Sensitivity of GOCE gravity gradients to crustal thickness and density variations: Case study for the Northeast Atlantic region

Abstract

We discuss the gravity gradient signal measured at the height of the GOCE satellite and compare it with the gravity gradients related to the density contrast between crust and mantle. The gravity gradients are reduced for the topographic masses to emphasize the lithospheric signal. Comparison with the Moho-related signal shows that with a density contrast of 400 kg/m 3, the amplitude of the calculated gradients is almost twice that of the observed field. The differences can only partly be explained by the uncertainty of the crustal thickness, but is clearly related to the applied density contrast. Calculation of the gravity gradients requires a reduced density contrast, which is an important consideration for establishing global models, which might otherwise overestimate crustal thickness.