GLOBAL WARMING
Ice shelf cracking up
Scientists blame global warming for disintegration of the Wilkins
shelf
Published on March 27, 2008
Ice shelf cracking up
The Wilkins Ice Shelf on the Southwest Antarctic Peninsula has begun
to fall apart. The collapse of the shelf, about seven times the size
of Manhattan, has put an even greater portion of glacial ice at risk.
Antarctica's massive Wilkins Ice Shelf has started disintegrating
under the effect of global warming, satellite images by University of
Colorado's National Snow and Ice Data Centre showed.
The collapse of a substantial section of the shelf was triggered on
February 28 when an iceberg measuring 41 by 2.4 kilometres broke off
its southwestern front. That movement led to disintegration of the
shelf's interior, of which 414 square kilometres have already
disappeared, scientists said.
The Wilkins Ice Shelf is a broad plate of permanent floating ice
1,609km south of South America, on the southwest Antarctic Peninsula.
Now, as a result of recent losses, a large part of the 12,950-square-
kilometre shelf is supported by a narrow 5.6km strip of ice between
two islands, scientists said.
"If there is a little bit more retreat, this last 'ice buttress' could
collapse and we'd likely lose about half the total ice shelf area in
the next few years," NSIDC lead scientist Ted Scambos said.
"Wilkins is the largest ice shelf on West Antarctica yet to be
threatened. This shelf is hanging by a thread," David Vaughan of the
British Antarctic Survey said.
Jim Elliott, who was onboard a British Antarctic Survey aircraft sent
to video the damage, said the scene looked like a bomb site.
"I've never seen anything like this before - it was awesome," he said.
"We flew along the main crack and observed the sheer scale of movement
from the breakage. Big hefty chunks of ice, the size of small houses,
look as though they've been thrown around like rubble - it's like an
explosion."
"Climate warming in the Antarctic Peninsula has pushed the limit of
viability for ice shelves further south, setting some of them that
used to be stable on a course of retreat and eventual loss," Vaughan
said.
Vaughan said the Wilkins breakout would not affect sea levels because
it was already floating when it broke off.
With the Antarctic summer drawing to a close, scientists do not expect
the ice shelf to further disintegrate in the next several months.
AFP, Washington
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