A Gravity Inversion Strategy for Accurate Resolution of Intra-Crustal Structures Accounting for Moho Relief

The integration of gravity and topography data is a primary approach for investigating the crustal properties of terrestrial planets. While previous studies have extensively employed admittance analysis and gravity field models to estimate parameters like effective elastic thickness () and load density—particularly for Martian volcanic provinces—these methods often fail to resolve the detailed 3D distribution of subsurface structures.

Three-dimensional gravity inversion offers a powerful alternative for characterizing volcanic plumbing systems. However, existing applications often neglect the significant gravitational contribution of the crust-mantle interface (Moho relief) to Bouguer anomalies. Furthermore, as the spatial scale of investigation increases, the curvature of the planetary surface must be rigorously accounted for to avoid modeling errors.

To address these challenges, this study proposes an advanced 3D gravity inversion framework. We integrate the high-resolution MRO120F gravity model with recent crustal thickness models to isolate "residual" Bouguer anomalies that specifically reflect intra-crustal density variations. By incorporating spherical coordinate corrections and stripping the gravitational effects of the Moho, we reconstruct the 3D subsurface geological structure of a representative Martian volcanic region. Our results demonstrate that this refined inversion strategy significantly improves the resolution of magmatic features, providing new insights into the magmatic origins and evolutionary mechanisms of planetary volcanoes. In the future, we plan to apply this method to the geological structure analysis of the Tianwen landing area, providing a reference for subsequent Mars research plans. In the future, we plan to apply this method to the geological structure analysis of the Tianwen landing area, providing a reference for subsequent Mars research plans.