Glaciers

Question 1

Champlain Sea

Answer 1

clay deposits dating from that time
Laurentide Ice sheet = melted = Champlain Sea
Isolatic rebound = Champlain Sea Basin
Leda clay = quick clay –> clay particles are bonded together by salt irons

Question 2

Ice sheet

Answer 2

cover continents
2 remaining: Greenland and Antarctica

ice shelves = extensions of ice sheet into the ocean

Question 3

glacial formations created by ice sheet

Answer 3

roches moutonnes
= pattern of stress on a bedrock surface beneath a sliding glacier

striations:
= long + narrow scratch
= on surface of rocks
= glaciers flow over land = reveal direction

Eratics:

Question 4

Glaciers retreat creations

Answer 4

= When the glacier advances it plucks and abrades the bedrock below

Glacier Till = deposited assorted rock debris

End Moraines = named for their size (smaller) and location

Recessional Moraines = that record a stepwise retreat of the glaciers

Kettles lakes = water filled bowl shape lakes

Fjords = located on the coasts of continents

Eskers = a long sinuous deposit due to the retreat of a glacier

Question 5

Alpine Glaciers

Answer 5

alpine glaciers = go through the same processes as Continental glaciers, but because of the folding and high Mountains, some of the formations are different.
Alpine glaciers or Valley Glaciers provide most of the world with fresh clean water.

Glaciers form on land when more snow falls in the winter than melts in the summer.
= This happens in the zone of accumulation.

The six-sided snowflakes change to firn (aka corn snow) and continued accumulation causes the trapped air to be expelled from the firn and flue glacial ice is then formed
= Zone of firm glacial ice

Once the ice attains a thickness of about 30 m,
it begins to deform as a viscous fluid, and flows
guided by its own weight. (plastic flow)
= Zone of flowage.

Glaciers finally ablate, or waste away, by
melting when the temperature conditions
become warmer.
= Zone of Ablation

Question 6

isostatic rebound

Answer 6

the rise of land masses that were depressed by the huge weight of ice sheets during the last ice age

Question 7

alpine glaciers

Answer 7

valley glaciers

zones:

// snowffall = accumulation
// snow melt = ablation

1) accumulation zone
–more snow fall (winter) than snow melt (summer)
2) zone of firm glacial ice
–firn = corn snow
–trapped air expelled = flue glacial ice
3) zone of flowage = plastic flow
–thickness of ice = deformation = viscous fluid + flow guided by own weight
4) ablation zone
= wastage

+ calving = icebergs (water)

Question 8

formation

Answer 8

burial and metamorphosis of snow

Question 9

two main mechanisms of subglacial erosion

Answer 9

Glacial abrasion, the wearing down of bedrock surfaces

Glacial plucking or quarrying, the removal of rock fragments and blocks from the bed

Question 10

quick clay / leda clay

Answer 10

Clay particles that are bonded together with salt ions
// water