Map of the Atacama Desert: the area most commonly defined as Atacama is in yellow. In orange are the outlying arid areas of the southernChala,Altiplano,Puna de Atacama, andNorte Chico. The vertical extent of the satellite photo is approximately 2,600 km, encompassing the desert and surrounding regions.
TheAtacama Desert (Spanish:Desierto de Atacama;Spanish pronunciation:[ataˈkama]) is a desertplateau located on thePacific coast ofSouth America, in the north ofChile. Stretching over a 1,600-kilometre-long (1,000-mile) strip of land west of theAndes Mountains, it covers an area of 105,000 km2 (41,000 sq mi),[2] which increases to 128,000 km2 (49,000 sq mi) if the barren lower slopes of the Andes are included.[3]
The Atacama Desert is the driest nonpolar desert in the world, and the second driest overall, behind some specific spots within theMcMurdo Dry Valleys.[4][5][6][7] It is the onlytrue desert to receive less precipitation thanpolar deserts, and the largestfog desert in the world. The area has been used as an experimentation site forMars expedition simulations due to its similarities to the Martian environment.
The constanttemperature inversion caused by the cool north-flowingHumboldt ocean current and the strongPacific anticyclone contribute to the extreme aridity of the desert.[8] The most arid region of the Atacama Desert is situated between two mountain chains, the Andes and theChilean Coast Range, which are high enough to prevent moistureadvection from either the Pacific or the Atlantic Ocean, creating a two-sidedrain shadow effect.[9] These same geographic conditions moderate airflows to produce consistently mild temperatures throughout the desert, with only a few periods of freezing temperatures in winter or very warm days during summer.
According to theWorld Wide Fund for Nature, the Atacama Desertecoregion occupies a continuous strip for nearly 1,600 kilometres (1,000 mi) along the narrow coast of the northern third ofChile, from nearArica (18°24′S) southward to nearLa Serena (29°55′S).[10] TheNational Geographic Society considers the coastal area of southernPeru to be part of the Atacama Desert[11][12] and includes the deserts south of theIca Region in Peru. However, other sources consider that the part of the desert in Peru is a different ecosystem, and should properly be named as Pampas de la Joya desert.
TheCoastal Cliff of northern Chile west of theChilean Coast Range is the main topographical feature of the coast.[13] The geomorphology of the Atacama Desert has been characterized as a low-relief bench "similar to a giant uplifted terrace" by Armijo and co-workers.[14] The intermediate depression (or Central Valley) forms a series ofendorheic basins in much of the Atacama Desert south of latitude 19°30'S. North of this latitude, the intermediate depression drains into the Pacific Ocean.[15]
In December 2023, scientists, for the first time, reported on a recently discovered area in the territory ofPuna de Atacama, which may have similarities to Earth during theArchean eon and thus to the environment of thefirst life forms on Earth. It could as well be similar to conceivably-hospitable conditions on the planetMars during earlier Martian times.[16]
The Atacama has acold desert climate (in theKöppen climate classification,BWk) with generally mild temperatures year-round and only slight temperature differences across seasons. Rather than the intense heat of many other deserts around the world, the almost total lack of precipitation is the most prominent characteristic of the Atacama Desert.[18]
A flat area of the Atacama Desert between Antofagasta andTaltal
The Atacama Desert is commonly known as the driest place in the world, especially the surroundings of the abandoned Yungay mining town, where theUniversity of Antofagasta Desert Research Station is located,[19][20] inAntofagasta Region, Chile.[21] The average rainfall is about 15 mm (0.6 in) per year,[22] although some locations receive only 1 to 3 mm (0.04 to 0.12 in) in a year.[23] Moreover, some weather stations in the Atacama have never received rain. Periods up to four years have been registered with no rainfall in the central sector, delimited by the cities ofAntofagasta,Calama andCopiapó.[24] Evidence suggests that the Atacama may not have had any significant rainfall from 1570 to 1971.[2]
Feral donkey in the Atacama desert
The Atacama Desert may be the oldest desert on earth, and has experienced hyper aridity since at least theMiddle Miocene, since the establishment of a proto-Humboldt current in conjunction with the opening of the Tasmania-Antarctic passage ca. 33Ma.[25] The opening of the Tasmania-Antarctic passage allowed for cold currents to move along the west coast of South America, which influenced the availability of warm humid air to travel from the Amazon Basin to the Atacama. Though there was a general lack of humid air after 33 Ma, there were punctuated intervals of increased humidity,[26] such as between around 10.86 and 6.4 Ma, when the Tiliviche Palaeolake existed before turning into asalar sometime before the Middle Pliocene.[27] The long history of aridity raises the possibility thatsupergene mineralisation, under the appropriate conditions, can form in arid environments, instead of requiring humid conditions.[28] The presence ofevaporite formations suggests that in some sections of the Atacama Desert, arid conditions have persisted for the last 200 million years (since theTriassic).
