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The Calving of the Ayles Ice Shelf
The Ayles Ice Shelf is located on the north coast of Ellesmere Island in Nunavut, Canada, approximately 800 km from the North Pole.
On August 13 2005, a huge section of the Ayles Ice Shelf broke off into the Arctic Ocean. This process is called calving. The resulting ice island is currently trapped in winter fast ice off the coast of Ellesmere Island. The ice island is approximately 66 square kilometers in size, roughly the size of 11,000 football fields. It measures 15 km long by 5km wide and is 30 to 40 m thick. The Ayles ice island represents the largest break-up of an ice shelf in the Canadian Arctic in 30 years. The ice in the Ayles Ice Island is suspected to be up to 4,500 years old.
The ice island apparently calved off from the Ayles Ice Shelf because of anomalously warmer temperatures and persistent offshore or along shore winds. The sea ice that normally presses along the north coast of Ellesmere Island, even in summer, was replaced by an open water lead in the days leading up the August 13th 2005, which allowed the shelf to slip into the water and drift rapidly to the west.
How was the Ayles Ice Island discovered?
The fracture of the Ayles Ice Shelf was first noticed by ice analyst Laurie Weir, of the Canadian Ice Service, during routine monitoring of the eastern Arctic. Canadian RADARSAT satellite images taken of Ellesmere Island and its surrounding ice between early August and mid August 2005 showed that a massive section of the Ayles Ice Shelf had broken way on August 13th.
A discussion with fellow sea ice forecaster Trudy Wohlleben led to a meeting with Luke Copland, assistant professor at the University of Ottawa, who suggested the event be documented with a study and paper. Over the next several months, Copland (University of Ottawa), Weir (CIS) and Derek Mueller (University of Fairbanks Alaska) did post-analyses on RADARSAT, MODIS and ASTER images, and seismologic records until the fracture time was pinpointed down to the actual hour of the breakup. In less than an hour, between 1730-1830z on August 13 2005, a broad crack opened in the Ayles Ice Shelf and a massive section broke off into the sea. Once the time of the event was determined, detailed temperature and wind profiles were gathered to complete the picture.
Time series of MODIS satellite scenes showing the breakup of the Ayles Ice Shelf. All dates are in 2005, all times are in zulu (= GMT). Red arrow in first image shows location of the initial fracture. Image source: NASA
The event came to the media's attention after Luke Copland attended and presented the case in Cambridge England in August of 2006 and also when Derek Mueller and Warwick Vincent briefed Can West Reporter Margaret Munro at the ArcticNet Annual Science Meeting (ASM) in Victoria just before Christmas 2006.
The annual ArcticNet Science Meeting focuses on climate change in the North and is one of the main Arctic science meetings in North America. The ArcticNet meeting was the first scientific opportunity to present Luke Copland and Warwick Vincent’s observations from the ArcticNet summer field season and to place them in the broader context of climate change. It was also the first opportunity to present their findings to the ArcticNet partners including Inuit Tapiriit Kanatami and Parks Canada. Covering the meeting was Can West reporter Margaret Munro. She had read an abstract in the ArcticNet program, written by Julie Veillette, referring to the break-up of the Ayles shelf. Margaret Munro approached Derek Mueller and Warwick Vincent for more information.
The paper outlining the entire shelf break up has gone into review to the Geophysical Research Letters.
Where can I find more information on the Ayles Ice Island?
Where is the Ayles Ice Island going? (August 2005)
Only time will tell. If we continue to see open water leads along the coast of Ellesmere Island in summer, the ice island may break free of the sea ice and get caught up in the Beaufort Gyre Circulation and drift southwestwards. It may end up drifting into the Queen Elizabeth Islands or it may make it all the way to the Beaufort Sea. If the ice island were to reach the Beaufort Sea, it could become a problem for shipping and oil platforms.
Beacons have been placed on each of the Ayles Ice Island fragments to facilitate tracking their movement:
- Map of the eastern fragment's location and movement
- Map of the western fragment's location and movement
Ayles Ice Island Update October 2008
Shifting sea ice in Queen's Channel has fractured the Ayles ice island fragment into 3 pieces and several smaller fragments. The tracking beacon is located on the largest fragment which is identified in the image below. These fragments will continue to be monitored.
Previous Ayles Ice Island updates and associated imagery are located on our Ayles Ice Island: Past Updates and Images page.
The Canadian Ice Service thanks NASA, The Canadian Space Agency and MacDonald Dettwiler and Associates LTD. for providing imagery used on this web site.