Patagonian Glaciers Melting
- Scientists: Patagonian Glaciers Melting
Mon Nov 17, 8:24 AM ET
By ALEXA STANARD, Associated Press Writer
BUENOS AIRES, Argentina - When Borge Ousland and Thomas Ulrich
trekked across the vast and wild Patagonian glaciers, they braved
heavy snows and bitterly cold temperatures - nothing to make them
think the ice was melting beneath their feet.
"We had ... a lot of snow. We got a meter (3 feet) of snow in one
night," said Ousland after the pair completed the 54-day crossing of
While the two European adventurers became the first to cross the
icefields unaided on Oct. 16, a day later the glaciers made news of
their own: A study published Oct. 17 in the journal Science found
that the Patagonian glaciers melted at twice the rate in 1995-2000 -
when compared with measurements from 1975 to 2000.
Three top scientists used maps, satellite imagery and digital
elevation models to measure the change in velocity of 63 Patagonian
glaciers over 25 years.
They found the glaciers are losing the equivalent of 10 cubic miles
of ice every year - enough to raise the world's sea level an
estimated four-one thousandths of an inch.
The shrinking is reflective of rising global temperatures,
scientists say, and is happening to glaciers around the world. As
the melting causes sea levels to rise and freshwater supplies to
disappear, scientists warn of potential worldwide economic and
environmental disaster if the process isn't reversed.
The biggest factor driving the thinning of Patagonia's glaciers is
higher temperatures, said Eric Rignot of the National Aeronautics
and Space Administration and one of the study's authors.
But he said the glaciers themselves play a role as many are prone
to "calving" - the process by which icebergs break off into
surrounding oceans and lakes.
"These types of glaciers are unstable, and more sensitive to climate
change," Rignot said. "If the climate warms, they can go into a
state of retreat. Once they start to advance, they do it quickly."
Rignot was joined in the study by Andres Rivera of the University of
Chile and Gino Casassa of that country's Center of Scientific
They reported that the melting of the Patagonian icefields now
accounts for 9 percent of annual global sea-level change from
Located near the southernmost tip of South America, the Patagonian
glaciers cover a remote region totaling 6,600 square miles. Enormous
glaciers, some blinding white and others a deep blue, fill a rugged
landscape of rivers, fjords and virgin pine forests.
Some parts receive up to 100 feet of snow a year.
Given the size of the Patagonian icefields, Rignot believes their
research will help to understand how other large ice sheets, like
those of Greenland and Antarctica, will respond to future climate
Global temperatures have been warming steadily since the mid-1970s.
Some temperature variation is normal, Rivera said, but the increases
over the past thirty years are much higher than the natural
variation observed before that time.
Many scientists believe greenhouse gases, created by human activity,
are the main cause of rising temperatures. But Rignot said
scientists cannot be sure that human activity is causing glacier
"Glaciers are melting because it's warmer...," Rignot said. "Whether
the cause of warming is from human activity or natural cycles, we
can't say for sure."
Higher temperatures, regardless of their cause, can wreak economic
and environmental havoc, scientists say.
"The glaciers are a symptom of a global malaise, rather like a fever
might indicate that you have a virus," said Raymond Bradley,
director of the Climate System Research Center at the University of
The Patagonian glaciers were hard to study in the past, Bradley
said, but with NASA (news - web sites)'s new radar imaging
technology, the glaciers are yielding information that confirms a
"It turns out what is happening there is what is happening in other
places, like Peru, Bolivia and Colombia - all of the high mountain
glaciers are melting," Bradley added.
In North America, similar changes have been noticed in glaciers in
Washington state's Cascade mountains, Glacier National Park in
Montana and Canada.
Almost 80 percent of the ice on Mount Kilimanjaro in Kenya is gone,
Bradley said. New Guinea's glaciers are vanishing, as is Arctic sea
"It's all part of the same phenomenon, which is global warming
(news - web sites)," Bradley said.
A glacier is an extended mass of ice that forms from snow
accumulation over years and then moves slowly outward. As glaciers
melt, they can form mountain lakes that can build up and suddenly
burst through dams and flood surrounding areas, Rivera said.
This has happened in Peru, Nepal and Alaska.
Italy had a close call this past summer when a lake suddenly formed
from melting ice in the Alps, threatening villages below and forcing
the Italian army to pump water away.
Still, many communities depend on glacier runoff for their
freshwater supplies. Rignot said as glaciers shrink, those supplies
"If it rains, you have water," he said. "If it doesn't rain, you
have no water."
Rignot cited the near-total disappearance of the Chacaltaya glacier
near La Paz, Bolivia, as an example. The city is scrambling to find
new freshwater sources, he said. Peru and Ecuador face similar
The process could reverse itself, albeit slowly, said Rivera.
With decades of cooler temperatures, he said, the Patagonian
glaciers could begin to expand again.
If greenhouse gases are reduced, climate trends could start moving
in the other direction. "If climate signals change in the future,
glaciers will respond," Rivera said.
The scientists hope their study draws attention to the need to
protect the Patagonian icefields. "The region is amazing," Rivera
said. "It's one of the most beautiful regions on Earth."
The melting glaciers are actually Gaia's way of COOLING or feeding
back less electro-mechanical feedbacks. What is occurring is less
snow means less hydrology to the marine biosphere and shorter
river/rainy season run off. As a consequence, the marine biosphere
lacks nutrients, and hydrates lack weighing down sediments, and the
result is a less conductive near shore boundry. Drought ensues.
Fires burn and increase particles in the air which are lifeless--IOWs
w/out specified charge and weight and size that feeds back optimal
heat for convection. Fair weather conditions then persist along the
ocean terresphere boundries and heat escapes to space.
This is very consistant w/ the Eocine, where the microbial biosphere
was dramatically depleted despite much "warmer" conditions.