Что такое atacama desert

Atacama Desert

The Atacama Desert of Chile covers the northern third of the country stretching more than 600 miles (1,000km), and straddles the southern border of Peru. Bound on the west by barren hills and mountains on the Pacific coast, it extends east into the Andes Mountains. At an average elevation of about 13,000 feet (4 kilometers) it is not only the highest desert in the world, but also one of the coldest, with temperatures averaging between 0°C-25°C.

The center of the Atacama, a place climatologists refer to as «absolute desert,» is known as the driest place on Earth. For as long as people have been recording rainfall, none has ever been measured in this area. There are some sections of the desert with an annual average rainfall of 0.6 mm to 2.1 mm, allowing for only sparse vegetation. Though limited, the existence of plant and animal life in such a harsh environment testifies to adaptability and determination to survive.

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Despite extremes and desolation there is stunning beauty. With the Andes as a backdrop the desert contains five snow topped volcanoes, which are the highest volcanoes in the world and the highest elevations in South America.

Geography

Sparsely populated and virtually rainless, the Atacama Desert forms a narrow strip on the coast of Chile, between 600—700 miles long. The average width, from the Pacific Ocean on the west, to the Andes Mountains on the east, is less than 60 miles (100 km). The north end of the desert lies at Chile’s border with Peru, while the south stretches to the bend of the Loa River and the mountains separating the Salado-Copiapó drainage basins.

The average rainfall in the desert ranges from 0.6 mm (in Arica) to 2.1 (in Iquique). However, there are some areas which have never recorded rainfall. Dr. Tibor Dunai, who spoke before the American Geophysical Union, told the BBC in a news article: «We found loose sediment surfaces that would be washed away by any desert rainfall and these are older than 20 million years,» he said. This is much older than other hyper-arid regions, such as the Dry Valleys of Antarctica (10-11 million years) and the Namib Desert in Africa (5 million years). «The origin of the aridity in the Atacama dates back to the opening of ocean pathways—the opening between South America and Antarctica, and between Australia and the Antarctic. [1]

What are known as «fog-zone plant communities» have developed due to the entrapment of clouds by mountains or steep coastal slopes. These communities lie near the coast and in lower portions of numerous gorges between sea level and 1,100 m. Short-lived perennial and woody scrub vegetation grow there.

Other areas receive marine fog, providing sufficient moisture for hypolithic algae, lichens, and even some cacti. In these areas, even decomposition does not occur. Dead vegetation may be thousands of years old. A recent innovation has made it possible to catch water from the air. With the use of mesh nets, water is trapped and trickled off via piping into storage tanks.

In the southern desert, fog-zone vegetation supports approximately 230 species of vascular plants. Included are the dominant species of Euphorbia lactiflua and Eulychnia iquiquensis. Other shrubby species in the zone include Echinopsis coquimbana, Oxalis gigantea, Lycium stenophyllum, Proustia cuneifolia, Croton chilensis, Balbisia penduncularis, and Tillandsia geissei. Bromeliads are also present along the coastal flats in this southern part, and include Deuterocohni chrysantha and Puya boliviensis.

Astrobiologists are studying the Atacama to discover clues which may unlock secrets of life on other planets and the possibility of survival there. They are also studying the growth of plants in extreme places in order to develop plants that could be grown off—world.

Biodiversity

The plant and animal life in the Atacama survive under perhaps the earth’s most demanding conditions. There is a high incidence of endemic flora. Local populations have relied on some of the species for medicinal purposes for generations.

Approximately 550 species of vascular plants have been discovered in the Atacama, the most diverse being the families of Asteraceae, Nolanaceae, Cataceae, Boraginaceae, and Apiaceae. Three cacti are endemic to the northern part of the Atacama Desert; they are Eulychnia iquiquensis, Neoporteria sensu, and Copiapoa. There are also numerous endemic shrubs.

Animal life is very rare in this desert, though there are a few insects and lizards to be found. Mice and fox are also present, but in small number.

The fog-zone plant communities, or lomas, provide a friendlier environment. Birds such as the Peruvian song-sparrow, Pacific blue-black grassquit, and hummingbirds live there, for at least a portion of the year. Six restricted species can be found in the north region: Thick-billed miner, white-throated earthcreeper, cactus canastero, Chilean woodstar, slender-billed finch, and the tamarugo conebill, the latter three of which are considered threatened species.

