Licancabur

The Atacama Desert (Spanish: Desierto de Atacama) is a plateau in South America, covering a 600-mile (1,000 km) strip of land on the Pacific coast, west of the Andes mountains. It is, according to NASA, National Geographic and many other publications, the driest desert in the world. The Atacama occupies 40,600 square miles (105,000 km²) in northern Chile, composed mostly of salt basins (salares), sand, and felsic lava flows towards the Andes.

Salar de Atacama is the largest salt flat in Chile. It is located 55 km (34 mi) south of San Pedro de Atacama, is surrounded by mountains and has no drainage outlets. To the east is enclosed by the main chain of the Andes, while to the west lies a secondary mountain range of the Andes called Cordillera de Domeyko. Large volcanoes dominate the landscape, including the Licancabur, Acamarachi, Aguas Calientes and the Láscar. The latter is one of the most active volcanoes in Chile. All of them are located along the eastern side of the Salar de Atacama, forming a generally north-south trending line of volcanoes that separate it from smaller endorheic basins.

A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, volcanic ash and gases to escape from below the surface.

Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust in the interiors of plates, e.g., in the East African Rift, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "Plate hypothesis" volcanism. Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core-mantle boundary, 3,000 km deep in the Earth.

The II Antofagasta Region (Spanish: II Región de Antofagasta) is one of Chile's fifteen first-order administrative divisions. It comprises three provinces, Antofagasta, El Loa and Tocopilla. It is bordered to the north by Tarapacá and by Atacama to the south and is the second-largest region of Chile.

The capital of the region is the port city of Antofagasta, another important city is Calama.

A region is said to be arid when it is characterized by a severe lack of available water, to the extent of hindering or even preventing the growth and development of plant and animal life. As a result, environments subject to arid climates tend to lack vegetation and are called xeric or desertic.

A desert climate (in the Köppen climate classification BWh, BWkl, BWn), also known as an arid climate, is a climate that does not meet the criteria to be classified as a polar climate, and in which precipitation is too low to sustain any vegetation at all, or at most a very scanty scrub.

An area that features this climate usually experiences less than 250 mm (10 inches) per year of precipitation and in some years may experience no precipitation at all. In some instances, an area may experience more than 250 mm of precipitation annually, but is considered a desert climate because the region loses more water via evapotranspiration than falls as precipitation (Tucson, Arizona and Alice Springs, Northern Territory are examples of this).

There fare usually two or three variations of a desert climate: a hot desert climate (BWh), a cold desert climate (BWk) and, sometimes, a mild desert climate (BWn). Furthermore, to delineate "hot desert climates" from "cold desert climates", there are three widely used isotherms: either a mean annual temperature of 18°C, or a mean temperature of 0°C or -3°C in the coldest month, so that a location with a "BS" type climate with the appropriate temperature above whichever isotherm is being used is classified as "hot semi-arid" (BWh), and a location with the appropriate temperature below the given isotherm is classified as "cold semi-arid" (BWk).

To determine whether a location has an arid climate, the precipitation threshold must first be determined. Finding the precipitation threshold (in millimeters) involves first multiplying the average annual temperature in °C by 20, then adding 280 if 70% or more of the total precipitation is in the high-sun half of the year (April through September in the Northern Hemisphere, or October through March in the Southern), or 140 if 30%–70% of the total precipitation is received during the applicable period, or 0 if less than 30% of the total precipitation is so received. If the area's annual precipitation is less than half the threshold, it is classified as a BW (desert climate).

Chile (ⁱ/ˈtʃɪliː/ or /ˈtʃɪleɪ/), officially the Republic of Chile (Spanish: República de Chile [reˈpuβlika ðe ˈtʃile] ( listen)), is a country in South America occupying a long, narrow strip of land between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far south. Along with Ecuador, it is one of two countries in South America that do not border Brazil. Chilean territory includes the Pacific islands of Juan Fernández, Salas y Gómez, Desventuradas and Easter Island. Chile also claims about 1,250,000 square kilometres (480,000 sq mi) of Antarctica, although all claims are suspended under the Antarctic Treaty.

This is a list of active volcanoes in Chile - volcanoes that have erupted at least once in the Holocene. Some notable extinct volcanoes are also included.

Licancabur is a highly symmetrical stratovolcano on the southernmost part of the border between Chile and Bolivia. It is located just southwest of Laguna Verde in Bolivia. The volcano dominates the landscape of the Salar de Atacama area. The lower two thirds of the northeastern slope of the volcano belong to Bolivia, 5,400 m (17,717 ft) from the foot at 4,360 m (14,304 ft), while the rest and biggest part, including the higher third of the northeastern slope, the crater and summit, belong to Chile.

The summit and the crater are located entirely in Chile, slightly over 1 km (3,281 ft) to the south west of the international borders, it is about 400 m (1,312 ft) wide and contains a 70 m (230 ft) by 90 m (295 ft) crater lake, Licancabur Lake, which is ice-covered most of the year. This is one of the highest lakes in the world, and despite air temperatures which can drop to -30 °C, it contains planktonic fauna.

Licancabur's most recent volcanic activity produced extensive lava flows which extend 6 km down the northwest and southwest flanks, with older lava flows reaching 15 km (9 mi) and pyroclastic flow deposits as far as 12 km (7 mi) from the peak. Extensive Inca ruins, located on the summit, provide proof of pre-Columbian ascents as well as evidence for the absence of major eruptions over the past 500-1.000 years.

The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Colombia, Bolivia, Peru, Ecuador, Chile and Argentina. It formed as a result of 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. While some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences within volcanic zones and even between neighboring volcanoes. Despite being a type location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a large range of volcano-tectonic settings, such as rift systems and extensional zones, transpressional faults, subduction of mid-ocean ridges and seamount chains apart from a large range on crustal thicknesses and magma ascent paths, and different amount of crustal assimilations.

Nevado del Ruiz in Colombia is the northernmost member of the Andean Volcanic Belt. South of latitude 49° S within the Austral Volcanic Zone volcanic activity decreases with the southernmost volcano Fueguino in Tierra del Fuego archipelago.