Greenland Glaciers More Vulnerable than Thought

November 3, 2017

greenlandnewmap17

The closer we look, the more we see.

NASA Jet Propulsion Lab:

New maps of Greenland’s coastal seafloor and bedrock beneath its massive ice sheet show that two to four times as many coastal glaciers are at risk of accelerated melting as previously thought.

Researchers at the University of California at Irvine (UCI), NASA and 30 other institutions have published the most comprehensive, accurate and high-resolution relief maps ever made of Greenland’s bedrock and coastal seafloor. Among the many data sources incorporated into the new maps are data from NASA’s Ocean Melting Greenland (OMG) campaign.

Lead author Mathieu Morlighem of UCI had demonstrated in an earlier paper that data from OMG’s survey of the shape and depth, or bathymetry, of the seafloor in Greenland’s fjords improved scientists’ understanding not only of the coastline, but of the inland bedrock beneath glaciers that flow into the ocean. That’s because the bathymetry where a glacier meets the ocean limits the possibilities for the shape of bedrock farther upstream.

greenlandbathy

New view, bottom, shows more detail of Greenland coastal seabottom

The nearer to the shoreline, the more valuable the bathymetry data are for understanding on-shore topography, Morlighem said. “What made OMG unique compared to other campaigns is that they got right into the fjords, as close as possible to the glacier fronts. That’s a big help for bedrock mapping.” Additionally, the OMG campaign surveyed large sections of the Greenland coast for the first time ever. In fjords for which there are no data, it’s difficult to estimate how deep the glaciers extend below sea level.h as the conservation of mass.
On October 23, the five-year OMG campaign completed its second annual set of airborne surveys to measure, for the first time, the amount that warm water around the island is contributing to the loss of the Greenland ice sheet. Besides the one-time bathymetry survey, OMG is collecting annual measurements of the changing height of the ice sheet and the ocean temperature and salinity in more than 200 fjord locations. Morlighem looks forward to improving BedMachine’s maps with data from the airborne surveys.
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One Response to “Greenland Glaciers More Vulnerable than Thought”

  1. wpNSAlito Says:

    Note to other readers: Greenland maps on the JPL article have much higher resolution.


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