Resources

The Atacama was one of Chile’s chief sources of wealth until World War I. Prior to that time, that nation had a monopoly on the nitrate trade worldwide. Three million tons were extracted in some years. The taxes alone on these exports amounted to 50 percent of the government’s revenues. Since that time, sulfur has been mined, as well as copper, which is the region’s chief source of revenue, providing over 30 percent of the world’s copper supply. The Atacama border dispute between Chile and Bolivia began in the 1800s over these resources.

The coastal cities of Iquique, Caldera, Antofagasta, Taltal, Tocopilla, Mejillones, and Pisagua have ports, while railroads cut through the mountain barriers to the interior.

The environment offers little support to agriculture, but some farming is done near the river oases. Lemons are grown on the shores of the salt marshes, while potatos and alfalfa are grown near the Loa River.

Abandoned mines

Currently, the Atacama Desert is littered with approximately 170 abandoned nitrate (or «saltpeter») mining towns, almost all of which were shut down decades after the invention of synthetic nitrate in Germany at the turn of the twentieth century. Some of these abandoned towns include Chacabuco, Humberstone, Santa Laura, Pedro de Valdivia, Puelma, Maria Elena and Oficina Anita. Chacabuco is a special case, since it was later converted into a concentration camp during Pinochet’s regime. To this day it is surrounded by 98 lost landmines and is guarded by one man, who lives there alone.

Concerns

Of archaeological importance are the lomas formations. These beautiful and rare sites draw both tourists as well as scientists wishing to study the area. Environmentalists are concerned that the public has not been educated sufficiently enough to understand the delicate balance that is needed in this environment.

Roads and mining operations have caused some damage. Overgrazing of domestic livestock has occurred in the north, as has commercial gathering of rare plants, including cacti and bulbs. The area of Quebrada El León has been overused, but with an opportunity for recuperation, could become a valuable nature reserve, providing for further study and pleasure.

The desert has three protected areas;

Most threats to this ecoregion are closely associated increased urbanization, pollution, road construction, livestock grazing, fuelwood gathering, commercial plant collecting, and erosion.

History

Human habitation

Archaeological evidence indicates that the San Pedro area was the center of a Paleolithic civilization that built rock fortresses on the steep mountains encircling the valley. The Atacameños, an extinct Native culture different from that of the Aymaras to the north and the Diaguitas to the south, were the original inhabitants of the Atacama.

The Atacama is sparsely populated today, with less than one million inhabitants in its 40,600 square miles (105,200 square kilometers). The populations are centered in the coastal cities, fishing villages, oasis communities and scattered mining camps. In the altiplano, the descendants of the region’s pre-Columbian natives (mostly Aymara and Atacama Indians) herd llamas and alpacas and grow crops with water from snowmelt streams.

International disputes

Border disputes filled much of the nineteenth century, between the nations of Chile, Bolivia, and Peru. This was due to the abundance of mineral resources, particularly sodium nitrate. The mining industry was controlled by Chile and Great Britain, though the area itself was owned by Bolivia and Peru.

The disputes eventually erupted into the War of the Pacific, which raged from 1879 to 1883. The Treaty of Ancón of 1883, gave Chile permanent ownership of areas previously controlled by Peru and Bolivia. Bolivia lost its entire Pacific coastline, becoming a landlocked nation.

Notes

References

External links

All links retrieved November 9, 2021

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Атакама

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Смотреть что такое «Атакама» в других словарях:

Атакама — У этого термина существуют и другие значения, см. Атакама (значения). Атакама Desierto de Atacama … Википедия

Атакама — (Atacama, индейск. пустынная область) пустыня на С. Чили, на западных склонах Анд. Длина около 1000 км. Включает Береговую Кордильеру высотой до 3200 м, Продольную долину и западные склоны Кордильеры Домейко (высота до 4325 м). Относится… … Большая советская энциклопедия