Aridity in Atacama Desert predates the rise of the Central Andes, yet hyper-aridity is generally thought to have resulted from the rise of the Andes.[29] As such it is hypothesised it had climatic conditions akin to theNamib Desert prior to the rise of the mountains.[29]
The southern part of the desert, between 25° and 27°S, may have been glacier-free throughout theQuaternary (including duringglaciations), thoughpermafrost extends down to an altitude of 4,400 m (14,400 ft) and is continuous above 5,600 m (18,400 ft). Studies by a group of British scientists have suggested that some river beds have been dry for 120,000 years.[35] However, some locations in the Atacama receive a marinefog known locally as thecamanchaca, providing sufficient moisture for hypolithicalgae,lichens, and even somecacti—the genusCopiapoa is notable among these.
Geographically, the aridity of the Atacama is explained by its being situated between two mountain chains (the Andes and the Chilean Coast Range) of sufficient height to prevent moistureadvection from either the Pacific or the Atlantic Oceans, a two-sided rain shadow.[9]
Despite modern views of the Atacama Desert as fully devoid of vegetation, in pre-Columbian and colonial times a large flatland area there known asPampa del Tamarugal was awoodland, but demand for firewood associated with silver andsaltpeter mining in the 18th and 19th centuries resulted in widespreaddeforestation.[36][A]
The lack of humidity, rain, and light pollution together produce a dusty, rocky landscape.[37]
In a region about 100 km (60 mi) south of Antofagasta, which averages 3,000 m (10,000 ft) in elevation, the soil has been compared to that ofMars. Owing to its otherworldly appearance, the Atacama has been used as a location for filming Mars scenes, most notably in the 2004 television seriesSpace Odyssey: Voyage to the Planets.
In 2003, a team of researchers published a report in which they duplicated the tests used by theViking 1andViking 2 Mars landers to detect life and were unable to detect any signs in Atacama Desert soil in the region of Yungay.[20] The region may be unique on Earth in this regard and is being used byNASA to test instruments for future Mars missions. The team duplicated the Viking tests in Mars-like Earth environments and found that they missed present signs of life in soil samples fromAntarctic dry valleys, the Atacama Desert of Chile and Peru, and other locales. However, in 2014, a new hyperarid site was reported,María Elena South, which was much drier than Yungay and, thus, a better Mars-like environment.[38]
Towards Atacama, near the deserted coast, you see a land without men, where there is not a bird, not a beast, nor a tree, nor any vegetation.
In 2008, thePhoenix Mars Lander detectedperchlorates on the surface of Mars at the same site where water was first discovered.[40] Perchlorates are also found in the Atacama and associated nitrate deposits have contained organics, leading to speculation that signs of life on Mars are not incompatible with perchlorates. The Atacama is also a testing site for the NASA-fundedEarth–Mars Cave Detection Program.[41]
In early 2019, extreme heat and wildfires in Chile resulted in heavy flooding in the Atacama.[51] At least 6 people died and 346 homes were destroyed.[52][53]
Rare rainfall events cause theflowering desert phenomenon in the southern Atacama Desert.
In spite of the geographic and climatic conditions of the desert, a rich variety of flora has evolved there. Over 500 species have been gathered within the border of this desert. These species are characterized by their extraordinary ability to adapt to this extreme environment.[54] The most common species are herbs and flowers such asthyme,llareta, andsaltgrass, and where humidity is sufficient, trees such as thechañar, thepimiento tree and the leafyalgarrobo.
The llareta is one of the highest-growing wood species in the world. It is found at altitudes between 3,000 and 5,000 m (9,800 and 16,400 ft). Its dense form is similar to a pillow some 3 to 4 m (9.8 to 13.1 ft) thick. It concentrates and retains the heat from the day to cope with low evening temperatures. The growth rate of the llareta has been recently estimated at 1.5 cm/year (0.59 in/year), making many llaretas over 3,000 years old. It produces a much-prized resin, which the mining industry once harvested indiscriminately as fuel, making this plant endangered.
