Vast
Ice Shelf Collapses In The Arctic
By Michael McCarthy
30 December 2006
The
Independent
A
vast ice shelf in the Canadian Arctic has broken up, a further sign
of the astonishing rate at which polar ice is now melting because of
global warming.
The Ayles ice shelf, more
than 40 square miles in extent - over five times the size of central
London - has broken clear from the coast of Ellesmere Island, about
500 miles south of the North Pole in the Canadian Arctic, it emerged
yesterday.
The broken shelf has formed
an ice island, in what a leading scientist described as a "dramatic
and disturbing event", citing climate change as the cause.
The news caps a dramatic
year of discovery about just how quickly the polar ice is disappearing.
It comes as America's leading
climate scientist, James Hansen, warns in today's Independent that the
Earth is being turned into "a different planet" because of
the continuing increase in man-made emissions of greenhouse gases.
The break-up of the Ayles
shelf occurred 16 months ago, in an area so remote it was not at first
detected. "This is a dramatic and disturbing event," said
Professor Warwick Vincent of Laval University in Quebec City. "It
shows that we are losing remarkable features of the Canadian North that
have been in place for many thousands of years."Ice shelves float
on the sea, but are connected to land (as opposed to ice sheets, which
are wholly land-based). In the past five years, several ice shelves
along the fringes of the Antarctic peninsula have started to become
unstable or break up. The most spectacular was the 2002 collapse of
the Larsen B ice shelf, the size of Luxembourg.
Until now, there had not
been a similar event among the six major shelves remaining in Canada's
Arctic, which are packed with ancient ice that is more than 3,000 years
old.
Professor Vincent, who studies
Arctic ecosystems, travelled to the newly formed ice island and was
amazed at what he saw. "It's like a cruise missile has come down
and hit the ice shelf," he said. "Unusually warm temperatures
definitely played a major role. It is consistent with climate change."
The collapse was picked up by the Canadian Ice Service, which notified
Luke Copland, head of the new global ice laboratory at the University
of Ottawa. Using US and Canadian satellite images, as well as seismic
data - the event registered on earthquake monitors more than 150 miles
away - Professor Copland discovered that the ice shelf collapsed in
the early afternoon of 13 August 2005. Scientists were surprised at
the speed of the event, Professor Copland said - it took less than an
hour.
There have already been several
disturbing indications this year that the Arctic ice is melting at a
much faster rate than expected. In September, two Nasa reports showed
a great surge in the disappearance of the winter sea ice over the past
two years, with an area the size of Turkey disappearing in 12 months.
© 2006 Independent News
and Media Limited
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