Advancements in satellite gravity gradient data for crustal studies

In recent years, global gravity models, both based only on satellite data and from combination with terrestrial data, are increasingly available and particularly useful to construct regional models before more local interpretations on the exploration scale are carried out. Often it is challenging to distinguish clearly between near-surface and regional or even subcrustal signals in the gravity field. Applying simple techniques like wavelength-filtering might lead to an incorrect estimate of the regional and residual field, which may significantly alter estimates of the thickness of sedimentary basins or the size of mineral deposits. An alternative is to use satellite gravity gradients to establish the regional components before studying local geology. Sampietro (2011) presented a global Mohorovicic discontinuity (Moho) depth map, which sparked a discussion about the validity of such results. Especially the question remains about whether crustal thickness estimates based on Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite data have a higher accuracy than models based on global gravity models or terrestrial data. For example, the density contrast between crust and mantle remains a main factor of uncertainty.