World's Glaciers Rapidly Melting, Causing Quakelike Disruptions

http://abcnews.go.com/Technology/GlobalWarming/story?id=1760048&page=1

By CLAYTON SANDELL
ABCNEWS


March 23, 2006 - Glaciers and ice sheets at both ends of Earth are melting
ever more quickly from below due to warmer ocean waters, advancing
sometimes in enormous earth-shaking "jolts," new research by a NASA
scientist has found.


Scientists have already determined that Greenland's and Antarctica's
glaciers have melted at accelerating rates because of warmer air
temperatures. But in findings published today in the journal Science,
researchers have presented new evidence that warmer ocean temperatures also
melt the glaciers from below.

"There is a big temperature contrast between the warm ocean water and the
cold ice, and melting occurs at a very rapid rate," said Robert
Bindschadler, a glaciologist at the NASA Goddard Space Flight Center and
author of the study. "The melting reduces the friction that holds these
glaciers back, allowing them to accelerate."

That increased acceleration has led to an increasing frequency of "glacial
earthquakes," according to a separate paper also in Science.


Earthquakes on the Rise


The number of glacial earthquakes has doubled in the past five years as ice
sheets respond to a warming climate, according to a team led by Harvard
University researcher Göran Ekström. Most of the earthquakes occur in late
summer.

"People often think of glaciers as inert and slow moving, but in fact they
can also move rather quickly," Ekström said in a statement. "Some of
Greenland's glaciers, as large as Manhattan and as tall as the Empire State
Building, can move 10 meters in less than a minute, a jolt that is
sufficient to generate moderate seismic waves."

To Ekström, the reason behind all the increased glacier activity is clear.

"I think it is very hard not to associate this with global warming," he
said.

Bindschadler, who spoke with reporters on a conference call, said his new
findings are consistent with other recent research that shows Greenland and
Antarctica melting faster, also because of global warming.

In early March, scientists reported that Greenland's glaciers moved at
twice their expected speed, up to 120 feet per day, which has nearly
doubled the amount of fresh water being dumped into the ocean in only five
years.






"I think what's going to happen in the future is a continued acceleration
of sea level rise," Bindschadler said. "The rate is going to increase and
the magnitude is going to increase. And that's what alarms me about this."






Bindschadler said he is working to better understand the processes at work
so that scientists can better predict what will happen with some degree of
certainty.






"But this does not comfort me in my view of the future," he said.


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