Antarctic Circle

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Antarctic Circle

The Antarctic Circle is one of the five major circles (or parallels) of latitude

Circle of latitude

A circle of latitude, on the Earth, is an imaginary east-west circle connecting all locations that share a given latitude. A location's position along a circle of latitude is given by its longitude....
that mark maps of the Earth

Earth

Earth is the third planet from the Sun. Earth is the largest of the terrestrial planets in the Solar System in diameter, mass and density. It is also referred to as the World and Wiktionary:Terra.Note that by International Astronomical Union convention, the term "Terra" is used for naming extensive land masses, rather...
. As of 2000, it lies at latitude

Latitude

Latitude, usually denoted symbolically by the Greek letter phi gives the location of a place on Earth north or south of the equator. Lines of Latitude are the horizontal lines shown running east-to-west on maps ....
66°

Degree (angle)

A degree , usually denoted by ? , is a measurement of plane angle, representing 1/360 of a Turn ; one degree is equivalent to p/180 radians....
33' 39? (or 66.56083°) south of the equator

Equator

The equator is the intersection of the Earth's surface with the Plane perpendicular to the Earth's rotation and containing the Earth's center of mass....
. The area south of the Antarctic Circle is known as the Antarctic, and the zone immediately to the north is called the Southern Temperate Zone

Temperate

In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally mild, rather than extreme hot or cold....
.

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The Antarctic Circle is one of the five major circles (or parallels) of latitude

Circle of latitude

Earth

Latitude

Degree (angle)

A degree , usually denoted by ? , is a measurement of plane angle, representing 1/360 of a Turn ; one degree is equivalent to p/180 radians....
33' 39? (or 66.56083°) south of the equator

Equator

Temperate

Arctic Circle

The Arctic Circle is one of the five major circle of latitude that mark maps of the Earth. It is the parallel of latitude that runs 66degree 33'39? north of the Equator....
.

Every place south of the Antarctic Circle experiences a period of twenty-four hours' continuous daylight at least once per year, and a period of twenty-four hours' continuous night time at least once per year. That is to say, there is at least one whole day during which the sun does not set, and at least one whole day during which the sun does not rise. On the Antarctic Circle these events occur, in principle, exactly once per year, at the December solstice and June solstice respectively. This happens because the earth's axis is tilted, by approximately 23.5 degrees, relative to ecliptic

Ecliptic

The ecliptic is the apparent path that the Sun traces out in the sky during the year. As it appears to move in the sky in relation to the stars, the apparent path aligns with the planets throughout the course of the year....
(the plane of the earth's orbit around the sun). At the June solstice the southern hemisphere is tilted away from the Sun to its maximum extent, and the region of permanent darkness reaches its northern limit; at the December solstice the southern hemisphere is tilted towards the Sun to its maximum extent, and the region of permanent sunlight reaches its northern limit.

In practice several other factors affect the appearance of continuous day or night, the most important being atmospheric refraction

Atmospheric refraction

Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of altitude....
, the altitude of the observer above sea level, mirage

Mirage

A mirage is a naturally occurring optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky. The word comes to English via the French language mirage, from the Latin mirare, meaning "to look at, to wonder at"....
s, and the fact that the sun is a sphere rather than a point. Mirages on the Antarctic continent tend to be even more spectacular than in Arctic regions, creating, for example, a series of apparent sunsets and sunrises while in reality the sun remains under the horizon.

