Wednesday, January 16, 2008

Alaska glacier speed-up tied to internal plumbing issues

Glacier melting appears to much more complicated than we thought. A story from Terra Daily describes a recent study of how glaciers lose mass and move: A University of Colorado at Boulder study indicates meltwater periodically overwhelms the interior drainpipes of Alaska's Kennicott Glacier and causes it to lurch forward, similar to processes that may help explain the acceleration of glaciers observed recently on the Greenland ice sheet that are contributing to global sea rise.

According to CU-Boulder Professor Robert Anderson of the Institute of Arctic and Alpine Research, the amount of water passing through conduits inside and underneath the Kennicott Glacier increases during seasonal melting and also following annual flooding from a nearby lake. The addition of excess water from melting and flooding causes water to back up into a honeycomb of passages inside the glacier, he said, suggesting the resulting increase in water pressure causes the glacier to slide more rapidly down its bedrock valley....

Alaska's Kennicott Glacier recently has been observed by scientists to be lurching, a result of meltwater and floodwater overwhelming its interior plumbing. Credit: Robert. S. Anderson/University of Colorado at Boulder

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