WORLD
Antarctic lake mission targets life and climate signs
Baku, October 12 (AZERTAC). A pioneering British expedition to sample a lake under the Antarctic ice hopes to find unknown forms of life and clues to future climate impacts.
The mission will use hot water to melt its way through ice 3km (2 miles) thick to reach Lake Ellsworth, which has been isolated from the outside world for at least 125,000 years - maybe a million.
The team hopes to be the first to sample a sub-glacial Antarctic lake.
An engineering team leaves the UK later this week along with 70 tonnes of gear.
The project, funded to the tune of £7m by the UK`s Natural Environment Research Council, aims to obtain samples of the lake water itself and of sediment on the lake floor.
"Our project will look for life in Lake Ellsworth, and look for the climate record of the West Antarctic Ice Sheet," said the project`s principal investigator Professor Martin Siegert from Edinburgh University.
"If we`re successful, we`ll make profound discoveries on both the limits to life on Earth and the history of West Antarctica," he said.
Understanding the West Antarctic Ice Sheet is crucial to forecasting future climate change impacts, as it holds enough ice to raise sea levels globally by at least 3m (10ft) and perhaps 7m (23ft).
Exploring sub-glacial lakes may also help scientists design missions to search for life on other worlds such as Jupiter`s moon Europa, which is thought to feature a liquid ocean beneath a thick layer of ice.
Lake Ellsworth is about 10km long and 2-3km wide - about the same size as Lake Windermere, England`s biggest.
But that is where the similarity ends.
Ellsworth lies in a valley in the bedrock of Antarctica, with 3km of ice above.
The water is kept liquid by natural geothermal heat coming from the Earth`s interior.
It has been mapped by using ground-penetrating radar and seismic tests.
Among other things, those investigations revealed that the lake has a soft floor, which presumably means a thick layer of sediment.
But reaching the lake and taking samples involves a mission that pushes the boundaries of engineering skill and ingenuity.
The hot-water drill is basically a spraying device on the bottom of a hose 3.2km long.
Ninety thousand litres of pure water will be made at the Ellsworth site by heating and then filtering ice, using a boiler taken along for the purpose.
It will be pumped down the 3.2km-long hose and out of the nozzles at the bottom.
With the water at a scalding 97C, it should melt a smooth, uniform hole about 36cm across down to the bottom of the ice.
A 5m-long probe will then be lowered through the hole and into the lake, carrying 24 flasks that will gather water samples at various depths.
It will also carry lights and a high-definition video camera, and filters to draw solids from the water.
Much of the equipment has been designed and built at the National Oceanography Centre (NOC) in Southampton, under the supervision of Matt Mowlem.