Glaciation Flashcards
What are ice advantages called?
Glaciation
As well as ice sheets, what did glaciers do?
They filled and eroded the valleys
What happened 18000 years ago?
In Europe, ice sheets spread down from the north as the climate changed
What is a glacier
A mass of moving ice
What does it move like
It moves in a valley, like a river, or flow out from a mountainous area across a plain, like a tongue of ice
Where are they found?
They are found in high latitude = closer to the poles further away from the equator
High altitude = away from the poles glaciers only exist in mountainous terrains. As long as the Mountain is high enough there will be glaciers close to the equator
How does it form
They developed where the temperature is cold enough to allow snow to accumulate over periods of years
What is the four step process?
- snow flakes collect or accumulate in a hollow in a mountain side
- more and more snow falls on the flakes increasing the density or weight
- the increased weight compresses the snow at the bottom into solid ice
- if the ice does not melt and the snow continues to fall, the ice mass (glacier) will get bigger and heavier. Gravity causes it to go down hill slowly
What is advancement, retreating and melting
Advancement= accumulation > melting
Retreat= melting> accumulation
Melting= abrasion
What is frost shattering ?
A type of weathering where water repeatedly freezes and puts pressure on the rocks to break them down
What is abrasion
A process of erosion where moraine carried by the glacier wears away the sides and floor of the valley
What is plucking
Glacial ice freezes onto rocks and as it moves away pulls large pieces of Rock with it
What are cirques/ corries ?
a half-open steep-sided hollow at the head of a valley or on a mountainside, formed by glacial erosion.
What are aretes?
a sharp mountain ridge.
What are pyramidal peaks
A pyramidal peak is formed where three or more corries and arêtes meet. The glaciers have carved away at the top of a mountain, creating a sharply pointed summit