Atacama by NASA World Wind
|Countries||Chile, Peru, Bolivia, Argentina|
|Area||105,000 km2 (40,541 sq mi)|
The Atacama Desert (Spanish: Desierto de Atacama) is a plateau in South America, covering a 1,000-kilometre (600 mi) strip of land on the Pacific coast, west of the Andes mountains. It is, according to NASA, National Geographic and other sources, the driest desert in the world. The Atacama occupies 105,000 square kilometres (41,000 sq mi) composed mostly of salt lakes (salares), sand, and felsic lava flows towards the Andes.
The Atacama Desert ecoregion, as defined by the World Wide Fund for Nature (WWF), extends from a few kilometers south of the Peru–Chile border to about 30° south latitude. To the north lies the Peruvian Sechura Desert ecoregion, whilst to the south is the Chilean Matorral ecoregion.
The National Geographic Society, by contrast, considers the coastal area of southern Peru to be part of the Atacama Desert. It includes in this definition the deserts south of the Ica Region in Peru.
To the east lies the less arid Central Andean dry puna ecoregion. The drier portion of this ecoregion is located south of the Loa River between the parallel Sierra Vicuña Mackenna and Cordillera Domeyko. To the north of the Loa lies the Pampa del Tamarugal.
The Atacama Desert is commonly known as the driest place in the world, especially the surroundings of the abandoned Yungay town (in Antofagasta Region, Chile). The average rainfall in the Chilean region of the Atacama Desert is .004 inches per year, meaning it gets 4 inches of rain in a thousand years. Some weather stations in the Atacama have never received rain. Periods of up to four years have been registered with no rainfall in the central sector, delimited by the cities of Antofagasta, Calama and Copiapó, in Chile. Evidence suggests that the Atacama may not have had any significant rainfall from 1570 to 1971. It is so arid that mountains that reach as high as 6,885 metres (22,589 ft) are completely free of glaciers and, in the southern part from 25°S to 27°S, may have been glacier-free throughout the Quaternary, though permafrost extends down to an altitude of 4,400 metres (14,400 ft) and is continuous above 5,600 metres (18,400 ft). Studies by a group of British scientists have suggested that some river beds have been dry for 120,000 years. However, some locations in the Atacama receive a marine fog known locally as the camanchaca, providing sufficient moisture for hypolithic algae, lichens and even some cacti—the genus Copiapoa is notable among these. Geographically, the aridity can be explained by the following reasons:
- The desert is located on the leeward side of the Chilean Coast Range, so little moisture from the Pacific Ocean can reach the desert.
- The Andes are so high that they block convective clouds, which might bring precipitation, formed above the Amazon Basin from entering the desert from the east.
- An inversion layer is created by the cold Humboldt current and the South Pacific High.
- The rain that would change the climate of the land mostly falls at sea instead. Largely this is caused by the cold waters of the Humboldt current just off shore. The temperature change causes most of the clouds and the rain to occur over the ocean instead of over the land. The Humboldt Current transports cold water from Antarctica towards the north the length of the Chilean and Peruvian coasts; this water that makes the western sea breezes cold, reducing evaporation and creating a thermic inversion—cold air immobilized under a cover of tepid air—prevents the formation of large, rain-producing clouds.
In July 2011, an extreme Antarctic cold front broke through the rain shadow, bringing 80 centimetres (31 in) of snow to the plateau, stranding residents across the region, particularly in Bolivia, where many drivers became stuck in snow drifts and emergency crews became overtaxed with a large number of rescue calls.
This phenomenon is called the altiplano winter, which can produce a little rain and abundant electrical storms, and occurs in January and February. In 2012, the altiplano winter saw floods in San Pedro de Atacama.
At night the temperature fluctuates to as low as −25°C in the zone of Ollagüe, while during the day the temperature can be between 25–30°C in the shade. The difference between the summer and the winter is minimal, because it is situated at the border of the tropic of Capricorn. In summer, the morning ambient temperature is 4–10°C and the maximum it reaches is 45°C which is full solar radiation. The solar radiation is very high in the ultraviolet spectrum, making the use of glasses and UV sunscreens indispensable.
