Editing Ellesmere Island (section)

==Geography==
[[File:Ellesmere topo.png|thumb|left|Topography of Ellesmere Island]]
[[File:Wfm ellesmere island.jpg|thumb|left|Satellite image montage showing Ellesmere Island and its neighbours]]

Ellesmere Island is the northernmost island of the [[Arctic Archipelago]] in [[Northern Canada|Canada's Far North]] and one of the [[Extreme points of the Arctic|world's northernmost land masses]]. It is exceeded in this regard only by neighbouring [[Greenland]], which extends about {{cvt|60|km}} closer to the north pole. Ellesmere's northernmost point, [[Cape Columbia]] (at {{coord|83|06|41|N|69|57|13|W|region:CA-NU_scale:2000000|notes=<ref>{{Cite cgndb|OADRA|Cape Columbia}}</ref>|name=Cape Columbia}}), is less than {{cvt|800|km}} from the north pole, while its southern coasts at 77°N are well within the Arctic Circle.{{r|"Dick"|p=7}}

Ellesmere has the highest and longest mountain ranges in eastern North America and is the most mountainous island in the Arctic Archipelago. It has over half of the archipelago's ice cover, with ice caps and glaciers across 40% of its surface. Its extensive coastline includes some of the world's longest fiords.{{r|"Dick"|p=7–9}}

To the west, Ellesmere is separated from [[Axel Heiberg Island]] by [[Nansen Sound|Nansen]] and [[Eureka Sound]]s, the latter of which narrows to {{cvt|13|km}}. [[Devon Island]] is to the south across [[Jones Sound]]; at the west end of the sound, they are separated by [[North Kent Island]] and two channels which narrow to {{cvt|4|and|10|km}}. Greenland is to the east across [[Nares Strait]]; the strait narrows to {{cvt|46|km}} at Cape Isabella on [[Smith Sound]] and further north narrows to {{cvt|19|km}} at [[Robeson Channel]]. These channels and straits typically freeze over in winter,{{r|"Dick"|p=9–11}} though winds and currents leave pockets of open water (temporary [[lead (sea ice)|leads]] and persistent [[polynya]]s) in Nares Strait.{{r|"Dick"|p=20–21}} To the north of Ellesmere is the [[Arctic Ocean]], with [[Lincoln Sea]] to the northeast.{{r|"Dick"|p=7}}

===Protected areas===
More than one-fifth of the island is protected as [[Quttinirpaaq National Park]] (formerly Ellesmere Island National Park Reserve), which includes seven [[fjord]]s and a variety of [[glacier]]s, as well as [[Lake Hazen]], North America's largest lake north of the [[Arctic Circle]]. [[Barbeau Peak]], the highest mountain in Nunavut ({{cvt|2616|m|disp=sqbr}}) is located in the [[British Empire Range]] on Ellesmere Island. The most northern [[mountain range]] in the world, the [[Challenger Mountains]], is located in the northeast region of the island. The northern lobe of the island is called [[Grant Land]].
[[File:AirForceGlacier.jpg|thumb|Air Force glacier in Quttinirpaaq National Park]]
[[File:Tanquary Fiord 16 1997-08-05.jpg|thumb|[[Gull Glacier]] in [[Tanquary Fiord]]]]
[[File:Ellesmere2008-396 (2738914609).jpg|thumb|Hiking on Ellesmere Island]]
The [[Salix arctica|Arctic willow]] is the only [[Woody plant|woody]] species to grow on Ellesmere Island.<ref name="KemmickPoles"/>

In July 2007, a study noted the disappearance of habitat for [[Anseriformes|waterfowl]], [[invertebrate]]s, and [[algae]] on Ellesmere Island. According to [[John Smol]] of [[Queen's University at Kingston|Queen's University]] in [[Kingston, Ontario]], and Marianne S. V. Douglas of the [[University of Alberta]] in [[Edmonton]], warming conditions and evaporation have caused low water levels and changes in the chemistry of ponds and wetlands in the area. The researchers noted that "In the 1980s they often needed to wear hip waders to make their way to the ponds...while by 2006 the same areas were dry enough to burn."<ref name="enn"/>

