Records show that average winter temperatures are 10 degrees higher in parts of Antarctica today than they were 50 years ago. If that warming trend continues, say many climate experts, the vast Antarctic ice sheets could melt, causing catastrophic coastal flooding as the world`s oceans rise.

Ironically, say researchers, the most pristine continent on Earth is heating up primarily because of increased greenhouse gas emissions from cars, power plants and other human endeavors elsewhere on the planet.

But new geologic evidence unearthed from deep-sea mud deposits strongly suggests that Antarctica experienced periods of extreme warming and cooling long before the invention of the automobile.

"We`ve got a sedimentary record that reveals very significant changes in water temperature and ice melt during the past 7,000 years," says Robert Dunbar, professor of geological and environmental sciences at Stanford. "The cause of these highly variable climate changes is still a mystery."

Glacial evolution

Dunbar and Boston University collaborators Richard W. Murray and Kelly A. Kryc will present their findings at the annual meeting of the American Geophysical Union (AGU) in San Francisco on Dec. 14, during a session titled, "Antarctic Glacial Evolution: the Marine Geologic Record II."

The researchers based their study on a bioigeochemical analysis of sediments obtained during a recent cruise of the JOIDES Resolution, a research vessel operated by the Ocean Drilling Program (ODP) - an international project dedicated to exploring the geological history and evolution of the Earth. ODP is principally funded by the National Science Foundation with additional support from institutions representing nearly two dozen other countries, in
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Contact: Mark Shwartz
mshwartz@stanford.edu
650-723-9296
Stanford University
14-Dec-2001