^^ Flashcards
Where does freeze thaw weathering take Place
Happens in places where temperature rises above and falls below freezing
Step by step to freeze thaw
Water collects
Overnight the water freezes and expands
This expansion puts stress and pressure on the sides of the rock
During the day when the temperature rises the ice thaws and contracts
This happens and eventually the rocks crack
Defin corrie
This is a steep sided hollow at the had of a glaciated valley. It is often described as an armchair shaped hollow.
How is a corrie formed
Snow and ice collects in the hollows
As ice moves down he mountain it erodes the back and bottom of the hollow
An attraction for a corrie
Steep slopes and cold snowy winters can attract skiers
How are u shaped valleys formed ?
As the glacier flows down an old v shaped valley
As the glacier flows it erodes the sides and bottom of the valley
The valley becomes U shaped with very steep sides and a flat bottom.
What is abrasion
This is the wearing away of the rocks at the base and sides of the glacier by the scoring action of ice containing rocks plucked from the earths surface
What are striations
Long grooves in the bed rock which is caused by abrasion. It leaves the bedrock a smooth polish finish
What is plucking
Plucking is when rocks and stones become frozen to the base of the glacier and are plucked from the ground as the glacier moves
What is an arête
2 corries eroding back to back create an arête.
Between corries there are steep rocky ridges called aretes
What is an pyramidal peak
3 or more corries form around a mountain they cut back to leave a horn or pyramidal peak
What is a ribbon lake
These are long narrow lakes found on the valley floors. The meltwater fills the area
Tarn ?
A lake that forms in a corrie
Define crevasses
These are very large cracks in the ice can be several metres wide and many metres deep
When does deposition occur
Deposition occurs when a rise in temperature causes ice to melt and the glacier is no longer able to carry as much material so it dumps it
WHat is moraine
Moraine is a type of landform that is created when a glacier deposits the material that has been transporting
Where is a moraine deposited
It is deposited at the end and sides of the glacier.
Medial moraine is)
Carried in middle of glacier
Lateral moraine is
Carried at the sides
Ground moraine?
Carried in the ground
Terminal moraine
The furthest the glacier reached before it stated to die
Where is a recessional moraine carried
Material at the snout as the glacier retreats or advances
What are erratics
Erratics are large boulders that have been carried by the glacier and then deposited in an area of different rock type, so that they look completely out of place
What is a drumlin
These are smooth mounds of deposited material that are formed parallel to the direction of the movement of the glacier.
What end of the drumlin is steeper
Stops end is the steeper of the two and used to face ice flow
What is freeze thaw weathering ?
A type of weathering where water repeatedly freezes and puts pressure on rocks to break them down
