Pre-processing of gravity data for 3 D-modelling of the lithospheric underground in the Ligurian Sea

The Ligurian Sea in the western Mediterranean Sea is a back arc basin created through the Apennines Calabrian subduction zone between 30 and 15 Ma ago. The inner geological structure of this basin is not well known. To improve the knowledge about the density distribution of the crust and lithosphere, we performed a pre-processing of gravity data prior to 3D-modelling. This work is related to research in the MB-4D priority and AlpArray project. The satellite gravity gradients from GOCE were directly interpreted and used for filtering of different wavelengths to calculate residual fields, Bouguer and Free-Air anomalies as well as invariants and Euler-Deconvolutions. Furthermore, seismic profiles from several ship-borne surveys as well as OBS measurements of the AlpArray project (LOBSTER, GEOMAR, Kiel) and bathymetry data contributed additional information. The processed data show an unknown anomaly offshore Marseille and the possibility of several underground structures with different densities. The basin itself is characterized by a mass surplus and positive anomalies with a maximum between Corsica and north-west Italia, while the anomalies underneath Corsica and Sardinia are neutral to negative. The derived information will be used in the 3D-modelling software IGMAS+ to execute an inversion for the area and create a model of the mass distribution beneath the Ligurian Sea and its margins.