Due to gradual changes in the tilt of the Earth's axis, the Antarctic Circle is slowly moving. See circles of latitude

Circle of latitude

Geography and demographics

The continent

Continent

A continent is one of several large landmasses on Earth. They are generally identified by convention rather than any strict criteria, with seven regions commonly regarded as continents ? they are : Asia, Africa, North America, South America, Antarctica, Europe, and Australia ....
of Antarctica

Antarctica

Antarctica is Earth's southernmost continent, overlying the South Pole. It is situated in the Antarctica of the southern hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean....
forms a land mass covering much of the area within the Antarctic Circle. There is no permanent human population on Earth south of the Antarctic Circle. There are, however, several Antarctic research centers from various nations that are inhabited by teams of scientists that rotate on a seasonal basis. In previous centuries, some semi-permanent whaling stations were established on the continent and some of the whalers would live there for a year or more. At least three children have been born in Antarctica, albeit in stations north of the Antarctic Circle. See Demographics of Antarctica

Demographics of Antarctica

Antarctica has no indigenous inhabitants, but there are permanently- and seasonally-staffed research stations, and former whaling settlements. The largest of these, McMurdo Station, has a population of about 1200 residents....
.

Starting at the Prime Meridian

Prime Meridian

The Prime Meridian is the meridian at which longitude is defined to be 0?.The Prime Meridian and the opposite 180th meridian , which the International Date Line generally follows, form a great circle that divides the Earth into the Eastern Hemisphere and Western Hemispheres....
and heading eastwards, the Antarctic Circle passes through:

