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Espen

Soon it will not be worth giving them names. Or maybe better Costa del Serson or Costa del Hunt?

Kevin McKinney

Poignant to think that Harold Serson's colleagues probably thought that they were honoring him in quasi-permanent fashion.

"Sic transit gloria mundi"--but not always quite that suddenly.

logicman

Thanks for the giant plug, Neven!

There is a very high resolution image of the remnants of the Ward Hunt ice shelf in 2010 over at NASA.
http://earthobservatory.nasa.gov/IOTD/view.php?id=45463
MODIS images show that the break-up continued after the date of the NASA image - August 18 2010.

The large remaining piece is bonded at each end to ice domes. The lines between the shelf ice and the dome ice can just about be seen in some MODIS images.

I have had my eye on this area throughout summer. The shelf appears to have some fissures but overall it hasn't budged.

MY best guess is that because it is so well bonded to solid ice at each end it will not detach as spectacularly as other shelves but will first break up in situ. Maybe as early as next summer.

Andrew Xnn

Maybe a future post around this topic could be titled:

"We did it to our Shelves"


Kevin McKinney

CBC coverage of the story is here:

http://www.cbc.ca/news/technology/story/2011/09/28/north-ice-shelves.html

The written copy adds nothing to Neven's post, but there is a video interview with Dr. Mueller that is of interest.

Timothy Chase

I noticed this new post this morning but at work they still have me on IE6 and I am not supposed to comment at blogs.

Anyway, I seem to remember that when the Arctic becomes "ice free" they actually expect some ice to remain, the stuff that would be toughest to melt. I thought it was the Canadian shelves. Maybe someone can correct me if I was wrong. In either case it looks like this permanent ice is much more frail than that.

Trying to find out I did some digging in news archives and while I didn't find what I was looking for I did find this bit which may be of interest:

Until this year, other than the big section that broke off the Ayles ice sheet in 2005, there hadn't been any evidence of changes in Arctic ice shelves. This year a threshold appears to have been crossed because the remaining ice shelves are covered in zig-zagging cracks, Copland said: "Things are changing really quickly in the Arctic."

Arctic Meltdown Signals Long-Term Trend
By Stephen Leahy
UXBRIDGE, Canada , Sep 5, 2008 (IPS)
http://www.ipsnews.net/news.asp?idnews=43803

Neven, thank you for this year's coverage of the Arctic, for covering this story, and for keeping this blog open even as the Arctic does its annual "recovery."

Rich and Mike Island

How much ice is in the Ellesmere ice sheets on land? With the ice shelves breaking up, the glaciers will flow faster into the ocean. Will that raise the oceans by milimeters? Or inches?

We live on a barrier island, every inch counts!

Michael Fliss

Below is a favorite image of mine of Dr. Derek Mueller wading in a meltwater lake of the Markham Ice Shelf. This is the true image of our graphs, our math, our maps of bright, false colors: The meeting of two ends of the food chain that need each other.

http://www.people.trentu.ca/~dmueller/iceshelfloss2008/markham.html

Michael Fliss

It is just stunning to see in the animations below how rapidly, in only days, these massive areas of ice break away from the ice shelf where they have been secured for thousands of years and stream towards the Beaufort Sea.

http://www.people.trentu.ca/~dmueller/iceshelfloss2008/serson.html

http://www.people.trentu.ca/~dmueller/iceshelfloss2008/wardhunt.html

Michael Fliss

A unique ecosystem was lost with the crumbling of the Ward Hunt Ice Shelf and the destruction of its epishelf lake. The change was sudden and gone was the chance to study microbial communities that form the base of the food chain from which arctic ocean life draws its energy.

http://earthobservatory.nasa.gov/Features/wardhunt/

Neven

Thanks for those great links, Michael!

And thanks to you too, Timothy.

Twemoran

Ward-Hunt's bifurcation was noted on September 11th on this blog, it was still holding together on the 9th.

The discussion was in the historical minimum in sea ice extent tread. ;-)

Andrew Xnn

Here's an article about 2002 observations regarding the breakup of the Ward Hunt Ice shelf:

http://earthobservatory.nasa.gov/Features/wardhunt/

"Changes became apparent in the 1950s when ice-shelf investigators examined early 20th-century records of Arctic explorer Robert Peary. “It was already clear there was a vast region — much greater than today — of thick, ancient ice floating on the ocean. We estimate that this ice has now retreated by about 90 percent relative to Peary’s observations,” said Vincent."

Andrew Xnn

Here's a 1986

http://pubs.aina.ucalgary.ca/arctic/Arctic39-1-15.pdf

"The largest observed ice island calving occurred at Ward Hunt Ice Shelf (Fig. l ) , where almost 600km2 of ice broke away at some time between August 1961 and April 1962 (Hattersley-Smith, 1963)."

and

"During the period 1959-74 some 48 km2,involving 3.3 km3, of ice calved from Milne and Ayles ice shelves and the
remainder of Ayles Ice Shelf moved some way out of the mouth of Ayles Fiord. Although the total loss of ice from these events is
much less than the massive loss from Ward Hunt Ice Shelf, it still constitutes a considerable loss, indicating the ice shelves remain unstable and prone to disintegration. In 1982 Area B (Fig. 2B) was severely fractured and considered likely to disintegrate. This had occurred by spring 1985. Despite the large change at the front of Ward Hunt Ice Shelf in 1962, the ice front remains changeable, since between 1980 and 1983 a total of about 80 km2 of ice was lost,including three large ice islands (Jeffries and Serson, 1983).

Any ice front can be expected to be unstable,and the periodic calving of ice islands and thick sea ice might be a normal process akin to, but smaller scale than, iceberg calvings from a glacier. Further losses from the ice shelves and landfast sea ice of northern Ellesmere Island are to be expected, and it is clear that there is a quite rapid degeneration of thick sea ice where calvings occur."

Chris Reynolds

Neven,

Just posted a response to your post, which follows on from Andrew Xnn's point about the earlier Vincent paper of 2001.

http://dosbat.blogspot.com/2011/09/loss-of-ellesmere-ice-shelves.html

In my usually rambling style I digressed to address Pierre over at Tamino's.

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