Ice formation in subglacial Lake Vostok, Central Antarctica

The investigation of chemical and isotopic properties in the lake ice from the Vostok ice core gives clues to the mechanisms involved in ice formation within the lake. A small lake water salinity can be reasonably deduced fro m the chemical data. Possible implications for the water circulation of Lak e Vostok are developed. The characteristics of the isotopic composition of the lake ice indicate that ice formation in Lake Vostok occurred by frazil ice crystal generation due to supercooling as a consequence of rising water s and a possible contrast in water salinity. Subsequent consolidation of th e developed loose ice crystals results in the accretion of ice to the ceili ng of the lake. (C) 2000 Elsevier Science B.V. All rights reserved.