Life forms are thriving in water beneath permanent polar ice

The Earth's poles are not wastelands as so often portrayed. Humans travelled the Arctic Circle at least 30,000 years ago and microbes have been discovered thriving in water trapped beneath permanent polar ice.

"Life at the Earth's poles" was the theme applied to a group of talks by archeologists and biologists who search for signs of life in some of the most remote and inhospitable places on the planet.

Hunters pursuing the woolly mammoth reached the Arctic Circle 30,000 years ago, said Dr William Fitzhugh, director of Arctic studies at the Smithsonian Institution in Washington.

Humans moved into permanent settlements in Northern Canada 4,000 years ago, and preserved on Wrangel Island far north of the Siberian coast in the Arctic Ocean is "a perfectly frozen site with bones and wood and artefacts", he said.

Other unexpected life forms populate these frozen wastes, explained Prof John Priscu of Montana State University. He has studied numerous sub-glacial lakes, bodies of water trapped beneath tonnes of permanent ice.

He and his research group did extensive studies in the McMurdo Dry Valley region of Antarctica, where the average annual temperature does not rise above minus 30 degrees.

"Instead of life on the surface, it is down in the ice," he told a session of the American Association for the Advancement of Science annual meeting.

The water trapped deep under the ice provides "an oasis for life in what would otherwise appear to be an inhospitable environment".

Samples recovered from McMurdo showed the water contained thriving colonies of cyanobacteria and other microbes.

Dramatic discoveries could be made when scientists finally reach Lake Vostok, a massive water lake covered by Antarctic ice no less than four kilometres thick.

Vostok is about the size of Lake Ontario (14,000 sq km) and is a kilometre deep. The ice has left the lake completely isolated from modern life forms for perhaps 20 million years.

The thinking is that the lake may harbour unique microbial life.

"There should be a thriving population of organisms in Lake Vostok. We are aiming to develop drilling technologies that will not cause contamination," Prof Priscu said.

This would allow a sample of Vostok water to be recovered while protecting the lake from bacterial newcomers.