Inversion of airborne gravity data acquired over subglacial lakes in East Antarctica

Airborne gravity data have been acquired over the two largest subglacial lakes in East Antarctica. 2D inversion of these data was performed for several fixed values of density contrast in order to estimate bathymetry and sediment thickness. For Lake Vostok the best agreement between profiles derived from gravity inversion and seismic soundings is achieved for densities 2.55 g cm(-3) for host rock and 1.85 g cm(-3) for sediment. The result shows a topographic rise of the lake bottom dividing the lake into two sub-basins. Our inversion results suggest that water thickness in Lake Concordia does not exceed 200 m for all possible density contrasts between ice/water and surrounding rock; the sediment layer cannot be resolved.