January 28, 2011

Russian Scientists Drilling At Mysterious Antarctica Lake

Scientists studying the world's most enigmatic lake have only 165 feet left to drill as time is running out.

Vostok is a sub-glacial lake in Antarctica, hidden about 13,000 ft beneath the ice sheet.

With the Antarctic summer almost over, temperatures will soon start to drop.

Scientists will leave the remote base on February 6, when conditions are still mild enough for a plane to land.

The team has not stopped drilling for weeks.

"It's like working on an alien planet where no one has been before," Valery Lukin, the deputy head of Russia's Arctic and Antarctic Research Institute (AARI) in St Petersburg, which oversees the project, told BBC News.

"We don't know what awaits us down there," he said, adding that personnel at the station have been working shifts, drilling 24 hours a day.

However, some experts remain concerned that probing the lake's water could contaminate the pristine ecosystem and cause irreversible damage.

The sub-glacial lake is located underneath the remote Vostok station in Antarctica.

Overlaid by about 2.5 miles of ice, it has been isolated from the rest of the world for millions of years. 

Some scientists say that the ice cap above and at the edges has created a hydrostatic seal with the surface, preventing lake water from escaping or anything else from getting inside.

If the Russian team gets through to the lake, they hope to encounter life forms that have never been seen.

The coldest temperature ever found on Earth was recorded on July 21, 1983 at the Vostok station of -129 degrees Fahrenheit.

Normally, water in such extreme conditions exists in an ice state.  When the 1970s British scientists in Antarctica received strange radar readings at the site, the presence of a liquid, freshwater lake below the ice did not instantly spring to mind.

Satellites found images outlining the lake's contours in 1996.

Space radar revealed that the sub-glacial body of fresh water was one of the largest lakes in the world.

Scientists believe that conditions in the lake have probably remained unchanged for about 15 million years since it has remained sealed off from the rest of the world.

For liquid water to exist in Antarctica, glaciologists suggest that the ice cap serves as a giant insulating blanket, able to capture the Earth's geothermal heat to melt the bottom of the ice sheet.

Scientists started drilling and managed to go as deep as about 11,800ft.  However, the project ground to a halt in 1998 when the untouched waters were only about 430ft away.

"We had to stop because of the concerns of possible contamination of the lake," explained Alexey Ekaikin, a member of the current expedition, who spoke to the BBC Russian Service from Vostok station.

He said that drilling was resumed in 2004, when the team came up with new, ecologically safe methods of probing the lake.

The scientists submitted a final environmental evaluation of the project in November, 2010 to the Antarctic Treaty's environmental protection committee and were given the go-ahead to sample the ancient waters.

The team said that instead of drilling into the lake, they would go down until a sensor on the drill detects free water.

They would take the drill out without going any further and adjust the pressure so that instead of any liquid in the borehole falling down into the lake, water in the lake would be sucked up.

The drill would be taken away and left for quite some time to freeze, creating a plug of frozen ice in the bottom of the hole.

Finally, the team would drill down again to take a sample of that ice and analyze it.

However, the work has found repeated delays due to technical difficulties.

"Up until three kilometers down, drilling is usually relatively easy - it has been done in Greenland and here in Antarctica. But after three km and as we near the bottom [of the ice sheet], the ice temperature gets very close to the ice melting point, and all sorts of problems begin," Ekaikin told BBC.

Lukin said that additional difficulties come from the changing structure of the ice.  After about 11,800ft, the ice is pure frozen lake water, composed of huge round monocrystals of three-feet or more in diameter and is as hard as glass.

The team has been advancing at about five-feet a day and they have just about 165 more feet to go.

Ekaikin told BBC that having analyzed the ice cores obtained so far, the scientists have already discovered some bacteria are likely to be living at the bottom of the lake, where the water is warmer because of the heat coming up from the Earth.

Sampling the waters could move scientists a step closer to understanding of similar glacial conditions on Jupiter's moon Europa.

Researchers believe a huge ocean, hidden within a thick shell of ice, covers it.

Some international observers say that the project is a threat to the ancient sub-glacial lake.

"It's probably almost impossible to make something absolutely, utterly and totally clean," Dr Andy Smith, a glaciologist at the British Antarctic Survey, told BBC.

"It's worth [sampling the waters], as even though originally it seemed a really wild thing to expect, there will be life there - anywhere we go on the planet where there's an extreme environment, we always find life.

"But we have to make a huge effort not to spoil the environment by being interested in it," he added.

However, Russians working in Antarctica believe the risks are virtually non-existent ad the possibility of a great discovery makes it entirely worthwhile.


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