19/05/2005 - An iceberg
more than twice the size of Malta has arrived
in the backyard of Australia’s Casey station
in Antarctica,
The 50km-long iceberg, 788 square kms in
area, is known as B15G. It is part of a
massive iceberg, B15, that broke away the
Ross Ice Shelf in Antarctica in March 2000.
Station leader Jeremy Smith says that B15G
is clearly visible as a long ice cliff stretching
along the horizon.
“As the Antarctic winter closes in B15G
appears as a grey line occupying ninety
degrees of arc and defining half our horizon,
in places gleaming where the sun reflects
off an ice cliff. But often it is sulking
in shadow and difficult to distinguish from
the sky in the background,” Dr Smith said.
Dr Smith says that a mathematically-minded
wag on station has calculated that the iceberg
comprises more than 220 cubic km of ice,
enough for 15,000,000,000,000,000 (or 15
thousand million, million) ice cubes. It
also equates to around 200,000 billion litres
of fresh water.
A number of these huge icebergs have spent
the past few years off the coast of George
V Land (approximately longitude 150 E) to
the east of the Mertz Glacier.
B15G has been drifting slowly from east
to west with the ocean current known as
the East Wind Drift and passed the French
Antarctic station, Dumont D’Urville in August
2004.
In the past months it has moved a distance
of more than a thousand kilometres, past
Law Dome and arrived in Vincennes Bay off
Casey station the week before last.
Glaciologists say B15G now appears to have
become grounded and could stay for days,
weeks or even months. In time, though, it
is expected to continue its westward drift
around the continent.
Meanwhile there are no known immediate
negative impacts for wildlife in the area
and there is no concern of damage to landforms.
B15G is the first iceberg of such huge
proportions observed to have entered Vincennes
Bay having moved about 150 kms south over
the continental shelf, well south of the
typical drift path expected to be followed.
