Tropic of Capricorn
The Tropic of Capricorn (or the Southern Tropic) is the circle of latitude that contains the subsolar point on the December (or southern) solstice. It is thus the southernmost latitude where the Sun can be directly overhead. Its northern equivalent is the Tropic of Cancer.
The Tropic of Capricorn is one of the five major circles of latitude that mark maps of Earth. As of 23 June 2018, its latitude is 23°26′12.8″ (or 23.43689°) south of the Equator, but it is very gradually moving northward, currently at the rate of 0.47 arcseconds, or 15 metres, per year.
Geography and environment
The Tropic of Capricorn is the dividing line between the Southern Temperate Zone to the south and the tropics to the north. The Northern Hemisphere equivalent of the Tropic of Capricorn is the Tropic of Cancer.
The position of the Tropic of Capricorn is not fixed, but rather it varies in a complex manner over time; see under circles of latitude for information.
In Australia, areas on the Tropic have some of the most variable rainfall in the world and thus even the wetter areas cannot be generally farmed, since irrigation sources invariably dry up in drought years. In southern Africa, where rainfall is more reliable, farming is possible, though yields are low even with fertilisers.
In South America, whilst in the continental cratons soils are almost as old as in Australia and Southern Africa, the presence of the geologically young and evolving Andes means that this region is on the western side of the subtropical anticyclones and thus receives warm and humid air from the Atlantic Ocean. As a result, areas in Brazil adjacent to the Tropic are extremely important agricultural regions, producing large quantities of crops such as sugarcane, and the natural rainforest vegetation has been almost entirely cleared, except for a few remaining patches of Atlantic Forest. Further south in Argentina, the temperate grasslands of the Pampas region is one of the most productive agricultural regions in the world, producing of wheat, soybeans, maize, and beef, making the country one of the largest worldwide agricultural exporters, similar to the role played by the Prairies region in Canada.
West of the Andes, however, the Humboldt Current makes conditions extremely arid, creating the Atacama Desert, one of the driest in the world, so that no glaciers exist between Volcán Sajama at 18˚30'S and Cerro Tres Cruces at 27˚S. Vegetation here is almost non-existent, though on the eastern slopes of the Andes rainfall is adequate for rainfed agriculture.
Further south in the region of Patagonia, shared between Argentina and Chile, climate becomes colder, with heavy snowfall in the winter months and throughout the year. On the Western portion of Patagonia, climate is more humid, and dominated by fjords, coniferous forests and lakes owing to the presence of thawing currents from the permafrost in the peaks of the Andes mountains which divide the region. This makes the region a popular destination for ski and winter sports, particularly on the Argentine city of Bariloche and surrounding area. On the Eastern portion of Patagonia climate is generally cold and dry steppe, with high mesas and strong wind conditions.
Around the world
Starting at the Prime Meridian and heading eastwards, the Tropic of Capricorn passes through 10 countries:
Co-ordinates Country, territory or sea Notes Atlantic Ocean Namibia Erongo, Khomas, Hardap, Khomas (again), and Omaheke regions Botswana Kgalagadi, Kweneng and Central districts South Africa Limpopo Province Mozambique Gaza and Inhambane provinces Indian Ocean Mozambique Channel Madagascar Toliara and Fianarantsoa provinces Indian Ocean Australia Western Australia, Northern Territory and Queensland Coral Sea Passing just south of Cato Reef in Australia's Coral Sea Islands Territory Pacific Ocean Passing just north of the Minerva Reefs ( Tonga), and just south of Tubuai ( French Polynesia) Chile Antofagasta Region Argentina Jujuy, Salta, Jujuy (again), Salta (again) and Formosa provinces Paraguay Boquerón, Presidente Hayes, Concepción, San Pedro and Amambay departments Brazil Mato Grosso do Sul, Paraná, and São Paulo states Atlantic Ocean
Places located along the Tropic of Capricorn
The following cities and landmarks are either located near the Tropic of Capricorn, or the tropic passes through them.
Atsimo-Andrefana Region, Madagascar
The Tropic of Capricorn marked in Jujuy Province in northern Argentina
Roadway plaque marking the Tropic of Capricorn in the city of Santana do Parnaíba, Brazil, at the correct latitude for year 1917.
List of countries entirely south of the Tropic of Capricorn
As the major portion of earth's land is located in the Northern Hemisphere there are only four countries entirely south of the Tropic of Capricorn (there are 74 countries entirely north of the Tropic of Cancer):
The Tropic of Capricorn is so named because, when it was named about 2,000 years ago, the sun was also in the direction of the constellation Capricornus (capricorn is Latin for goat horn) at the December solstice. In modern times the sun appears in the constellation Sagittarius during this time. The change is due to precession of the equinoxes. The word "tropic" itself comes from the Greek trope (τροπή), meaning turn, change in direction or circumstances, referring to the fact that the sun appears to "turn back" at the solstices.
Length of the Tropic on 11 June 2015, at 23°26′14″S is 36,788 kilometres (22,859 mi).
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- Temporal Epoch Calculations
- Useful constants" See: Obliquity of the ecliptic
- Montana State University: Milankovitch Cycles & Glaciation