Wikipedia
The Antarctic Circle is the most southerly of the five major circles of latitude that mark maps of the Earth. The region south of this circle is known as the Antarctic, and the zone immediately to the north is called the Southern Temperate Zone. South of the Antarctic Circle, the sun is above the horizon for 24 continuous hours at least once per year (and therefore visible at midnight) and below the horizon for 24 continuous hours at least once per year (and therefore not visible at noon); this is also true within the equivalent polar circle in the Northern Hemisphere, the Arctic Circle.
The position of the Antarctic Circle is not fixed; as of , it runs south of the Equator. Its latitude depends on the Earth's axial tilt, which fluctuates within a margin of 2° over a 40,000-year period, due to tidal forces resulting from the orbit of the Moon. Consequently, the Antarctic Circle is currently drifting southwards at a speed of about per year.
Usage examples of "antarctic circle".
Soon after arriving near the Antarctic Circle, the crew took six whales as the ship sailed in the open water between the shore, often threading its way through a sea of icebergs.
Then Wilson came to the conclusion that the animal was a sea-elephant commonly found at Macquarie Island, but never before seen within the Antarctic circle.
Their northern end must likewise be visible from the long antarctic circle coast line at Queen Mary Land.
From this fact he has drawn the conclusion that the Antarctic Circle encloses considerable continents, as icebergs cannot form in open sea, but only on the coasts.
From this fact he has drawn the conclusion that the Antarctic Circle incloses considerable continents, as icebergs cannot form in open sea, but only on the coasts.
Australia-sized Haelen decked the south pole, extending an arm past the Antarctic Circle.
Titus would still have time to get to the Antarctic Circle before the party ended, and he’.
The air was chilly, but warmer than he had ever expected so deep in the antarctic circle.