Monday, February 13, 2012

GeoMedia: Russian Scientists reach Lake Vostok

Recently a team of scientists from Russia, working in Antarctica, broke some new scientific ground...or should I say ice? For the past few years the researchers have been drilling into the Antarctic ice in an effort to reach the lake trapped 3-4 km beneath it called Lake Vostok. Lake Vostok is a massive subglacial lake that is liquid despite the fact that it is trapped beneath the Antarctic Ice Sheet. It is kept from freezing by a combination of the immense pressure exerted by the ice sheet above (350 atmospheres) and geothermal heat from below, which combined keep the lake at -3 degrees. It is 15,000 square kilometres in size and up to 800 metres deep, making it one of the largest lakes in the world.

LA Times

However, while subglacial lakes such as this are a rarity compared to the usual article, it is one of ~300 others in Antarctica that have been detected using geophysical means such as seismic testing and gravity surveys and have been completely isolated from the rest of the world for...well, we don't know quite how long, but at least 1,000,000 years.

Map of Antarctica showing Lake Vostok and other subglacial lakes. (Source: BBC)
So the obvious question to be asked here is why would we want to drill into a pristine lake that has never seen the effect of human kind? Well, there is a lot that we can learn from sampling such a rare place. One of the main reasons that I have seen discussed in the media is the potential for finding all sorts of funky new microorganisms that have never been discovered before an have evolved over the last million years in complete darkness and isolation. Sampling such an incredibly isolated environment will further allow us to understand how the process of evolution occurs on our own planet, but also possibly on others where we can only dream/hope that life exists. For example, the ice covered moon of Jupiter called Europa, which is believed to have a liquid ocean beneath a hard icy shell, could possibly support life similar to that in Lake Vostok. In fact, sampling of the ice above the lake has yielded a few bacteria trapped within it, which are believed to have come from the lake itself as the ice directly above the lake is lake water that has frozen onto the bottom of the glacier.

Siegert, M.J. et al. Physical, chemical and biological processes in Lake Vostok and other Antarctic subglacial lakes. Nature 414, 603-609 (2001)

Another reason that we are interested in this lake is a little closer to home than extraterrestrial bacteria. Drilling into the lake gives us the ability to sample lake sediments and understand the hydrogeology of Antarctica, neither of which we have ever had an opportunity to do. The opportunity to study ancient lake sediments is a particularly valuable one as the sediment residing at the bottom of Lake Vostok has lain undisturbed for the past million years making it one of the oldest lake sediment records that I have heard of and certainly the most undisturbed. The sediments will give us clues to the past climate conditions on Antarctica and changes over time allowing us to understand the climate record much further back in time than we do presently as well as extrapolate to the very ancient past and future.

Of course, drilling 3 kilometres down into Antarctica is not without its environmental concerns. The primary ones being will the drilling contaminate the lake? This was a very real, and extremely undesirable, possibility as in order to keep the drill going and the hole open the team was forced to inject fluids. However, the Russian team has assured the scientific community that this outcome has been avoided and that the lake has not been contaminated. 

That is all for now. Feel free to post any comments or questions.



Siegert, M.J. et al. Physical, chemical and biological processes in Lake Vostok and other Antarctic subglacial lakes. Nature 414, 603-609 (2001)

Lamont-Doherty Earth Observatory:

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