Glacier

• Glacier = moving mass of ice (a few meters/day)
• Acts as an agent of erosion, transportation & deposition
• Carries rock debris → strong abrasive power

 Types of Glaciers

1. Continental Glaciers

• Large ice sheets
• Found in:
  • Antarctica
  • Greenland

2. Ice Caps

• Cover mountain tops
• Feed valley glaciers

3. Piedmont Glaciers

• Form a continuous sheet at the mountain base
• Example: Southern Alaska

4. Valley (Alpine) Glaciers

• Found in high mountain ranges
• In India:
  • Siachen Glacier (≈72 km)
  • Gangotri Glacier (≈25 km)

 Glacial Erosional Landforms

1. Cirque / Corrie

• A bowl-shaped hollow on mountain side
• Steep on 3 sides, open on 1 side
• Flat bottom
• May form Tarn Lake after melting

2. Glacial Trough (U-shaped Valley)

• Modified river valley
• Broad floor + steep sides
• Uniform vertical & lateral erosion
• Mature stage valley

3. Hanging Valley

• The smaller tributary valley remains at a higher level
• Joins the deeper main valley
• Often forms waterfalls

4. Arete

• Narrow sharp ridge
• Formed between two cirques

5. Horn

• Pyramidal peak
• Formed when 3+ cirques erode a summit
• Example: Matterhorn (Switzerland)

6. Fjord

• A drowned U-shaped valley at the coast
• Deep, narrow, steep-sided
• Found in:
  • Norway
  • New Zealand
  • Greenland

 Glacial Depositional Landforms

1. Outwash Plain (Till Plain)

• Stratified sediments
• Sand, gravel, clay
• Formed at the glacier’s melting front

2. Moraine

• Accumulation of debris
• Types:
  • Ground moraine
  • Lateral moraine
  • Terminal (End) moraine
  • Medial moraine

3. Esker

• Long winding ridge
• Deposited by sub-glacial streams
• Often used for roads

4. Drumlin

• Inverted boat-shaped hill
• Indicates glacier movement direction

5. Kame Terraces

• Irregular mound-like deposits
• Form along glacier sides

6. Kettle Holes

• Depressions in the outwash plain
• Formed due to the melting of buried ice blocks
• May become kettle lakes

Glacial Cycle of Erosion

Youth

• Cirque formation
• Initial valley cutting
• Aretes & horns developing

Maturity

• Hanging valleys visible
• The glacial trough is well developed
• Stepped valley profile

Old Age

• Fully developed U-shaped valley
• Prominent depositional features
• Outwash plain formation

Rapid Revision Table

Erosional	Depositional
Cirque	Moraine
Arete	Esker
Horn	Drumlin
U-shaped valley	Kame
Hanging valley	Kettle hole
Fjord	Outwash plain