The Wilkins Ice Shelf off the Antarctic Peninsula is seen breaking up January 18, 2009. (Xinhua/Reuters File Photo)
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BEIJING,April 29-- A New York
City-sized Antarctic ice shelf has broken into icebergs this month after the
collapse of an ice bridge widely blamed on global warming, a scientist said
Tuesday.
"The northern ice front of the Wilkins Ice Shelf has
become unstable and the first icebergs have been released," Angelika Humbert,
glaciologist at the University of Muenster in Germany, said of European Space
Agency satellite images of the shelf.
Humbert told Reuters about 700 sq km (270.3 sq mile)
of ice -- bigger than Singapore or Bahrain and almost the size of New York City
-- has broken off the Wilkins this month and shattered into a mass of icebergs.
She said 370 sq kms of ice had cracked up in recent
days from the Shelf, the latest of about 10 shelves on the Antarctic Peninsula
to retreat in a trend linked by the U.N. Climate Panel to global warming.
The new icebergs added to 330 sq kms of ice that
broke up earlier this month with the shattering of an ice bridge apparently
pinning the Wilkins in place between Charcot island and the Antarctic Peninsula.
Nine other shelves -- ice floating on the sea and
linked to the coast -- have receded or collapsed around the Antarctic peninsula
in the past 50 years, often abruptly like the Larsen A in 1995 or the Larsen B
in 2002.
The trend is widely blamed on climate change caused
by heat-trapping gases from burning fossil fuels, according to David Vaughan, a
British Antarctic Survey scientist who landed by plane on the Wilkins ice bridge
with two Reuters reporters in January.
Humbert said by telephone her estimates were that the
Wilkins could lose a total of 800 to 3,000 sq kms of area after the ice bridge
shattered.
The Wilkins shelf has already shrunk by about a third
from its original 16,000 sq kms when first spotted decades ago, its ice so thick
would take at least hundreds of years to form.
Temperatures on the Antarctic Peninsula have warmed
by up to 3 Celsius (5.4 Fahrenheit) this century, Vaughan said, a trend climate
scientists blame on global warming from burning fossil fuels in cars, factories
and power plants.
The loss of ice shelves does not raise sea levels
significantly because the ice is floating and already mostly submerged by the
ocean.
But the big worry is that their loss will allow ice
sheets on land to move faster, adding extra water to the seas.
Wilkins has almost no pent-up glaciers behind it, but
ice shelves further south hold back vast volumes of ice.
The Arctic Council, grouping nations with territory
in the Arctic, is due to meet in Tromsoe, north Norway, Wednesday to debate the
impact of melting ice in the north.
(Source:
chinadaily.com.cn/Agencies)
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