Canberra - An iceberg the size of urban Sydney has broken away
from east Antarctica, but not due to climate change, the Australian
Antarctic Divisions (AAD) said on Tuesday.
The 1,636-square-kilometre table iceberg "calved" from the Amery Ice
Shelf, the third-largest on the ice continent, located between
Australia's Davis and Mawson research stations, on September 26.
The iceberg, officially called D-28, separated from the front of the
ice shelf, which scientists had been monitoring closely since the
early 2000s, according to AAD, an Australian government agency.
It had been predicted that a large iceberg would break off between
2010-2015.
"We don't think this event is linked to climate change," said Helen
Amanda Fricker, a professor at the US-based Scripps Institution of
Oceanography.
"It's part of the ice shelf's normal cycle, where we
see major calving events every 60-70 years."
The last major calving event on the Amery Ice Shelf, which has an
estimated floating ice area of 60,000 square kilometres, was in
1963-64.
"We knew it would happen eventually, but just to keep us all on our
toes, it is not exactly where we expected it to be," Fricker said.
Ice shelves are floating platforms of ice attached to coastlines.
Ben Galton-Fenzi, a glaciologist with AAD, said the fracture will not
directly affect sea levels.
"But what will be interesting to see is how the loss of this ice will
influence the ocean melting under the remaining ice shelf and the
speed at which the ice flows off the continent," he said.