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Huge Arctic ice shelf breaks away

By: Dr. Jeff Masters, 12:28 AM GMT on December 31, 2006

A huge ice shelf 25% larger than the island of Manhattan broke off of Canada's Arctic coast in 2005, according to a press release issued Thursday by researchers at the University of Ottawa's Laboratory for Cryospheric Research. The Ayles Ice Shelf, located on the northern coast of Ellesmere Island, was about 66 square kilometers in area and 100 feet thick. The ice shelf has drifted about 50 km, and is now a big iceberg about 800 km south of the North Pole. It is expected to slowly melt over the next few years and drift into the Beaufort Sea, where it may pose a threat to shipping and oil and gas developments. Melt water from the giant new iceberg will not contribute significantly to sea level rise, since it was already floating on the ocean surface (think how ice cubes floating in a cup of water do not raise the level of the water after they melt). A slight sea level rise will occur, because the melting fresh water will displace denser salty ocean water. The addition of the ice shelf's fresh water to the Arctic Ocean will not freshen the ocean detectably, since the ice shelf will melt slowly and is a relatively small chunk of ice in a huge ocean.

Figure 1. October 21, 2003 image of the northern coast of Canada's Ellesmere Island, showing the location of the Ward Hunt Ice Sheet, which broke up in 200-2003, and the Ayles Ice Sheet, which broke away in August 2005. Image credit: NASA.

Figure 2. NASA Modis satellite image from August 13, 2005, showing the Ayles Ice Shelf detaching from Ellesmere Island.

The Ayles Ice Shelf actually broke off on August 13, 2005, and created tremors strong enough to be detected by seismographs 250 km away. The break off was not announced until researchers had time to study the event. The ice shelf was one of six large ice shelves remaining in the Canadian Arctic. The region's largest ice shelf, the Ward Hunt Ice Shelf, broke up in 2000-2003. In both cases, the warming of the average air temperature by 1.8 �C in the past 40 years is thought to be the cause. Unusually warm temperatures in 2005 proved to be the final blow to the ice sheet. The hot summer of 2005 led to the greatest loss of Arctic ice ever observed--about a 20% decrease over the levels observed in 1979, when reliable record keeping began. The ice shelves along the northern coast of Ellesmere Island have thinned 90% since they were discovered in 1906 by polar explorer Robert Peary.

While much of the past warming of the Arctic can be attributed to natural causes, a significant and growing portion of the warming is thought to be due to human-caused climate change, according to the Arctic Climate Impact Assessment (ACIA), a 2004 study compiled by 300 expert Arctic scientists. Considering that radiocarbon dating of driftwood on the Ayles Ice Shelf puts its age at 3,000 years old, I think it is very unlikely that the shelf would have collapsed without the aid of warming from greenhouse gases emitted by humans. The Arctic is expected to warm another 2-4 �C by the end of the century, which should permanently destroy all the remaining ice shelves in the Arctic. These ice shelves hold a rare and unique ecosystem of cold-adapted organisms, and their loss will mean something irreplaceable and fascinating will be forever lost.

I'll have much more to say on what's going on in the Arctic in early 2007. Have a Happy New Year, everyone! My resolution will be to appreciate all that I have, and all the beauty and diversity the world has to offer. Much that is unique and beautiful on Earth will be lost to future generations. It's up to us to appreciate these things now--and work to save what we can, without crippling civilization in the process.

