Why Glaciers Exist in the Southern Andes

Climatic & Topographic Drivers

• High latitude (35°–55°S): Reduced solar insolation → cold temperatures.
• High elevation: Peaks >6,000 m; adiabatic cooling.
• Westerly moisture: Pacific winds hit Andes → orographic lift → heavy snowfall on western slopes.
• Rain shadow: Eastern slopes drier; glaciers concentrated west.
• Seasonal radiation balance: Winter accumulation > summer ablation.
• Favorable terrain: Cirques, valleys, steep slopes collect and flow ice.

Glacial Legacy

Current glaciers are remnants of the Patagonian Ice Sheet (last glacial maximum ~18,000 years ago), now confined to highest, wettest zones.