{{Short description|Ice shelf in the Arctic Ocean}} {{Use mdy dates|date=October 2022}} [[File:Ward Hunt Island, Ice Shelf 06.jpg|thumb|[[Ward Hunt Island]], Ward Hunt Ice Shelf and Cape Columbia, Ellesmere Island, Canada. View towards east.]] [[File:Ward Hunt Island, Ice Shelf 05.jpg|thumb|Ward Hunt Ice Shelf, north of Ellesmere Island, Canada. View from Ward Hunt Ice Rise towards west, July 1988.]] The '''Ward Hunt Ice Shelf''' is the largest [[ice shelf]] in the [[Arctic]], located near [[Ward Hunt Island]], on the north coast of [[Ellesmere Island]], Nunavut, Canada. During the 20th century the [[Ellesmere Ice Shelf]] broke up into six separate shelves, the largest being Ward Hunt. Ward Hunt Ice Shelf is currently about {{cvt|400|km2}} in size, and has been in place for approximately 4,000 years<ref>{{Cite journal|last1=Antoniades|first1=D.|last2=Francus|first2=P.|last3=Pienitz|first3=R.|last4=St-Onge|first4=G.|last5=Vincent|first5=W. F.|date=November 22, 2011|title=Holocene dynamics of the Arctic's largest ice shelf|journal=Proceedings of the National Academy of Sciences|language=en|volume=108|issue=47|pages=18899–18904|doi=10.1073/pnas.1106378108|issn=0027-8424|pmc=3223438|pmid=22025693|doi-access=free}}</ref> as part of a continuous ice shelf that encompassed the northern coast of Ellesmere Island until the beginning of the twentieth century.<ref name="Ljunggren"/> In 2005 one of the other shelves, the {{cvt|25|sqmi|order=flip}} [[Ayles Ice Shelf]], calved completely.<ref name="Ljunggren"/>
The Ellesmere ice shelf was documented by the [[British Arctic Expedition]] of 1875–76, in which Lieutenant [[Pelham Aldrich]]'s party went from [[Cape Sheridan]] (82.47°N, 61.50°W) west to [[Cape Alert]] (82.27°N, 85.55°W), including the Ward Hunt Ice Shelf.<ref>[[Martin O. Jeffries|Jeffries, Martin O]]. [http://pubs.aina.ucalgary.ca/arctic/Arctic39-1-15.pdf Ice Island Calvings and Ice Shelf Changes, Milne Ice Shelf and Ayles Ice Shelf, Ellesmere Island, N.W.T.] {{Webarchive|url=https://web.archive.org/web/20190928113808/http://pubs.aina.ucalgary.ca/arctic/Arctic39-1-15.pdf |date=September 28, 2019 }}. ''Arctic'' 39 (1) (March 1986)</ref> Reports from Robert Peary's expedition in 1906 described a “broad glacial fringe” covering much of the coast of northwestern Ellesmere Island.<ref>{{Cite book|last=Peary|first=Robert E.|title=Nearest the Pole; a narrative of the Polar expedition of the Peary Arctic club in the S.S. Roosevelt, 1905–1906, by R.E. Peary, U.S.N. With ninety-five photographs by the author, two maps and a frontispiece in colour by Albert Operti.|date=1907|publisher=Doubleday, Page & Co.|location=New York|doi=10.5962/bhl.title.6868|url=https://www.biodiversitylibrary.org/item/29932}}</ref>
The Ward Hunt ice sheet began breaking up approximately 100 years ago, but was believed to have stabilized by the early 1980s. However, in April 2000, satellite images revealed that a large crack in the ice had begun to form, and in 2003, it was announced that the ice sheet had split completely in two in 2002, releasing a huge pool of fresh water from the largest [[epishelf lake]] in the Northern Hemisphere, located in [[Disraeli Fjord]].<ref name="scott">{{cite web|url=http://earthobservatory.nasa.gov/Features/wardhunt/|title=Breakup of the Ward Hunt Ice Shelf|author=Michon Scott|date=January 20, 2004|publisher=Earth Observatory, NASA Goddard Space Flight Center|accessdate=December 30, 2011}}</ref> In April 2008, it was discovered that the shelf was fractured into dozens of deep, multi-faceted cracks.<ref>{{cite news|url=https://www.thestar.com/News/Canada/article/413838 |title=Cracks in Arctic ice shelf signal its demise |author=Bob Weber, The Canadian Press | work=The Star | location=Toronto | date=April 12, 2008 | accessdate=May 27, 2010}}</ref> In late July 2008, it was announced that nearly {{cvt|8|sqmi|order=flip}} broke away from the shelf.<ref name="Ljunggren">{{cite web |url=https://www.reuters.com/article/scienceNews/idUSN2931485920080729?sp=true |title= Giant chunks break off Canadian ice shelf |accessdate=July 29, 2008 |author=David Ljunggren |date=July 29, 2008|publisher=Reuters}}</ref> In August 2010, another {{cvt|50|km2}} calved off from the northeast quarter of the ice shelf.<ref>{{cite web|url=http://visibleearth.nasa.gov/view.php/id=45463|archive-url=https://web.archive.org/web/20150210011438/http://visibleearth.nasa.gov/view.php/id=45463|url-status=dead|archive-date=February 10, 2015|title=Break-up on the Ward Hunt Ice Shelf|date=August 18, 2010|author=NASA Visible Earth|accessdate=February 9, 2015}}</ref>
The icebergs released by the breakup now pose a potential danger to shipping and offshore development in the region. Loss of microbial ecosystems caused by the release of the freshwater may also have far-ranging ecological impacts.<ref>{{cite web|url=http://www.weather.com/outlook/weather-news/news/articles/canadian-arctic-nearly-loses-entire-ice-shelf_2011-09-30|title=Canadian Arctic Nearly Loses Entire Ice Shelf|date=September 30, 2011|author=The Associated Press|publisher=The Weather Channel|accessdate=September 30, 2011}}</ref>
The breakup of the Ward Hunt Ice Shelf is tied to steady and dramatic increases in the average temperature of the region over the past centuries, correlated with long term [[global warming]] resulting from the ongoing warming since the last ice age ended at the start of the [[Holocene]] period.<ref name="bbc">{{cite web|url=https://news.bbc.co.uk/2/hi/science/nature/3132074.stm|title=Arctic ice shelf splits |date=September 23, 2003|publisher=BBC News|access-date=December 30, 2011}}</ref><ref name="nrdc">{{cite web|url=http://www.nrdc.org/globalwarming/qthinice.asp|title=Global Warming Puts the Arctic on Thin Ice|publisher=Natural Resources Defense Council|accessdate=December 30, 2011}}</ref>
[[Al Gore]] mentions the Ward Hunt Ice Shelf in his 2007 documentary ''[[An Inconvenient Truth]]''.
==References== {{Reflist}}
==External links== * [http://www.ec.gc.ca/glaces-ice/default.asp?lang=En&n=02F0FDF6-1&offset=5 Ward Hunt Ice Shelf], Environment Canada * [https://web.archive.org/web/20040123233449/http://earthobservatory.nasa.gov/Study/wardhunt/ * http://www.nasa.gov/missions/earth/f_iceshelf.html NASA.gov] * http://www.commondreams.org/headlines03/0924-06.htm
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[[Category:Ellesmere Island]] [[Category:Ice shelves of the Qikiqtaaluk Region]]