News

British team set to embark on ambitious Antarctic mission to sample ancient buried lake

(11 September 2012)

Antarctic map Lake Ellsworth location

After 16 years of planning the countdown is on for one of the most ambitious scientific missions to Antarctica, and Durham University experts are awaiting the results with great interest.

In October a 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 that may live in subglacial Lake Ellsworth on the West Antarctic Ice Sheet.

Professor Mike Bentley, Department of Geography, Durham University, will lead the team back in the UK that will analyse the sediment samples brought up from the dark icy depths.

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 sterilised to space industry standards to ensure this unexplored lake remains pristine.

Durham University is playing a key role as the project team seeks to discover secrets in the sediments. Analysis of the sediments from the sediment corer will reveal clues to microbial life and help scientists assess the present-day stability of the West Antarctic Ice Sheet and the likely consequences for future sea-level rise. Water and sediments samples will be analysed by consortium members in research institute and university laboratories throughout the UK with Durham University’s Professor Mike Bentley leading that section of the project.

Working with Dr Dom Hodgson from BAS, Mike and Dom have been designing a corer that can retrieve a long sample of the mud on the lake floor, and which has been laid down over thousands of years. They have planned a range of laboratory analyses that will be carried out on this sub-glacial mud. These will tell us about processes in the lake, how the lake environment changes through time, and may even include preserved remains of microscopic life that once lived in the lake.

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 of a chilly minus 25°C and wind speeds averaging 25 knots.

Professor Bentley said: “This extraordinary research project crosses the frontiers of exploration. It’s a trip into the unknown sub-glacial world that will yield new knowledge about the evolution of life on Earth and other planets, and will provide vital clues about the Earth's past climate.

“Building the sediment corerhas been an immense challenge and it is great news that the equipment has arrived safely on site and the final preparations are being made for the drilling.”

Programme Manager Chris Hill from the British Antarctic Survey said: “This time last year a small ‘advance party’ transported nearly 70 tonnes of equipment 16,000 km from the UK to the drilling site.  Now, one year later, we will ship another 26 tonnes of equipment on to the continent so that we can complete stage two of this challenging field mission. We set foot on the ice again in October and hope to bring samples to the surface in December 2012 – an historic moment we have all been waiting for.”

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 litres of water for the hot-water drill. The drill will pressurise the water to 2,000 psi and then pump this water at 210 litres per minute through a 3.5km bespoke hose to create a 360mm wide borehole.

This research has been made possible through the unique partnership created by two Natural Environment Research Council (NERC) Centres of Excellence, and eight UK universities. The Lake Ellsworth consortium programme is funded by NERC and draws together the UK’s top engineering, scientific and logistical capacities.

• Department of Geography
• Lake Ellsworth Project