Vertical crustal deformation velocity and its influencing factors over the Qinghai–Tibet Plateau based on satellite gravity data

Abstract

The uplift of the Qinghai–Tibet Plateau (TP) strongly influences climate change, both regionally and globally. Surface observation data from this region have limited coverage and are difficult to obtain. Consequently, the vertical crustal deformation velocity (VCDV) distribution of the TP is poorly constrained. In this study, the VCDV from the TP was inverted by using data from the gravity recovery and climate experiment (GRACE). We were able to obtain the vertical crustal movement by deducting the hydrological factors, based on the assumption that the gravity signal detected by GRACE is mainly composed of hydrological factors and vertical crustal movement. From the vertical crustal movement, we inverted the distribution of the VCDV across the TP. The results showed that the VCDV of the southern, eastern, and northern TP is ~1.1 mm/a, ~0.5 mm/a, and −0.1 mm/a, respectively, whereas that of the region between the Qilian Haiyuan Fault and the Kunlun Fault is ~0.0 mm/a. These results are consistent with the distribution of crustal deformation, thrust earthquakes and faults, and regional lithospheric activity. The hydrology, crustal thickness, and topographic factors did not change the overall distribution of the VCDV across the TP. The influence of hydrological factors is marked, with the maximum differences being approximately −0.4 mm/a in the northwest and 1.0 mm/a in the central area. The results of this study are significant for understanding the kinematics of the TP.

Keywords

• grace (gravity recovery and climate experiment)
• qinghai–tibet plateau
• crustal vertical deformation
• hydrological factors
• crustal thickness