Chapter 6: Deserts of South America
South America is not only about lush rainforests and fertile grasslands — it also has some of the most unique deserts in the world, shaped by the interplay of the Andes Mountains and Pacific Ocean currents.
🌎 6.1 Atacama Desert
- Location: Northern Chile (extending slightly into southern Peru).
- Climate: Driest desert in the world – some weather stations have recorded no rainfall for centuries.
- Cause:
- Rain shadow effect of Andes.
- Cold Humboldt Current suppresses evaporation → prevents rainfall.
- Features:
- Rich in copper & nitrates.
- Home to large observatories (clear skies, no pollution).
- Salar de Atacama (salt flats).
- Economic Importance: Chile is the world’s largest copper producer.
🌎 6.2 Patagonian Desert (Patagonian Plateau)
- Location: Southern Argentina, east of the Andes.
- Type: Cold desert/steppe.
- Cause: Rain shadow of Andes + cold winds from the Pacific.
- Features:
- Sparse vegetation → grasses, shrubs.
- Rich in sheep grazing → wool industry.
- Oil & natural gas fields.
🌎 6.3 Sechura Desert
- Location: Coastal Peru (near Piura region).
- Cause: Influence of Humboldt Current (cold current → dry climate).
- Features:
- Sandy deserts near Pacific coast.
- Known for El Niño impact → sudden flooding during El Niño years.
🌎 6.4 Monte Desert (Argentina)
- Location: Eastern foothills of Andes in Argentina (Mendoza region).
- Features:
- Hot desert.
- Cacti, shrubs.
- Vineyards in irrigated parts (famous Argentine wines).
📌 UPSC Key Pointers
- Atacama Desert (Chile) → driest desert in the world; copper, astronomy, rain shadow + Humboldt Current.
- Patagonian Desert (Argentina) → cold desert; sheep grazing, oil & gas.
- Sechura Desert (Peru) → coastal desert; affected by El Niño.
- Monte Desert (Argentina) → cacti, vineyards.
- All deserts are linked to Andes (rain shadow) & ocean currents (Humboldt).