The desert is also home to cacti, succulents, and other plants that thrive in a dry climate. Cactus species here include thecandelabro andcardon, which can reach a height of 7 m (23 ft) and a diameter of 70 cm (28 in).
The Atacama Desertflowering (Spanish:desierto florido) can be seen from September to November in years with sufficient precipitation, as happened in 2015.[49][50]
The climate of the Atacama Desert limits the number of animals living permanently in this extreme ecosystem. Some parts of the desert are soarid, no plant or animal life can survive. Outside of these extreme areas, sand-coloredgrasshoppers blend with pebbles on the desert floor, andbeetles and theirlarvae provide a valuable food source in thelomas (hills). Desertwasps andbutterflies can be found during the warm and humid season, especially on the lomas. Redscorpions also live in the desert.
Liolaemus nitidus, a lizard native to the southern reaches of the Atacama Desert
A unique environment is provided by somelomas, where the fog from the ocean provides enough moisture for seasonal plants and a few animal species. Surprisingly fewreptile species inhabit the desert and even feweramphibian species. TheVallenar toad (also called the Atacama toad), lives on thelomas, where it lays eggs in permanent ponds or streams.Iguanas andlava lizards inhabit parts of the desert, whilesalt flat lizards,Liolaemus, live in the dry areas bordering the ocean.[55] One species,Liolaemus fabiani, is endemic to theSalar de Atacama, the Atacama salt flat.[56]
Birds are one of the most diverse animal groups in the Atacama.Humboldt penguins live year-round along the coast, nesting in desert cliffs overlooking the ocean. Inland, high-altitude salt flats are inhabited byAndean flamingos, whileChilean flamingos can be seen along the coast. Other birds (including species ofhummingbirds andrufous-collared sparrow) visit thelomas seasonally to feed on insects, nectar, seeds, and flowers. Thelomas help sustain several threatened species, such as the endangeredChilean woodstar.
Because of the desert's extreme aridity, only a few specially adapted mammal species live in the Atacama, such asDarwin's leaf-eared mouse. The less arid parts of the desert are inhabited by theSouth American gray fox and theviscacha (a relative of thechinchilla). Larger animals, such asguanacos andvicuñas, graze in areas where grass grows, mainly because it is seasonally irrigated by melted snow. Vicuñas need to remain near a steady water supply, while guanacos can roam into more arid areas and survive longer without fresh water.South American fur seals andSouth American sea lions often gather along the coast.
View ofCaspana, a village andLikan Antai settlement in the interior Atacama DesertView ofChuquicamata, a large, state-owned copper mine
The Atacama is sparsely populated, with most towns located along the Pacific coast.[57] In interior areas, oases and some valleys have been populated for millennia and were the location of the most advanced pre-Columbian societies found in Chile.[citation needed]
The Chinchorro culture developed in the Atacama Desert area from 7000 BCE to 1500 BCE. These peoples were sedentary fishermen inhabiting mostly coastal areas. Their presence is found from today's towns ofIlo, in southern Peru, toAntofagasta in northern Chile. Presence of fresh water in the arid region on the coast facilitated human settlement in these areas. The Chinchorro were famous for their detailedmummification and funerary practices.[58]
San Pedro de Atacama, at about 2,400 m (8,000 ft) elevation, is like many of the small towns. Before theInca Empire and prior to the arrival of the Spanish, the extremely arid interior was inhabited primarily by theAtacameño tribe. They are noted for building fortified towns calledpucarás, one of which is located a few kilometers from San Pedro de Atacama. The town's church was built by theSpanish in 1577.
The Atacameño[59] were an extinct Indigenous South American culture,[60] different from theAymara to the north and theDiaguita to the south.
The oasis settlement ofPica has Pre-hispanic origins and served as an important stopover for transit between the coast and theAltiplano during the time of theInca Empire.[61]
The coastal cities originated in the 16th, 17th, and 18th centuries during the time of theSpanish Empire, when they emerged as shipping ports forsilver produced inPotosí and other mining centers. At the end of the 18th century, Carlos IV defines the southern border of the Viceroyalty of Peru at the port of Nuestra Señora del Paposo.
View of a forest inPampa del Tamarugal fromChile Route 5. These forests were once devastated by the demand of firewood associated with saltpeter mining.