Jeff Masters

Climate Change

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Yeah that true
Guessing in Tropical Tropical terms can be a dicey thing.I concentrate on the Storm prior to and at landfall as it occurs.As that is where the effects count.
LOL... even if they forecast 20 storms, that means nothing, as last year made very clear. Also, even if there were 20 storms and many very powerful storms, they could all recurve out to sea; many storms do not mean a bad season. Example: 1995 - all Atlantic storms recurved out to sea with only Gulf/Caribbean storms hitting the U.S. (of course Opal did hit the U.S. as a major hurricane, but I am leaving that for another day); only a few storms formed near the U.S. last year or in areas where they could hit land; who says that this year will be different (like 2004 and 2005, where steering patterns favored landfalls).
Like Michael says.Its impacts that count.The 92 year is a good reminder.The A storm didnt start to Aug...and look what happened.
Yeah Just Thinck how bad some of the Predictions or guesses were made by Meteroligists.
whats a hypercane season?
92 tracks...Link Now I have to go start the lawnmower...LOL
That was a long time ago
La nina's displace the Bermuda high further west.Opposite with El Nino.
TSR's forecast comes out on Friday.Mine on Thursday night.See my blog archive for my December forecast for the 2007 Hurricane season.
Raining down here aross miami its been an ugly afternoon.Light rain has been falling since around 2:30pm this afternoon.Hopefully things will light up by tommorow.
Its going to be an interesting Hurricane Season This Year
Hopefully we will have persistant troffiness turning everthing out to sea like we saw in 06.
Did you get my Email 23? over WU
Sure did thunderstorm2...Thanks
No problem
ive got a whole load of stuff on my blog about Climate Change. It took me a while to write
Yea i saw it,looks great.
Im hoping to find more stuff
If any hurricane come towards Florida im looking forward to experience the wind because it would be my first time. But if Florida gets hit by a very powerfull Hurricane then i might not enjoy it
Temperature departures since December 1st::

Thunderstorm2 check your mail!Thanks
Will Do
23 Check your mail
My blog on giant eyewalls has been updated and now includes an in depth analysis on Hurricane Katrina. Feel free to visit and leave comments.
Thunderstorm2 check your mail!Thanks
23 check your mail thanks
23 check your mail thanks

For how many consecutive days will St. Louis experience above normal temperatures (25 as of Jan 2nd)?

How much snow will St. Louis get this winter season (July-June, currently 4.4 inches)?

What will be the main form of severe weather affecting the U.S. in 2007?

What part of the country will get the worst severe weather in 2007 (damage, deaths, etc; related to previous question)?

Note that the last two questions are related; you can't say that hurricanes will cause the most severe weather and then answer Midwest because the Midwest doesn't get hurricanes. Also, for comparison, 10.5 inches of snow fell last winter and there were 44 days of continuously above normal temperatures. Also, answering "same as 2006" for the last question means the same thing as saying that severe thunderstorms/tornadoes will be the main threat because the worst severe weather occurred from these in the Missouri-Illinois-Tennessee regions.
It sure got quiet in here all of a sudden.

Winter will make a comeback the week after next week:


Weather bureau warns of 'perfect storm' in [Western Australia]

Above is a link to an ABC (Australian Broadcasting Corporation) news article that is a little alarming.
GFS doesn't seem to think much of it.
La Nina bringing yet another weak storm into So Cal. Yesterday it was expected to bring around 0.25 inches. Today its down to 0.05-0.10 and most local weather man agree that you shouldnt be shocked if your area doesnt get any rain at all.

No one is talking about how dry it is down here in So Cal cause the rainbucket for Downtown LA has been very lucky and been under some heavyer showers. Southern LA county, Orange county, and San Diego county have been bone dry and not real change expected.

GFS for the past few days was advertising next week a very cold snap with very limited moisture for all of the west. Very cold with snow levels in Norhern Cal down to 500 feet. Has pulled back on that prediction today.(note cold snaps that make it far into the south west mostly only happen Durning La Nina year)

Anyways where ever El Nino is hiding its dong a good job.
This was Max Mayfield's last official day as NHC Director
wheres dr m and his new update where aron have not her from him in a long time
It's La Nina, not El Nina.
and what do u mean by average them?
LOL - actually it's an El Nino just now, not la Nina or el Nina..
Isobel was too large and unorganized to rapidly intensify. Lucky break for Australia there.

BoM Isabel forecast map.
Area of Responsibility
Perth Bureau of Metoerological
Region: Northwest Australia

Current Storm Status
Tropical Low 01U (Ex-Isobel)
20.1S 119.8E -- 30 knots 992 hpa

Warning Alert
Former Tropical Cyclone Isobel has sustained winds of 30 knots with wind gusts of 45 knots.

70 nm east of Port Hedland and is reported moving south-southeast at 15 knots (28 km/h)

Tropical Cyclone Warning Cancelled
The will be the final warning on this system