Atacama Desert

About Atacama Desert

• Location: The Atacama Desert is located in northern Chile, near the borders of Peru, Bolivia and Argentina in South America.
• It stretches along the Pacific coast for about 1,000 km, flanked by the towering Andes Mountains to the east and the Chilean Pacific Ocean coast range to the west.
• It is the driest non-polar desert in the world and the largest fog desert on Earth.
  • A fog desert is a type of desert where fog drip supplies the majority of moisture needed by animal and plant life.
• Climate: The Atacama has a cold desert climate (in the Köppen climate classification, BWk) with generally mild temperatures year-round and only slight temperature differences across seasons.
  • The average rainfall is about 15 mm per year, although some locations receive only 1 to 3 mm in a year.
• Three different reasons contribute to the Atacama Desert being the driest place on earth. These are-

• 1. The desert sits on the wrong side of the Andes with regards to prevailing winds.
     • The prevailing south-east trade winds carrying moist air are forced to rise. The moisture condenses, and falls on the opposite side of the Andes to the Atacama. This is commonly known as a rain shadow.
  2. The second reason is high air pressure. Essentially, descending air warms up, meaning that any moisture within turns to water vapour (gas, not liquid) as opposed to rain.
  3. Finally, the last reason is the cold Humboldt Current from the Pacific Ocean. Any onshore winds are chilled so they are unable to pick up moisture from the ocean.
• Terrain: The wider Atacama region includes closed drainage basins, salt flats, volcanic landscapes and high-altitude lagoons along the Andes.
• Biological diversity: The species diversity of the Atacama Desert is highly restricted.
• Resources: The Desert contains the world’s largest supply of sodium nitrate.
  • It is also 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 Atacama is a globally important centre for astronomy because it combines very dry air, high elevation, clear skies and low atmospheric water vapour at suitable sites.
  • A major facility is the Atacama Large Millimeter/submillimeter Array (ALMA).