Atacama Desert: One of Earth's Driest Places

The Atacama Desert in northern Chile is **among the driest non-polar places on Earth**, with some weather stations never recording rainfall.

Why So Dry?

• Rain Shadow: Andes block Amazon moisture; Chilean Coast Range blocks Pacific moisture.
• Cold Humboldt Current: Cools onshore air, preventing convection and rain formation.
• Subsidence: Persistent high-pressure zone (South Pacific High) causes descending dry air.

Extreme Aridity

• Yungay region: Hyper-arid core; <1 mm/year average; decades without rain.
• Soil similarity to Mars: Used by NASA for rover testing (Viking, Mars Science Laboratory).
• Microbial life only: In most hyper-arid zones; fog oases (lomas) support limited flora/fauna.

Resources and Value

Rich in nitrate (historical fertilizer), copper (Chuquicamata, Escondida), lithium (Salar de Atacama—~30% world supply), and unparalleled astronomical seeing (ALMA, VLT, E-ELT telescopes).

Its extreme aridity makes it a unique natural laboratory and economic zone.