Атакама — Центральные Анды. Пустыня Атакама. Атакама (Atacama), пустыня на севере Чили, вдоль Тихоокеанского побережья, между 22—27°ю. ш. (длина около 1000 км). Включает Береговую Кордильеру (высота до 3200 м); западные склоны Кордильеры Домейко (до… … Энциклопедический справочник «Латинская Америка»

Атакама — (Atacama), пустыня на севере Чили, в Южной Америке, вдоль берега Тихого океана, между 22 27º ю. ш.; осадков менее 50 мм в год. Пересекается рекой Лоа. Крупные месторождения медных руд (Чукикамата, Эль Сальвадор), селитры (Тальталь), поваренной… … Энциклопедический словарь

Атакама — пустыня, побережье Тихого океана на С. Чили. Упоминается в документах с первой половины XVI в. На языке одного из местных индейских племен атакама пустынная земля … Топонимический словарь

Атакама — (Salar de Atacama), крупный солончак в Северной Чили. Находится в тектонической депрессии у восточного подножия Кордильеры Домейко, на высоте около 2400 м. Длина около 90 км, ширина до 45 км. Запасы минерализованных подземных вод. Средний приток… … Энциклопедический справочник «Латинская Америка»

Атакама — іменник жіночого роду пустеля в Південній Америці … Орфографічний словник української мови

Атакама — (Atacama Desert)Atacama Desert, пустыня, самая сухая область Южной Америки, протяженность с С., от границы Перу, на Ю. в Чили ок. 965 км. В соленых бассейнах добывают нитраты, йод, буру … Страны мира. Словарь

Атакама (область) — Область Атакама исп. Región de Atacama Герб Флаг … Википедия

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Atacama Desert

The Atacama Desert is a plateau that occupies the northwest parts of the Chilean coast on the continent of South America. It is the driest desert on the earth coming second only to the Antarctica. It is, in fact, 50 times drier than California’s Death Valley. This is ironic considering the desert is next to the world’s largest water body-the Pacific Ocean. On your first trip to the Atacama Desert, you’d be forgiven for comparing it to other places beyond our atmosphere. The vast landmass is rocky, with jagged ravines and mountains horizon. While the conditions in the Atacama are generally not fit for humans to live in, some regions can be quite lively. Especially in the city of San Pedro, which is at the heart of the desert. Below is an in-depth profile of the Atacama Desert based on its location, weather, plant and animal life, and general significance of the region.

Geography And Location Of The Atacama

The Atacama Desert is 1,600 kilometers (994.2 miles) long. It is a continuous strip of land occupying an area of over 105,000 square kilometers in the coastal region of northern Chile. It extends from the border of Peru near Arica (18°24′ S) and runs southwards to near La Serena (29° 55′ S).

Topographically, the Atacama is a plateau with rises 610 meters above sea level with some of its elevations rising higher than 8000 feet. To the east of the desert are the Andes Mountains. It borders the Pacific Ocean to the west. The Atacama Desert has an average width of less than 100 km. The coastal mountains of the Atacama range between 500 and 1000 meters high.

The desert is a series of dry salt basins. Cretaceous sediments form most of the coastal mountains. The sediments comprise mainly of limestone and sandstone that covers a lower layer of crystalline rocks. The Atacama soils have been likened the samples obtained from Mars.

The soils limit plant growth because they have extremely low carbon and nitrogen content. In fact, the total carbon levels of the Atacama soils are significantly lower than those present in the Sahara and Mojave Deserts. The Atacama Desert has the largest deposits of sodium nitrate in the world. It also has vast copper deposits, making it a prominent mining site.

Climate Of The Atacama Desert

By definition, a desert should be a very hot region that lacks any meaningful precipitation. The Atacama Desert, oddly enough, is very cold. Temperatures fall anywhere between 0° and 25° Celsius (32° to 75° F). The Iquique range, for instance, has records average monthly temperatures of 21° C (70° F) in March to 14.5° C (56° F) in September.

Rainfall is virtually nonexistent in the Atacama. For the last 400 years, the Atacama Desert has not seen a drop of rain. In a rather bizarre occurrence, however, the desert received torrential rain between March 24 and 26, 2015. The rains even caused flash floods. While this is a rare occurrence, it is possible climatically. Other than that, occasional fogs are the only source of moisture. The annual rainfall in Arica is 0.6 millimeters (mm)/0.025 inches and Iquique’s is 2.1mm/0.08 inches.

