Letters to Nature
Nature 403, 643-646 (10 February 2000) | doi:10.1038/35001049; Received 20 July 1999; Accepted 26 November 1999
Water exchange between the subglacial Lake Vostok and the overlying ice sheet
Martin J. Siegert1, Ron Kwok2, Christoph Mayer3 and Bryn Hubbard4
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK
- California Institute of Technology, Jet Propulsion Laboratory, Pasadena, California 91109, USA
- Alfred-Wegener-Institute for Polar and Marine Research, Department of Geophysics, Bremerhaven, Germany
- Centre for Glaciology, Institute of Geography and Earth Sciences, University of Wales, Aberystwyth SY23 3DB, UK
Correspondence to: Martin J. Siegert1 Correspondence and requests for materials should be addressed to M.J.S. (e-mail: Email: m.j.siegert@bristol.ac.uk).
It has now been known for several years that a 200-km-long lake, called Lake Vostok, lies beneath the ice sheet on which sits Vostok Station in Antarctica1, 2, 3, 4, 5. The conditions at the base of the ice sheet above this subglacial lake can provide information about the environment within the lake, including the likelihood that it supports life2. Here we present an analysis of the ice-sheet structure from airborne 60-MHz radar studies, which indicates that distinct zones of basal ice loss and accretion occur at the ice–water interface. Subglacial melting and net ice loss occur in the north of the lake and across its 200-km-long western margin, whereas about 150 m of ice is gained by subglacial freezing in the south. This indicates that significant quantities of water are exchanged between the base of the ice sheet and the lake waters, which will enrich the lake with gas hydrates, cause sediment deposition and encourage circulation of the lake water.