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Salar de Atacama

by Selina Toplitsch

Map
General information

Salars (salt flats) are characteristic features of the Atacama Desert as well as of the Altiplano which is rather arid as well. The Salar de Atacama, with its area of approx. 3000 square kilometres, fills an endorheic basin west of the Altiplano. No continuous lake can form in this place due to the extreme aridity. Surface and subsurface inflow from the surrounding mountains allow some irrigated agriculture and the existence of settlements such as San Pedro de Atacama or Toconao near the margins of the salar. In total, the catchment area of the Salar de Atacama includes an area of approx. 15,000 square kilometres, where various types of salt are dissolved in flowing water, which are then transported into the salar and precipitate as the water evaporates. It is mainly the volcanic activity in the main range of the Andes which leads to the high diversity in minerals. The solids transported into the salar are deposited as well: the coarse and medium-grained material settles near the edge of the salar, whereas the fine material is transported all the way to the centre. This transition can be nicely seen when approaching one of the lagoons in the salar (such as Laguna Chaxa or Laguna Tebinquinche).

The Salar de Atacama: an endorheic basin

This 3D views allows you to observe the Salar the Atacama from different perspectives. Use the left mouse button for rotating the view, the mouse wheel for zooming, and the right mouse button for panning.

The Salar de Atacama fills a tectonic basin between the more than 4000 m high Cordillera Domeyko in the west and the main range of the Andes with its almost 6000 m high stratovolcanoes - such as the Licancabur - in the east. This landscape forms part of a large-scale system of tectonic horsts and grabens, oriented in north-south direction. It has developed through the subduction of the Nazca Plate beneath the South American Plate, and the related compressive processes. The Salar de Atacama is located at 2300 m asl. and has a maximum depth of 1700 m. The Cordillera de la Sal, up to approx. 200 m high, runs through the western portion of the Salar de Atacama.

Visit the contribution on the Cordillera de la Sal and learn more about the evolution of the entire salar!

This scene was generated with the QGIS plugin Qgis2threejs and uses the following libraries: three.js http://threejs.org/ (LICENSE) and Proj4js http://trac.osgeo.org/proj4js/ (LICENSE). Background: Stamen Terrain.

Exercise

The Salar de Atacama in numbers

First, try to estimate the components of water input to the salar. Write your estimates in millions of cubic metres into the corresponding text boxes in the graphics and note that the order of magnitude of the average annual precipitation in the area of the salar is approx. 10 mm.

Show solution

mill. m3/a
mill. m3/a
mill. m3/a
Exercise

Where does all the salt go to?

Each year, it is mainly the surface and subsurface inflows which bring approx. 300,000 tons of dissolved salt into the Salar de Atacama. The core of the salar consists of 90 per cent sodium chloride (NaCl). It precipitates through evaporation of the water.

Assume a density of 2 tons per cubic metre of salt and calculate:

  1. By how many millimetres does the surface of the salar rise each year?
  2. How old is the salar, if a constant salt input and an average depth of one kilometre is assumed?


mm/a

mill. a
Show solution

What the surface can tell us

Salar de Atacama

Click on the arrows or into the image to switch between views of the Salar de Atacama and the Salinas Grandes.

The Salinas Grandes del Noroeste are located in the border area between the provinces of Salta und Jujuy in Argentina - east of the main range of the Andes - in an endorheic basin of the Altiplano at approx. 3400 m asl. As it can be seen on the photographs, the surface structure of the Salinas Grandes differs quite much from the Salar de Atacama.

What could be the reason for this difference?

Show solution

Changes in the Salar de Atacama

29 April 1990

Click on the arrows or into the figure to travel in time and to see the changes that have occurred since 1990.

What could happen here, in the southern part of the Salar de Atacama? What could be the reason for the observed changes?

Show solution

Data base: Landsat | Band combinations 4-3-2 of Landsat 5 (1990, 2000, and 2010) and Landsat 8 (2018)

Lithium batteries are used for electric cars, cameras, laptops, mobile phones, and other types of devices.

Lithium mining in the Salar de Atacama has a direct impact on the water resources. The extraction of brine from the groundwater results in the lowering of the groundwater level and the salt fields. The reason for that is the deliberate steaming of the water in order to increase the lithium concentration in the basins, without measures to regain the water and to lead it back into the groundwater. Consequently, meadows and wetlands are susceptible to desiccation, posing a direct threat to these fragile habitats, the bird species there, and the pastures. Also the appearance of the lagoons may change drastically.

A further aspect are dust clouds, which are a result of the lithium mining, too. The dust includes high amounts of minerals, such as lithium carbonate, reaching some of the villages such as Socaire and Peine, pastures, and protected areas. This dust may result in health problems and pollutes soils and water.

Such as all types of mining, also lithium mining has some social consequences. On the one hand it generates labour, but on the other hand most of it consists of low-income jobs. Highly qualified jobs are often occupied by people from the capital city or from abroad.

References and links

Alonso, H. & Risacher, F. (1996): Geoquimica del Salar de Atacama, parte 1: origen de los componentes y balance salino. Andean Geology 23(2): 113-122 [Access source]

Blümel, W.D. (2013): Wüsten. Entstehung-Kennzeichen-Lebensraum. Stuttgart

Borsdorf, A. & Stadel, C. (2013): Die Anden. Ein geographisches Portrait. Berlin

Kampf, S.K., Tyler, S.W., Ortiz, C.A., Munoz, J.F. & Adkins, P.L. (2005): Evaporation and land surface energy budget at the Salar de Atacama, Northern Chile. Journal of Hydrology 310(1-4): 236-252 [Access source]

Risacher, F. & Alonso, H. (1996): Geoquimica del Salar de Atacama, parte 2: evolucion de las aguas. Andean Geology 23(2): 123-134 [Access source]

GLOBAL 2000: Was ist Lithium und wofür wird es gebraucht? [Access source]

German-language Wikipedia article on the Salar de Atacama [Access source]

German-language Wikipedia article on the Salinas Grandes [Access source]

This contribution was revised, extended, and translated from German by Martin Mergili.