The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the
longest continental mountain range in the world, forming a continuous
highland
Highlands or uplands are areas of high elevation such as a mountainous region, elevated mountainous plateau or high hills. Generally, ''upland'' refers to a range of hills, typically from up to , while ''highland'' is usually reserved for range ...
along the western edge of
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...
. The range is long and wide (widest between
18°S and
20°S latitude
In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...
) and has an average height of about . The Andes extend from south to north through seven South American countries:
Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
,
Chile
Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...
,
Bolivia
Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...
,
Peru
Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...
,
Ecuador
Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...
,
Colombia
Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...
, and
Venezuela
Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...
.
Along their length, the Andes are split into several ranges, separated by intermediate
depressions. The Andes are the
location of several high
plateau
In geology and physical geography, a plateau (; ; : plateaus or plateaux), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. ...
s—some of which host major cities such as
Quito
Quito (; ), officially San Francisco de Quito, is the capital city, capital and second-largest city of Ecuador, with an estimated population of 2.8 million in its metropolitan area. It is also the capital of the province of Pichincha Province, P ...
,
Bogotá
Bogotá (, also , , ), officially Bogotá, Distrito Capital, abbreviated Bogotá, D.C., and formerly known as Santa Fe de Bogotá (; ) during the Spanish Imperial period and between 1991 and 2000, is the capital city, capital and largest city ...
,
Cali
Santiago de Cali (), or Cali, is the capital of the Valle del Cauca department, and the most populous city in southwest Colombia, with 2,280,522 residents estimate by National Administrative Department of Statistics, DANE in 2023. The city span ...
,
Arequipa
Arequipa (; Aymara language, Aymara and ), also known by its nicknames of ''Ciudad Blanca'' (Spanish for "White City") and ''León del Sur'' (Spanish for "South's Lion"), is a city in Peru and the capital of the eponymous Arequipa (province), ...
,
Medellín
Medellín ( ; or ), officially the Special District of Science, Technology and Innovation of Medellín (), is the List of cities in Colombia, second-largest city in Colombia after Bogotá, and the capital of the department of Antioquia Departme ...
,
Bucaramanga
Bucaramanga () is the capital and largest city of the department of Santander Department, Santander, Colombia. Bucaramanga has the fifth-largest economy by GDP in Colombia, has the lowest unemployment rate and is the ninth most populous city i ...
,
Sucre
Sucre (; ) is the ''de jure'' capital city of Bolivia, the capital of the Chuquisaca Department and the sixth most populous city in Bolivia. Located in the south-central part of the country, Sucre lies at an elevation of . This relatively high ...
,
Mérida,
El Alto
El Alto (Spanish for "The Heights") is the List of Bolivian cities by population, second-largest city in Bolivia, located adjacent to La Paz in Pedro Domingo Murillo Province on the Altiplano highlands. El Alto is today one of Bolivia's fastest- ...
, and
La Paz
La Paz, officially Nuestra Señora de La Paz (Aymara language, Aymara: Chuqi Yapu ), is the seat of government of the Bolivia, Plurinational State of Bolivia. With 755,732 residents as of 2024, La Paz is the List of Bolivian cities by populati ...
. The
Altiplano Plateau is the world's second highest after the
Tibetan Plateau. These ranges are in turn grouped into three major divisions based on climate: the
Tropical Andes, the
Dry Andes, and the
Wet Andes.
The Andes are the
highest mountain range outside of
Asia
Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...
. The range's highest peak, Argentina's
Aconcagua
Aconcagua () is a mountain in the Principal Cordillera of the Andes mountain range, in Mendoza Province, Argentina. It is the highest mountain in the Americas, the highest outside Asia, and the highest in both the Western Hemisphere and the ...
, rises to an elevation of about above sea level. The
peak of
Chimborazo
Chimborazo () is a stratovolcano situated in Ecuador in the Cordillera Occidental (Ecuador), Cordillera Occidental range of the Andes. Its last known Types of volcanic eruptions, eruption is believed to have occurred around AD 550. Although not ...
in the Ecuadorian Andes is farther from the
Earth's center than any other location on the Earth's surface, due to the
equatorial bulge resulting from the
Earth's rotation
Earth's rotation or Earth's spin is the rotation of planet Earth around its own Rotation around a fixed axis, axis, as well as changes in the orientation (geometry), orientation of the rotation axis in space. Earth rotates eastward, in progra ...
. The world's highest
volcano
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most oft ...
es are in the Andes, including
Ojos del Salado on the Chile-Argentina border, which rises to .
The Andes are also part of the
American Cordillera, a chain of
mountain
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher t ...
ranges (
cordillera) that consists of an almost continuous sequence of mountain ranges that form the western "backbone" of the
Americas
The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ...
and
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...
.
Etymology
The
etymology
Etymology ( ) is the study of the origin and evolution of words—including their constituent units of sound and meaning—across time. In the 21st century a subfield within linguistics, etymology has become a more rigorously scientific study. ...
of the word ''Andes'' has been debated. The majority consensus is that it derives from the
Quechua word "east"
[Teofilo Laime Ajacopa, Diccionario Bilingüe Iskay simipi yuyayk'ancha, La Paz, 2007 (Quechua–Spanish dictionary)] as in ''
Antisuyu
Antisuyu ( , ; ) was the eastern part of the Inca Empire which bordered on the modern-day Upper Amazon region which the Asháninka, Anti inhabited. Along with Chinchaysuyu, it was part of the ''Inca Government#Organization of the empire, Hanan ...
'' (Quechua for "east region"),
[ one of the four regions of the ]Inca Empire
The Inca Empire, officially known as the Realm of the Four Parts (, ), was the largest empire in pre-Columbian America. The administrative, political, and military center of the empire was in the city of Cusco. The History of the Incas, Inca ...
.
The term '' cordillera'' comes from the Spanish word ''cordel'' "rope" and is used as a descriptive name for several contiguous sections of the Andes, as well as the entire Andean range, and the combined mountain chain along the western part of the North and South American continent
A continent is any of several large geographical regions. Continents are generally identified by convention (norm), convention rather than any strict criteria. A continent could be a single large landmass, a part of a very large landmass, as ...
s.
Geography
The Andes can be divided into three sections:
: The Southern Andes in Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
and Chile
Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...
, south of Llullaillaco,
: The Central Andes in Peru
Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...
and Bolivia
Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...
, and
: The Northern Andes in Venezuela
Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...
, Colombia
Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...
, and Ecuador
Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...
.
At the northern end of the Andes, the separate Sierra Nevada de Santa Marta
The Sierra Nevada de Santa Marta (English: ''Snow-Covered Mountain Range of Saint Martha'') is an isolated mountain range in northern Colombia, separate from the Andes range that runs through the north of the country. Reaching an elevation of ...
range is often, but not always, treated as part of the Northern Andes.