Since the desert is located about 2,500 meters (6,561 feet) above sea level, it records very low humidity in the air (10% or less). This leads to the low and dry temperatures. The Andes Range also contributes to the lack of moisture in the desert because it creates the rain shadow effect. The range, which runs across the Atacama, creates a natural barrier to most winds blowing from the Amazon.

Plants And Animals Of The Atacama Desert

Plant and animal life in the Atacama Desert is scarce. In fact, there is almost no vegetation in the northern coastal region. The few plant species found in the region are mainly cacti: Eulychnia iquiquensis and Copiapoa spp. They grow at altitudes of 500 meters. The Iquique region is home to a community of Tillandsia landbeckii, a shrub endemic to Chile. The shrubs grow at elevations of between 990 and 1100 meters (3,248 and 3,608 feet).

The region near Antofagasta town is also devoid of vegetation, except for the Eulychnia iquiquensis and Copiapoa spp. The coastal plateaus are home to brush plants such as the Heliotropium pycnophyllum and the Lycium deserti. These plants rely on fog moisture for survival. Isolated mountains and steep coastal slopes trap fog creating a zone of concentrated moisture against the hillsides. The moisture favors the development of plant communities called Loma in the fog zones. Lomas are a major tourist attraction in the Atacama Desert.

Animals are rare in the Atacama. Some of the mammalian species found in the region include the Atacama Myotis, which is a bat species; the Elegant Fat-tailed Opossum; the Osgood’s Leaf-eared Mouse; and the Elegant Fat-tailed Opossum. Llamas and huemul deer can also be spotted in the region.

The Atacama also has a variety of bird species. The coastal areas have traces of seagulls and pelicans. During Austral winters, the Rufous-collared Sparrow, and the Blue-black Grassquit visit the Lomas to feed on hatched insect pupae. Hummingbird species also visit the Lomas. The northern region of the Atacama Desert is home to restricted and threatened bird species, including the Tamarugo Conebill, Chilean Woodstar, Cactus Canastero, White-throated Earthcreeper, Slender-billed Finch, and the Thick-billed Miner.

The only reptile that thrives in the Atacama Desert is the South American Leaf-toed Gecko. It is found only in southern Peru and Chile. The Vallenar toad represents the near-endemic amphibians in the desert. It lives in areas with steams and oases. They breed in streams, rivers and permanent water pools such as tanks.

People And Cultures Of The Atacama Desert

The largest town in the Atacama region is San Pedro de Atacama. It may humor you to learn that despite the Atacama being the driest and one of the harshest environments on the plant, it has a rich cultural history that dates about 11,000 years back. Back then, the desert’s original occupants were highly skilled in fishing, basketry, pottery, and metallurgy. Evidence of this ancient life is neatly tucked in a small San Pedro museum. Today, however, the population is modernized.

San Pedro is home to many luxurious resorts, hotels, restaurants and other popular tourist attractions. People come from all over the world to see the breathtaking landscapes, scenery, and Lomas. For survival, some of the communities living in the Atacama have devised innovative ways of getting water. In the northern Chile village of Chungungo, people harvest water from the fog that blows from the Pacific Ocean.

For decades, the desert has been a prominent mining site for copper. Between the 16th and 18th centuries, the desert’s inhabitants mined silver. Atacama Desert has also been a rich source of sodium nitrate and it still is. The chemical is used to manufacture fertilizer and explosives. Several cities along the Pacific Ocean and near the Atacama Desert serve as ports to transport the minerals. Major organizations such as NASA and the European Southern Observatory conduct space exploration and astronomy activities especially because the sky is cloudless at night, and the soil in the Atacama Desert is similar to that in Mars.

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Геологи нашли свидетельства внеземного происхождения стекол Атакамы

Вкрапления частиц в стекле, которые встречаются в объектах космического происхождения. Изображение получено при помощи регистрации обратно-рассеянных электронов.

