Evidence of 14 New Subglacial Lakes in the Dome C-Vostok Area

Abstract

In the last few years subglacial lakes have been of great interest to the scientific community for various reasons. The lakes could be an unknown extreme habitat, which have been isolated from the terrestrial biosphere for a long time. They may have formed before the ice sheet and could perhaps reveal environmental conditions prior to its formation. Lastly, they may play a role in the current dynamics of the ice sheet. Strong radar reflections from the base of the ice sheet can generally be ascribed to either water-saturated basal sediments or subglacial lakes (Oswald & Robin, 1973). Based on radar data alone, the identification of lakes is possible if other features are present: flat and quite horizontal reflectors with nearly constant echo intensity and sharp edges similar to the margins of a catchment basin (Siegert et al., 1996; Siegert & Ridley, 1998; German & Siegert, 1999; Siegert, 2000; Tabacco et al., 2002). Subglacial lakes can be expressed in the overlying ice sheet as extremely flat surfaces with respect to the surrounding slopes (Ridley et al., 1993; Kapitsa et &l996 ; Siegert & Ridley,1998; Tabacco et al., 2002). To date, about 70 lakes have been discovered in all of Antarctica (Siegert et al.,1996); 21 of these are located in the Dome C-Vostok region.