The relative humidity in the air is about 18% in the interior, but very high near the coast, reaching up to 98% during the winter months. The atmospheric pressure is 1017 millibars. There are seasonal tornado-like winds or blizzards whose velocity can easily reach 100 km/h, generally registered at midday. The topography of the zone slopes downwards gradually towards the sea, but its average relative height is 400–1500 meters above sea level.
One can witness the Atacama Desert flowering in September–November in years in which there was some precipitation. In Spanish, this is called the Desierto florido. The desert is also home to cacti, succulents and other examples of xerophilous flowers.
Comparison to Mars 
In a region about 100 kilometres (60 mi) south of Antofagasta, which averages 3,000 metres (10,000 ft) height, the soil has been compared to that of Mars. Owing to its otherworldly appearance, the Atacama has been used as a location for filming Mars scenes, most notably in the television series Space Odyssey: Voyage To The Planets.
In 2003, a team of researchers published a report in the journal Science in which they duplicated the tests used by the Viking 1 and Viking 2 Mars landers to detect life, and were unable to detect any signs in Atacama Desert soil. The region may be unique on Earth in this regard and is being used by NASA 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 from Antarctic dry valleys, the Atacama Desert of Chile and Peru, and other locales.
In 2008, the Phoenix Mars Lander detected perchlorates on the surface of Mars at the same site where water was first discovered. 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-funded Earth-Mars Cave Detection Program.
Valle de la Luna 
The Valle de la Luna in English, the Valley of the Moon, is another area of the Atacama Desert which is said to look like the surface of the moon. It lies 13 kilometres (8 mi) to the west of the town, San Pedro de Atacama.
Human occupation 
The Atacama is sparsely populated, with most cities located along the Pacific coast. In interior areas, oases and some valleys have been populated for millennia, being the seat of the most advanced Pre-Columbian societies found in Chile. These oases have had little population growth and urban development, and have, since the 20th century, faced conflicts over water resources that are needed for the coastal cities and the mining industry.
San Pedro de Atacama, at about 2,000 metres (7,000 ft) elevation, is a typical example. Its church was built by the Spanish in 1577. In pre-Hispanic times, before the Inca empire, the extremely arid interior was inhabited mainly by the Atacameño tribe. The tribe is noted for the construction of fortified towns called pucarás, one of which can be seen a few kilometers from San Pedro de Atacama.
The coastal cities originated in the 16th, 17th, and 18th centuries during the time of the Spanish Empire, when they emerged as shipping ports for silver produced in Potosí and other mines. During the 19th century the desert came under control of Bolivia, Chile, and Peru, and soon became a zone of conflict as a result of unclear borders and the discovery of sodium nitrate deposits. After the War of the Pacific, in which Chile annexed most of the desert, cities along the coast developed into international ports, and many Chilean workers migrated there.
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. Mineworkers and mining companies came into conflict, and protests spread throughout the region.
Abandoned nitrate mining towns 
The desert has rich deposits of copper and other minerals, and the world's largest natural supply of sodium nitrate, which was mined on a large scale until the early 1940s. The Atacama border dispute over these resources between Chile and Bolivia began in the 19th century.
Now the desert is littered with approximately 170 abandoned nitrate (or "saltpetre") mining towns, almost all of which were shut down decades after the invention of synthetic nitrate in Germany at the turn of the 20th century (see Haber process). The towns include Chacabuco, Humberstone, Santa Laura, Pedro de Valdivia, Puelma, María Elena, and Oficina Anita.
The Atacama Desert is rich in metallic mineral resources such as copper, gold, silver and iron as well as non metallic minerals including important deposits of boron, lithium, sodium nitrate and potassium salts. The Salar de Atacama is a place where bischofite is extracted. These resources are exploited by various mining companies such as Codelco, Lomas Bayas, Mantos Blancos, and Soquimich.
Astronomical observatories 
Because of its high altitude, nearly non-existent cloud cover, dry air, and lack of light pollution and radio interference from the very widely spaced cities, the desert is one of the best places in the world to conduct astronomical observations. The European Southern Observatory operates two major observatories in the Atacama:
A new radio astronomy telescope, called ALMA, built by Europe, Japan, the United States, Canada and Chile in the Llano de Chajnantor Observatory officially opened on 3 October 2011. A number of radio astronomy projects, such as the CBI, the ASTE and the ACT, among others, have been operating in the Chajnantor area since 1999.