The Leeward Antilles islands Aruba
Aruba, officially the Country of Aruba, is a constituent island country within the Kingdom of the Netherlands, in the southern Caribbean Sea north of the Venezuelan peninsula of Paraguaná Peninsula, Paraguaná and northwest of Curaçao. In 19 ...
, Bonaire
Bonaire is a Caribbean island in the Leeward Antilles, and is a Caribbean Netherlands, special municipality (officially Public body (Netherlands), "public body") of the Netherlands. Its capital is the port of Kralendijk, on the west (Windward an ...
, and Curaçao
Curaçao, officially the Country of Curaçao, is a constituent island country within the Kingdom of the Netherlands, located in the southern Caribbean Sea (specifically the Dutch Caribbean region), about north of Venezuela.
Curaçao includ ...
, which lie in the Caribbean Sea
The Caribbean Sea is a sea of the Atlantic Ocean, North Atlantic Ocean in the tropics of the Western Hemisphere, located south of the Gulf of Mexico and southwest of the Sargasso Sea. It is bounded by the Greater Antilles to the north from Cuba ...
off the coast of Venezuela
Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...
, were formerly 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
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...
and Caribbean plates.
Geology
The Andes are an 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 tectonic plate
Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...
processes extending during the Mesozoic
The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...
and Tertiary eras, caused by the subduction of oceanic crust
Oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramaf ...
beneath the South American Plate
The South American plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African plate, with which it forms the southern part of the Mid ...
as the Nazca Plate
The Nazca plate or Nasca plate, named after the Nazca region of southern Peru, is an oceanic list of tectonic plates, tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru– ...
and South American Plate converge. These processes were accelerated by the effects of climate. As the uplift of the Andes created a rain shadow on the western fringes of Chile
Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...
, ocean current
An ocean current is a continuous, directed movement of seawater generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, sh ...
s and prevailing winds carried moisture away from the Chilean coast. This caused some areas of the subduction zone to be sediment-starved, which in turn prevented the subducting plate from having a well lubricated surface. These factors increased the rate of contractional coastal uplift in the Andes. The main cause of the rise of the Andes is the contraction of the western rim of the South American Plate
The South American plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African plate, with which it forms the southern part of the Mid ...
due to the subduction of the Nazca Plate
The Nazca plate or Nasca plate, named after the Nazca region of southern Peru, is an oceanic list of tectonic plates, tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru– ...
and the Antarctic Plate. To the east, the Andes range is bounded by several sedimentary basin
Sedimentary basins are region-scale depressions of the Earth's crust where subsidence has occurred and a thick sequence of sediments have accumulated to form a large three-dimensional body of sedimentary rock They form when long-term subsidence ...
s, such as the Orinoco Basin, the Amazon Basin
The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...
, the Madre de Dios Basin, and the Gran Chaco, that separate the Andes from the ancient craton
A craton ( , , or ; from "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two topmost layers, the crust and the uppermost mantle. Having often survived cycles of merging and rifting of contine ...
s in eastern South America. In the south, the Andes share a long boundary with the former Patagonia Terrane. To the west, the Andes end at the Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...
, although the Peru-Chile trench can be considered their ultimate western limit. From a geographical approach, the Andes are considered to have their western boundaries marked by the appearance of coastal lowlands and less-rugged topography. The Andes also contain large quantities of iron ore
Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the f ...
located in many mountains within the range.
The Andean orogen has a series of bends or oroclines. The Bolivian Orocline is a seaward-concave bending in the coast of South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...
and the Andes Mountains at about 18° S. At this point, the orientation of the Andes turns from northwest in Peru
Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...
to south in Chile
Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...
and Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
. The Andean segments north and south of the Orocline have been rotated 15° counter-clockwise to 20° clockwise respectively. The Bolivian Orocline area overlaps with the area of the maximum width of the Altiplano Plateau, and according to Isacks (1988) the Orocline is related to crustal shortening. The specific point at 18° S where the coast
A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...
line bends is known as the Arica Elbow. Further south lies the Maipo Orocline, a more subtle orocline between 30° S and 38°S with a seaward-concave break in the trend at 33° S. Near the southern tip of the Andes lies the Patagonian Orocline.
Orogeny
The western rim of the South American Plate
The South American plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African plate, with which it forms the southern part of the Mid ...
has been the place of several pre-Andean orogenies since at least the late Proterozoic and early Paleozoic
The Paleozoic ( , , ; or Palaeozoic) Era is the first of three Era (geology), geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma a ...
, when several terranes and microcontinents collided and amalgamated with the ancient craton
A craton ( , , or ; from "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two topmost layers, the crust and the uppermost mantle. Having often survived cycles of merging and rifting of contine ...
s of eastern South America, by then the South American part of Gondwana
Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...
.
The formation of the modern Andes began with the events of the Triassic
The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...
, when Pangaea began the breakup that resulted in developing several rift
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben ...
s. The development continued through the Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...
Period. It was during the Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
Period that the Andes began to take their present form, by the uplifting, faulting, and folding of sedimentary
Sedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedime ...
and metamorphic rocks of the ancient cratons to the east. The rise of the Andes has not been constant, as different regions have had different degrees of tectonic stress, uplift, and erosion
Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...
.
Across the Drake Passage lie the mountains of the Antarctic Peninsula
The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martin in Argentina, and originally as Graham Land in the United Kingdom and the Palmer Peninsula in the United States, is the northernmost part of mainland Antarctica.
...
south of the Scotia Plate, which appear to be a continuation of the Andes chain.
The far east regions of the Andes experience a series of changes resulting from the Andean orogeny. Parts of the Sunsás Orogen in Amazonian craton disappeared from the surface of the earth, being overridden by the Andes. The Sierras de Córdoba, where the effects of the ancient Pampean orogeny can be observed, owe their modern uplift and relief to the Andean orogeny in the Tertiary. Further south in southern Patagonia, the onset of the Andean orogeny caused the Magallanes Basin to evolve from being an extensional back-arc basin
A back-arc basin is a type of geologic Structural basin, basin, found at some convergent boundary, convergent plate boundaries. Presently all back-arc basins are submarine features associated with island arcs and subduction zones, with many found ...
in the Mesozoic
The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...
to being a contractional foreland basin
A foreland basin is a structural basin that develops adjacent and parallel to a mountain belt. Foreland basins form because the immense mass created by crustal thickening associated with the evolution of a mountain belt causes the lithospher ...
in the Cenozoic
The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...
.
Seismic activity
Tectonic forces above the subduction zone along the entire west coast of South America where the Nazca Plate
The Nazca plate or Nasca plate, named after the Nazca region of southern Peru, is an oceanic list of tectonic plates, tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru– ...
and a part of the Antarctic Plate are sliding beneath the South American Plate
The South American plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African plate, with which it forms the southern part of the Mid ...
continue to produce an ongoing orogenic event resulting in minor to major earthquake
An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...
s and volcanic eruption
A volcanic eruption occurs when material is expelled from a volcanic vent or fissure. Several types of volcanic eruptions have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior h ...
s to this day. Many high-magnitude earthquakes have been recorded in the region, such as the 2010 Maule earthquake (M8.8), the 2015 Illapel earthquake (M8.2), and the 1960 Valdivia earthquake (M9.5), which as of 2024 was the strongest ever recorded on seismometers.
