Glaciers

Question 1

What are glaciers inputs?

Answer 1

• snowfall
• rock
• weathering
• energy- kinetic/ thermal/ potential

Question 2

What are glaciers outputs?

Answer 2

• melt water
• evaporation
• deposition

Question 3

Why do glaciers move?

Answer 3

• gravity (downhill)
• gradient= steeper the glop, the more movement
• ice thickness= influences basal temperature
• glacial budget= positive budget causes glacier to advance

Question 4

What are two ways a glacier moves?

Answer 4

1) Basal sliding
2) Internal deformation

Question 5

What is basal sliding?

Answer 5

Movement of warm based glaciers
Consists of 3 mechanisms:
1) slippage=ice slides over valley floor because reduce friction due to melt water
2) creep= when ice deforms under pressure due to an obstruction
3) bed deformation= when ice is carried by saturated bed sediments moving beneath it

Question 6

What is internal deformation?

Answer 6

How cold based glaciers move
Two concepts:
1) intergranular flow= when ice crystals re- orinate and move in relation to each other
2) laminar flow= movement of individual layers with the glaciers

Question 7

How does glacier ice form?

Answer 7

As more snow falls than ablates, the weight on the underlying snow increases. Eventually the weight packs the snow so tightly that glacier ice is formed

Question 8

What factors affect the rate of erosion?

Answer 8

• ice thickness-greater thickness= larger pressure
• hardness of particles and bedrock
• presence of basal debris- abrasion increases with amount of basal debris

Question 9

What are the two types of glaciers?

Answer 9

1) temperate-melt in summer
2) polar- move by internal deformation