British Scientists To Explore Lost Antarctic Lake

Lake Ellsworth Ice Mission Q&A

Updated: 7:42am UK, Saturday 08 December 2012

As the scientists prepare to start drilling, Sky's Thomas Moore answers the key questions about the project.

Where is Lake Ellsworth?

The lake is under the West Antarctic ice sheet, 70km west of the Ellsworth Mountains.

Seismic studies suggest it is approximately 150m deep and is roughly the same size as Windermere.

There are over 360 sub-glacial lakes known to exist below Antarctica's vast ice sheet.

How remote is it?

The team has travelled 16,000km to reach Lake Ellsworth, flying first to the southern tip of Chile and then on to the drilling site in a smaller aircraft that is able to land on ice. In all, the flight time was five days.

Equipment was air-freighted to a runway on the Union Glacier and then hauled by tractor train 280km through the Ellsworth mountain range.

What are living conditions like?

The team will spend six weeks at the camp. Outside the wind-chill can dip to minus 70 degrees Celsius.

They will sleep in four-man clam tents. In the 24-hour daylight of the Antarctic summer, temperatures inside are generally between four and 20 degrees.

A larger tent serves as a kitchen, dining area and office.

A chef provides freshly-cooked food - even bread.

How will the engineers drill through the ice?

The team had to design a sophisticated hot-water drilling rig that could bore through the ice without contaminating the pristine waters of the lake.

Around 90,000 litres of water will be heated to 90 degrees Celsius by a 1.5 MW boiler and pumped at high pressure through a 3.2km continuous hose that has been made to support its own weight and the heavy drill head.

The drill should melt a 36cm borehole through the 3km of ice in around 100 hours.

Once drilling starts there is no turning back - the water in the hose would quickly freeze.

And then?

Once they breakthrough into the lake, scientists will drop down a titanium probe to sample the water at various depths. Built by the National Oceanography Centre in Southampton, it contains 3,000 individual components.

Then they will use a highly specialised sediment corer to take a 3m column of the lake-bed.

The equipment has been sterilised to space-industry standards using hydrogen peroxide vapour to prevent surface microbes contaminating the lake.

All this has to be done within 24 hours or the borehole will be too narrow to retrieve the samples

Won't the scientists risk a geyser when they drill through to the lake?

Millions of tonnes of ice are pressing down on the lake. But the engineers have a plan to stop the water bursting back up to the surface when they breakthrough.

The first borehole will stop at 300m, where they will create a cavity. A second borehole will go through the cavity down to the lake. The cavity controls the pressure of the water.

What if they don't find life?

The scientists say that, too, would be significant. It would show there is a limit at which no life can exist on our planet.

But they are confident they will find microbes - wherever else there is water on Earth there is life.

And that would encourage scientists who believe there may be life in the seas below the icy crust of Jupiter's moon Europa.

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