[lit-ideas] Global warming and Ice shelves

 
This week has been a madhouse here and I haven't been able to read all of  
the posts to Lit-id yet, so I don't know what the global warming thread has  
become or if it has died out, but I do find this article very interesting.   I 
would love to have been there and seen it.
 
Julie Krueger
 
 
     
 
Ancient ice shelf breaks free from Canadian  Arctic


TORONTO, Ontario (AP) -- A giant ice  shelf the size of 11,000 football 
fields has snapped free from Canada's  Arctic, scientists said.
The mass of ice broke clear 16 months ago from the coast of Ellesmere  
Island, about 800 kilometers (497 miles) south of the North Pole, but no  one 
was 
present to see it in Canada's remote north. 
Scientists using satellite images later noticed that it became a newly  
formed ice island in just an hour and left a trail of icy boulders  floating in 
its 
wake. (_Watch the satellite images that clued in  ice watchers_ 
(javascript:cnnVideo('play','/video/tech/2006/12/29/morriset.canada.arctic.ice.breakup.cbc',
'2007/01/12');) ) 
Warwick Vincent of Laval University, who studies Arctic conditions,  traveled 
to the newly formed ice island and could not believe what he  saw. 
"This is a dramatic and disturbing event. It shows that we are losing  
remarkable features of the Canadian North that have been in place for many  
thousands of years. We are crossing climate thresholds, and these may  signal 
the 
onset of accelerated change ahead," Vincent said Thursday. 
In 10 years of working in the region he has never seen such a dramatic  loss 
of sea ice, he said. 
The collapse was so powerful that earthquake monitors 250 kilometers  (155 
miles) away picked up tremors from it. 
The Ayles Ice Shelf, roughly 66 square kilometers (41 square miles) in  area, 
was one of six major ice shelves remaining in Canada's Arctic. 
Scientists say it is the largest event of its kind in Canada in 30  years and 
point their fingers at climate change as a major contributing  factor. 
"It is consistent with climate change," Vincent said, adding that the  
remaining ice shelves are 90 percent smaller than when they were first  
discovered 
in 1906. 
"We aren't able to connect all of the dots ... but unusually warm  
temperatures definitely played a major role." 
Laurie Weir, who monitors ice conditions for the Canadian Ice Service,  was 
poring over satellite images in 2005 when she noticed that the shelf  had split 
and separated. 
Weir notified Luke Copland, head of the new global ice lab at the  University 
of Ottawa, who initiated an effort to find out what  happened. 
Using U.S. and Canadian satellite images, as well as data from seismic  
monitors, Copland discovered that the ice shelf collapsed in the early  
afternoon 
of August 13, 2005. 
"What surprised us was how quickly it happened," Copland said. "It's  pretty 
alarming. 
"Even 10 years ago scientists assumed that when global warming changes  occur 
that it would happen gradually so that perhaps we expected these ice  shelves 
just to melt away quite slowly, but the big surprise is that for  one they 
are going, but secondly that when they do go, they just go  suddenly, it's all 
at once, in a span of an hour." 
Within days, the floating ice shelf had drifted a few miles  (kilometers) 
offshore. It traveled west for 50 kilometers (31 miles) until  it finally froze 
into the sea ice in the early winter. 
The Canadian ice shelves are packed with ancient ice that dates back  over 
3,000 years. They float on the sea but are connected to land. 
Derek Mueller, a polar researcher with Vincent's team, said the ice  shelves 
get weaker and weaker as the temperature rises. He visited  Ellesmere's Ward 
Hunt Ice Shelf in 2002 and noticed it had cracked in  half. 
"We're losing our ice shelves, and this a feature of the landscape that  is 
in danger of disappearing altogether from Canada," Mueller said. "In  the 
global perspective Antarctica has many ice shelves bigger than this  one, but 
then 
there is the idea that these are indicators of climate  change." 
The spring thaw may bring another concern as the warming temperatures  could 
release the ice shelf from its Arctic grip. Prevailing winds could  then send 
the ice island southwards, deep into the Beaufort Sea. 
"Over the next few years this ice island could drift into populated  shipping 
routes," Weir said. "There's significant oil and gas development  in this 
region as well, so we'll have to keep monitoring its location over  the next 
few 
years." 
Copyright 2006 The _Associated Press_ 
(http://www.cnn.com/interactive_legal.html#AP) . All rights reserved.This  
material may not be published, broadcast, 
rewritten, or  redistributed.
          
      Find this article at:  
http://www.cnn.com/2006/TECH/science/12/29/canada.arctic.ap/index.html    
     (javascript:void(printArticle());)

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