An Alternative Method to Moho Topography Recovery from GOCE Gravity Gradients and Its Application in the Tibetan Plateau

Summary Gravity data is widely applied to determine Moho topography due to globally dense and homogeneous gravity observations. Compared with gravity data, gravity gradients can reveal more details of Moho structure, which are more competitive. However, gravity gradients must be transformed into gravity data for common Vening Meinesz-Moritz (VMM) methods, which causes loss of some high-frequency signals. Thus, an improved method by constructing direct function relation between Moho topography and gravity gradients is proposed in this paper. Subsequently, A case study in Tibetan Plateau is conducted using this improved method, and a new Moho topography with higher spatial resolution is determined. More refined tectonic implications can be also revealed from this new Moho topography: (1) the prevailing wavelengths of detected Moho folds are approximately 578 km in the east-west direction and approximately 515 km - 708 km in the north-south direction; (2) two possible lower crustal mass flow channels can be identified clearly according to the traces leaving on Moho topography in the southeastern Tibetan Plateau (3) clearer Moho subsidence, approximately 5 km, can be observed in the central Tarim Basin.