Mystery Beneath The Antarctic Ice

Lake Ellsworth was mapped in detail by scientists using seismic survey techniques. They discovered a hidden lake 12km long, 3km wide and 150m deep, roughly the same size and depth as Windermere in the UK. 

 Photo: Neil Ross, University of Edinburgh 

Search for life

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 the potential origin of and constraints for life on Earth, and may provide clues to the evolution of life on other extraterrestrial environments. If no life is found in the lake this could be even more significant because it will define limits at which life can no longer exist on the planet.

Collecting a sediment core from a lake that is pitch black, has been sealed off for tens of thousands if not millions on years will answer big science questions. What is the possibility of life on other planets? What can we learn about the evolution of life on Earth?  How can we understand the ancient history of oceans and ice sheets?

Collecting a sample from the sediments locked beneath subglacial Lake Ellsworth is the perfect opportunity to find out about the fundamentals of life on Earth: 

• Microbes can live within rocks and sediments
• Microbes produce oxygen which is essential for creating an atmosphere
• Lake Ellsworth may provide clues about the pre-conditions for life on Earth and other planets
• The top layer of sediments may contain life forms
• Is Earth unique or could there be life on other planets?

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.

 

Water sampling probe

The unique five-metre long water sampling probe was designed and built by engineers at the National Oceanography Centre in Southampton. Made of the highest grade of titanium to ensure maximum sterility and strength, it will collect 24 water samples at different lake depths. It will also capture the top layer of sediments at the lake-floor / water interface.

Sediment corer

Scientists at British Antarctic Survey and Durham University, working in partnership with Austrian business UWITEC, have designed and built a sediment corer, which can extract a core up to three metres long. The unique percussion-driven piston corer is strong enough to penetrate even the most compacted glacial sediments to extract a core sample.

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.

 

Credit:  British Antarctic Survey 

 

Getting Ready

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 team of science and engineering experts has been brought together by the mission’s Principal Investigator Martin Siegert from the University of Bristol. He says:

“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. The team’s mission is to get into the deep field and bring back clean, valid samples of lake water and lake-bed sediments, which can be brought back to the UK for in depth analysis.”

Programme Manager Chris Hill from the British Antarctic Survey says: ”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.”

Professor John Parnell from the School of Geosciences at the University of Aberdeen says: ”For years we have speculated that new forms of microbial life could have evolved in the unique habitats of Antarctica’s subglacial lakes. When we get the lake water samples back to the UK our analysis will focus on investigating the water for evidence of chemical compounds that microbes – tiny organisms – living in the lake might have produced.

“Finding evidence of such compounds would show us that if life can withstand even the deepest, darkest and most isolated conditions for more than a million years, then it has the ability to exist anywhere – and by that I mean not just on Earth. We will use advanced pieces of kit that allow us to analyse extremely small volumes of water – just a few millimetres – and is highly sensitive to the existence of any chemical compounds which may be present.”

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 is at the frontier of exploration and 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.

Contacts and sources:
Heather Martin
British Antarctic Survey

More videos: http://www.ellsworth.org.uk/vidclips.html