The amount, magnitude, and type of seismic activity varies greatly along the subduction zone. These differences are due to a wide range of factors, including friction between the plates, angle of subduction, buoyancy of the subducting plate, rate of subduction, and hydration value of the mantle material. The highest rate of seismic activity is observed in the central portion of the boundary, between 33°S and 35°S. In this area, the angle of subduction is very low, meaning the subducting plate is nearly horizontal. Studies of mantle hydration across the subduction zone have shown a correlation between increased material hydration and lower-magnitude, more-frequent seismic activity. Zones exhibiting dehydration instead are thought to have a higher potential for larger, high-magnitude earthquakes in the future.
The mountain range is also a source of shallow intraplate earthquakes within the South American Plate. The largest such earthquake (as of 2024) struck Peru in 1947 and measured 7.5. In the Peruvian Andes, these earthquakes display normal (1946
1946 (Roman numerals, MCMXLVI) was a common year starting on Tuesday of the Gregorian calendar, the 1946th year of the Common Era (CE) and ''Anno Domini'' (AD) designations, the 946th year of the 2nd millennium, the 46th year of the 20th centur ...
), strike-slip (1976), and reverse ( 1969, 1983) mechanisms. The Amazonian Craton is actively underthrusted beneath the sub-Andes region of Peru, producing thrust faults. In Colombia, Ecuador, and Peru, thrust faulting occurs along the sub-Andes due in response to contraction brought on by subduction, while in the high Andes, normal faulting occurs in response to gravitational forces.
In the extreme south, a major transform fault
A transform fault or transform boundary, is a fault (geology), fault along a plate boundary where the motion (physics), motion is predominantly Horizontal plane, horizontal. It ends abruptly where it connects to another plate boundary, either an ...
separates Tierra del Fuego from the small Scotia Plate.
Volcanism
The Andes range has many active volcanoes distributed in four volcanic zones separated by areas of inactivity. The Andean volcanism is a result of the subduction of the Nazca Plate and Antarctic Plate underneath the South American Plate. The belt is subdivided into four main volcanic zones that are separated from each other by volcanic gaps. The volcanoes of the belt are diverse in terms of activity style, products, and morphology. Although some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences inside volcanic zones and even between neighboring volcanoes. Despite being a typical location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a large range of volcano-tectonic settings, such as rift systems, extensional zones, transpressional faults, subduction of mid-ocean ridge
A mid-ocean ridge (MOR) is a undersea mountain range, seafloor mountain system formed by plate tectonics. It typically has a depth of about and rises about above the deepest portion of an ocean basin. This feature is where seafloor spreading ...
s, and seamount chains apart from a large range of crustal thicknesses and magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...
ascent paths, and different amount of crustal assimilations.
Ore deposits and evaporites
The Andes Mountains host large ore and salt
In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...
deposits, and some of their eastern fold and thrust belts act as traps for commercially exploitable amounts of hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...
s. In the forelands of the Atacama Desert
The Atacama Desert () is a desert plateau located on the Pacific Ocean, Pacific coast of South America, in the north of Chile. Stretching over a strip of land west of the Andes Mountains, it covers an area of , which increases to if the barre ...
, some of the largest porphyry copper mineralizations occur, making Chile and Peru the first- and second-largest exporters of copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...
in the world. Porphyry copper in the western slopes of the Andes has been generated by hydrothermal fluids (mostly water) during the cooling of plutons or volcanic systems. The porphyry mineralization further benefited from the dry climate that reduced the disturbing actions of meteoric water. The dry climate in the central western Andes has also led to the creation of extensive saltpeter deposits that were extensively mined until the invention of synthetic nitrate
Nitrate is a polyatomic ion with the chemical formula . salt (chemistry), Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are solubility, soluble in wa ...
s. Yet another result of the dry climate are the salars of Atacama and Uyuni, the former being the largest source of lithium
Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...
and the latter the world's largest reserve of the element. Early Mesozoic and Neogene
The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...
plutonism in Bolivia's Cordillera Central created the Bolivian tin belt as well as the famous, now mostly depleted, silver deposits of Cerro Rico de Potosí.
Climate
The Andes Mountains is connected to the climate of South America, particularly through the hyper-arid conditions of the adjacent Atacama Desert
The Atacama Desert () is a desert plateau located on the Pacific Ocean, Pacific coast of South America, in the north of Chile. Stretching over a strip of land west of the Andes Mountains, it covers an area of , which increases to if the barre ...
. The Atacama Bench, a prominent low-relief feature along the Pacific seaboard, serves as a key geomorphological record of the long-term interplay between Andean tectonics and Cenozoic climate. While the initial uplift and shortening of the Andes were driven by the subduction of the Nazca Plate beneath the South American Plate, arid climate acted as an important feedback mechanism. Reduced erosion rates in the increasingly arid Atacama region may have effectively stopped tectonic activity in certain parts of the mountain range. This lack of erosion could have facilitated the eastward propagation of deformation, leading to the widening of the Andean orogen over time. Thus, the Atacama Desert and its geological features, like the Atacama Bench, offer critical insights into the coupled evolution of the Andes Mountains and the changing regional climate.
History
The Andes Mountains, initially inhabited by hunter-gatherers, experienced the development of agriculture
Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...
and the rise of politically centralized civilizations, which culminated in the establishment of the century-long Inca Empire
The Inca Empire, officially known as the Realm of the Four Parts (, ), was the largest empire in pre-Columbian America. The administrative, political, and military center of the empire was in the city of Cusco. The History of the Incas, Inca ...
. This all changed in the 16th century, when the Spanish conquistador
Conquistadors (, ) or conquistadores (; ; ) were Spanish Empire, Spanish and Portuguese Empire, Portuguese colonizers who explored, traded with and colonized parts of the Americas, Africa, Oceania and Asia during the Age of Discovery. Sailing ...
s colonized the mountains in advance of the mining
Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...
economy.
In the tide of anti-imperialist nationalism, the Andes became the scene of a series of independence wars in the 19th century, when rebel forces swept through the region to overthrow Spanish colonial rule. Since then, many former Spanish territories have become five independent Andean states.
Climate and hydrology
The climate in the Andes varies greatly depending on latitude, altitude, and proximity to the sea. Temperature, atmospheric pressure, and humidity decrease in higher elevations. The southern section is rainy and cool, while the central section is dry. The northern Andes are typically rainy and warm, with an average temperature of in Colombia
Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...