Longitude	Territory or sea	Notes
0° Prime Meridian The Prime Meridian is the meridian at which longitude is defined to be 0?.The Prime Meridian and the opposite 180th meridian , which the International Date Line generally follows, form a great circle that divides the Earth into the Eastern Hemisphere and Western Hemispheres....	Southern Ocean Southern Ocean The Southern Ocean, also known as the Great Southern Ocean, the Antarctic Ocean and the South Polar Ocean, comprises the southernmost waters of the World Ocean south of 60th parallel south latitude....	north of Queen Maud Land Queen Maud Land Queen Maud Land is an English translation of Dronning Maud Land, the official name in use by Norwegian authorities and British Antarctic Survey on the part of Antarctica claimed by Norway as a dependent territory, on 14 January 1939....
30° E 30th meridian east The meridian 30? east of Prime Meridian is a line of longitude that extends from the North Pole across the Arctic Ocean, Europe, Turkey, Africa, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole....	Southern Ocean Southern Ocean The Southern Ocean, also known as the Great Southern Ocean, the Antarctic Ocean and the South Polar Ocean, comprises the southernmost waters of the World Ocean south of 60th parallel south latitude....	north of Queen Maud Land Queen Maud Land Queen Maud Land is an English translation of Dronning Maud Land, the official name in use by Norwegian authorities and British Antarctic Survey on the part of Antarctica claimed by Norway as a dependent territory, on 14 January 1939....
60° 60th meridian east The meridian 60? east of Prime Meridian is a line of longitude that extends from the North Pole across the Arctic Ocean, Europe, Asia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole....	Southern Ocean Southern Ocean The Southern Ocean, also known as the Great Southern Ocean, the Antarctic Ocean and the South Polar Ocean, comprises the southernmost waters of the World Ocean south of 60th parallel south latitude....	north of Queen Maud Land Queen Maud Land Queen Maud Land is an English translation of Dronning Maud Land, the official name in use by Norwegian authorities and British Antarctic Survey on the part of Antarctica claimed by Norway as a dependent territory, on 14 January 1939.... , Amery Ice Shelf Amery Ice Shelf The Amery Ice Shelf is a broad ice shelf at the head of Prydz Bay between the Lars Christensen Coast and Ingrid Christensen Coast. It is part of Mac Robertson Land....
90° 90th meridian east The meridian 90? east of Prime Meridian is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole....	Wilkes Land Wilkes Land Wilkes Land is a large district of land in eastern Antarctica, formally claimed by Australia as part of the Australian Antarctic Territory, though the validity of this claim has been placed in abeyance for the period of the operation of the Antarctic Treaty, to which Australia is a signatory....
120° 120th meridian east The meridian 120? east of Prime Meridian is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Indian Ocean, Australia, the Southern Ocean, and Antarctica to the South Pole....	Wilkes Land Wilkes Land Wilkes Land is a large district of land in eastern Antarctica, formally claimed by Australia as part of the Australian Antarctic Territory, though the validity of this claim has been placed in abeyance for the period of the operation of the Antarctic Treaty, to which Australia is a signatory....
150° E 150th meridian east The meridian 150? east of Prime Meridian is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Pacific Ocean, Australasia, the Southern Ocean, and Antarctica to the South Pole....	Southern Ocean Southern Ocean The Southern Ocean, also known as the Great Southern Ocean, the Antarctic Ocean and the South Polar Ocean, comprises the southernmost waters of the World Ocean south of 60th parallel south latitude....	north of Victoria Land Victoria Land Victoria Land is a region of Antarctica bounded on the east by the Ross Sea and on the west by Wilkes Land. It was discovered by Captain James Clark Ross in January 1841 and named after the Victoria of the United Kingdom....
180° 180th meridian The 180th meridian or antimeridian is the meridian defined as 180? longitude. It is the line of longitude exactly opposite the Prime Meridian....	Southern Ocean Southern Ocean The Southern Ocean, also known as the Great Southern Ocean, the Antarctic Ocean and the South Polar Ocean, comprises the southernmost waters of the World Ocean south of 60th parallel south latitude....	Ross Sea Ross Sea The Ross Sea is a deep Headlands and bays of the Southern Ocean in Antarctica between Victoria Land and Marie Byrd Land. It was discovered by James Clark Ross in 1841....
150° W 150th meridian west The meridian 150? west of Prime Meridian is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole....	Southern Ocean Southern Ocean The Southern Ocean, also known as the Great Southern Ocean, the Antarctic Ocean and the South Polar Ocean, comprises the southernmost waters of the World Ocean south of 60th parallel south latitude....	north of Marie Byrd Land Marie Byrd Land Marie Byrd Land is the portion of Antarctica lying east of the Ross Ice Shelf and the Ross Sea and south of the Pacific Ocean, extending eastward approximately to a line between the head of the Ross Ice Shelf and Eights Coast....
120° 120th meridian west The meridian 120? west of Prime Meridian is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole....	Southern Ocean Southern Ocean The Southern Ocean, also known as the Great Southern Ocean, the Antarctic Ocean and the South Polar Ocean, comprises the southernmost waters of the World Ocean south of 60th parallel south latitude....	Amundsen Sea Amundsen Sea The Amundsen Sea is an arm of the Southern Ocean off Marie Byrd Land in western Antarctica. It is bounded by Thurston Island to the east and Cape Dart to the west....
90° 90th meridian west The meridian 90? west of Prime Meridian is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Gulf of Mexico, Central America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole....	Southern Ocean Southern Ocean The Southern Ocean, also known as the Great Southern Ocean, the Antarctic Ocean and the South Polar Ocean, comprises the southernmost waters of the World Ocean south of 60th parallel south latitude....	Peter Island Peter Island Peter Island is a private island located in the British Virgin Islands, about 5.2 miles south-west from Road Harbour , Tortola, is part of the BVI archipelago that runs along the Sir Francis Drake Channel....
60° 60th meridian west The meridian 60? west of Prime Meridian is a line of longitude that extends from the North Pole across the Arctic Ocean, Greenland, North America, the Atlantic Ocean, South America, the Southern Ocean, and Antarctica to the South Pole....	Graham Land Graham Land Graham Land is that portion of the Antarctic Peninsula which lies north of a line joining Cape Jeremy and Cape Agassiz. This description of Graham Land is consistent with the 1964 agreement between the United Kingdom UK-APC and the United States Advisory Committee on Antarctic Names, in which the name "Antarctic Peninsula" was approved for t...
30° W 30th meridian west The meridian 30? west of Prime Meridian is a line of longitude that extends from the North Pole across the Arctic Ocean, Greenland, the Atlantic Ocean, the Southern Ocean, and Antarctica to the South Pole....	Weddell Sea Weddell Sea The Weddell Sea is part of the Southern Ocean. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula....

Antarctic Circle

Geography and demographics

See also

External links