化了垂直速度场,通过活动块体模型,从地壳运动、块体运动与应变、块体相对运动等多个方面研究了青藏高原地壳运动与构造形变特征。研究表明,青藏高原地壳形变具有明显的分区特征,南北向收缩主要表现在拉萨块体,东西向伸展主要表现在巴颜喀拉块体,中部羌塘块体没有明显水平挤压,但地壳隆升速率最大,且水平面积有扩大趋势,本文研究能够在一定程度上支持青藏高原地壳增厚学说。

2020 height measurement of Mount Qomolangma has obtained rich GNSS monitoring data of Qinghai-Tibet Plateau and its surrounding areas.This paper collected the long-term observation data of GNSS from CMONOC and Nepal CORS network,got the 3D velocity field of GNSS for more than 20 years,and used GRACE model to eliminate the influence of non-tectonic load deformation and improve the accuracy of vertical velocity field.Then,it studied the characteristics of crustal movement and tectonic deformation of the Qinghai-Tibet Plateau from many aspects such as crustal movement,block movement and strain,block relative movement through the block model.The results show that the crustal deformation of the Qinghai-Tibet Plateau has obvious zoning characteristics.The north-south contraction is mainly manifested in the Lasa block,the east-west extension is mainly manifested in the Bayankala block,and the Qiangtang block has no obvious horizontal compression,but the crustal uplift rate is the largest,and the horizontal area tends to expand.The results of this paper can support the crustal thickening theory of the Qinghai-Tibet Plateau.