The
Arctic Circle is one of the five major
circles of latitude that mark maps of the
Earth. For Epoch 2010, it is the parallel of
latitude that runs 66° 33′ 44″ (or 66.5622°) north of the
Equator.
[1]
The region north of this circle is known as the
Arctic, and the zone just to the south is called the
Northern Temperate Zone. The equivalent
polar circle in the
Southern Hemisphere is called the
Antarctic Circle.
The Arctic Circle marks the southern extremity of the
polar day (24-hour sunlit day, often referred to as the "midnight sun") and
polar night (24-hour sunless night). North of the Arctic Circle, the
sun is above the
horizon for 24 continuous
hours at least once per
year and below the horizon for 24 continuous hours at least once per year. On the Arctic Circle those events occur, in principle, exactly once per year, at the June and December
solstices, respectively.
In fact, because of
atmospheric refraction and because the sun appears as a disk and not a point, part of the midnight sun may be seen on the night of the
northern summer solstice up to about 50
′ (90 km (56 mi)) south of the Arctic Circle; similarly, on the day of the
northern winter solstice, part of the sun may be seen up to about 50′ north of the Arctic Circle. That is true at sea level; those limits increase with elevation above sea level although in mountainous regions, there is often no direct view of the horizon.
The position of the Arctic Circle is not fixed, but directly depends on the Earth's
axial tilt, which fluctuates within a margin of 2° over a 40,000 year period,
[2] notably due to
tidal forces resulting from the
orbit of the Moon. The Arctic Circle is currently drifting northwards at a speed of about 15 m (49 ft) per year, see
Circle of latitude for more information.
Geography
Relatively few people live north of the Arctic Circle due to the
Arctic climate. The three largest communities above the Arctic Circle are situated in Russia;
Murmansk (population 325,100),
Norilsk (135,000), and
Vorkuta (85,000).
Tromsø (in Norway) has about 62,000 inhabitants. In contrast, the largest North American community north of the circle,
Barrow, Alaska, has approximately 4,000 inhabitants.
Rovaniemi (in Finland), which lies slightly south of the line, has a population of approximately 58,000, and is the largest settlement in the immediate vicinity of the Arctic Circle.
The Arctic Circle passes through the
Arctic Ocean, the
Scandinavian Peninsula,
North Asia,
Northern America and
Greenland. The land on the Arctic Circle is divided among eight countries:
Norway,
Sweden,
Finland,
Russia, the
United States (i.e.
Alaska),
Canada,
Denmark (i.e.
Greenland) and passes through the small Icelandic island of
Grímsey just north of
Iceland.
Starting at the
Prime Meridian and heading eastwards, the Arctic Circle passes through:
Co-ordinates | Country, territory or sea | Notes |
66°34′N 000°00′E / 66.567°N 0°E / 66.567; 0 (01 Prime Meridian) | Arctic Ocean | Norwegian Sea |
66°34′N 012°48′E / 66.567°N 12.8°E / 66.567; 12.8 (02 Nordland County, Norway) | Norway | Nordland County |
66°34′N 015°31′E / 66.567°N 15.517°E / 66.567; 15.517 (03 Norrbotten County, Sweden) | Sweden | Norrbotten County |
