Giant Crack Found in Antarctic Ice
Using satellite images, scientists have now given Antarctica
its second annual physical examination, and they have found a giant
crack in a glacier that may produce a major iceberg in less than 18
months (bottom right image).
The researchers from the U.S. Geological Survey (USGS)
and NASA discovered the 25-kilometer-long crackspanning more than
two thirds of the glacierusing NASA's Landsat 7 satellite, which
passes over the continent 16 times a day on its nearly pole-to-pole
orbit. The satellite takes about 300 pictures of the continent during
the Antarctic summer (November through February). On the last picture
of the site, taken 10 months ago, there was no crack in the ice shelf
(top right image).
To determine how quickly the crack was growing, the scientists
needed additional data, which they obtained by combining their findings
with earlier observations from NASA's Terra satellite, the Canadian
Space Agency's RADARSAT and the European Space Agency's Radar Imager.
"Most of this crack formed very rapidly, in less than five weeks,"
says Robert Blindschadler, a glaciologist at NASA's Goddard Space Flight
Center. "Right now it is growing much more slowly, at about 13
meters a day." Harald Franzen
Source: http://www.sciam.com/news/032601/2.html
We told them so in 1997. (See Global
Warming No. 218)
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