A hidden Antarctic lake may have been sealed for millions of years
Lake Vostok, largest of Antarctica’s 675 known subglacial lakes and sixteenth worldwide by area, lies beneath Russia’s Vostok Station under 3,488 metres of East Antarctic ice. Climate layers in the ice span 400,000 years, while the water below may have sat apart far longer.
The station, and so the lake, take their name from the Vostok, a 900-ton sloop sailed by Admiral Fabian von Bellingshausen, and the word means East. The site sits near the southern Pole of Cold: on 21 July 1983 the station logged −89 °C, the lowest natural temperature ever measured on Earth. The lake water itself stays liquid at about −3 °C because of the crushing weight above it.
Peter Kropotkin had already argued in the nineteenth century that ice-sheet pressure could melt basal water. Andrey Kapitsa’s seismic soundings of 1959 and 1964 hinted at liquid water, British airborne radar in the early 1970s strengthened the case, and in 1991 J. P. Ridley of University College London turned the ERS-1 satellite toward the ice cap’s centre and confirmed it. On 5 February 2012 Russian drillers finished a 3,768-metre core and reached the lake surface; lake ice was recovered on 10 January 2013 even as borehole fluids mixed with rising water.
The basin is a tectonic trough about 50 kilometres wide, set in a broad collision zone between the buried Gamburtsev Mountains and the Dome C region. Antarctica was not always frozen: about 66 million years ago, still joined to Australia, it was tropical to subtropical and home to marsupials, after Africa had split away around 160 million years ago and India around 125 million.
Astrobiologists compare the sealed habitat to Europa’s and Enceladus’s ice-covered oceans. Estimates suggest the water body itself could have stayed cut off for roughly fifteen to twenty-five million years. A central island was mapped in 2005; nearby 90 Degrees East and Sovetskaya lakes may share subglacial river links.
Source: Lake Vostok
