Wednesday, March 10, 2010

Subglacial Lake Research


Researchers have thawed ice estimated to be perhaps a million years old or more from above Lake Vostok, an ancient lake that lies hidden more than two miles beneath the frozen surface of Antarctica using novel genomic techniques to determine how tiny, living "time capsules" survived the ages in total darkness, in freezing cold, and without food and energy from the sun.

Lake Vostok is located beneath four kilometers of ice in East Antarctica. The lake is approximately 250 km long and 50 km wide. The overlying ice provides a continuous paleo-climatic record of 400,000 years, although the lake water itself may have been isolated for as long as 15 million years.

Because of the long isolation, it's believed that Lake Vostok could contain new lifeforms, and unique geochemical processes. For five years, scientists in Russia and the United States have sought to probe the ancient lake to discover the secrets lying inside this pristine body of water.

A major issue is the reality that it is impossible to penetrate an isolated ecosystem without contaminating it. The catch 22 inherent in Lake Vostok is that the very thing that make it potentially unique: because of its millennia of isolation from the rest of the world, it cannot be explored without introduction of microbes from the outer world.

NASA has expressed interest in exploring the lake to search for microbes that might be similar to ones on other planets. How the bacteria get energy to survive is an important unanswered question. The lake could be an analog to Jupiter's moon Europa or subsurface where conditions are similar.

The ice segments were cut from an 11,866-foot ice core drilled in 1998 through a joint effort involving the United States, Russia, and France. The core was taken from approximately two miles below the surface of Antarctica and 656 feet (200 meters) above the surface of the lake, and has since been stored at -35 degrees Celsius at the National Ice Core Laboratory, Denver, Colo.

"This lake may have been isolated for that long - 15 million years," said Lanoil, the principal investigator of the research project. "After nearly a year of preparation and verifying protocols, we are now ready to process the samples, and will examine the DNA of these microorganisms to understand how they survived in such an extreme environment."

No comments: