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)|
|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: http://www.ldeo.columbia.edu/~mstuding/vostok.html