Moho Depth of the East China Sea Inversed Using Gravity Data

The Moho surface is the interface between the crust and the upper mantle. The study of the Moho surface is helpful to understand the deep tectonic evolution of the Earth. In previous studies, due to the different gravity inversion methods and data used, the depth inversion results of the Moho surface in the East China Sea are uncertain. High-precision terrain and freeair gravity anomaly data are collected in the East China Sea, the Bouguer gravity anomaly is calculated, and the Bouguer gravity anomaly characteristics are analyzed. The gravitational anomaly data of the two profiles, which are Datian Fujian China to Hualian Taiwan China profile and the East China Sea Shelf Basin to the Philippine Basin profile, are extracted. The crust density and the Moho depth of the two profiles are obtained by human-machine interaction forward and inversion fitting technique. The gravity anomaly caused by the Moho surface is extracted by the upward continuation. The Parker-Oldenburg interface inversion is performed under the constraint of the two profiles inversion results and the seismic detection results to obtain the Moho depth in the area. The inversion results show that the Moho depth in the East China Sea has a variation range of -34.4~-8.8 km, whose structure is characterized by two concave and two convex.