. The climate is known to change drastically in rather short distances. Rainforest
Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...
s exist just kilometers away from the snow-covered peak of Cotopaxi. The mountains have a large effect on the temperatures of nearby areas. The snow line
The climatic snow line is the boundary between a snow-covered and snow-free surface. The actual snow line may adjust seasonally, and be either significantly higher in elevation, or lower. The permanent snow line is the level above which snow wil ...
depends on the location. It is between in the tropical Ecuadorian, Colombian, Venezuelan, and northern Peruvian Andes, rising to in the drier mountains of southern Peru and northern Chile south to about 30°S before descending to on Aconcagua at 32°S, at 40°S, at 50°S, and only in Tierra del Fuego at 55°S; from 50°S, several of the larger glaciers descend to sea level.
The Andes of Chile and Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
can be divided into two climatic and glaciological zones: the Dry Andes and the Wet Andes. Since the Dry Andes extend from the latitudes of the Atacama Desert
The Atacama Desert () is a desert plateau located on the Pacific Ocean, Pacific coast of South America, in the north of Chile. Stretching over a strip of land west of the Andes Mountains, it covers an area of , which increases to if the barre ...
to the area of the Maule River, precipitation is more sporadic, and there are strong temperature oscillations. The line of equilibrium may shift drastically over short periods of time, leaving a whole glacier in the ablation area or in the accumulation area.
In the high Andes of Central Chile and Mendoza Province, rock glaciers are larger and more common than glaciers; this is due to the high exposure to solar radiation
Sunlight is the portion of the electromagnetic radiation which is emitted by the Sun (i.e. solar radiation) and received by the Earth, in particular the visible light perceptible to the human eye as well as invisible infrared (typically p ...
. In these regions, glaciers occur typically at higher altitudes than rock glaciers.[ The lowest active rock glaciers occur at 900 m a.s.l. in ]Aconcagua
Aconcagua () is a mountain in the Principal Cordillera of the Andes mountain range, in Mendoza Province, Argentina. It is the highest mountain in the Americas, the highest outside Asia, and the highest in both the Western Hemisphere and the ...
.
Though precipitation increases with height, there are semiarid conditions in the nearly highest mountains of the Andes. This dry steppe
In physical geography, a steppe () is an ecoregion characterized by grassland plains without closed forests except near rivers and lakes.
Steppe biomes may include:
* the montane grasslands and shrublands biome
* the tropical and subtropica ...
climate is considered to be typical of the subtropical position at 32–34° S. The valley bottoms have no woods, just dwarf scrub. The largest glaciers, for example the Plomo Glacier and the Horcones Glaciers, do not even reach in length and have only insignificant ice thickness. At glacial times, however, 20,000 years ago, the glaciers were over ten times longer. On the east side of this section of the Mendozina Andes, they flowed down to and on the west side to about above sea level. The massifs of Aconcagua
Aconcagua () is a mountain in the Principal Cordillera of the Andes mountain range, in Mendoza Province, Argentina. It is the highest mountain in the Americas, the highest outside Asia, and the highest in both the Western Hemisphere and the ...
(), Tupungato (), and Nevado Juncal () are tens of kilometres away from each other and were connected by a joint ice stream network. The Andes' dendritic glacier arms, components of valley glaciers, were up to long and over thick, and spanned a vertical distance of . The climatic glacier snowline (ELA) was lowered from to at glacial times.
Flora
The Andean region cuts across several natural and floristic regions, due to its extension, from Caribbean
The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...
Venezuela to cold, windy, and wet Cape Horn passing through the hyperarid Atacama Desert
The Atacama Desert () is a desert plateau located on the Pacific Ocean, Pacific coast of South America, in the north of Chile. Stretching over a strip of land west of the Andes Mountains, it covers an area of , which increases to if the barre ...
. Rainforest
Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...
s and tropical dry forests used to encircle much of the northern Andes but are now greatly diminished, especially in the Chocó and inter-Andean valleys of Colombia. Opposite the humid Andean slopes are the relatively dry Andean slopes in most of western Peru, Chile, and Argentina. Along with several Interandean Valles, they are typically dominated by deciduous
In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...
woodland, shrub and xeric vegetation, reaching the extreme in the slopes near the virtually lifeless Atacama Desert.
About 30,000 species of vascular plants live in the Andes, with roughly half being endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to the region, surpassing the diversity of any other hotspot. The small tree '' Cinchona pubescens'', a source of quinine
Quinine is a medication used to treat malaria and babesiosis. This includes the treatment of malaria due to ''Plasmodium falciparum'' that is resistant to chloroquine when artesunate is not available. While sometimes used for nocturnal leg ...
that is used to treat malaria
Malaria is a Mosquito-borne disease, mosquito-borne infectious disease that affects vertebrates and ''Anopheles'' mosquitoes. Human malaria causes Signs and symptoms, symptoms that typically include fever, Fatigue (medical), fatigue, vomitin ...
, is found widely in the Andes as far south as Bolivia. Other important crops that originated from the Andes are tobacco
Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...
and potato
The potato () is a starchy tuberous vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are underground stem tubers of the plant ''Solanum tuberosum'', a perennial in the nightshade famil ...
es. The high-altitude '' Polylepis'' forests and woodlands are found in the Andean areas of Colombia
Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...
, Ecuador
Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...
, Peru
Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...
, Bolivia
Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...
, and Chile
Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...
. These trees, by locals referred to as Queñua, Yagual, and other names, can be found at altitudes of above sea level. It remains unclear if the patchy distribution of these forests and woodlands is natural, or the result of clearing that began during the Inca
The Inca Empire, officially known as the Realm of the Four Parts (, ), was the largest empire in pre-Columbian America. The administrative, political, and military center of the empire was in the city of Cusco. The History of the Incas, Inca ...
n period. Regardless, in modern times, the clearance has accelerated, and the trees are now considered highly endangered
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
, with some believing that as little as 10% of the original woodland remains.
Fauna
The Andes are rich in fauna: With almost 1,000 species, of which roughly 2/3 are endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to the region, the Andes are the most important region in the world for amphibian
Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...
s.[Tropical Andes](_blank)
– biodiversityhotspots.org The diversity of animals in the Andes is high, with almost 600 species of mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
s (13% endemic), more than 1,700 species of birds (about 1/3 endemic), more than 600 species of reptile
Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...
s (about 45% endemic), and almost 400 species of fish (about 1/3 endemic).
The vicuña
The vicuña (''Lama vicugna'') or vicuna (both , very rarely spelled ''vicugna'', Vicugna, its former genus name) is one of the two wild South American camelids, which live in the high alpine tundra, alpine areas of the Andes; the other cameli ...
and guanaco can be found living in the Altiplano
The Altiplano (Spanish language, Spanish for "high plain"), Collao (Quechuan languages, Quechua and Aymara language, Aymara: Qullaw, meaning "place of the Qulla people, Qulla") or Andean Plateau, in west-central South America, is the most extens ...