During the 19th century, the desert came under control ofBolivia, Chile and Peru. With the discovery ofsodium nitrate deposits and as a result of Chilean expansion plans, the area soon became a zone of conflict and resulted in theWar of the Pacific. Chile annexed most of the desert, and cities along the coast developed into international ports, hosting many Chilean workers who migrated there.[62][63][64]
With the guano and saltpeter booms of the 19th century, the population grew immensely, mostly as a result of immigration from central Chile. In the 20th century, the nitrate industry declined and at the same time, the largely male population of the desert became increasingly problematic for the Chilean state. Miners and mining companies came into conflict, and protests spread throughout the region.
Around 1900, there were irrigation system ofpuquios spread through the oases of Atacama Desert.[65] Puquios are known from the valleys ofAzapa andSibaya and the oases ofLa Calera,Pica-Matilla andPuquio de Núñez.[65] In 1918, geologistJuan Brüggen mentioned the existence of 23socavones (shafts) in the Pica oasis, yet these have since been abandoned due to economic and social changes.[65]
The desert has rich deposits ofcopper and otherminerals and the world's largest natural supply ofsodium nitrate, which was mined on a large scale until the early 1940s. TheAtacama border dispute over these resources between Chile and Bolivia began in the 19th century and resulted in theWar of the Pacific.[66]
The Atacama Desert is rich in metallic mineral resources such as copper, gold, silver and iron, as well as nonmetallic minerals including important deposits of boron, lithium, sodium nitrate, and potassium salts. The Salar de Atacama is wherebischofite is extracted.[citation needed] The Atacama Desert is also the world's largest source ofiodine-bearing minerals, with some areas having iodine concentrations hundreds of times larger than the average levels in Earth's crust.[67] These resources are exploited by various mining companies such as Codelco, Lomas Bayas, Mantos Blancos, and Soquimich.[68][69]
In recent years, large amounts of used clothing imported from overseas have begun to accumulate in portions of the desert. Because of the dry conditions, they do not decompose at the normal rate, and fires have exposed nearby residents to air pollution.[70]
Because of its high altitude, nearly nonexistent cloud cover, dry air, and freedom from light pollution and radio interference from widely populated cities and towns, this desert is one of the best places in the world to conduct astronomical observations.[72][73] Hundreds of thousands of stars can be viewed via telescope since the desert experiences more than 200 cloudless nights each year. A number of telescopes have been installed to helpastronomers from across the globe study the universe.[74] Aradio astronomy telescope, called theAtacama Large Millimeter Array, built byEuropean countries,Japan, theUnited States,Canada, andChile in theLlano de Chajnantor Observatory officially opened on 3 October 2011.[75] A number of radio astronomy projects, such as theCBI, theASTE and theACT, among others, have been operating in the Chajnantor area since 1999. On 26 April 2010, theESO council decided to build a fourth site,Cerro Armazones, to be home to theExtremely Large Telescope.[76][77][78] Construction work at the ELT site started in June 2014.[79] TheCarnegie Institution for Science operates theLas Campanas Observatory with several telescopes in the southern portion of the desert.
The Atacama Desert is popular with all-terrain sports enthusiasts. Various championships have taken place here, including the Lower Atacama Rally, Lower Chile Rally, Patagonia-Atacama Rally, and the latterDakar Rally's editions. The rally was organized by theAmaury Sport Organisation and held in 2009, 2010, 2011, and 2012. The dunes of the desert are ideal rally races located in the outskirts of the city of Copiapó.[80] The 2013 Dakar 15-Day Rally started on 5 January in Lima, Peru, through Chile,Argentina and back to Chile finishing in Santiago.[81] Visitors also use the Atacama Desertsand dunes forsandboarding (Spanish:duna).
A week-long foot race called the Atacama Crossing has the competitors cross the various landscapes of the Atacama.[82]
An event called Volcano Marathon takes place near theLascar volcano in the Atacama Desert.[83]
Eighteensolar powered cars were displayed in front of the presidential palace (La Moneda) in Santiago in November 2012.[84] The cars were then raced 1,300 km (810 mi) through the desert from 15–19 November 2012.[85]
Most people who go to tour the sites in the desert stay in the town of San Pedro de Atacama.[86] The Atacama Desert is in the top three tourist locations in Chile. The specially commissioned ESO hotel is reserved for astronomers and scientists.[87]
Since 2024 the Spanish companyGrenergy is building the “Oasis de Atacama” storage battery from photovoltaic energy. It has a capacity of about 2 GW solar together with 11 gigawatt hours (GWh) of storage.[88]
Grenergy has an agreement withBYD for the supply of large-scale storage systems for a total capacity of 3GWh for Oasis de Atacama.[89]
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