North Pole

An azimuthal projection showing the Arctic Ocean and the North Pole. The map also shows the 75th parallel north and 60th parallel north.
Sea ice at the North Pole in 2006

The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is (subject to the caveats explained below) defined as the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface.

The North Pole is the northernmost point on the Earth, lying diametrically opposite the South Pole. It defines geodetic latitude 90° North, as well as the direction of true north. At the North Pole all directions point south; all lines of longitude converge there, so its longitude can be defined as any degree value. Along tight latitude circles, counterclockwise is east and clockwise is west. The North Pole is at the center of the Northern Hemisphere.

While the South Pole lies on a continental land mass, the North Pole is located in the middle of the Arctic Ocean amid waters that are almost permanently covered with constantly shifting sea ice. This makes it impractical to construct a permanent station at the North Pole (unlike the South Pole). However, the Soviet Union, and later Russia, constructed a number of manned drifting stations on a generally annual basis since 1937, some of which have passed over or very close to the Pole. Since 2002, the Russians have also annually established a base, Barneo, close to the Pole. This operates for a few weeks during early spring. Studies in the 2000s predicted that the North Pole may become seasonally ice-free because of Arctic ice shrinkage, with timescales varying from 2016[1][2] to the late 21st century or later.

The sea depth at the North Pole has been measured at 4,261 m (13,980 ft) by the Russian Mir submersible in 2007[3] and at 4,087 m (13,410 ft) by USS Nautilus in 1958.[4][5] The nearest land is usually said to be Kaffeklubben Island, off the northern coast of Greenland about 700 km (430 mi) away, though some perhaps semi-permanent gravel banks lie slightly closer. The nearest permanently inhabited place is Alert in the Qikiqtaaluk Region, Nunavut, Canada, which is located 817 km (508 mi) from the Pole.

Precise definition

The Earth's axis of rotation – and hence the position of the North Pole – was commonly believed to be fixed (relative to the surface of the Earth) until, in the 18th century, the mathematician Leonhard Euler predicted that the axis might "wobble" slightly. Around the beginning of the 20th century astronomers noticed a small apparent "variation of latitude," as determined for a fixed point on Earth from the observation of stars. Part of this variation could be attributed to a wandering of the Pole across the Earth's surface, by a range of a few metres. The wandering has several periodic components and an irregular component. The component with a period of about 435 days is identified with the eight-month wandering predicted by Euler and is now called the Chandler wobble after its discoverer. The exact point of intersection of the Earth's axis and the Earth's surface, at any given moment, is called the "instantaneous pole", but because of the "wobble" this cannot be used as a definition of a fixed North Pole (or South Pole) when metre-scale precision is required.

It is desirable to tie the system of Earth coordinates (latitude, longitude, and elevations or orography) to fixed landforms. Of course, given plate tectonics and isostasy, there is no system in which all geographic features are fixed. Yet the International Earth Rotation and Reference Systems Service and the International Astronomical Union have defined a framework called the International Terrestrial Reference System.

Other Languages
Afrikaans: Noordpool
Alemannisch: Nordpol
አማርኛ: ስሜን ዋልታ
aragonés: Polo Norte
asturianu: Polu Norte
azərbaycanca: Şimal qütbü
تۆرکجه: قوزئی قوطبو
Bân-lâm-gú: Pak-ke̍k
башҡортса: Төньяҡ полюс
беларуская: Паўночны полюс
беларуская (тарашкевіца)‎: Паўночны полюс
български: Северен полюс
Boarisch: Noadpoi
bosanski: Sjeverni pol
буряад: Хойто туйл
català: Pol Nord
čeština: Severní pól
dansk: Nordpolen
davvisámegiella: Davvipola
Deutsch: Nordpol
Ελληνικά: Βόρειος Πόλος
español: Polo norte
Esperanto: Norda poluso
euskara: Iparburua
فارسی: قطب شمال
Fiji Hindi: North Pole
français: Pôle Nord
Frysk: Noardpoal
galego: Polo Norte
贛語: 北極點
한국어: 북극점
hornjoserbsce: Sewjerny čop
Bahasa Indonesia: Kutub Utara
interlingua: Polo Nord
italiano: Polo nord
Basa Jawa: Kutub Lor
къарачай-малкъар: Шимал полюс
Кыргызча: Түндүк уюл
latviešu: Ziemeļpols
Limburgs: Naordpoeal
magyar: Északi-sark
македонски: Северен пол
Bahasa Melayu: Kutub Utara
монгол: Умард туйл
Nederlands: Noordpool
日本語: 北極点
norsk: Nordpolen
norsk nynorsk: Nordpolen
occitan: Pòl Nòrd
oʻzbekcha/ўзбекча: Shimoliy qutb
ਪੰਜਾਬੀ: ਉੱਤਰੀ ਧਰੁਵ
پنجابی: اتلا قطب
Piemontèis: Pòl Nòrd
português: Polo Norte
Qaraqalpaqsha: Arqa polyus
română: Polul Nord
Runa Simi: Chinchay qhipa
русиньскый: Северный пол
саха тыла: Хоту полюс
Scots: North Powl
sicilianu: Polu Nord
Simple English: North Pole
slovenčina: Severný pól
slovenščina: Severni tečaj
Soomaaliga: Cirifka waqooyi
српски / srpski: Сјеверни пол
srpskohrvatski / српскохрватски: Sjeverni pol
svenska: Nordpolen
Tagalog: Hilagang Polo
tarandíne: Pole nord
татарча/tatarça: Төньяк котып
Türkçe: Kuzey Kutbu
Türkmençe: Demirgazyk polýus
українська: Північний полюс
ئۇيغۇرچە / Uyghurche: شىمالى قۇتۇپ
vepsän kel’: Pohjoižnaba
Tiếng Việt: Bắc Cực
Võro: Põh'anaba
文言: 北極
吴语: 北極點
ייִדיש: צפון פאלוס
粵語: 北極
žemaitėška: Šiaurės puolios
中文: 北极点