High‐Precision Vertical Movement and Three‐Dimensional Deformation Pattern of the Tibetan Plateau
High‐Precision Vertical Movement and Three‐Dimensional Deformation Pattern of the Tibetan Plateau
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DOI：
10.1029/2021jb023202
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发表时间：
2022-03
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通讯作者：
Yanqiang Wu;Zhijiang Zheng;J. Nie;Liu Chang;Guangli Su;Haiquan Yin;Hongbao Liang;Y. Pang
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作者：
Yanqiang Wu;Zhijiang Zheng;J. Nie;Liu Chang;Guangli Su;Haiquan Yin;Hongbao Liang;Y. Pang
青藏高原海拔高，断裂系统复杂。高精度的垂直运动数据可以为理解青藏高原的增长和扩张提供重要的约束。我们收集了约11.6万km的水准测量数据、21个连续GNSS数据集及其连接测量数据，并采用Helmert联合平差方法对这些数据进行联合处理，获得了青藏高原及其周边地区的高精度垂直速度场。主要结果如下：（a）高原南缘、东北缘和东南缘以垂直隆升为主，隆升速率分别为2.0-3.0、1.0-3.8和1.0-2.0 mm/a：（B）甘孜断裂带南段沿着有明显的沉降，垂直速率为-3.3 ~-0.5 mm/a;（c）速度剖面显示，青藏高原不同地区的垂直形变各不相同，主要由大型走滑和逆冲断层（如昆仑、甘孜和龙门山断层）提供。大部分的地表抬升是由青藏高原内部的地壳缩短所调节的;藏东地区垂直速率的突变和藏南地区广泛分布的地表沉降是地壳流动和重力塌陷的结果。总体而言，青藏高原具有持续变形的特点，复杂的构造过程适应了大的空间变化。
The Tibetan Plateau is characterized by high elevation and complex fault systems. High‐precision vertical movement data can provide important constraints for understanding the growth and expansion of the Tibetan Plateau. We collected approximately 116,000 km of leveling data, 21 continuous GNSS data sets, and their connecting surveying data; we jointly processed these data using a Helmert joint adjustment method to acquire the high‐precision vertical velocity field of the Tibetan Plateau and its surrounding areas. The primary results are as follows: (a) Vertical uplift is dominant on the southern, northeastern, and southeastern margins of the plateau, with uplift rate ranges of 2.0–3.0, 1.0–3.8, and 1.0–2.0 mm/yr, respectively; (b) Conspicuous subsidence is located along the southern portion of the Ganzi fault, with vertical rates ranging from −3.3 to −0.5 mm/yr; (c) Velocity profiles show that vertical deformation varies in different parts of the Tibetan Plateau, which is mostly accommodated by large strike‐slip and thrust faults, such as the Kunlun, Ganzi, and Longmenshan faults. Most of the surface uplift is accommodated by crustal shortening in the interior of the Tibetan Plateau; abrupt changes in vertical rates in eastern Tibet and the widely distributed surface subsidence of southeastern Tibet are consequences of crustal flow and gravitational collapse. Overall, the Tibetan Plateau is characterized by continuous deformation, with large spatial variations accommodated by complicated tectonic processes.