http://story.news.yahoo.com/news?tmpl=story&cid=624&ncid=624&
e=1&u=/ap/20031016/ap_on_sc/glacier_melt_1
Fri, Oct 24, 2003
Study:
South America Glaciers Melting Faster
WASHINGTON - Melting
of glaciers in the Patagonian ice fields
of southern Argentina and Chile has doubled in recent years,
caused by higher temperatures, lower snowfall and a more rapid
breaking of icebergs, a study suggests.
Using satellites from
the National Aeronautics and Space Administration
and the Defense Department, researchers measured the loss from
two
ice fields on the southern tip of South America and found that
the
rate of melting doubled from 1995 to 2000 when compared with earlier
measurements.
A report on the findings
appear Friday in the journal Science.
The two ice fields
cover a total of 6,600 square miles and contain
63 glaciers. Some dump their water into the ocean, while others
flow
into high lakes.
Researchers estimated
that the glaciers are losing the equivalent
of 10 cubic miles of ice every year now. This is enough to annually
raise the world's sea level by about four-one thousandths of an
inch,
the scientists calculated.
This means that the
mountain glaciers in Patagonia are contributing
an unusually large amount of water to the sea when compared with
some much larger ice fields, the researchers said.
Alaska, for instance,
has five times more ice than Patagonia.
Yet, the melt off from Patagonia is almost a third as much as
the melt off from Alaska's mountain glaciers.
The researchers concluded
that the Patagonia ice is melting
faster now due to warmer air temperatures, a decrease in
precipitation and a more rapid breaking of pieces of icebergs
into the ocean, known as calving.
The study was conducted
by Eric Rignot of the Jet Propulsion
Laboratory in Pasadena, Calif.; Andres Rivera of the University
of Chile in Santiago, and Gino Casassa of the Center of Scientific
Studies in Valdivia, Chile.
Mountain glaciers are
retreating in many parts of the world
and earlier studies have shown the melting high altitude ice
is helping to boost a gradual rise sea level. The researchers
estimate that water from the Patagonia ice fields is contributing
about 9 percent of the sea level rise caused by the melting of
mountain glaciers. Alaska's contribution to water reaching the
sea from mountain glaciers is estimated at about 30 percent.
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On the Net:
Science: www.sciencemag.org
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