Moho depth inversion in the Tibetan Plateau from high-precision gravity data  

作　　者：HuiYou He Jian Fang HePing Sun DongMei Guo ZhiXin Xue Jing Hou 

机构地区：[1]State Key Laboratory of Geodesy and Earth’s Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430077,China [2]Wuhan Gravitation and Solid Earth Tides National Observation and Research Station,Wuhan 430071,China [3]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Earth and Planetary Physics》2023年第4期487-498,共12页地球与行星物理（英文版）

基　　金：the National Natural Science Foundation of China(Grant No.42192535);the Open Fund of Wuhan,Gravitation and Solid Earth Tides,National Observation and Research Station(No.WHYWZ202204);the Strategic Pioneer Science and Technology Special Project of the Chinese Academy of Sciences(Grant No.XDB18010304);the National Natural Science Foundation of China(Grant No.41874096).

摘　　要：The Tibetan Plateau(TP)is the youngest orogenic belt resulting from a continental collision on the Earth.It is a natural laboratory for studying continental dynamics,such as continental convergence,plate subduction,and plateau uplift.Investigating the deep structure of the TP has always been a popular issue in geological research.The Moho is the boundary between the crust and the mantle and therefore plays a crucial role in the Earth’s structure.Parameters such as depth and lateral variation,as well as the fine structure of the crust-mantle interface,reveal the lithospheric dynamics in the TP.Two methods are generally employed to study the Moho surface:seismic detection and gravity inversion.Seismic detection has the characteristic of high precision,but it is limited to a few cross-sectional lines and is quite costly.It is not suitable for and cannot be carried out over a large area of the TP.The Moho depth over a large area can be obtained through gravity inversion,but this method is affected by the nature of gravity data,and the accuracy of the inversion method is lower than that of seismic detection.In this work,a high-precision gravity field model was selected.The Parker-Oldenburg interface inversion method was used,within the constraints of seismic observations,and the Bott iteration method was introduced to enhance the inversion efficiency.The Moho depth in the TP was obtained with high precision,consistent with the seismic detection results.The research results showed that the shape of the Moho in the TP is complex and the variation range is large,reaching 60−80 km.In contrast with the adjacent area,a clear zone of sharp variation appears at the edge of the plateau.In the interior of the TP,the buried depth of the Moho is characterized by two depressions and two uplifts.To the south of the Yarlung Zangbo River,the Moho inclines to the north,and to the north,the Moho depresses downward,which was interpreted as the Indian plate subducting to the north below Tibet.The Moho depression on the north side of

关 键 词：GRAVITY MOHO Tibetan Plateau SGG-UGM-2(2159-order high-precision gravity field model) 

分 类 号：P631.1[天文地球—地质矿产勘探] P542[天文地球—地质学]