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NASA animates 20,000 years of Antarctic ice history

A computer animation of the ice sheet before (top) and after it receded

Watch a computer animation of the ice sheet shrinking
249 K / 8 sec. / 240x180
QuickTime movie
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February 3, 1999
Web posted at: 3:18 p.m. EST (2018 GMT)

GREENBELT, Maryland (CNN) -- Scientists studying the shrinking of the Antarctic ice sheet can now watch a movie of the phenomenon.

The National Aeronautics and Space Administration has developed 3-D computer animation showing the retreat of the west Antarctic ice sheet over 20,000 years, speeded up into a few minutes of dramatic video footage.

"The purpose of the visual is to emphasize the changes that have taken place," said Robert Bindschadler, a glaciologist at the NASA Goddard Space Flight Center in Maryland.

"During the last 20,000 years, the west Antarctic ice sheet lost two-thirds of its mass and raised the sea level 10 meters. It still contains enough ice to raise the sea level by another 5 meters if it were to lose the remainder of its mass,' Bindschadler said.

During the last 30 years, scientists have become increasingly concerned about the effects global warming might have on the west Antarctic ice sheet. Specifically, some researchers have expressed concern that rapid melting of the sheet could contribute to a catastrophic rise in sea levels around the world.

The majority of the west Antarctic ice sheet sits atop dry land, while the east Antarctic ice sheet is grounded below sea level. Changes in the east Antarctic sheet would have little effect on sea levels since the ice displaces water, but a complete melt of west Antarctic ice would pour new water into the oceans.

antarctica landscape
Scientists say the ice sheet has lost two-thirds of its mass  

Bindschadler said there is evidence that the west Antarctic ice sheet may have melted and reformed several times during the past 11 million years.

The computer animation begins with Antarctica at the peak of the last Ice Age about 20,000 years ago, and shows the gradual shrinking of the west ice sheet.

"About 12,000 years ago, it began a dramatic retreat," Bindschadler said. "We're not sure if the retreat is still taking place -- that's one of the main questions we're trying to answer."

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