Headlines > News > NASA Ice Satellite Maps Profound Polar Thinning

NASA Ice Satellite Maps Profound Polar Thinning

Published by Matt on Fri Sep 25, 2009 3:49 pm via: source
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Researchers have used NASA’s Ice, Cloud and Land Elevation Satellite (ICESat) to compose the most comprehensive picture of changing glaciers along the coast of the Greenland and Antarctic ice sheets.

A web of satellite tracks, from NASA's Ice, Cloud, and land Elevation Satellite, reveal areas of dynamic thinning (red) in Antarctica and Greenland. Credit: British Antarctic Survey/NASA

A web of satellite tracks, from NASA's Ice, Cloud, and land Elevation Satellite, reveal areas of dynamic thinning (red) in Antarctica and Greenland. Credit: British Antarctic Survey/NASA

The new elevation maps show that all latitudes of the Greenland ice sheet are affected by dynamic thinning – the loss of ice due to accelerated ice flow to the ocean. The maps also show surprising, extensive thinning in Antarctica, affecting the ice sheet far inland. The study, led by Hamish Pritchard of the British Antarctic Survey in Cambridge, England, was published September 24 in Nature.

ICESat’s precise laser altimetry instrument, launched in 2003, has provided a high-density web of elevation measurements repeated year after year across the Greenland and Antarctic ice sheets. With the dense coverage, the research team could distinguish which changes were caused by fast-flowing ice and which had other causes, such as melt.

The maps confirm that the profound ice sheet thinning of recent years stems from fast-flowing glaciers that empty into the sea. This was particularly the case in West Antarctica, where the Pine Island Glacier was found to be thinning between 2003 and 2007 by as much as 6 meters per year. In Greenland, fast-flowing glaciers were shown to thin by an average of nearly 0.9 meters per year.

Satellite data shows fast ice thinning (red) along the coast of West Antarctica. The inset shows satellite tracks over Pine Island Glacier, from NASA's Ice, Cloud, and land Elevation Satellite, which reveal dynamic thinning concentrated on the fast-flowing areas. Credit: British Antarctic Survey/NASA

Satellite data shows fast ice thinning (red) along the coast of West Antarctica. The inset shows satellite tracks over Pine Island Glacier, from NASA's Ice, Cloud, and land Elevation Satellite, which reveal dynamic thinning concentrated on the fast-flowing areas. Credit: British Antarctic Survey/NASA

4 Comments
poincare432
I am having a little trouble interpreting the images. Clearly the red and yellow stands out as areas of higher ice loss, while the dark blue areas indicate ice is accumulating. But for Antarctica, there appear to be vast swaths of the continent where it's hard to interpret the colour - is it in aggregate right around the 0 mark, or is it slightly on the yellow/negative side?
slythere
Pictures no good.
Must show animation!
mpaullloyd
I am left wondering why we are not seeing the total area of ice here? Yes it may be thinning on the very edge of the landmass but what is happening out at sea? Is the ice simply melting or spreading over a wider area? How thick is it and has the total amount reduced or increased? It is worth noting that the total area of ice at the North Pole has increased significantly over the last two years. Also, given the limited time frame for Antarctic surveys what are we comparing this current information with?
rrvau
I wonder what the date of the image is? Southern hemisphere late summer/autumn? With regard to Greenland, how do they think it came upon its name? The seem to forget that Greenlanders used to be able to grow crops and farm during and prior to the viking era.
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