An integrated gravity model for Europeʹs crust and upper mantle

We present an integrated gravity model of the European lithosphere based on an analysis of a number of new data-sets, leading to a much higher resolution than provided by previous models. First of all, a recent crustal model (EuCRUST-07) is used to quantify the crustal contribution to the observed gravity field and to identify the effect of mantle heterogeneity. The new gravity field model is based on a combination of satellite (CHAMP and GRACE) and terrestrial data. We also use these data-sets to estimate residual mantle gravity anomalies and residual topography, reflecting the effect of mantle density variations induced by temperature and compositional heterogeneity. The separation of these effects is vital for a proper assessment of mantle structure and evolution. In addition, we utilize a new tomographic model for P- and S-velocity anomalies beneath Europe, which is a-priori corrected for crustal structure using EuCRUST-07. The seismic velocity anomalies were subsequently converted into temperature anomalies using a mineral physics approach. We estimate the effect of temperature variations on the gravity field and subtract it from the total mantle field. The residual fields point to an important role of compositional density anomalies in the upper mantle. A number of key features of the compositional density distribution, so far invisible in seismic tomography data, are detected for the first time.