Canadian Ice Shelves Breaking up at High Speed
As Patrick Lockerby noted back in April:
The oldest non-glacial ice in the northern hemisphere is a small remnant of the former Ellesmere Ice Shelf which began forming about 5500 years ago. That remnant is breaking up. Where the ice shelf has vanished the fjords are free of perennial ice for the first time in 3000 to 5500 years. It seems likely that very soon the oldest non-glacial ice will be a mere 5 years old, or less.
And in the seminal paper by Polyak et al 2010, History of sea ice in the Arctic, it says:
The severity of present ice loss can be highlighted by the breakup of ice shelves at the northern coast of Ellesmere Island, which have been stable until recently for at least several thousand years based on geological data.
Here are the visuals (found on this web page from Carleton University):
Map of Ellesmere Island ice shelves on August 8th 2005: Ice shelves are outlined in black. Blue denotes the coast of Ellesmere Island. Left to Right: Serson, Petersen, Milne, Ayles, Ward Hunt and Markham, MODIS images from the Rapid Response Project at NASA/GSFC. Maps courtesy of Derek Mueller, Carleton University.
By July 21st 2011 the Serson Ice Shelf was divided into Serson A and B. The Ayles and Markham Ice Shelves had completely disappeared:
After this year's melting season Serson B is all but gone on August 26th 2011, and now it's the large Ward Hunt Ice Shelf that has been divided into a western and eastern part.
Again, from the Carleton University web page: