Subglacial Lake Vostok in Antarctica (update)

Russian team prepares to penetrate Lake Vostok

The lake, which lies four kilometres below the icy surface of Antarctica, is unique in that it's been completely isolated from the other 150 subglacial lakes on the continent for such a long time. It's also oligotropic, meaning that it's supersaturated with oxygen -- levels of the element are 50 times higher than those found in most typical freshwater lakes.

When the sample can be recovered, however, it's hoped that it'll shed light on extremophiles -- lifeforms that survive in extreme environments. Life in Lake Vostok would need adaptions to the oxygen-rich environment, which could include high concentrations of protective enzymes. The conditions in Lake Vostok are very similar to the conditions on Europa and Enceladus, so could also strengthen the case for extraterrestrial life.

Michael Studinger, Lamont-Doherty Earth Observatory
  Lake Vostok lies in the heart of the Antarctic continent hidden beneath 4 kilometers of ice (see map). As big as Lake Ontario in North America, Lake Vostok is one of the world's biggest freshwater lakes. Lake Vostok has been covered by the vast Antarctic ice sheet for up to 25 million years. The lake was named for the Russian research station that sits above its southern tip - a place where in 1983 the temperature fell below -129°F (-89°C), the coldest ever recorded temperature on Earth. More than 145 lakes have been identified beneath the thick Antarctic ice sheet. Most of these lakes, covered between 3-4 kilometers of ice, are several kilometers long (see map). One of these lakes, Lake Vostok (left), is an order of magnitude larger than all other known lakes (slide show).

LA Times article about my field work at Vostok (lots of pictures)
Flash animation of subglacial Lake Vostok 

Russian polar researchers plan to reach Lake Vostok in this season

“This is the largest lake under an ice layer that has been ever discovered. Undoubtedly, its study will expand our knowledge of biology, the evolution of life under extreme conditions of which we know nothing, geological development of the Antarctic before it was covered with an ice layer. Naturally, this will be an excellent natural material for developing technology and solving problems in engineering and conducting space experiments aimed at searching for life on other planets of the Solar System,” Valery Lukin said.

Russian glaciologists have already made a discovery when they studied bore specimens received during drilling the ice layer over the lake. They discovered the DNA of hemophilic bacteria that usually live in hot-water springs. Their presence in the ice layer witnesses the geothermal activity on the bed of the lake. The main task before the scientists is to collect a sample of water from the lake. It is a specific “capsule from the distant past”, and by opening it, scientists will get an opportunity to reveal a large number of secrets in the history of our planet. They plan to do this very carefully using specially developed technology. Experts assure that there will be no penetration of air from the atmosphere in the relict lake and there is no threat to its ecology.

Update Februari 02 2012

Scientists close to entering Vostok, Antarctica’s biggest subglacial lake - The Washington Post

After drilling for two decades through more than two miles of antarctic ice, Russian scientists are on the verge of entering a vast, dark lake that hasn’t been touched by light for more than 20 million years. 
Scientists are enormously excited about what life-forms might be found there but are equally worried about contaminating the lake with drilling fluids and bacteria, and the potentially explosive “de-gassing” of a body of water that has especially high concentrations of oxygen and nitrogen. 
To prevent a sudden release of gas, the Russian team will not push the drill far into the lake but just deep enough for a limited amount of water — or the slushy ice on the lake’s surface — to flow up the borehole, where it will then freeze. 
Reaching Lake Vostok would represent the first direct contact with what scientists now know is a web of more than 200 subglacial lakes in Antarctica — some of which existed when the continent was connected to Australia and was much warmer. They stay liquid because of heat from the core of the planet.