Detaset for Global Mantle Gravity Gradient Disturbances and Their Implications on Mantle Dynamics

The variation in mantle density is crucial for understanding mantle structure and dynamics, as well as elucidating the mechanism driving crustal tectonic movements and surface deformation. Mantle gravity and its gradient disturbances serve as primary data for estimating mantle density heterogeneity. However, these gravity signals are masked by the highly heterogeneous crust. In this study, we utilize the latest crustal model, Earth Crustal Model 1 (ECM1), and a spatial-domain three-dimensional gravity gradient forward modeling method to calculate the gravity gradient disturbances of the crustal layers. By removing the crustal response from the global gravity gradient data observed by the GOCE satellite, we obtain the new global mantle gravity gradient disturbances (MGGDs). A detailed analysis of mid-ocean ridges (MORs), cratons, and subduction zones yields the following insights: (1) At MORs, the MGGDs highlight the upwelling of hot mantle materials and the heated, thinned lithosphere beneath the MORs. In Large Igneous Provinces (LIPs), the vertical MGGDs are significantly negative, indicating the low-density composition caused by hot spot activities. (2) Most cratons exhibit high-density anomalies due to their cold, thick lithospheric roots. However, some ancient Archean cratons display low-density anomalies because the compositional changes resulting from the high depletion of lithospheric roots may outweigh the effects of low temperatures on density. (3) At subduction zones, MGGDs reveal subducting plates and the induced mantle convection. High-density subducting plates typically cause positive vertical MGGDs, whereas melting and up mantle flow associated with plate subduction often result in negative vertical gravity gradient disturbances near subduction zones.