Glaciers Part 2

Question 1

Define the mass balance gradient

Answer 1

The entire system that includes the accumulation and ablation of ice on a glacier

Question 2

Define regelation

Answer 2

pressure fluctuations in ice causes ice to melt (obstacle causes high pressure, melting) and then refreeze (obstacle leaves, water refreezes)

Question 3

Define plucking

Answer 3

Ice moves up over an obstacle, causing a high pressure that melts water. As the water moves past the object, it refreezes, but in the process picks up rocks and sediment and boulders

Question 4

Define abrasion

Answer 4

The rocks frozen int he glacier move over the substrate, carving grooves in it

Question 5

Describe competence

Answer 5

a measure of flow strength, as gaged by the size of the

largest particle it can carry.

Question 6

What are glaciers deposits of sediment, rocks, and gravel called?

Answer 6

till

Question 7

What is the consistency of till?

Answer 7

Diamictons (poorly sorted, massive mixes of mud, sand and gravel

Question 8

Define drumlins

Answer 8

streamlined hills generated beneath flowing glacier ice

Question 9

Define a moraine

Answer 9

Mound of sediment (commonly mix of till and well sorted sand

and gravel), typically generated at the edge (end or sides) of a glacier.

Question 10

Define eskers

Answer 10

Elongate ridge of sand and gravel generated by meltwater
flowing along base of glacier. Eskers commonly link to large fanshaped
sand and gravel bodies (outwash) generated where the
stream expands and decelerates at ice front.

Question 11

What evidence exists that Canada was (almost entirely) covered by glacier
ice during the last glaciation?

Answer 11

• Striations
• Landforms
• Till and dispersal trains within
• Isostatic rebound
• Disrupted drainage