Glaciers Flashcards
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
Glacier input
The main input is snow. Over time, the
weight of the snow compacts it from
powdery into glacial ice.
Process of a glacier
The weight of the compacted ice then
combines with gravity to make the glacier
move slowly downhill. As it does so, it moves
sediment that has dropped onto it - and also
erodes its valley
The output of a glacier
The main outputs from the system
include ice and meltwater -together with lots of sediment
Whats the accumilation zone in glaciers
The accumulation zone is where there are inputs into the
glacial budget.
What is the ablation zone in glaciers
The ablation zone is where there are outputs from the glacial
budget
How does the glacial budget vary
The glacial budget varies during the course of a year. In the summer,
ablation will be at its highest, because of rapid melting of ice. During
the winter, higher amounts of snowfall and limited melting will result
in accumulation being greater than ablati
what do glaciated valleys look like and how did they form?
Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring.
What is freeze thaw
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 are the types of erosion in a glacier
Freeze thaw,abrasion,plucking
What are striation
these grooves on the exposed rock of the Roche Moutonnée were created by abrasions caused by debris embeded in the base of the glacier
