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Ayles Ice Shelf

The Calving of the Ayles Ice Shelf

The Alyes Ice Shelf is located on the north coast of Ellesmere Island in Nunavut, Canada, approximately 800 km from the North Pole.

Ellesmere Island in relation to the rest of the world
Ellesmere Island in relation to the rest of the world.

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.

Arctic sea ice has experienced enhanced summertime retreats for several decades, adding to evidence of significant warming near the North Pole. This break-up event serves as a sentinel to the changing arctic environment.

MODIS image of Ellesmere Island and Ayles Ice Shelf
MODIS Image of Ayles Ice Shelf - August 13 2005

This web page will continue to be updated with information on the ice island's movement and break-up. New images will be posted when available. For more information on how an ice island breaks up and the factors affecting the drift of large masses of ice, please see our Education Corner.

Common questions asked about the Ayles Ice Shelf

What is the difference between an ice island and an iceberg?

An Ice Island is a large piece of floating ice protruding about 5 m above sea level, which has broken away from an Arctic ice shelf. They have a thickness of 30-50 m and an area of from a few thousand square metres to 500 sq. km or more. They are usually characterized by a regularly undulating surface giving a ribbed appearance from the air.

An Iceberg is a massive piece of ice of greatly varying shape, protruding 5 m or more above sea level, which has broken away from a glacier and which may be afloat or aground. They may be described as tabular,domed, pinnacled, wedged, drydocked or blocky. Sizes of icebergs are classed as small, medium, large and very large.

Note: Ice Island is an Arctic term. In Antarctica, ice islands and calved-off glacier ice are both called icebergs.

What is an Ice Shelf?

An Ice Shelf is a floating ice sheet of considerable thickness showing 2 m or more above sea level, attached to the coast. They usually have great horizontal extent and a level or gently undulating surface. Ice shelf growth occurs by annual snow accumulation and also by the seaward extension of land glaciers. Limited areas may be aground. The seaward edge is termed an ice front.

To learn more about sea ice, ice islands and icebergs, please visit the Education Corner on the Canadian Ice Service web site.

Would rising sea levels have contributed to the break-up of the Ayles Ice Shelf?

We have no data to indicate that there is or was a rise in the sea level. More likely offshore winds leading up to the fracture could have created a chaotic sea, pushing the arctic sea ice away from the shelf front... no doubt sea swell may have played a part in the fracture.

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.

MODIS time sequence of Ayles ice shelf collapse

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?

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.

Ice Shelf Break-up Time Sequence

Where is the Ayles Ice Island Now?

A beacon has been dropped on the Ayles Ice Island to facilitate tracking its movement. You can view a map of the beacon's movement at SailWX Info.

September 04 2007 - Ayles Ice Island Fractures

September 06 2007 - Zoom In


Ayles Ice Island Break-up Timeline

September 03 2007 September 04 2007 September 06 2007



September 14 2007

One segment of the ice island fragment is moving towards Norwegian Bay while the other appears to be heading towards Penny Strait.

September 16 2007

September 23 2007

September 30 2007

By the end of September the two islands had become separated by Amund Ringnes island, with one island moving into Massy Sound and the other into Hassel Sound. Daily temperatures at months end average near -15C. New and young ice is forming between floes of multi-year sea ice. Radarsat images between September 23 and September 30th show that the drift rates of the island impeded by the growing ice pack, slow to about 3 km per day. We are continuing to follow their progress using satellite imagery and a drift beacon believed to be now residing on the eastern most piece. The latest positions taken from the imagery are 78 41n/ 95 47w and 78 23n/ 98 49w.


Previous Ayles Ice Island updates and associated imagery are located on our Ayles Ice Island: Past Updates and Images page.

Where do I find more information about Canadian glaciers?

Canadian Glacier Information Centre

National Glaciology Group

State of the Canadian Cryosphere

National Atlas of Canada

Glaciers of North America - GLACIERS OF CANADA; Glaciers of the Arctic Islands; Ellesmere Island Ice Shelves and Ice Islands by Martin O. Jeffries

Vincent, W.F., J.A.E. Gibson, M.O. Jeffries. Ice-shelf collapse, climate change, and habitat loss in the Canadian high Arctic. Polar Record 37 (201): 133-142 (2001).


The Canadian Ice Service thanks NASA and The Canadian Space Agency for providing imagery used on this web site.