===Climate===
Ellesmere Island has a [[tundra climate]] ([[Köppen climate classification|Köppen]] ''ET'') and an [[ice cap climate]] ([[Köppen climate classification|Köppen]] ''EF'') with the temperature being cold year-round.{{citation needed|date=May 2023}} Two semi-permanent air systems dominate the weather: the high-pressure northern [[polar vortex]] and a low-pressure area which forms in different sites between Baffin Bay and the Labrador Sea.{{r|"Dick"|p=25}} Prevailing winds on Ellesmere are northwesterly, cold, and of low humidity due to ice cover over the Arctic Ocean.{{r|"Dick"|p=32–33}} Seasonal shifts on Ellesmere are sudden and striking: winters are long and harsh, summers short and relatively abundant, with spring and autumn being brief intervals of transition.{{r|"Dick"|p=42}}

Fog regularly occurs near open water in September.{{r|"Dick"|p=22}} While the major air systems strengthen towards their annual peak in winter, the Arctic and Atlantic air masses collide in autumn to produce severe storms at Ellesmere.{{r|"Dick"|p=22, 25}} The storm season peaks in October and persists until the sea freezes.{{r|"Dick"|p=46}} The polar vortex strengthens during the polar night and gives rise to easterly winds which are major hazards for populations, especially given the very low temperatures. January winds have been recorded at {{cvt|104|kph}} with gusts to {{cvt|130|–|145|kph}} at Fort Conger and {{cvt|65|–|80|kph}} at Lake Hazen.{{r|"Dick"|p=25}} Very cold temperatures continue until April and no month passes without experiencing freezing temperatures.{{r|"Dick"|p=33}}

Snowfall begins in late August and does not melt until the June thaw. The seasonal shift in daylight is also extreme.{{r|"Dick"|p=42}} The polar night lasts from four-and-a-half months in the north to about three months in the south.{{r|"Dick"|p=44}}

====Regional variation====

Ellesmere's Arctic marine climate is strongly affected in the north by Arctic Ocean currents and the polar vortex, while the climate of the southeastern coast is influenced by the warm Atlantic water of the [[West Greenland Current]].{{r|"Dick"|p=23}} Interior regions shielded by the island's high mountain ranges experience distinctive [[continental climate|quasi-continental microclimates]].{{r|"Dick"|p=9}}

The highest precipitation is on the northern coast, averaging {{cvt|80|to|100|mm}}. On the south side of the Grant Land mountains, only {{cvt|20|mm}} reaches the Hazen Plateau.{{r|"Dick"|p=32–33}}

The average number of snow-free days varies from 45 days on the north coast to 77 days in the Eureka–Tanquary corridor.{{r|"Dick"|p=33}}

Winters are considerably colder in the interior. At Lake Hazen, Peary's expedition recorded daytime temperatures of {{cvt|-64|F|order=flip}} in February&nbsp;1900, and a Defence Research Board party recorded temperatures as low as {{cvt|-69.2|F|order=flip}} in the winter of 1957–58.{{efn|While Dick 2001 gives this temperature as {{cvt|-70|C}},{{r|"Dick"|p=43}} this is the only temperature the source provides in Celsius on that and the adjacent pages and appears to be a typo. Other sources for this International Geophysical Year observation station give the temperature as {{convert|-69.2|F}}, noting that this stands as the coldest temperature reported in the Arctic Archipelago.<ref>{{cite web|url=https://www.canadashistory.ca/explore/environment/canada-s-coldest-day|title=Canada's Coldest Day|website=Canada's History|first=David W.|last=Phillips|date=3 April 2016|publisher=Canada's History Society}}</ref> }} Nonetheless, there are archaeological remains of winter dwellings of both Independence and [[Thule people|Thule cultures]] in the interior.{{r|"Dick"|p=43–44}}
{{Grise Fiord weatherbox}}
{{Eureka, Nunavut weatherbox}}
{{Alert, Nunavut weatherbox}}

====Climate change====
<!--
Ice core samples from Ellesmere's ice caps show a general warming interval between 400 BCE and 1300 CE.{{r|"Dick"|p=27}}
-->
A [[Paleolimnology|paleolimnological]] study of algae in the sediments of shallow ponds on Cape Herschel (which faces Smith Sound on Ellesmere's eastern coast<ref name="Smol1994"/><ref>{{cite cgndb |id=OAHEA|name=Cape Herschel}}</ref>) found that the ponds had been permanent and relatively stable for several millennia until experiencing ecological changes associated with warming, beginning around 1850 and accelerating in the early 2000s. During the 23-year study period, an ecological threshold was crossed as several of the study ponds had completely desiccated while others had very reduced water levels. In addition, the wetlands surrounding the ponds were severely affected and dried vegetation could be easily burned.<ref name="Douglas2007"/>

