http://hisz.rsoe.hu/alertmap/index.php?smp=&lang=engArea: USA, State of Alaska, Chukchi Sea,
!!! WARNING !!!
Description:
Nine polar bears were observed in one day swimming in open ocean off Alaska's northwest coast, an increase from previous surveys that may indicate warming conditions are forcing bears to make riskier, long-distance swims to stable sea ice or land. The bears were spotted in the Chukchi Sea on a flight by a federal marine contractor, Science Applications International Corp. It was hired for the Minerals Management Service in advance of future offshore oil development. The MMS in February leased 2.76 million acres within an offshore area slightly smaller than Pennsylvania. Observers Saturday were looking for whales but also recorded walrus and polar bears, said project director Janet Clark. Many were swimming north and ranged from 15 to 65 miles off shore, she said. Department of Interior Secretary Dirk Kempthorne in May declared polar bears a threatened species because of an alarming loss of summer sea ice and forecasts the trend will continue.
Polar bears spend most of their lives on sea ice, which they use as a platform to hunt their primary prey, ringed seals. Shallow water over the continental shelf is the most biologically productive for seals, but pack ice in recent years has receded far beyond the shelf. Conservation groups fear that one consequence of less ice will be more energy-sapping, long-distance swims by polar bears trying to reach feeding, mating or denning areas. Steven Amstrup, senior polar bear scientist for the U.S. Geological Survey in Anchorage, said the bears could have been on a patch of ice that broke up northwest of Alaska's coast. "The bears that had been on that last bit of ice that remained over shallow shelf waters, are now swimming either toward land or toward the rest of the sea ice, which is a considerable distance north," he said in an e-mail response to questions. It probably is not a big deal for a polar bear in good condition to swim 10 or 15 miles, Amstrup said, but swims of 50 to 100 miles could be exhausting.
"We have some observations of bears swimming into shore when the sea ice was not visible on the horizon," he said. "In some of these cases, the bears arrive so spent energetically, that they literally don't move for a couple days after hitting shore." Only further research can tell the effect of greater swimming distances on polar bear populations, he said. "Polar bears can swim quite well, but they are not aquatic animals," he said. "Their home is on the surface of the ice." Satellite data Saturday showed the main body of pack ice about 400 miles offshore with one ribbon about 100 miles off Alaska's coast, said Mark Serreze of the National Snow and Ice Data Center. Clark said the animals' origin and destination could not be known without radio collar monitoring. "To go out there and say they were going from this point to this point would be complete speculation," Clark said. Observers have no indication of the fate of the nine polar bears observed Saturday.
-------------------------
and if that isn't bad enough - look at this:
Area: Greenland, , Northern regio,
!!! WARNING !!!
Description:
In northern Greenland, a part of the Arctic that had seemed immune from global warming, new satellite images show a growing giant crack and an 11-square-mile chunk of ice hemorrhaging off a major glacier, scientists said Thursday. And that's led the university professor who spotted the wounds in the massive Petermann glacier to predict disintegration of a major portion of the Northern Hemisphere's largest floating glacier within the year. If it does worsen and other northern Greenland glaciers melt faster, then it could speed up sea level rise, already increasing because of melt in sourthern Greenland. The crack is 7 miles long and about half a mile wide. It is about half the width of the 500 square mile floating part of the glacier. Other smaller fractures can be seen in images of the ice tongue, a long narrow sliver of the glacier. "The pictures speak for themselves," said Jason Box, a glacier expert at the Byrd Polar Research Center at Ohio State University who spotted the changes while studying new satellite images. "This crack is moving, and moving closer and closer to the front. It's just a matter of time till a much larger piece is going to break off.... It is imminent."
The chunk that came off the glacier between July 10 and July 24 is about half the size of Manhattan and doesn't worry Box as much as the cracks. The Petermann glacier had a larger breakaway ice chunk in 2000. But the overall picture worries some scientists. "As we see this phenomenon occurring further and further north — and Petermann is as far north as you can get — it certainly adds to the concern," said Waleed Abdalati, director of the Center for the Study of Earth from Space at the University of Colorado. The question that now faces scientists is: Are the fractures part of normal glacier stress or are they the beginning of the effects of global warming? "It certainly is a major event," said NASA ice scientist Jay Zwally in a telephone interview from a conference on glaciers in Ireland. "It's a signal but we don't know what it means." It is too early to say it is clearly global warming, Zwally said. Scientists don't like to attribute single events to global warming, but often say such events fit a pattern. University of Colorado professor Konrad Steffen, who returned from Greenland Wednesday and has studied the Petermann glacier in the past, said that what Box saw is not too different from what he saw in the 1990s: "The crack is not alarming... I would say it is normal."
However, scientists note that it fits with the trend of melting glacial ice they first saw in the southern part of the massive island and seems to be marching north with time. Big cracks and breakaway pieces are foreboding signs of what's ahead. Further south in Greenland, Box's satellite images show that the Jakobshavn glacier, the fastest retreating glacier in the world, set new records for how far it has moved inland. That concerns Colorado's Abdalati: "It could go back for miles and miles and there's no real mechanism to stop it."
----------------------------
Printer-friendly format
Email this thread to a friend
Bookmark this thread
(1000+ posts)
Send PM |
Profile |
Ignore
