Glaciers as systems (Inputs & Outputs)

Nearer source

• High altitudes = more precipition (mainly snow)
• Snow highly reflective, absorb less heat = melting less
• Stronger winds high altitudes, snow blown hollows/basins accumulates
• Temperature low, sublimation/other loses low meltwater likely refreeze
• Inputs exceed outputs = zone accumulation

Lower altitudes

• Dividing line = firn (or equilibrium) line
• Gravity transports ice down to line
• Difference total accumulation & ablation whole glacier one year = glacial budget/ mass balance
• Positive winter, negative summer balance
• Accumulation & ablation equal = steady state

• Snow falls flakes trap air as accumulate (alimentation)
• Compression upper layers snow
• Lower layers neve or firn
• Neve denser = ice pellets
• Compaction grains firn re-crystallise (turn blue-ish)
• 25-40 year form glacial ice temperate latitudes