By Sid Perkins
Imagine the consternation that your high school physics teacher would have shown if, during a lab demonstration, the little wheeled block placed on an inclined plane had violated the law of gravity. Imagine the block sometimes speeding up, sometimes slowing down, and sometimes stopping dead on the slope. Scientists have faced a similar situation as they’ve studied some of Antarctica’s most massive glaciers. The researchers are eager to understand the behavior of these ice streams because they have considerable influence on sea levels worldwide.
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Scientists estimate that ice streams contribute about 90 percent of the ice flowing directly off Antarctica into the surrounding sea. However, “we can’t now predict how much ice will flow into the sea in the future,” says Ted A. Scambos, a glaciologist at the National Snow and Ice Data Center in Boulder, Colo.