Gravity Gradient Inversion of Gravity Field and Steady‐State Ocean Circulation Explorer Satellite Data for the Lithospheric Density Structure in the Qinghai‐Tibet Plateau Region and the Surrounding Regions

Abstract

AbstractThe continuous uplift and evolution of the Qinghai‐Tibet Plateau region (TPR) represents one of the most important Cenozoic geological events on Earth. The deformation mechanism of the lithosphere in the TPR is still under debate. Relevant viewpoints can be informed by investigations of the lithospheric density structure in the Qinghai‐Tibet Plateau and surrounding regions (TP‐SRs). Considering investigating the fine‐scale lithospheric density structure of the large‐scale areas, the GOCE satellite data covering entire TP‐SRs are used in this study. GOCE gravity gradient data are first subjected to several corrections. Then, based on gravity gradient curvature (SI) calculation complemented with the preconditioned conjugate gradient algorithm, the distribution of SI and the lithospheric density structure at depths of 0–80 km in TP‐SRs are obtained. The effects of temperature differences and material composition on the lithospheric density distribution are further distinguished. The results show that in the crust, the density anomalies in the TPR are blocked by the surrounding hard blocks. In the upper mantle, the distribution of the density anomalies in the TPR is predominantly affected by the northward subduction of the Indian Plate and the high heat flux environment. The Longmen Shan Thrust Belt is found to have penetrated the lower crust but has not reached the depth of the upper mantle. The density anomalies in the basins on the northern side of the TPR exhibit features indicative of independent stable blocks.