A glacier is a huge mass of ice that moves slowly over land. Glaciers shape the land through processes of erosion, weathering, transportation and deposition, creating distinct landforms.
Erosion: The two main types of erosion are abrasion and plucking.
- Abrasion: rocks that have been frozen into the base and sides of the glacier scrape the rock beneath. The rocks scrape the bedrock like sandpaper, leaving scratches called striations behind.
- Plucking – rocks become frozen into the bottom and sides of the glacier. As the glacier moves downhill it ‘plucks‘ the rocks frozen into the glacier from the ground.
Weathering: During the day when temperatures are higher, the snow melts and water enters the cracks in the rock. When the temperature drops below 0°C the water in the crack freezes and expands by about 9 per cent. This makes the crack larger. As this process is repeated through continual thawing and freezing the crack gets larger over time. Eventually, pieces of rock break off.
Further Reading:
|
Related Links |
|
Comments