66°34′N 023°51′E / 66.567°N 23.85°E / 66.567; 23.85 (04 Lapland Province, Finland) | Finland | Lapland Province |
66°34′N 029°28′E / 66.567°N 29.467°E / 66.567; 29.467 (05 Karelia & Murmansk, Russia) | Russia | Republic of Karelia
Murmansk Oblast
Karelia again
Murmansk again |
66°34′N 033°25′E / 66.567°N 33.417°E / 66.567; 33.417 (06 Kandalaksha Gulf, White Sea) | White Sea | Kandalaksha Gulf |
66°34′N 034°28′E / 66.567°N 34.467°E / 66.567; 34.467 (07 Murmansk Oblast, Russia) | Russia | Murmansk Oblast – for about 7 km (4.3 mi) |
66°34′N 034°38′E / 66.567°N 34.633°E / 66.567; 34.633 (08 Kandalaksha Gulf, White Sea) | White Sea | Kandalaksha Gulf |
66°34′N 035°00′E / 66.567°N 35°E / 66.567; 35 (09 Murmansk Oblast, Kola Peninsula, Russia) | Russia | Murmansk Oblast (Kola Peninsula) |
66°34′N 040°42′E / 66.567°N 40.7°E / 66.567; 40.7 (10 White Sea) | White Sea |
|
66°34′N 044°23′E / 66.567°N 44.383°E / 66.567; 44.383 (11 Nenets Autonomous Okrug, Komi Republic & Yamalo-Nenets Autonomous Okrug, Russia) | Russia | Nenets Autonomous Okrug
Komi Republic
Yamalo-Nenets Autonomous Okrug |
66°34′N 071°05′E / 66.567°N 71.083°E / 66.567; 71.083 (12 Gulf of Ob) | Gulf of Ob |
|
66°34′N 072°27′E / 66.567°N 72.45°E / 66.567; 72.45 (13 Yamalo-Nenets Autonomous Okrug, Krasnoyarsk Krai, Sakha Republic & Chukotka Autonomous Okrug, Russia) | Russia | Yamalo-Nenets Autonomous Okrug
Krasnoyarsk Krai
Sakha Republic
Chukotka Autonomous Okrug |
66°34′N 171°01′W / 66.567°N 171.017°W / 66.567; -171.017 (14 Chukchi Sea, Arctic Ocean) | Arctic Ocean | Chukchi Sea |
66°34′N 164°38′W / 66.567°N 164.633°W / 66.567; -164.633 (15 Seward Peninsula, Alaska, United States) | United States | Alaska (Seward Peninsula) |
66°34′N 163°44′W / 66.567°N 163.733°W / 66.567; -163.733 (18 Kotzebue Sound, Arctic Ocean) | Arctic Ocean | Kotzebue Sound |
66°34′N 161°56′W / 66.567°N 161.933°W / 66.567; -161.933 (17 Selawik Lake, Alaska, United States) | United States | Alaska – passing through Selawik Lake |
66°34′N 141°00′W / 66.567°N 141°W / 66.567; -141 (18 Yukon, Northwest Territories & Nunavut, Canada) | Canada | Yukon
Northwest Territories – passing through the Great Bear Lake
Nunavut |
66°34′N 082°59′W / 66.567°N 82.983°W / 66.567; -82.983 (19 Foxe Basin, Hudson Bay) | Hudson Bay | Foxe Basin |
66°34′N 073°25′W / 66.567°N 73.417°W / 66.567; -73.417 (20 Nettilling Lake, Baffin Island, Nunavut, Canada) | Canada | Nunavut (Baffin Island – passing through Nettilling Lake) |
66°34′N 061°24′W / 66.567°N 61.4°W / 66.567; -61.4 (21 Davis Strait, Atlantic Ocean) | Atlantic Ocean | Davis Strait |
66°34′N 053°16′W / 66.567°N 53.267°W / 66.567; -53.267 (22 Greenland) | Greenland |
|
66°34′N 034°09′W / 66.567°N 34.15°W / 66.567; -34.15 (23 Denmark Strait, Greenland Sea, Atlantic Ocean) | Atlantic Ocean | Denmark Strait
Greenland Sea |
66°34′N 018°01′W / 66.567°N 18.017°W / 66.567; -18.017 (24 Grímsey, Iceland) | Iceland | Island of Grímsey |
66°34′N 017°59′W / 66.567°N 17.983°W / 66.567; -17.983 (25 Greenland Sea & Norwegian Sea, Atlantic Ocean) | Atlantic Ocean | Greenland Sea
Norwegian Sea |
|
A sign along the Dalton Highway marking the location of the Arctic Circle in Alaska.
A sign on the Vikingen island marking the Arctic Circle in Norway |