**Geography and Climate of Atacama Desert**
– The Atacama Desert spans around 1,600 kilometers along the Chilean coast, extending from Arica to La Serena and parts of southern Peru.
– It borders Peru to the north and the Chilean Matorral ecoregion to the south, featuring a low-relief bench formation.
– The desert is known for extreme aridity, with average rainfall of about 15mm per year and some areas receiving only 1 to 3mm annually.
– Evidence suggests the desert may have had no significant rainfall from 1570 to 1971, experiencing hyper-aridity since at least the Middle Miocene.
– The Atacama Desert is considered the driest place on Earth, with long-term arid conditions indicated by evaporite formations.
– Despite extreme aridity, some areas receive moisture from a marine fog known as the camanchaca.
**Comparison to Mars and Conservation**
– The Atacama Desert’s lack of humidity, rain, and light pollution creates a Mars-like landscape, making it ideal for simulating Mars environments.
– Soil in some parts has been compared to that of Mars, leading to its use for filming Mars scenes and conducting Mars expedition simulations.
– A portion of the desert is protected, covering 3% of the total area, with unique environmental conditions used for experimentation.
– The extreme aridity of the Atacama Desert is influenced by the Humboldt Ocean current and Pacific anticyclone, making it the driest nonpolar desert in the world and the largest fog desert.
– The desert is home to over 500 plant species adapted to extreme conditions, with rare rainfall events triggering phenomena like the flowering desert.
**Fauna, Flora, and Human Presence**
– The extreme climate of the Atacama Desert limits permanent animal residents, with desert-adapted insects, reptiles, amphibians, birds, and mammals found in the region.
– The flora includes herbs, flowers like thyme and llareta, and trees such as chañar and algarrobo, with over 500 plant species adapted to the desert conditions.
– Human presence in the desert is mostly along the Pacific coast, with interior areas hosting oases and valleys inhabited for millennia by pre-Columbian societies.
– The region is sparsely populated, with evidence of the most advanced pre-Columbian societies in Chile, showcasing ancient cultures and Spanish influence.
**History and Abandoned Mining Towns**
– The Atacama Desert has been home to various human settlements for thousands of years, with evidence of ancient cultures and a significant archaeological legacy left by the Chinchorro culture.
– The desert saw control by Bolivia, Chile, and Peru in the 19th century, leading to the War of the Pacific due to unclear borders and nitrate discovery.
– The region experienced a population boom from immigration during the peak of the nitrate industry, with the introduction of the puquios irrigation system around 1900.
– There are about 170 abandoned nitrate mining towns in the desert, rich in resources like copper, sodium nitrate, boron, and lithium, with pollution issues from mining activities.
**Astronomical Observatories and Other Uses**
– The Atacama Desert is ideal for astronomical observations due to its altitude and clear skies, hosting various telescopes for global astronomy research.
– Major observatories like the Atacama Large Millimeter Array (ALMA) and those operated by the European Southern Observatory are located in the desert.
– The desert is popular for all-terrain sports championships, including sandboarding, desert races like the Dakar Rally, foot races like the Atacama Crossing, and solar car racing events.
– San Pedro de Atacama serves as a hub for tourists visiting the desert, with attractions like the El Tatio Geyser and Termas Baños de Puritama offering unique experiences.
The Atacama Desert (Spanish: Desierto de Atacama) is a desert plateau located on the Pacific coast of South America, in the north of Chile. Stretching over a 1,600-kilometre-long (1,000-mile) strip of land west of the Andes Mountains, it covers an area of 105,000 km2 (41,000 sq mi), which increases to 128,000 km2 (49,000 sq mi) if the barren lower slopes of the Andes are included.
| Atacama Desert | |
|---|---|
 Atacama by NASA World Wind | |
 Map of the Atacama Desert: the area most commonly defined as Atacama is in yellow. In orange are the outlying arid areas of the southern Chala, Altiplano, Puna de Atacama, and Norte Chico. | |
| Ecology | |
| Realm | Neotropical |
| Biome | Deserts and xeric shrublands |
| Borders | |
| Geography | |
| Area | 104,741 km2 (40,441 sq mi) |
| Country | Chile |
| Coordinates | 24°30′S 69°15′W / 24.500°S 69.250°W |
| Conservation | |
| Protected | 3,385 km² (3%) |
The Atacama Desert is the driest nonpolar desert in the world, and the second driest overall, behind some specific spots within the McMurdo Dry Valleys. It is the only hot true desert to receive less precipitation than polar deserts, and the largest fog desert in the world. The area has been used as an experimentation site for Mars expedition simulations due to its similarities to the Martian environment.
The constant temperature inversion caused by the cool north-flowing Humboldt Ocean current and the strong Pacific anticyclone contribute to the extreme aridity of the desert. The most arid region of the Atacama Desert is situated between two mountain chains, the Andes and the Chilean Coast Range, which are high enough to prevent moisture advection from either the Pacific or the Atlantic Ocean, creating a two-sided rain shadow effect.