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Tides Control Flow of Antarctic Ice Streams



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The moon is often accused of causing lunacy, bringing on labor and transforming werewolves. Now it seems that in reality, the moon, through the tides, is responsible for the pattern of motion exhibited by ice streams in the Antarctic, according to a team of geologists from NASA, Penn State and University of Newcastle, Newcastle Upon Tyne, England.

"My observations from a few years ago were that Ice Stream D in the West Antarctic was slowing to about half average speed and then speeding up," says Dr. Sridhar Anandakrishnan, associate professor of geoscience, Penn State. "I thought that the speeding up and slowing down was tied to rising and falling of the ocean tides."

The ice streams in West Antarctica move large amounts of ice downward from the center of the glacier toward the ocean. Most of the glacier rests upon bedrock and/or rubble on land, but part of the glacier floats above the ocean. The grounding line, the line where the glacier stops being grounded and floats, is quite a distance back from the leading edge of the glacier.



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Some ice streams are moving rapidly, some are slowing down and others have completely stopped moving. Researchers have looked at a number of ice streams and recently, they discovered that Whillan's Ice Stream exhibits the most bizarre behavior because it actually stops dead and then slips for a short time, moving large distances, before it stops again.

For the full ice streams story, click here.