Multilayer Densities of the Crust and Upper Mantle in the South China Sea Using Gravity Multiscale Analysis

The South China Sea (SCS) is the result of several major tectonic plates’ interaction, and a more detailed density structure essential to study evolution marginal seas. In past decades, studies in SCS have focused on profiles, lateral has been less mentioned by scholars. Previously, gravity data used many times SCS; this can satisfy demands large-scale studies, but point that cannot be ignored method certain deficiencies vertical resolution. Therefore, paper applies multiscale analysis isolate Bouguer anomaly signal SCS, then uses power spectrum estimate mean field source depth, which corresponds decomposed signal. On basis, we modeled stratified crustal upper mantle structures determine distribution at different depths. results show following: (1) There are two large high-density materials SCS. first one located near Yinggehai Basin, where depth ranges from 42.4 km 71.2 km, with diameter nearly 220 km; second northwest sub-basin, 106.8 128.8 probably part Paleo-Pacific remnant (2) proto subduction zone northwestern Sulu northeast–southwest trend.