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

The Tibetan Plateau (TP) is the youngest orogenic belt formed by continental collision on Earth. It a natural laboratory for studying dynamics such as convergence, plate subduction, and plateau uplift. Studying its deep structure has always been hot issue in geological research. Moho interface between crust mantle an important of Earth's circle. Its depth, lateral variation, fine crust-mantle are parameters to reveal process lithospheric TP. study surface generally two methods: seismic gravity. Seismic detection characteristics high precision, but they limited along few cross-sectional lines have cost. not suitable cannot be carried out large area TP; Gravity inversion can obtain large-area affected gravity data methods, accuracy lower than that seismic. In this paper, high-precision field model selected. With constraint observation, Parker-Oldenburg method used, Bott iteration introduced improve efficiency. depth TP obtained, consistent with results. research results show shape complex, variation range large, reaching 60-80 km. sharp contrast adjacent area, there clear sharpness zone at plateau's edge. TP's interior, Moho's buried characterized "two depressions uplifts". south Yarlung Zangbo River (YZR) inclines north, north depresses downward, interpreted Indian subducts below Tibet. depression side Qiangtang block (QTB), up 72 km deep, may related southward subduction lithosphere. uplift QTB same strike Bangong-Nujiang suture (BNS), which reflect compensated low-density low-velocity mantle.