Scientists await samples from buried lake

Sat, Sep 8, 2012, 01:00

POLAR SCIENTISTS will receive a Christmas present like no other this year – water samples and mud from an Antarctic lake buried under 3km of solid ice.

While this might not be everyone’s choice for yuletide cheer, they will be priceless gifts given that Lake Ellsworth has been sealed up under the ice and isolated from the rest of the planet for hundreds of thousands of years.

Retrieving the samples is the culmination of a three-year, €10 million effort called the Subglacial Lake Ellsworth Programme.

It is extreme in every way imaginable, said Prof Martin Siegert, the programme’s principal investigator from the University of Bristol.

The mission, which came under initial discussion 20 years ago, required the development of unique new equipment and engineering techniques that will have their first outing during the drilling and sample recovery mission.

It has been as elaborate as any deep-space mission given the harsh weather and challenging goals, with the main aim of getting through the ice and down into the lake without causing any environmental impact on the unique body of water.

Every piece of technology from the custom-built hot water drill to the sediment corer and water sample collecting probe have been sterilised to space industry standards to ensure Lake Ellsworth remains pristine after the mission, said programme manager Chris Hill from the British Antarctic Survey, the main sponsor for the expedition.

So much effort was put into this aspect of the mission that it has doubled the amount of time required to prepare for and undertake the drilling programme, Mr Hill said.

Some 70 tonnes of sterilised equipment have already been moved the 16,000km from Britain to Antarctica, with more to follow next month.

Those travelling will find conditions on the ground very difficult on the west Antarctic ice sheet, with typical temperatures of minus 25 degrees and wind speeds of 25 knots.

Lakes such as Ellsworth remain absolutely balmy in comparison with typical temperatures of minus 1.5, and remain ice free due to geothermal heating, Prof Siegert said.

The sediment and water will be subjected to rigorous testing when it is returned to labs.

The probe will allow water to be taken at several depths so that layering can be compared.

However, the scientists will be far more interested to see if filters mounted on the equipment manage to catch any living organism.

These organisms would most likely be bacteria or single-celled creatures.

Scientists have no way to know in advance whether Ellsworth managed to support life, a session at the UK Festival of Science in Aberdeen heard.

They took the view that given micro-organisms have managed to colonise the harshest of environments on Earth, it is probable that the lake will also have a collection of unique animals.

Besides such creatures, researchers are hoping to learn something else of great importance, said Prof Siegert.

Sediment in the lake would have been deposited when no ice covered its surface, when the 3km of ice last melted away.

The hope is that clues related to the climate change that drives the building and collapse of polar ice may be found.

This is information that could be of importance to understand where today’s climate change is going.