Past Antarctic Melts Raised Sea Levels 16 Feet. By Seth Borenstein, AP, March 19, 2009. "New information on Antarctica's regularly melting distant past is giving scientists a glimpse into what may be a flooded future as the planet warms up. The West Antarctic ice sheet collapsed periodically between 3 million and 5 million years ago, adding more than 16 feet to global sea level, according to the first examination of soil cores far below the surface of the Ross ice shelf. Also, new computer models suggest that warmer waters nearby attacked the ice from below, triggering those collapses... The complete collapse of west Antarctica won't happen too quickly -- it will be hundreds if not a thousand years from now -- slower than some of the most dire predictions, the studies' authors said. Scientists said the core samples indicated the massive ice sheet on West Antarctica regularly melted about every 40,000 years during a period when the climate was about 5 degrees warmer than now and carbon dioxide levels were slightly higher. The past melts coincided with regular changes in Earth's tilt, something that isn't occurring now."
2009-03-23
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