, while the closely related domesticated llama
The llama (; or ) (''Lama glama'') is a domesticated South American camelid, widely used as a List of meat animals, meat and pack animal by Inca empire, Andean cultures since the pre-Columbian era.
Llamas are social animals and live with ...
and alpaca
The alpaca (''Lama pacos'') is a species of South American camelid mammal. Traditionally, alpacas were kept in herds that grazed on the level heights of the Andes of Southern Peru, Western Bolivia, Ecuador, and Northern Chile. More recentl ...
are widely kept by locals as pack animal
A pack animal, also known as a sumpter animal or beast of burden, is a working animal used to transport goods or materials by carrying them, usually on its back.
Domestic animals of many species are used in this way, among them alpacas, Bact ...
s and for their meat
Meat is animal Tissue (biology), tissue, often muscle, that is eaten as food. Humans have hunted and farmed other animals for meat since prehistory. The Neolithic Revolution allowed the domestication of vertebrates, including chickens, sheep, ...
and wool
Wool is the textile fiber obtained from sheep and other mammals, especially goats, rabbits, and camelids. The term may also refer to inorganic materials, such as mineral wool and glass wool, that have some properties similar to animal w ...
. The crepuscular (active during dawn and dusk) chinchillas, two threatened members of the rodent
Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...
order, inhabit the Andes' alpine regions.[Eisenberg, J.F.; & Redford, K.H. (2000). ''Mammals of the Neotropics, Volume 3: The Central Neotropics: Ecuador, Peru, Bolivia, Brazil.'' ][Eisenberg, J.F.; & Redford, K.H. (1992). ''Mammals of the Neotropics, Volume 2: The Southern Cone: Chile, Argentina, Uruguay, Paraguay.'' ] The Andean condor, the largest bird of its kind in the Western Hemisphere
The Western Hemisphere is the half of the planet Earth that lies west of the Prime Meridian (which crosses Greenwich, London, United Kingdom) and east of the 180th meridian.- The other half is called the Eastern Hemisphere. Geopolitically, ...
, occurs throughout much of the Andes but generally in very low densities.[Fjeldsaa, J.; & Krabbe, N. (1990). ''Birds of the High Andes: A Manual to the Birds of the Temperate Zone of the Andes and Patagonia, South America.'' ] Other animals found in the relatively open habitats of the high Andes include the huemul, cougar
The cougar (''Puma concolor'') (, ''Help:Pronunciation respelling key, KOO-gər''), also called puma, mountain lion, catamount and panther is a large small cat native to the Americas. It inhabits North America, North, Central America, Cent ...
, foxes in the genus '' Pseudalopex'',[ and, for birds, certain species of tinamous (notably members of the genus '' Nothoprocta''), Andean goose, giant coot, flamingos (mainly associated with hypersaline lakes), lesser rhea, Andean flicker, diademed sandpiper-plover, ]miners
A miner is a person who extracts ore, coal, chalk, clay, or other minerals from the earth through mining. There are two senses in which the term is used. In its narrowest sense, a miner is someone who works at the rock face (mining), face; cutt ...
, sierra-finches and diuca-finches.[
]Lake Titicaca
Lake Titicaca (; ; ) is a large freshwater lake in the Andes mountains on the border of Bolivia and Peru. It is often called the highest navigable lake in the world. Titicaca is the largest lake in South America, both in terms of the volume of ...
hosts several endemics, among them the highly endangered Titicaca flightless grebe[ and Titicaca water frog.][Stuart, Hoffmann, Chanson, Cox, Berridge, Ramani and Young, editors (2008). ''Threatened Amphibians of the World.'' ] A few species of hummingbirds, notably some hillstars, can be seen at altitudes above , but far higher diversities can be found at lower altitudes, especially in the humid Andean forests ("cloud forest
A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest, is a generally tropical or subtropical, evergreen, Montane forest, montane, Tropical and subtropical moist broadleaf forests, moist forest characteri ...
s") growing on slopes in Colombia, Ecuador, Peru, Bolivia, and far northwestern Argentina.[ These forest-types, which includes the Yungas and parts of the Chocó, are very rich in flora and fauna, although few large mammals exist, exceptions being the threatened mountain tapir, spectacled bear, and yellow-tailed woolly monkey.][
Birds of humid Andean forests include mountain toucans, quetzals, and the Andean cock-of-the-rock, while mixed-species flocks dominated by tanagers and furnariids are commonly seen—in contrast to several vocal but typically cryptic species of ]wrens
Wrens are a family (biology), family, Troglodytidae, of small brown passerine birds. The family includes 96 species and is divided into 19 genus, genera. All species are restricted to the New World except for the Eurasian wren that is widely di ...
, tapaculos, and antpittas.[
A number of species such as the royal cinclodes and white-browed tit-spinetail are associated with ''Polylepis'', and consequently also threatened.][
]
Human activity
The Andes Mountains form a north–south axis of cultural influences. A long series of cultural development culminated in the expansion of the Inca civilization and Inca Empire
The Inca Empire, officially known as the Realm of the Four Parts (, ), was the largest empire in pre-Columbian America. The administrative, political, and military center of the empire was in the city of Cusco. The History of the Incas, Inca ...
in the central Andes during the 15th century. The Incas formed this civilization through imperialistic militarism
Militarism is the belief or the desire of a government or a people that a state should maintain a strong military capability and to use it aggressively to expand national interests and/or values. It may also imply the glorification of the mili ...
as well as careful and meticulous governmental management. The government sponsored the construction of aqueducts and roads in addition to pre-existing installations. Some of these constructions still exist today.
Devastated by European diseases and by civil war
A civil war is a war between organized groups within the same Sovereign state, state (or country). The aim of one side may be to take control of the country or a region, to achieve independence for a region, or to change government policies.J ...
, the Incas were defeated in 1532 by an alliance composed of tens of thousands of allies from nations they had subjugated (e.g. Huancas, Chachapoyas, Cañaris) and a small army of 180 Spaniards led by Francisco Pizarro
Francisco Pizarro, Marquess of the Atabillos (; ; – 26 June 1541) was a Spanish ''conquistador'', best known for his expeditions that led to the Spanish conquest of the Inca Empire.
Born in Trujillo, Cáceres, Trujillo, Spain, to a poor fam ...
. One of the few Inca sites the Spanish never found in their conquest was Machu Picchu, which lay hidden on a peak on the eastern edge of the Andes where they descend to the Amazon. The main surviving languages of the Andean peoples are those of the Quechua and Aymara language families. Woodbine Parish and Joseph Barclay Pentland surveyed a large part of the Bolivian Andes from 1826 to 1827.
Cities
In modern times, the largest cities in the Andes are Bogotá
Bogotá (, also , , ), officially Bogotá, Distrito Capital, abbreviated Bogotá, D.C., and formerly known as Santa Fe de Bogotá (; ) during the Spanish Imperial period and between 1991 and 2000, is the capital city, capital and largest city ...
