Glaciers Part 2 Flashcards Preview

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Flashcards in Glaciers Part 2 Deck (11):
1

Define the mass balance gradient

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

2

Define regelation

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

3

Define plucking

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

4

Define abrasion

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

5

Describe competence

a measure of flow strength, as gaged by the size of the
largest particle it can carry.

6

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

till

7

What is the consistency of till?

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

8

Define drumlins

streamlined hills generated beneath flowing glacier ice

9

Define a moraine

Mound of sediment (commonly mix of till and well sorted sand
and gravel), typically generated at the edge (end or sides) of a glacier.

10

Define eskers

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.

11

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

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