Posted on 09/23/2003 5:56:43 AM PDT by pa_dweller
The largest ice shelf in the Arctic has fractured, releasing all the water from the freshwater lake it dammed.
The Ward Hunt Ice Shelf is located on the north coast of Ellesmere Island in Canada's Nunavut territory.
The huge mass of floating ice, which has been in place for at least 3,000 years, is now in two major pieces.
The scientists who report the break-up in the journal Geophysical Research Letters (GRL) say it is further evidence of ongoing and accelerated climate change in the north polar region.
The researchers - Warwick Vincent and Derek Mueller of Laval University in Quebec City, Canada; and Martin Jeffries of the University of Alaska Fairbanks, US - have been studying the shelf onsite and through satellite radar imagery and helicopter overflights.
Lost water
They say the fracturing - which has been developing since the spring of 2000 - is the end result of a three-decade-long decline.
"We're now seeing some very extensive fractures in it that extend many kilometres horizontally across the ice-shelf; and they extend all the way through from the top to the bottom, many tens of metres through the ice shelf. And we've never seen fractures like this," Dr Jeffries told the BBC.
They warn that major free-floating ice islands could pose a danger to shipping and to drilling platforms in the Beaufort Sea.
The immediate consequence of the rupture has been the loss of almost all of the freshwater from the Northern Hemisphere's largest epishelf lake (a body of mostly freshwater trapped behind an ice shelf).
The freshwater lay in the 30-kilometre- [20-mile] long Disraeli Fiord.
At its deepest, the freshwater measured 43 metres [140 feet], and sat atop 360 metres [1,200 feet] of denser ocean water.
Other worlds
The loss of fresh and brackish water has changed the environment for the microscopic animals and algae living in the area.
"These are very rare and unusual ecosystems and they have been studied as possible analogues for life on a colder Earth and life on the planets," Dr Jeffries said.
"And if we are losing them, we are losing the opportunity to study life earlier in Earth history and elsewhere in the Solar System."
Scientists monitor continuously ice-shelf development in both the Arctic and the Antarctic.
In the southern polar region, recent times have witnessed some dramatic changes.
Last year, the 3,250-square-km Larsen B Ice Shelf on the Antarctic Peninsula shattered over a period of a month into thousands of icebergs.
The peninsula is one of the three fastest-warming regions on Earth - temperatures have gone up 2.5 degrees in 50 years.
Global change
Mueller, Vincent, and Jeffries say their calculations suggest changes of a similar nature have been taking place in the Ellesmere Island area.
A century ago, the entire northern coast of the island was reported to be fringed with a continuous ice shelf. About 90% of that ice area had been lost by 1982, the scientists say.
The precise timing of the break-up of the remnant Ward Hunt Ice Shelf may have been influenced by freeze-thaw cycles, wind, and tides, they tell GRL.
Other factors may include changes in Arctic Ocean temperature, salinity, and flow patterns, they add.
"Computer models show quite convincingly that global climate change would be manifested first and amplified in the polar regions and in particular in the Arctic," Dr Jeffries said
"Our observations at Ward Hunt Ice Shelf fit in with a broader picture of Arctic change which fits in with our understanding of how the Arctic climate would respond to global change."
That's because Dr Jeffries and the others are real scientist doing real science.
What precisly could we do about natural changes in the Earth's climate and assuming man is responsible what can we actually do to revert the process ?
Obviously it's time to get off the planet...
Not so fast. Lots of differing opinions by smart people on that question. Some "evidence" gathered by some methods and in some locations show warming, others cooling.
Yes, you're right (with a hangdog look). I thought of that but got cold feet!
The reason canaries were taken into mines is because there was a demonstrated relationship between gas concentrations and dying birds. There is as yet no demonstrated relationship between human activity and climate change on a global scale.
If you want to ignore the clear signals from the planet and make inane comments about SUVs - feel free, but the signs of global warming are there.
in·ane
1. Lacking in sense; empty-headed; silly: an inane person. 2. Empty of meaning; pointless; foolish: an inane remark. 3. Having no contents or inner substance; void; empty.I chose SUV's because they are a current touchstone for a lot of opposing positions on various issues. Please choose one of the above definitions and explain how it applies to my SUV comment in light of the constant drone of 'this causes global warming' or 'that causes global warming'.
Were it not for the Republican-caused power failure which caused my home Cray to crash, and the VRWC taking away my grant money, I would have had hard numbers for you today. In the meantime, you Freeper fellows will just have to live in suspense.
One thing I know for sure and with scientific certainty: women and minorities will continue to suffer most because the Republicans do not care about Global Warming.
The largest ice shelf in the Arctic, a solid feature for 3,000 years, has broken up, scientists in the United States and Canada said on September 22, 2003. They said the Ward Hunt Ice Shelf, on the north coast of Ellesmere Island in Canada's Nunavut territory, broke into two main parts, themselves cut through with fissures. A freshwater lake drained into the sea, the researchers reported. (Reuters Graphic)
Figure 1-3 Climate of the last 12,000 years
Agriculture and the age of man happened because of the exit of earth from a 90 thousand year old ice age into that moderate climate. I don't buy the rhetoric of warmer is bad nor that warmer is necessarily even where we are actually headed, nor do many scientists in a position to judge the science of such matters:
Petition Project: http://www.oism.org/pproject/s33p357.htm
During the past 2 years, more than 17,100 basic and applied American scientists, two-thirds with advanced degrees, have signed the Global Warming Petition.
Specifically declaring:
"There is no convincing scientific evidence that human release of carbon dioxide, methane, or other greenhouse gasses is causing or will, in the foreseeable future, cause catastrophic heating of the Earth's atmosphere and disruption of the Earth's climate."
Signers of this petition so far include 2,660 physicists, geophysicists, climatologists, meteorologists, oceanographers, and environmental scientists (select this link for a listing of these individuals) who are especially well qualified to evaluate the effects of carbon dioxide on the Earth's atmosphere and climate.
Signers of this petition also include 5,017 scientists whose fields of specialization in chemistry, biochemistry, biology, and other life sciences (select this link for a listing of these individuals) make them especially well qualified to evaluate the effects of carbon dioxide upon the Earth's plant and animal life.
Nearly all of the initial 17,100 scientist signers have technical training suitable for the evaluation of the relevant research data, and many are trained in related fields.
I'll bet those suckers broke the damn thing!
Then they'd better get on with it quickly, eh? Time's a'wasting.
I think what he's really afraid of is having to go out and find a non-subsidized job.
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