, with a metropolitan population of over ten million, and Santiago
Santiago (, ; ), also known as Santiago de Chile (), is the capital and largest city of Chile and one of the largest cities in the Americas. It is located in the country's central valley and is the center of the Santiago Metropolitan Regi ...
, Medellín
Medellín ( ; or ), officially the Special District of Science, Technology and Innovation of Medellín (), is the List of cities in Colombia, second-largest city in Colombia after Bogotá, and the capital of the department of Antioquia Departme ...
, Cali
Santiago de Cali (), or Cali, is the capital of the Valle del Cauca department, and the most populous city in southwest Colombia, with 2,280,522 residents estimate by National Administrative Department of Statistics, DANE in 2023. The city span ...
, and Quito
Quito (; ), officially San Francisco de Quito, is the capital city, capital and second-largest city of Ecuador, with an estimated population of 2.8 million in its metropolitan area. It is also the capital of the province of Pichincha Province, P ...
. Lima
Lima ( ; ), founded in 1535 as the Ciudad de los Reyes (, Spanish for "City of Biblical Magi, Kings"), is the capital and largest city of Peru. It is located in the valleys of the Chillón River, Chillón, Rímac River, Rímac and Lurín Rive ...
is a coastal city adjacent to the Andes and is the largest city of all Andean countries. It is the seat of the Andean Community of Nations.
La Paz
La Paz, officially Nuestra Señora de La Paz (Aymara language, Aymara: Chuqi Yapu ), is the seat of government of the Bolivia, Plurinational State of Bolivia. With 755,732 residents as of 2024, La Paz is the List of Bolivian cities by populati ...
, Bolivia's seat of government, is the highest capital city in the world, at an elevation of approximately . Parts of the La Paz conurbation, including the city of El Alto
El Alto (Spanish for "The Heights") is the List of Bolivian cities by population, second-largest city in Bolivia, located adjacent to La Paz in Pedro Domingo Murillo Province on the Altiplano highlands. El Alto is today one of Bolivia's fastest- ...
, extend up to .
Other cities in or near the Andes include Bariloche, Catamarca, Jujuy, Mendoza, Salta
Salta () is the capital and largest city in the Provinces of Argentina, Argentine province of Salta Province, the same name. With a population of 618,375 according to the 2010 census, it is also the List of cities in Argentina, 7th most-populous ...
, San Juan, Tucumán, and Ushuaia
Ushuaia ( , ) is the capital city, capital of Tierra del Fuego Province, Argentina, Tierra del Fuego, Antártida e Islas del Atlántico Sur Province, Argentina. With a population of 82,615 and a location below the 54th parallel south latitude, U ...
in Argentina; Calama and Rancagua in Chile; Cochabamba
Cochabamba (; ) is a city and municipality in central Bolivia in a valley in the Andes mountain range. It is the capital (political), capital of the Cochabamba Department and the list of cities in Bolivia, fourth largest city in Bolivia, with ...
, Oruro, Potosí, Sucre
Sucre (; ) is the ''de jure'' capital city of Bolivia, the capital of the Chuquisaca Department and the sixth most populous city in Bolivia. Located in the south-central part of the country, Sucre lies at an elevation of . This relatively high ...
, Tarija, and Yacuiba in Bolivia; Arequipa
Arequipa (; Aymara language, Aymara and ), also known by its nicknames of ''Ciudad Blanca'' (Spanish for "White City") and ''León del Sur'' (Spanish for "South's Lion"), is a city in Peru and the capital of the eponymous Arequipa (province), ...
, Cajamarca, Cusco
Cusco or Cuzco (; or , ) is a city in southeastern Peru, near the Sacred Valley of the Andes mountain range and the Huatanay river. It is the capital of the eponymous Cusco Province, province and Cusco Region, department.
The city was the cap ...
, Huancayo, Huánuco, Huaraz, Juliaca, and Puno in Peru; Ambato, Cuenca, Ibarra, Latacunga, Loja, Riobamba, and Tulcán :''"Tulcan" is also an alternative spelling of tulchan''
Tulcán () is the capital of the province of Carchi Province, Carchi in Ecuador and the seat of Tulcán Canton. The population of the city of Tulcán was 56,719 in the 2022 census. Tulcán ...
in Ecuador; Armenia
Armenia, officially the Republic of Armenia, is a landlocked country in the Armenian Highlands of West Asia. It is a part of the Caucasus region and is bordered by Turkey to the west, Georgia (country), Georgia to the north and Azerbaijan to ...
, Cúcuta, Bucaramanga
Bucaramanga () is the capital and largest city of the department of Santander Department, Santander, Colombia. Bucaramanga has the fifth-largest economy by GDP in Colombia, has the lowest unemployment rate and is the ninth most populous city i ...
, Duitama, Ibagué, Ipiales, Manizales, Palmira, Pasto, Pereira, Popayán, Rionegro
Rionegro () is a city and municipality in Antioquia Department, Colombia, located in the subregion of Eastern Antioquia. The official name of the city is Ciudad Santiago de Arma de Rionegro. Rio Negro means "Black River" in Spanish, as the cit ...
, Sogamoso, Tunja, and Villavicencio in Colombia; and Barquisimeto, La Grita, Mérida, San Cristóbal, Tovar, Trujillo, and Valera in Venezuela. The cities of Caracas
Caracas ( , ), officially Santiago de León de Caracas (CCS), is the capital and largest city of Venezuela, and the center of the Metropolitan Region of Caracas (or Greater Caracas). Caracas is located along the Guaire River in the northern p ...
, Valencia
Valencia ( , ), formally València (), is the capital of the Province of Valencia, province and Autonomous communities of Spain, autonomous community of Valencian Community, the same name in Spain. It is located on the banks of the Turia (r ...
, and Maracay are in the Venezuelan Coastal Range, which is a debatable extension of the Andes at the northern extremity of South America.
Transportation
Cities and large towns are connected with asphalt-paved roads, while smaller towns are often connected by dirt roads, which may require a four-wheel-drive vehicle.
The rough terrain has historically put the costs of building highway
A highway is any public or private road or other public way on land. It includes not just major roads, but also other public roads and rights of way. In the United States, it is also used as an equivalent term to controlled-access highway, or ...
s and railroad
Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...
s that cross the Andes out of reach of most neighboring countries, even with modern civil engineering
Civil engineering is a regulation and licensure in engineering, professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads ...
practices. For example, the main crossover of the Andes between Argentina and Chile is still accomplished through the Paso Internacional Los Libertadores. Only recently have the ends of some highways that came rather close to one another from the east and the west been connected. Much of the transportation of passengers is done via aircraft.
There is one railroad that connects Chile with Peru via the Andes, however, and there are others that make the same connection via southern Bolivia.
