Exam Flashcards
What is a Cold Environment
Areas of land permanently covered by ice. They are covered by glaciers, ice sheets and have frozen soil/rock. The temperature is constantly below freezing.
What is a glacier
A glacier is a huge mass of ice that moves slowly over land. It forms when there is a build up of snow over a number of years. They can be found at altitude or sea level. They are known as rivers of ice.
What are the physical processes of Erosion
Plucking
Abrasion
Freeze thaw
What is plucking
When meltwater at the base of the glacier freezes on the rock surface. As the glacier moves forward it extracts pieces of the rock surface
What is Abrasion
Rock fragments in the ice grind against the rock over which the ice is moving and wears away the land.
What is freeze thaw
This is a type of weathering. Water settles into cracks in the rock, then freezes and expands. This puts pressure on the surrounding rock. As it thaws, the pressure is released. As this repeats, rocks break away.
What is the formation of a corrie
‘Chair shaped’ formation
Why does a small glacier eventually form
Snow accumulates in sheltered hollow and becomes compacted
Why is the back wall of a corrie very steep
Due to plucking and freeze-thaw weathering
How does the glacier move
Under its own weight in a circular way called rotational slip
How is the hollow deepened
By plucking and abrasion
Why does a lip form at the front of the corrie
There is less erosion at the front of the corrie
Once the ice has melted what often forms in the hollow
A tarn
What is an Arête
Arêtes are knife-edged ridges formed between two corries.
What is a Pyramidal peak
A pyramidal peak is formed where three or more corries and arêtes meet.