Other uses 
The Atacama Desert received a number of all-terrain sports enthusiasts. Various championships have taken place here including the Lower Atacama Rally, Lower Chile Rally, Patagonia-Atacama Rally and the latter Dakar Rally's editions. It got serious in 2009, 2010, 2011, and 2012, and were organized by the A.S.O. The dunes of this desert are ideal for this type of sport, located in the outskirts of the city of Copiapó. Chile will host Dakar Rally events for the foreseeable future. The 2013 Dakar 15-Day Rally started on January 5 in Lima Peru, through Chile, Argentina and back to Chile finishing in Santiago. Sandboarding is also an activity in the Atacama Desert. It is also called duna in Spanish because it makes use of sand dunes.
A week-long foot race called the Atacama Crossing is a race in which the competitors cross the various landscapes of the Atacama.
Solar car racing 
Most people who go to tour the sites in the desert stay in the town of San Pedro de Atacama. The Atacama Desert is in the top three tourist locations in Chile. The specially commissioned ESO hotel is reserved for astronomers.
El Tatio Geyser 
There are geysers 80 km from the town of San Pedro de Atacama. There are about 80 geysers that lie in a valley. They are closer to the town of Chiu Chiu.
Termos Baños de Puritama 
Baños de Puritama are rock pools which are 37 miles from the geysers.
Protected areas 
See also 
- Vesilind, Priit J. (August 2003). "The Driest Place on Earth". National Geographic Magazine. Retrieved 2 April 2013. (Excerpt)
- "Even the Driest Place on Earth Has Water". Extreme Science. Retrieved 2 April 2013.
- Mckay, Christopher P. (May–June 2002). "Two dry for life: the Atacama Desert and Mars". AdAstra: 30–33.
- Jonathan Amos (8 December 2005). "Chile desert's super-dry history". BBC News. Retrieved 29 December 2009.
- Wright, John W. (ed.); Editors and reporters of The New York Times (2006). The New York Times Almanac (2007 ed.). New York, New York: Penguin Books. p. 456. ISBN 0-14-303820-6.
- "Atacama desert". Terrestrial Ecoregions. World Wildlife Fund. Retrieved 11 March 2008.
- Handwerk, Brian (23 October 2006). "Viking Mission May Have Missed Mars Life, Study Finds". National Geographic News. National Geographic Society. Retrieved 3 April 2013.
- Minard, Anne (25 June 2007). "Giant Penguins Once Roamed Peru, Fossils Show". National Geographic News. National Geographic Society. Retrieved 3 April 2013.
- "Yungay – the driest place in the world". Wondermondo. 3 November 2010. Retrieved 3 April 2013.
- Boehm, Richard G.; Armstrong, David G.; Hunkins, Francis P.; Reinhartz, Dennis; Lobrecht, Merry (2005). The World and its People (Teacher's wraparound ed.). New York: Glencoe/McGraw-Hill. p. 276. ISBN 0-07-860977-1.
- "Chile desert's super-dry history". BBC News. 8 December 2005. Retrieved 25 April 2010.
- Veblen, Thomas T., ed. (2007). The Physical Geography of South America. Oxford [u.a.]: Oxford Univ. Press. p. 160. ISBN 9780195313413.
- "Snow Comes to the Atacama Desert". ESO. Retrieved 3 April 2013.
- "Hyper-Arid Atacama Desert Hit By Snow". BBC News. 7 July 2011. Archived from the original on 8 July 2011. Retrieved 7 July 2011.
- "The Climate of Chile". This is Chile. Retrieved 3 December 2012.
- "Inundación en San Pedro de Atacama deja 800 afectados y 13 turistas evacuados". El Mostrador. 11 February 2012. Retrieved 3 December 2012.
- "Tourism in San Pedro de Atacama restricted by floods". This is Chile. Retrieved 3 December 2012.
- Braudel, Fernand (1992). The Perspective of the World. Berkeley, CA: University of California Press. p. 388. ISBN 0-520-08116-1.
