SYDNEY: New analysis has indicated that contrary to the belief that
there is large-scale melting of ice over most of Antarctica, ice is
actually
expanding in a large portion of the continent.
Antarctica has 90 per cent of the Earth's ice and 80 per cent of its
fresh water. Extensive melting of Antarctic ice sheets would be
required to raise
sea
levels substantially, and ice is melting in parts
of west Antarctica.
The destabilization of the Wilkins ice shelf generated international
headlines this month.
However, according to a report in the Australian, the picture is
very different in east Antarctica, which includes the territory
claimed by Australia.
East Antarctica is four times the size of west Antarctica and parts
of it are cooling. The Scientific Committee on Antarctic Research
report noted that the
South
Pole had shown "significant cooling in recent
decades".
According to Australian Antarctic Division glaciology program head
Ian Allison, sea ice losses in west Antarctica over the past 30
years had been more than offset by increases in the Ross Sea region,
just one sector of east Antarctica.
"Sea ice conditions have remained stable in Antarctica generally,"
Dr Allison said.
The melting of sea ice - fast ice and pack ice - does not cause sea
levels to rise because the ice is in the water.
Sea levels may rise with losses from freshwater
ice
sheets on the polar caps.
In Antarctica, these losses are in the form of icebergs calved from
ice shelves formed by glacial movements on the mainland.
Dr Allison said there was not any evidence of significant change in
the mass of ice shelves in east Antarctica nor any indication that
its ice cap was melting.
"The only significant calvings in Antarctica have been in the west,"
he said.
Ice core drilling in the fast ice off Australia's Davis Station in
East Antarctica by the Antarctic Climate and
Ecosystems Co-Operative Research Centre shows that
last year, the ice had a maximum thickness of 1.89m, its densest in
10 years.
The average thickness of the ice at Davis since the 1950s is 1.67m.
A paper to be published soon by the British Antarctic Survey in the
journal Geophysical Research Letters is expected to confirm that
over the past 30 years, the area of sea ice around the continent has
expanded.