Peter Schultz et al./Geology, 2021

Анализ геологических данных помог найти доказательства гипотезы о том, что стеклянные куски в пустыне Атакама, вероятно, образовались из частей метеорного тела, упавшего на Землю 12 тысяч лет назад. Геологи провели повторный анализ стекол, найденных в Чили еще в 2012 году. Результаты, опубликованные в журнале Geology, ставят под сомнение предыдущую теорию возникновения стекла.

В 2012 году чилийские геологи обнаружили на севере Чили, недалеко от пустыни Атакама крупные образцы стекла. Они были разбросаны вдоль побережья на участке длиною 75 километров. Тогда ученые предположили, что куски породы образовались после падения метеороида.

Фотографии найденных стеклянных образцов

Peter Schultz et al./Geology, 2021

В 2021 году группа американских и чилийских геологов под руководством профессора геологии Брауновского университета Питера Шульца (Peter Schultz) провела новое исследование и анализ стеклянных образцов показал, что изначальное предположение о внеземном происхождении более вероятно.

Ученые собрали более 300 кусков стекла, из которых подготовили тонкие отшлифованные образцы различного размера. Химический состав пластин определили при помощи энергодисперсионной спектроскопии. Авторы отметили, что исследованные образцы содержат тысячи минеральных зерен и мелких обломков горных пород, нетипичных для местных отложений. Минералы схожи по составу с образцами кометы Вильда-2, доставленными на Землю миссией NASA Stardust. В составе стекла также обнаружили циркон и продукты его разложения — диоксиды циркония и кремния. Это возможно только при температурах выше 1670 градусов Цельсия, одно горение растительности не могло привести к такому результату.

(A) Расположение скоплений стекол, найденных на побережье Чили. (B) Фотография стеклянных образований в пустыне Атакама.

Peter Schultz et al./Geology, 2021

Ученые предполагают, что появление стекол 12 тысяч лет назад совпадает с массовым вымиранием живого мира в четвертичном периоде в Южной Америке. Биологи считают, что основная причина вымирания — это изменение климата. Авторы предположили, что в то время пустыня Атакама могла быть районом с влажным климатом и густыми лесами, а осколки метеороида могли упасть в леса и поджечь их. При таком сценарии после пожара могли образоваться стекла. Но геологи до сих пор не понимают, почему спустя тысячелетия стеклянные куски так и не ушли под землю.

Не все ученые, однако, разделяют мнение исследовательской команды Шульца. Например, физик Марк Бослоу (Mark Boslough) из Национальной лаборатории Сандия, который является специалистом в изучении планетарных воздействий и глобальных катастроф, не согласен со всем, что они заявляют. Об этом он написал в своем твиттере, отметив, что рецензировал научную статью. Бослоу также обратил внимание на то, что взрывы метеорных тел или болидов, оставляющие следы, случаются редко, а свидетельства со временем стираются.

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Atacama Desert

From Wikipedia, the free encyclopedia

The Atacama Desert (Spanish: Desierto de Atacama) is a desert plateau in South America covering a 1,600 km (990 mi) strip of land on the Pacific coast, west of the Andes Mountains. The Atacama Desert is the driest nonpolar desert in the world, [A] as well as the only true desert to receive less precipitation than the polar deserts and the largest fog desert in the world. Both regions have been used as experimentation sites on Earth for Mars expedition simulations. According to estimates, the Atacama Desert occupies 105,000 km 2 (41,000 sq mi), [6] or 128,000 km 2 (49,000 sq mi) if the barren lower slopes of the Andes are included. [7] Most of the desert is composed of stony terrain, salt lakes (salares), sand, and felsic lava that flows towards the Andes.

The desert owes its extreme aridity to a constant temperature inversion due to the cool north-flowing Humboldt ocean current and to the presence of the strong Pacific anticyclone. [8] The most arid region of the Atacama Desert is situated between two mountain chains (the Andes and the Chilean Coast Range) of sufficient height to prevent moisture advection from either the Pacific or the Atlantic Ocean, a two-sided rain shadow. [9]

Despite modern views of Atacama Desert as fully devoid of vegetation, in pre-Columbian and Colonial times a large flatland area known as Pampa del Tamarugal was a woodland but demand for firewood associated with silver and saltpeter mining in the 18th and 19th centuries resulted in widespread deforestation. [10] [B]

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