Vostok: The lake that time forgot

Sun, 02/05/2012 - 18:09 — Ben Gilliland

We often hear remote areas being referred to as ‘untouched by man’, or as an ‘unspoiled wilderness’ but, by the very nature of mankind’s effect on the planet, such descriptions are (sadly) untrue. If it is open to the air, or watered by rivers, something of man will be imprinted upon it. There are no unspoiled environments left.

But what if we found a place that had been locked away from our influence – a bubble of untouched wilderness – a lost world?

Well, such a place does exist and, in the most remote region our planet, scientists are poised to take a first peek at its secrets.

Beneath four kilometres of Antarctic icesheet, Lake Vostok has been sealed away and isolated from the rest of the planet for almost 20 million years.

It is thought that the lake formed about 30million years ago, when Antarctica enjoyed a temperate climate. Then, about 20-15 million years ago, the climate suddenly cooled and glaciers formed in the mountains around Vostok. The ice sheets rolled down the mountains and across Lake Vostok – sealing it like the lid of giant sarcophagus.

Now, 20,000 millennia after the lake last saw the light of day and after more than 20 years of drilling, a team of Russian scientists are preparing to break the seal on this ‘lake that time forgot’. And they are hoping to find life.

When the lake formed, it would have been teeming with life – just as any body water in a temperate climate does. But, as the ice sheet formed over head, it would have slowly shut out the Sun’s light. As it darkened, plant life would have perished and large animal life would have quickly followed. So what are they hoping to find?

If there is any life left in Vostok it is likely to be microbial – extremely hardy bacteria that can survive extremes of temperature and (most importantly) survive without sunlight to fuel their growth.

In the absence of sunlight, these microbes would have to survive on chemicals pushed out from hydrothermal vents (hot springs) such as hydrogen sulphide. But such springs only occur in areas that are geologically active – where the Earth’s internal heat can escape to the surface and it has long been thought Antarctica is dead, geologically speaking, but new studies suggest that that this may not be the case beneath Lake Vostok.

If the area beneath the lake is still geologically active, there could be hot springs feeding life in lake’s depths. If they are there, the chances of finding life more complex than microbes increases.

Bacteria may not sound particularly exciting, but any microbial life that scientists do find will have been isolated from the rest of the planet for up to 20 million years. Entirely new species that bear no resemblance to the rest of life on Earth could have evolved and they, in turn, could give us an insight into how life evolved on our planet in the first place.

But the project isn’t without its problems. In order to investigate an untouched environment, you have to touch it and with that comes the risk of contamination. And the risk of contamination from the Russian hole is huge.

When they started drilling in 1990, scientists weren’t looking for a lake –  they were there to study the hundreds of thousands of years of climate data locked in the ice sheet. There were there to extract ice cores and preventing contamination wasn’t a priority. To keep their borehole from refrezzing, Russian engineers have used some 65 tonnes of oil-based kersone and, if some of that got into the lake, it could have a catastrophic effect on its ecosystem. There is also the risk that bacteria from the surface could hitch a ride on the drill and contaminate the system.

With this in mind, Nasa are formulating their own plans. They are developing a remote-controlled robotic laboratory that would squeeze spectrometers, microscopes, lights and cameras into a robot the size of a old-fashioned washing-up liquid bottle. It would, of course, need to be completely sterile, which rules out the hole drilled by Russia. So Nasa would have to drill their own hole. Let’s hope it doesn’t take them another 20 years.

 

 

via cosmonline.co.uk