Calculating ice discharge at the land-sea interface relies on the correct estimation of ice thicknesses along  the grounding line. This parameter can derive from radar sounding results or measured knowing the surface elevation, the mean ice and water densities and assuming  the floating ice in hydrostatic equilibrium. To provide a localized estimation of the mean ice densities and a more detailed mapping of ice thicknesses at and seaward of the grounding line, we integrate ICESat elevation data with radar-derived ice thicknesses. We analyse the glaciers both spatially and statistically using GIS technologies, to check the possible influence of geomorphological and glaciological factors on the empirical relationships between ice elevation and thickness. The main conclusion is that ice densities differ locally as a function of the ice types, allowing to detect three major glaciological regions in the Nansen Ice Sheet characterised by firn-covered glacier ice, blue ice and mixed marine-meteoric ice.