===Glaciers, ice caps and ice shelves===
[[File:Ellesmere Island 02.jpg|thumb|left|Glaciers of southeastern Ellesmere Island, June&nbsp;1975]]
[[File:Ward Hunt Island, Ice Shelf 02.jpg|thumb|Ward Hunt Island (foreground), Ward Hunt Ice Shelf and northern Ellesmere Island (left), July 1988]][[File:Ellesmere Island 06.jpg|thumb|left|The overhanging ice front of Webber Glacier with waterfalls. Debris rich layers of the ground moraine are sheared and folded into the ice of the advancing polar glacier. The glacier front is {{cvt|6|km}} broad and up to {{cvt|40|m}} high. Borup Fiord, Grant Land, Ellesmere Island, July&nbsp;1978]]
Large portions of Ellesmere Island are covered with glaciers and ice, with Manson Icefield ({{cvt|6200|km2}}) and Sydkap ({{cvt|3700|km2}}) in the south; [[Prince of Wales Mountains|Prince of Wales Icefield]] ({{cvt|20700|km2}}) and [[Agassiz Ice Cap]] ({{cvt|21500|km2}}) along the central-east side of the island, and the Northern Ellesmere icefields ({{cvt|24400|km2}}).<ref name="Wolken"/>

The northwest coast of Ellesmere Island was covered by a massive, {{cvt|500|km}} long [[ice shelf]] until the 20th century. The Ellesmere Ice Shelf shrank by 90 per cent in the 20th century due to warming trends in the Arctic,<ref name="Revkin"/>{{r|"Vincent2001"|p=133}} particularly in the 1930s and 1940s, a period when the largest [[Iceberg|ice islands]] (the {{cvt|200|mi2|order=flip}} T1 and the {{cvt|300|sqmi|order=flip}} T2 ice islands) were formed leaving the separate [[Alfred Ernest Ice Shelf|Alfred Ernest]], Ayles, Milne, Ward Hunt, and [[Markham Ice Shelf|Markham]] Ice Shelves.{{citation needed|date=May 2023}} The [[Ward Hunt Ice Shelf]], the largest remaining section of thick (>10&nbsp;m, >30&nbsp;ft{{citation needed|date=May 2023}}) [[Fast ice|landfast]] sea ice along the northern coastline of Ellesmere Island, lost almost {{cvt|600|km2}} of ice in a massive calving in 1961–1962. Five large ice islands which resulted account for 79% of the calved material.<ref name="Hattersley-Smith1963"/> It further decreased by 27% in thickness ({{cvt|13|m}}) between 1967 and 1999.<ref name="Vincent2001"/> A 1986 survey of Canadian ice shelves found that {{cvt|48|km2}} or {{cvt|3.3|km3}} of ice calved from the [[Milne Ice Shelf|Milne]] and [[Ayles Ice Shelf|Ayles]] ice shelves between 1959 and 1974.<!--not precisely true, these are the figures for ice islands created, not the ice calving. Needs rephrasing.--><ref name="Jeffries1986"/>

[[File:Osborn Range (05-08-97).jpg|thumb|The [[Osborn Range]] of the [[Arctic Cordillera]] mountain system]]
The breakup of the Ellesmere Ice Shelves has continued in the 21st century: the Ward Ice Shelf experienced a major breakup during the summer of 2002;<ref name="Nasa2004"/> the Ayles Ice Shelf calved entirely on 13&nbsp;August 2005; the largest breakoff of the ice shelf in 25 years, it may pose a threat to the oil industry in the [[Beaufort Sea]]. The piece is {{cvt|66|km2}}.<ref name="BBC2006"/> In April 2008, it was discovered that the Ward Hunt shelf was fractured, with dozens of deep, multi-faceted cracks<ref name="Weber2008"/> and in September 2008 the Markham shelf ({{cvt|50|km2}}) completely broke off to become floating [[sea ice]].<ref name="BBC2008"/>