There are multiple highways in Bolivia that cross the Andes. Some of these were built during a period of war between Bolivia and Paraguay
Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...
, in order to transport Bolivian troops and their supplies to the war front in the lowlands of southeastern Bolivia and western Paraguay.
For decades, Chile claimed ownership of land on the eastern side of the Andes. These claims were given up in about 1870 during the War of the Pacific
The War of the Pacific (), also known by War of the Pacific#Etymology, multiple other names, was a war between Chile and a Treaty of Defensive Alliance (Bolivia–Peru), Bolivian–Peruvian alliance from 1879 to 1884. Fought over Atacama Desert ...
between Chile and the allied Bolivia and Peru, in a diplomatic deal to keep Peru out of the war. The Chilean Army and Chilean Navy defeated the combined forces of Bolivia and Peru, and Chile took over Bolivia's only province on the Pacific Coast, some land from Peru that was returned to Peru decades later. Bolivia has been completely landlocked ever since. It mostly uses seaport
A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manc ...
s in eastern Argentina and Uruguay
Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...
for international trade because its diplomatic relations with Chile have been suspended since 1978.
Because of the tortuous terrain in places, villages and towns in the mountains—to which travel via motorized vehicle
A motor vehicle, also known as a motorized vehicle, automotive vehicle, automobile, or road vehicle, is a self-propelled land vehicle, commonly wheeled, that does not operate on railway track, rails (such as trains or trams), does not fly (such ...
s is of little use—are still located in the high Andes of Chile, Bolivia, Peru, and Ecuador
Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...
. Locally, the relatives of the camel
A camel (from and () from Ancient Semitic: ''gāmāl'') is an even-toed ungulate in the genus ''Camelus'' that bears distinctive fatty deposits known as "humps" on its back. Camels have long been domesticated and, as livestock, they provid ...
, the llama
The llama (; or ) (''Lama glama'') is a domesticated South American camelid, widely used as a List of meat animals, meat and pack animal by Inca empire, Andean cultures since the pre-Columbian era.
Llamas are social animals and live with ...
, and the alpaca
The alpaca (''Lama pacos'') is a species of South American camelid mammal. Traditionally, alpacas were kept in herds that grazed on the level heights of the Andes of Southern Peru, Western Bolivia, Ecuador, and Northern Chile. More recentl ...
continue to carry out important uses as pack animals, but this use has generally diminished in modern times. Donkey
The donkey or ass is a domesticated equine. It derives from the African wild ass, ''Equus africanus'', and may be classified either as a subspecies thereof, ''Equus africanus asinus'', or as a separate species, ''Equus asinus''. It was domes ...
s, mule
The mule is a domestic equine hybrid between a donkey, and a horse. It is the offspring of a male donkey (a jack) and a female horse (a mare). The horse and the donkey are different species, with different numbers of chromosomes; of the two ...
s, and horses are also useful.
Agriculture
The ancient peoples of the Andes such as the Incas have practiced irrigation
Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has bee ...
techniques for over 6,000 years. Because of the mountain slopes, terracing has been a common practice. Terracing, however, was only extensively employed after Incan imperial expansions to fuel their expanding realm. The potato
The potato () is a starchy tuberous vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are underground stem tubers of the plant ''Solanum tuberosum'', a perennial in the nightshade famil ...
holds a very important role as an internally consumed staple crop. Maize
Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native American ...
was also an important crop for these people, and was used for the production of chicha
''Chicha'' is a Fermentation, fermented (alcoholic) or non-fermented beverage of Latin America, emerging from the Andes and Amazonia regions. In both the pre- and post-Spanish conquest of Peru, Spanish conquest periods, corn beer (''chicha de jo ...
, important to Andean native people. Currently, tobacco
Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...
, cotton
Cotton (), first recorded in ancient India, is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure ...
, and coffee
Coffee is a beverage brewed from roasted, ground coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content, but decaffeinated coffee is also commercially a ...
are the main export crops. Coca, despite eradication programs in some countries, remains an important crop for legal local use in a mildly stimulating herbal tea
Herbal teas, technically known as herbal infusions, and less commonly called tisanes (UK and US , US also ), are beverages made from the infusion or decoction of herbs, spices, or other plant material in hot water. Often herb tea, or the plai ...
, and illegally for the production of cocaine
Cocaine is a tropane alkaloid and central nervous system stimulant, derived primarily from the leaves of two South American coca plants, ''Erythroxylum coca'' and ''Erythroxylum novogranatense, E. novogranatense'', which are cultivated a ...
.
Irrigation
In unirrigated land, pasture
Pasture (from the Latin ''pastus'', past participle of ''pascere'', "to feed") is land used for grazing.
Types of pasture
Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, c ...
is the most common type of land use. In the rainy season (summer), part of the rangeland is used for cropping (mainly potatoes, barley, broad beans, and wheat).
Irrigation is helpful in advancing the sowing data of the summer crops, which guarantees an early yield in periods of food shortage. Also, by early sowing, maize can be cultivated higher up in the mountains (up to ). In addition, it makes cropping in the dry season (winter) possible and allows the cultivation of frost-resistant vegetable crops like onion
An onion (''Allium cepa'' , from Latin ), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus '' Allium''. The shallot is a botanical variety of the onion which was classifie ...
and carrot.
Mining
The Andes rose to fame for their mineral wealth during the Spanish conquest of South America. Although Andean Amerindian peoples crafted ceremonial jewelry of gold and other metals, the mineralizations of the Andes were first mined on a large scale after the Spanish arrival. Potosí in present-day Bolivia
Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...
and Cerro de Pasco in Peru were among the principal mines of the Spanish Empire in the New World. Río de la Plata
The Río de la Plata (; ), also called the River Plate or La Plata River in English, is the estuary formed by the confluence of the Uruguay River and the Paraná River at Punta Gorda, Colonia, Punta Gorda. It empties into the Atlantic Ocean and ...
and Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
derive their names from the silver of Potosí.
Currently, mining in the Andes of Chile
Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...
and Peru
Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...
places these countries as the first and second major producers of copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...
in the world. Peru
Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...
also contains the 4th-largest goldmine in the world: the Yanacocha. The Bolivian Andes principally produce tin, although historically silver mining had a huge impact on the economy
An economy is an area of the Production (economics), production, Distribution (economics), distribution and trade, as well as Consumption (economics), consumption of Goods (economics), goods and Service (economics), services. In general, it is ...
of 17th-century Europe. In Chile in the higher portions of the Andes there are only mining districs dominated by large-scale mining, while medium and small-scale mining is more common at lower altitudes.
