Density heterogeneity of the lithospheric mantle - Testing the method for Siberia, North America and Europe

We present a method for regional lithospheric mantle density structure determination. The residual mantle gravity anomalies are based on gravity data derived from the GOCE geopotential model with crustal correction to the gravity field calculated from a number of regional crustal models. Calculated mantle gravity anomalies are converted to mantle density anomalies. Since the depth distribution of the gravitational sources is a priori unknown and cannot be uniquely determined from gravity data alone, independent information from seismic, thermal, and petrological studies are used to constrain the lithospheric thickness and the depth distribution of anomalous masses [1]. We calculate the lithospheric density distribution after removing the deep mantle contribution to the gravity field by wavelength filtering and assuming that the contribution of the convecting asthenosphere to the mantle gravity is insignificant. Uncertainties in the residual upper (lithospheric) mantle gravity anomalies result from uncertainties in the crustal structure and the velocity-density conversion. We apply our analysis to three test areas; Siberia (for which new regional crustal models have recently become available [2]), Europe and for North America.