From Wikipedia, the free encyclopedia
| Andes (Quechua: Anti(s/kuna)) |
| Range |
| |
| Countries | Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela |
|
| Cities | Bogotá, Santiago, Medellín, La Paz, Cali, Quito, Pasto, Bucaramanga, Arequipa, Mendoza, Cuenca, Cochabamba, Pereira, Ibagué, Salta, Manizales |
|
| Highest point | Mt. Aconcagua |
| - location | Las Heras Department, Mendoza, Argentina |
| - elevation | 6,962 m (22,841 ft) |
| - coordinates |  32°39′10″S 70°0′40″W / 32.65278°S 70.01111°W / -32.65278; -70.01111 |
|
| Length | 7,000 km (4,350 mi) |
| Width | 500 km (311 mi) |
|
Composite satellite image of the southern Andes |
The
Andes is the world's longest
continental mountain range. It is a continual range of highlands along the western coast of
South America. This range is about 7,000 km (4,300 mi) long, about 200 km (120 mi) to 700 km (430 mi) wide (widest between 18
degrees South and 20 degrees South
latitude), and of an average height of about 4,000 m (13,000 ft).
Along its length, the Andes is split into several ranges, which are separated by intermediate
depressions. The Andes is the location of several high plateaux – some of which host major
cities such as
Quito,
Bogotá,
Arequipa,
Medellín,
Sucre, and
La Paz.
The so-called
Altiplano plateau is the world's second-highest plateau following the
Tibetan plateau. The Andes extends to seven countries, in alphabetical order:
Argentina,
Bolivia,
Chile,
Colombia,
Ecuador,
Peru, and
Venezuela, some of which are known as the
Andean States.
The Andes range is the world's highest mountain range outside of the
continent of
Asia. The highest peak, Mt.
Aconcagua, rises to an elevation of about 6,962 m (22,841 ft) above
sea level. The
peak of
Mt. Chimborazo in the Ecuadorean Andes is located at the point on the surface of the Earth that is the most distant one from its centre. This is because of the Earth's
equatorial bulge that results from its
rotation. The world's highest volcanos are in the Andes, including
Ojos del Salado on the Chile-Argentina frontier which rises to 6,893 m (22,615 ft), and over 50 other volcanos that rise above 6,000 m.
The etymology of the word
Andes has been debated. The major consensus is that it derives from the
Quechua word
anti, which means "high crest". Others believe that
Andes comes from
Anti Suyu, one of the four regions of the Inca empire. It is more likely however that the word
Antisuyo derives from the use of
Anti to designate mountain chains. Derivation from the
Spanish andén (in the sense of cultivation
terrace) has also been proposed, yet considered very unlikely.
[edit] Geography
Aerial view of Aconcagua.
The Andes can be divided into three sections:
I. The Southern Andes in Argentina and Chile;
II. The Central Andes, including the Chilean and Peruvian cordilleras and parts of Bolivia;
III. The Northern Andes in Venezuela, Colombia, and Ecuador that consists of two parallel ranges, the Cordillera Occidental and the Cordillera Oriental. In Colombia, north its the border with Ecuador, the Andes split in three parallel ranges, the western, central, and eastern ranges. (The cordillera occidental, central, and oriental).
In the northern part of the Andes, the isolated
Sierra Nevada de Santa Marta range is often considered to be part of the Andes. The eastern range of Colombia is the only one that extends to Venezuela.
[1] The term
cordillera comes from the Spanish word meaning "cuerda", meaning "rope". The Andes range is about 200 km (124 mi) wide throughout its length, except in the Bolivian flexure where it is about 640 kilometres (398 mi) wide. The islands of the Dutch Caribbean
Aruba,
Bonaire, and
Curaçao, which lie in the
Caribbean Sea off the coast of Venezuela, were thought to represent the submerged peaks of the extreme northern edge of the Andes range, but ongoing geological studies indicate that such a simplification does not do justice to the complex tectonic boundary between the South-American and Caribbean plates.
[2]
[edit] Geology
The Andes are a
Mesozoic –
Tertiary orogenic belt of mountains along the
Pacific Ring of Fire, a zone of
volcanic activity that encompasses the Pacific rim of the Americas as well as the
Asia-Pacific region. The Andes are the result of
plate tectonics processes, caused by the
subduction of
oceanic crust beneath the
South American plate. The main cause of the rise of the Andes is the compression of western rim of the
South American Plate due to the subduction of the
Nazca Plate and the
Antarctic Plate. To the east, the Andes range is bounded by several
sedimentary basins such as
Orinoco,
Amazon Basin,
Madre de Dios and
Gran Chaco which separates the Andes from the ancient
cratons in eastern South America. In the south the Andes shares a long boundary with the former
Patagonia Terrane. To the west the Andes ends at the
Pacific Ocean, although the
Peru-Chile trench can be considerated its ultimate western limit. From a geographical approach the Andes are considered to have their western boundaries marked by the appearance of coastal lowlands and a less rugged topography.
[edit] Orogeny
The western rim of the
South American Plate has been the place of several pre-Andean orogenies since at least the of the late
Proterozoic and early
Paleozoic when several
terranes and
microcontinents collided and amalgamated with the ancient
cratons of eastern South America, by then the
South American part of
Gondwana.
The formation of the modern Andes began with the events of the
Triassic when Pangea begun to break up and several
rifts developed. It continued through the
Jurassic Period. It was during the
Cretaceous Period that the Andes began to take its present form, by the
uplifting,
faulting and
folding of
sedimentary and
metamorphic rocks of the ancient cratons to the east. The rise of the Andes has not been constant and different regions have had different degrees of tectonic stress, uplift, and
erosion.
Tectonic forces above the
subduction zone along the entire west coast of South America where the
Nazca Plate and a part of the
Antarctic Plate are sliding beneath the
South American Plate continue to produce an ongoing
orogenic event resulting in minor to major
earthquakes and
volcanic eruptions to this day. In the extreme south a major
transform fault separates
Tierra del Fuego from the small
Scotia Plate. Across the 1,000 km (620 mi) wide
Drake Passage lie the mountains of the
Antarctic Peninsula south of the Scotia Plate which appear to be a continuation of the Andes chain.
[citation needed]
[edit] Volcanism