There is a long history of mining in the Andes, from the Spanish silver
Silver is a chemical element; it has Symbol (chemistry), symbol Ag () and atomic number 47. A soft, whitish-gray, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. ...
mines in Potosí in the 16th century to the vast current porphyry copper deposits of Chuquicamata
Chuquicamata ( ; referred to as Chuqui for short) is the largest open-pit mining, open pit copper Mining, mine in terms of excavated volume in the world. It is located in the north of Chile, just outside Calama, Chile, Calama, at above sea level. ...
and Escondida in Chile and Toquepala in Peru. Other metals, including iron, gold, and tin, in addition to non-metallic resources are important. The Andes have a vast supply of lithium; Argentina, Bolivia, and Chile have the three largest reserves in the world respectively.
Peaks
This list contains some of the major peaks in the Andes mountain range. The highest peak is Aconcagua of Argentina.
Argentina
* Aconcagua
Aconcagua () is a mountain in the Principal Cordillera of the Andes mountain range, in Mendoza Province, Argentina. It is the highest mountain in the Americas, the highest outside Asia, and the highest in both the Western Hemisphere and the ...
,
* Cerro Bonete
Cerro Bonete is a mountain in the north of the province of La Rioja, Argentina, near the provincial border with Catamarca.
Its summit is 6,759 m above mean sea level, making it the fifth-highest separate mountain in the Americas (after Aconca ...
,
* Galán,
* Mercedario,
* Pissis,
The border between Argentina and Chile
* Cerro Bayo,
* Cerro Fitz Roy, or 3,405 m, Patagonia, also known as Cerro Chaltén
* Cerro Escorial,
* Cordón del Azufre,
* Falso Azufre,
* Incahuasi,
* Lastarria,
* Llullaillaco,
* Maipo,
* Marmolejo,
* Ojos del Salado,
* Olca,
* Sierra Nevada de Lagunas Bravas,
* Socompa,
* Nevado Tres Cruces, (south summit) (III Region)
* Tronador,
* Tupungato,
* Nacimiento,
Bolivia
* Janq'u Uma,
* Cabaraya,
* Chacaltaya,
* Chachacomani,
* Chaupi Orco,
* Huayna Potosí
Huayna Potosí is a mountain in Bolivia, located near El Alto and about 25 km north of La Paz in the Cordillera Real (Bolivia), Cordillera Real.
Huayna Potosí is the closest high mountain to La Paz. Surrounded by high mountains, it is ...
,
* Illampu
Illampu is the fourth highest mountain in Bolivia. It is located in the northern section of the Cordillera Real (Bolivia), Cordillera Real, part of the Andes, east of Lake Titicaca. It lies just north of the slightly higher Janq'u Uma, near the t ...
,
* Illimani,
* Laram Q'awa,
* Macizo de Pacuni,
* Mururata,
* Nevado Anallajsi,
* Nevado Charquini,
* Nevado Sajama,
* Patilla Pata,
* Tata Sabaya,
* Tunari,
* Uturuncu,
* Wayna Potosí,
Border between Bolivia and Chile
* Acotango,
* Aucanquilcha,
* Michincha,
* Iru Phutunqu,
* Licancabur,
* Olca,
* Parinacota Parinacota (in Hispanicized spelling), Parina Quta or Parinaquta ( Aymara, ''parina'' flamingo, ''quta'' lake, "flamingo lake", other Hispanicized spellings ''Parinaccota, Parinajota'') may refer to:
Lakes
* Parinaquta (Carabaya), in Peru, Puno ...
,
* Paruma,
* Pomerape,
Chile
* Monte San Valentin,
* Cerro Paine Grande,
* Cerro Macá, c.
* Monte Darwin, c.
* Volcan Hudson, c.
* Cerro Castillo Dynevor, c.
* Mount Tarn, c.
* Polleras, c.
* Acamarachi, c.
Colombia
* Nevado del Huila,
* Nevado del Ruiz,
* Nevado del Tolima,
* Pico Pan de Azúcar,
* Ritacuba Negro,
* Nevado del Cumbal,
* Cerro Negro de Mayasquer,
* Ritacuba Blanco,
* Nevado del Quindío,
* Puracé,
* Santa Isabel,
* Doña Juana,
* Galeras,
* Azufral,
Ecuador
* Antisana,
* Cayambe,
* Chiles,
* Chimborazo
Chimborazo () is a stratovolcano situated in Ecuador in the Cordillera Occidental (Ecuador), Cordillera Occidental range of the Andes. Its last known Types of volcanic eruptions, eruption is believed to have occurred around AD 550. Although not ...
,
* Corazón,
* Cotopaxi,
* El Altar,
* Illiniza,
* Pichincha,
* Quilotoa,
* Reventador,
* Sangay,
* Tungurahua,
Peru
* Alpamayo,
* Artesonraju,
* Carnicero,
* Chumpe,
* Coropuna,
* El Misti,
* El Toro,
* Huandoy,
* Huascarán,
* Jirishanca,
* Pumasillo,
* Rasac,
* Rondoy,
* Sarapo,
* Salcantay,
* Seria Norte,
* Siula Grande
Siula Grande is a mountain in the Huayhuash mountain range in the Peruvian Andes. It is high and has a subpeak, Siula Chico, high.
__NOTOC__
''Touching the Void'' ascent
In 1985, Siula Grande was climbed by Joe Simpson and Simon Yates. Alth ...
,
* Huaytapallana,
* Yerupaja,
* Yerupaja Chico,
Venezuela
* Pico Bolívar,
* Pico Humboldt,
* Pico Bonpland,
* Pico La Concha,
* Pico Piedras Blancas,
* Pico El Águila,
* Pico El Toro
* Pico El León
* Pico Mucuñuque
See also
* '' Andean Geology''—a scientific journal
In academic publishing, a scientific journal is a periodical publication designed to further the progress of science by disseminating new research findings to the scientific community. These journals serve as a platform for researchers, schola ...
* Andesite line
* Apu (god)
* Mountain passes of the Andes
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually highe ...
* List of mountain ranges
This is a list of mountain ranges on Earth and a few other astronomical object, astronomical bodies. First, the highest and longest mountain ranges on Earth are listed, followed by more comprehensive alphabetical lists organized by continent. Rang ...
* Sutter Buttes
Notes
References
*
* Biggar, J. (2005). ''The Andes: A Guide For Climbers''. 3rd. edition. Andes: Kirkcudbrightshire.
* de Roy, T. (2005). ''The Andes: As the Condor Flies.'' Firefly books: Richmond Hill.
* Fjeldså, J. & N. Krabbe (1990). ''The Birds of the High Andes.'' Zoological Museum, University of Copenhagen:
* Fjeldså, J. & M. Kessler (1996). ''Conserving the biological diversity of Polylepis woodlands of the highlands on Peru and Bolivia, a contribution to sustainable natural resource management in the Andes.'' NORDECO: Copenhagen.
Bibliography
*
*
External links
*
University of Arizona: Andes geology
Discover-peru.org: Regions and Microclimates in the Andes
{{Authority control
Mountain ranges of South America
*
Regions of South America
Physiographic divisions