Possible 1000-km “River” Channel May Drain Greenland’s Northern Ice Sheet More Rapidly

The Cryosphere, November 12

Perhaps related to the above, a 1000-kilometer channel under the Petermann Glacier in northern Greenland may provide more rapid run-off from the ice sheet than previously appreciated.  Researchers realized that current maps of the bedrock under this portion of the ice sheet showed this channel as “blocked” at key points: due not to measured changes in bedrock height, but lack of data on the actual topography.  When they instead used ice model simulations to map this valley, it created a free-flowing downhill “river” watercourse over 1000 km long under the ice.  If this new mapping is more accurate, such a sloping channel could serve to increase discharge and sea-level rise from this portion of Greenland more rapidly than projected.

https://tc.copernicus.org/articles/14/3747/2020/

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