Researchers Describe Overall Water Balance In Subglacial Lake Vostok

According to a paper to be published in the March 21 issue of Nature, the hydrodynamics of the lake may make it possible to search for evidence of life in the layers of ice that accumulate on the lake’s eastern shore. Scientists say such a possibility would provide another avenue for exploring the lake’s potential as a harbor of microscopic life, in addition to actually exploring the waters of the lake itself.

The paper is authored by Robin E. Bell of Columbia University’s Lamont-Doherty Earth Observatory and her colleagues. Their research, who were supported by the National Science Foundation (NSF), reveals that although the lake is perhaps millions of years old, its waters are relatively young. Bell's paper demonstrates that over a period of 13,300 years, all of the water was removed by the overlying ice sheet and replaced from other sources. The lake water captured by the moving ice sheet was carried as layers of ice over Lake Vostok’s eastern shoreline, and then eastward away from the lake. Exploring those ice layers, they argue, is equivalent to exploring the lake itself.

“Our study is a critical step in the exploration of Lake Vostok,” Bell said. “These frozen lake water samples will record the passage of the ice sheet and the processes across the lake. The data show that the location of the current research station on the lake may not be optimal for biological studies.”

Bell added that that “Lake Vostok is absolutely devoid of interference. The youngest water in it is 400,000 years old. It doesn’t know anything of human beings, fossil fuels, or plastics.

It is a window into life forms and climates of primordial eras.”

Radar maps of the Antarctic interior made in 1996 revealed that a lake lay under the ice sheet. Lake Vostok is thought to be one of the world’s largest, 48 kilometers (30 miles) wide by 225 kilometers (140 miles) long and 914 meters (3,000 feet) deep. Its waters have been sealed from air and light for perhaps as long as 35 million years under the tremendous pressure of the continental ice sheet.

An ice core -- one of the world’s longest -- was drilled by a joint U.S., Russian, and French team at Russia’s Vostok Station on the lake’s western shore. But coring was stopped roughly 100 meters (328 feet) above what is thought to be the surface of the water to prevent contamination of the lake. The ice layers reveal a 400,000-year environmental record with microorganisms present throughout most of the core.

During the 2000-2001 Antarctic research season, NSF supported a detailed aerial mapping of the lake by specially equipped Twin Otter aircraft fl