Cold Environments Flashcards
Name the 3 types of basal sliding
Slippage
Creep
Bed formation
Slippage
The bottom layer of the glacier is at pmp, so there is a layer of melt water. This lubricates the glacier to move.
What is creep?(regulation)
This is when the ice meets an obstacle on the valley floor, the pmp will increase so that it will melt as it is under pressure. This means that the glacier can flow around and over the obstacle and when it has passed it pmp will decrease and so the water will refreeze
What is bed deformation?
Moves on a layer of saturated sediments( which will be the lubricant) between the bed and glacier. The saturated lubricate the sediment. The water is under hydrostatic pressure and so the velocity increases
What is inter granular flow?
When ice crystals are added they will hit and reorientate them selves causes it to move slowly
Laminar flow
Movement of individual layers of the glacier
What is nivation?
Freeze thaw
Running water
Solifluction
Formation of a corrie
Nivation occurs in a small hollow
Snow builds up and causes plucking due to rotational slip
Abrasion due to scree
Rock lip is formed and slows due to friction
What is recessional moraine??
Formed at the end of a glacier
Along the valley floor
A retreating glacier remains stationary for a short period of time, while mounds of material build up
What is push moraine??
Can only be formed when a glacier has retreated and advanced
Material that has been deposited is pushed forward into mounds when it advances
Rocks are pushed in to an upwards position
What is lateral moraine??
When the glacier moves the valley walls are Brocken up by frost shattering
Ice falls on the surface and forms ridges of material along the valley sides
What is ground moraine??
As the glacier moves it deposits till all over the valley floor
Found where glacier ice meets rock underneath
Ice melts at a constant rate which can wash the the till away with melt water
What is medial moraine
It forms when two lateral moraine meet. The two moraines find them selves in the middle of the glacier surface.
Leaving behind a trail in the middle of the glacier
