Antarctic Glaciers Melting Faster
By Reuters
23 September ,
2004
Reuters
WASHINGTON - Glaciers once held up by a floating ice shelf off
Antarctica are now sliding off into the sea -- and they are going fast,
scientists said on Tuesday.
Two separate studies
from climate researchers and the space agency NASA show the glaciers
are flowing into Antarctica's Weddell Sea, freed by the 2002 breakup
of the Larsen B ice shelf.
Glaciers once held up by a floating ice shelf off Antarctica are now
sliding off into the sea -- and they are going fast, scientists said
on September 21, 2004. Two separate studies from climate researchers
and the space agency NASA show the glaciers are flowing into Antarctica's
Weddell Sea, freed by the 2002 breakup of the Larsen B ice shelf. The
Larsen ice shelf is shown Aug. 8, 2000. (NASA/USGS via Reuters)
Writing in the journal Geophysical Research Letters, the researchers
said their satellite measurements suggest climate warming can lead to
rapid sea level rise.
The teams at NASA's
Jet Propulsion Laboratory in Pasadena, California, the National Snow
and Ice Data Center at the University of Colorado in Boulder, and NASA's
Goddard Space Flight Center in Greenbelt, Maryland, said the findings
also prove that ice shelves hold back glaciers.
Many teams of researchers
are keeping a close eye on parts of Antarctica that are steadily melting.
Large ice shelves
in the Antarctic Peninsula disintegrated in 1995 and 2002 as a result
of climate warming. But these floating ice shelves did not affect sea
level as they melted.
Glaciers, however,
are another story. They rest on land and when they slide off into the
water they instantly affect sea level.
It was not clear
how the loss of the Larsen B ice shelf would affect nearby glaciers.
But soon after its
collapse, researchers saw nearby glaciers flowing up to eight times
faster than before.
"If anyone
was waiting to find out whether Antarctica would respond quickly to
climate warming, I think the answer is yes," said Theodore Scambos,
a University of Colorado glacier expert who worked on one study.
"We've seen
150 miles of coastline change drastically in just 15 years."
The affected area
is at the far northern tip of the Antarctic, just south of Chile and
Argentina. Temperatures there have risen by up to 4.5 degrees Fahrenheit
(2.5 degrees C) in the past 60 years -- faster than almost any region
in the world.
In the past 30 years,
ice shelves in the region have lost more than 5,200 square miles of
area.
"The Larsen
area can be looked at as a miniature experiment, showing how warming
can dramatically change the ice sheets, and how fast it can happen,"
Scambos said in a statement. "At every step in the process, things
have occurred more rapidly than we expected."
But not all the
melting in the Antarctic can be seen as a "miniature experiment."
The Ross ice shelf,
for example, is the main outlet for the West Antarctic Ice Sheet, with
several large glaciers that could, if they melted completely, raise
sea levels by 16 feet.
"While the
consequences of this area are small compared to other parts of the Antarctic,
it is a harbinger of what will happen when the large ice sheets begin
to warm," Scambos said. "The much larger ice shelves in other
parts of Antarctica could have much greater effects on the rate of sea
level rise."
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2004 Reuters Ltd.