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The icebergs moving around McMurdo Sound in the summer of 2004
and 2005 had spent the previous four years anchored fast near Ross Island, but by December 2004, two had
swung free
and were moving through the very waters Stone was trying to get supplies through. He might be able to
plot a course
around the icebergs, but what would he do if one of the icebergs moved into the shipping channel or
trapped the
supply ships? It was as if Stone were a highway planner trying to devise a detour around a pothole
larger than the
state of Rhode Island that moved unpredictably across the road. And the “pothole” had three
smaller
companions whose sizes were still best measured in kilometers.
The largest of the quartet was the B-15A iceberg, which measured 122 kilometers long by 28 kilometers
wide in late
2004. The second iceberg, C-16, was only a quarter of the size of B-15, but was still 48 kilometers long
by 18.5
kilometers wide. The other two bergs, B-15J and B15-K, had broken from B-15A and measured 56 by 41
kilometers and 59
by 9 kilometers, respectively.
In November 2004, B-15A had started to drift away from Ross Island and blockaded McMurdo Sound, freeing
the way for
B-15J to move. Its timing couldn’t have been worse. Supply ships were scheduled to arrive in
Antarctica at the
end of December and early January, and the fast-moving B-15A iceberg was blocking the northern section
of the
traditional shipping route. Meanwhile, the still stationary B-15K iceberg blocked the southern portion
of the
route. |
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Icebergs blocked
McMurdo in late 2004 and early 2005. MODIS acquired this image of B-15 in February 2005.
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“We were really, really worried at how we were going to supply McMurdo Sound,”
confides Stone, deep concern evident in his voice even months after the end of the season. To get the
ships
safely to McMurdo Station, Stone needed to know where the icebergs were going on a regular basis. When
the
bergs started to move, he turned to MODIS, a sensor on NASA’s Terra and Aqua satellites that
collects
daily imagery of the entire Earth.
MODIS Rapid Response Operation Antarctica
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U.S. Coast Guard icebreaker Polar Star (left) and U.S. Navy
tanker
USNS Paul Buck broke ice near McMurdo in February 2005. (Photo courtesy National Science
Foundation) |