MercoPress. South Atlantic News Agency

British team to drill sub-glacial Antarctic lake and define limits of life in the planet

The 12km long, 3km wide, 150 meters deep Lake Ellsworth is hidden under 3.5 km thick ice

After 16 years of planning the countdown is on for one of the most ambitious scientific missions to Antarctica. In October a 12-man team of British scientists, engineers and support staff will make the 16.000 km journey from the UK to go deep into the heart of the frozen continent to collect samples of water and sediments from an ancient lake buried beneath three kilometers of ice.

Their quest is to reveal vital secrets about the Earth’s past climate and discover life forms may that live in sub-glacial Lake Ellsworth on the West Antarctic Ice Sheet.

For the past three years a team of engineers from the British Antarctic Survey (BAS) and the National Oceanography Centre (NOC) have pushed the boundaries of polar technology to design and build a state-of-the-art titanium water-sampling probe and a bespoke sediment corer capable of being lowered down a three kilometer borehole in the ice made by a custom-built hot-water drill. To add to the challenge every piece of technology has to be sterilized to space industry standards to ensure this unexplored lake remains pristine.

Lake Ellsworth was mapped in detail by scientists using seismic survey techniques. They discovered a hidden lake 12km long, 3km wide and 150m deep. After setting up the science camp and preparing all the equipment to start the mission, the team will have just 24 hours to sample the lake before the borehole re-freezes and re-seals the lake. Typical working conditions will be in temperatures a chilly minus 25°C and wind speeds averaging 25 knots.

The mission’s Program Manager Chris Hill from BAS will be one of the first from the team on to the ice to prepare for the mission.

“This time last year a small ‘advance party’ transported nearly 70 tons of equipment 16,000 km from the UK to the drilling site. Now, one year later, we have shipped another 26 tons of equipment so that we can complete stage two of this challenging field mission. We hope to bring samples to the surface in December 2012 – an historic moment we have all been waiting for”, said Chris Hill

“For years we have speculated that new forms of microbial life could have evolved in the unique habitats of Antarctica’s sub-glacial lakes. Finding life in a lake that could have been isolated from the rest of the biosphere for up to half a million years will reveal much about the potential origin of and constraints for life on Earth, and may provide clues to the evolution of life on other extraterrestrial environments. If we find nothing this will be even more significant because it will define limits at which life can no longer exist on the planet”, according to BAS Microbiology Professor David Pearce who is heading up the search for life in the lake water.

The mission’s Principal Investigator Martin Siegert from the University of Bristol said that for the first time “we are standing at the threshold of making new discoveries about a part of our planet that has never been explored in this way. Finding life in a lake that could have been isolated for up to half a million years is an exciting prospect, and the lake-bed sediments have the potential to paint a picture of the history of the West Antarctic Ice Sheet in a way that we haven’t seen before”.

By December 2012 the team will have prepared the field camp and will begin the 100 hours of non-stop, hot-water drilling required to create the borehole through to Lake Ellsworth. They will then have 24 hours to deploy the water and sediment-sampling equipment. During this process the team will use a bespoke 1.5 MW boiler to melt ice to provide 90,000 liters of water for the hot-water drill. The drill will pressurize the water to 2,000 psi and then pump this water at 210 liters per minute through a 3.5km bespoke hose to create a 360mm wide borehole.