A 2018 study measured a 5.9% reduction in area amongst 1,773 glaciers in Northern Ellesmere island in the 16-year period 1999–2015 based on satellite data. In the same period, 19 out of 27 [[ice tongue]]s disintegrated to their grounding lines and ice shelves suffered a 42% loss in surface area.<ref name="White2018"/>

===Paleontology===
[[File:Arctic circle.svg|thumb|Canada's northern neighbours shown on a circumpolar projection of the [[Arctic]]]]
Schei and later [[Alfred Gabriel Nathorst]]<ref name="Nathorst1915"/> described the [[Paleocene]]-[[Eocene]] (ca. 55 Ma) [[fossil]] forest in the Stenkul Fiord sediments. The Stenkul Fiord site represents a series of [[River delta|deltaic swamp]] and [[floodplain]] forests.<ref name="Kalkreuth1996"/> The trees stood for at least 400 years. Individual stumps and stems of >1 m (>3&nbsp;ft) diameter were abundant, and are identified as ''[[Metasequoia]]'' and possibly ''[[Glyptostrobus]]''. Well preserved [[Pliocene]] [[peat]]s containing abundant vertebrate and plant [[macrofossil]]s characteristic of a [[taiga|boreal forest]] have been reported from [[Strathcona Fiord]].<ref name="Tedford2003"/><ref name="Ballantyne2010"/>

In 2006, [[University of Chicago]] [[Paleontology|paleontologist]] [[Neil Shubin]] and [[Academy of Natural Sciences of Drexel University|Academy of Natural Sciences]] paleontologist [[Ted Daeschler]] reported the discovery of the fossil of a [[Paleozoic]] (ca. 375 Ma) fish, named ''[[Tiktaalik|Tiktaalik roseae]]'', in the former [[stream bed]]s of Ellesmere Island. The fossil exhibits many characteristics of fish, but also indicates a [[transitional fossil|transitional]] creature that may be a predecessor of [[amphibian]]s, [[reptile]]s, birds, and [[mammal]]s, including humans.<ref name="Wilford2006"/>

In 2011, Jason P. Downs and co-authors described the [[Sarcopterygii|sarcopterygian]] ''[[Laccognathus embryi]]'' from specimens collected from the same locality that ''Tiktaalik'' was found.<ref name="NGS2011"/>

===Ecology===
The ecosystems of the High Arctic are considered to be young and underdeveloped, having only emerged since the glacial retreat of 8,000 to 6,000&nbsp;BCE. There is a lack of species diversity, with a small number of animal species and short food chains.{{r|"Dick"|p=30}}
[[File:OTC at Alexandra Fiord, Ellesmere Island.jpg|thumb|[[International Tundra Experiment]] on Ellesmere Island]]
These species have adapted to take advantage of the productive summer while surviving through winter scarcity. Zooplankton, for example, grow to a larger body size and produce larger eggs in greater numbers than in other regions.{{r|"Dick"|p=42–43}}

Aside from the polar desert conditions of much of the island, there are remarkably productive ecological zones in the arctic oasis of the Lake Hazen area and the polynyas of the island's coastal waters.{{r|"Dick"|p=33}}

====Insect ecology====
Ellesmere Island is noted as being the northernmost occurrence of [[Eusociality|eusocial]] insects; specifically, the [[bumblebee]] ''[[Bombus polaris]]''. There is a second species of bumblebee occurring there, ''[[Bombus hyperboreus]]'', which is a parasite in the nests of ''B. polaris''.<ref name="Milliron1966"/>

While non-eusocial, the Arctic woolly bear moth (''[[Gynaephora groenlandica]]'') can also be found at Ellesmere Island. While this species generally has a 10-year life cycle, its life is known to extend to up to 14 years at both the [[Alexandra Fiord]] lowland and Ellesmere Island.<ref name="Kukal1988"/><ref name="Barrio2013"/>

===Earth's magnetism===
In 2015, the Earth's [[Geomagnetic pole|geomagnetic north pole]] was located at approximately {{Coord|80.37|N|72.62|W|name=Geomagnetic North Pole 2015 est}}, on Ellesmere Island.<ref name="NGDC2018"/> It is forecast to remain on Ellesmere Island in 2020, shifting to {{Coord|80.65|N|72.68|W|name=Geomagnetic North Pole 2020 est}}.<ref name="NGDClimit"/>