- Thompson, Andrea (5 August 2008). "Scientists Set Record Straight on Martian Salt Find". Space.com. Retrieved 6 August 2008.
- Wynne, J.J.; Cabrol, N.A.; Chong Diaz, G.; Grin, G.A.; Jhabvala, M.D.; Moersch, J.E.; Titus, T.N. Earth–Mars Cave Detection Program Phase 2 – 2008 Atacama Desert Expedition (Report). http://www.explorers.org/flag_reports/Flag_52_-_J_Judson_Wynne_Flag_Report.pdf. Retrieved 3 April 2013.
- South America physical map
- Holsti, K.J. (1997). The State, War, and the State of War. Cambridge [u.a.]: Cambridge Univ. Press. p. 151. ISBN 0-521-57790-X.
- Clayton, Lawrence A. (1984). The Bolivarian Nations. The Forum Press. p. 26. ISBN 0-88273-603-5.
- St. John, Robert Bruce (1994). The Bolivia-Chile-Peru dispute in the Atacama Desert (Report). International Boundaries Research Unit. http://books.google.cl/books?id=KPORDM85EsIC&pg=PA1&dq=Atacama+desert+colonial+period&hl=en&sa=X&ei=MSG8UJOiG4Wu8ASPzoCoCQ&ved=0CCwQ6AEwAA#v=onepage&q=Atacama%20desert%20colonial%20period&f=false.
- "San Pedro de Atacama se transforma en una feria gigante". nacion.cl. 16 November 2012. Retrieved 3 December 2012.
- "Exploring the Atacama". yes. Retrieved 2012-12-03.
- Kogel, Jessica Elzea (2006). In Kogel, Jessica Elzea; Trivedi, Nikhil; Barker, James; Krukowski, Stanley. Industrial Minerals & Rocks: Commodities, Markets, and Uses (7th ed.). Littleton, Colo.: Society for Mining, Metallurgy, and Exploration. p. 605. ISBN 9780873352338.
- "New Movie: ALMA — In Search of Our Cosmic Origins". ESO. Retrieved 2 April 2013.
- Toll, Rosser (3 October 2011). "In Chile desert, huge telescope begins galaxy probe". AFP.com. Retrieved 3 October 2011.
- "Ruíz-Tagle ve difícil que Chile no esté en un nuevo Dakar". nacion.cl. 21 November 2012. Retrieved 3 December 2012.
- "Dakar Rally event 2013 to culminate in Chilean capital". yes. This is Chile. Retrieved 3 December 2012.
- "Atacama Crossing". yes. 4 deserts. Retrieved 3 December.
- "Los autos que competirán en la súper carrera solar de Atacama". nacion.cl. 8 November 2012. Retrieved 3 December 2012.
- "Nueva generación de autos solares son presentados en Chile". nacion.cl. 7 November 2012. Retrieved 3 December 2012.
- "Guide to Atacama Desert". Conde Nast Traveller. Conde Nast. Retrieved 3 April 2013.
- Vickers, Graham (2005). 21st Century Hotel. London: Laurence King. p. 122. ISBN 1856694011.
- Erfurt-Cooper, Patricia; Cooper, Malcolm, ed. (2010). Volcano and Geothermal Tourism: Sustainable Geo-resources for Leisure and Recreation. London: Earthscan. ISBN 9781844078707.
- Mroue, Haas; Schreck, Kristina; Luongo, Michael (2005). Frommer's Argentina & Chile (3rd ed.). Hoboken, N.J. [u.a.]: Wiley. p. 308. ISBN 9780764584398.
- Braudel, Fernand, The Perspective of the World, ISBN 0-520-08116-1, vol. III of Civilization and Capitalism 1984 (originally published in French, 1979).
- Sagaris, Lake. Bone and dream : into the world's driest desert. 1st ed. – Toronto : A.A. Knopf Canada, c2000. ISBN 0-676-97223-3
|Wikimedia Commons has media related to: Atacama Desert|
- "Mars-like Soils in the Atacama Desert, Chile, and the Dry Limit of Microbial Life", NASA press release
- "Roving robot finds desert life", article in Nature
- Photos of Atacama Desert landscape, flora and fauna
- "A Lady in the Atacama Desert, from the travel blog A Lady in London