09 February 2012

Antarctic Great Lake Glimpsed

UPDATE (16 February 2012,  12:55 pm):  A few follow-up pieces have been posted in the past couple days (see here and here; Nature News has another story with a great accompanying graphic that depicts the drilling operation in better scale; and a nod to Knight Sci Journalism Tracker for keeping an eye on this and collecting the various stories). They provide more context as to why scientists are interested in studying  subglacial lakes. They also discuss the friendly competition among the Russian group (who, though they are the first team to drill to such a lake, haven't yet sampled the water) and separate British and American teams, each of whom are evidently vying to be the first to actually collect subglacial lake water (all from different lakes, importantly). Though the latter two are getting a much later start on drilling, they plan to use hot water drills that can bore through ice at a much faster clip than the mechanical counterpart used by the Russian team. (I can't say it with certainty, but my guess is that the hot water drill(s) they intend to use are similar to those used in constructing the IceCube neutrino observatory near the South Pole, about which I recently wrote for EARTH Magazine. The IceCube hot water drills could bore 2.5-kilometer-deep holes in just a couple days.)

Regardless of who actually samples Antarctic subglacial lake water first--or perhaps rather, who analyzes and publicizes/publishes their results first--my humble opinion is that all the teams, if they can successfully collect samples, are likely to produce individually important findings. After all, there's no guarantee that all the lakes they're attempting to access feature identical conditions or, if present, identical microbial colonies. Each could provide different insights, contributing to a broader picture of the subglacial aqueous environment. Hopefully, when the time comes, whoever covers the story will bear this in mind.

Original Post:

A team of Russian scientists has managed at long last to finish drilling through 3,769 meters of ice below the East Antarctic Ice Sheet to the surface of a buried freshwater lake dubbed Lake Vostok. The achievement, likened in significance to man’s first flight into space by the head of the Russian Antarctic Expedition, opens for study an ancient massive lake — 250 kilometers long by 50 kilometers at its widest — that is thought to have been covered by ice for the last 15 to 20 million years.

 A RADARSAT image showing the outline of
Lake Vostok (Credit: NASA)
Located at the Vostok research station roughly 1,300 kilometers southeast of the South Pole, the project has been slowed by technological and practical challenges associated with working under such harsh conditions. These include the relatively short austral summer working season, extremely low temperatures and the necessity to keep the bore hole from refreezing around the drill bit.

While the breakthrough culminates the two-decade-long drilling effort, it also raises fresh hopes among scientists who suggest that microbes thought (though not yet known) to be present in the lake could provide a wealth of clues into how life adapted to survive under such conditions. Such microbes, presumably isolated from contact from outside species and conditions, may also provide insight about earlier life on earth as well as glimpses of how life might potentially thrive elsewhere in the solar system. Lake Vostok is seen as a possible analog for bodies of liquid water that exist below the rocky, frozen surfaces of moons including Jupiter’s Europa and Saturn’s Enceladus.

Confirmed by the Expedition on Wednesday — Russia’s official “Science Day” — breakthrough actually occurred this past Sunday. The team knew it was getting close to the lake’s surface when the drill hit liquid water on Saturday. That finding, determined to be a lens of meltwater encased in ice above the lake, set the stage for the final push through the last few meters.
Schematic illustration of Lake Vostok, buried beneath more than 3 kilometers
of glacial ice in East Antarctica. (Credit: Nicolle Rager Fuller / NSF)
When the drill did finally reach the lake, the tremendous release of pressure on the lake’s surface (enough to keep the water liquefied at -3C) forced fresh water an estimated 30 to 40 meters up the bore hole before it froze and replugged the column, the team said. This sudden burst of water, was an anticipated and integral part of efforts to prevent drilling fluids — kerosene and Freon used to keep water in the hole from refreezing around the drill — from reaching and contaminating the lake. Potential contamination, which would complicate efforts to study the Vostok’s pristine water and any life that may be present, has been a major concern for the researchers, as well as source of criticism of the effort.

The success of the contamination prevention efforts, along with whatever mysteries reside in Lake Vostok’s pressurized, pitch-black water, will have to wait a little while longer to be resolved. As the current drilling season winds down, the Russian team plans to leave the frozen plug in place until they can return next season to remove it and begin sampling. They’ll be joined on the continent by separate American and British teams attempting to access others among Antarctica’s 200-plus subglacial lakes.

For further coverage, check out some of the other recent reports:

- NY Times
- Washington Post
- Discovery News
- Science Magazine

On the Awesomeness Scale, drilling to…or rather, potentially being able to study the waters of, Lake Vostok (assuming it is not contaminated in the process) comes it at:

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