Glacial Processes

Question 1

What is a glacier?

Answer 1

huge mass of ice floating on the sea but still attached to the land (detached = iceberg)
-moving due to massive size and gravity, it lacks the strength to remain rigid in place

Question 2

Glacial Formation

Answer 2

• accumulation of snow when the snow never melts

- Ice Sheet Climate (high latitude or altitude) at Poles or tops of mountains * POLAR*

Question 3

What is the Zone of Accumulation?

Answer 3

Snowfield- the part of the glacier where we see additional material being added
Snow to Firn to Glacial Ice

Question 4

What is Firn?

Answer 4

like pebbles of snow, as it is going through the compression process

Question 5

How fast do glaciers form?

Answer 5

Slowly in dry climate (1000 years), quickly in wet climate (a few years)

Question 6

Glacial Mass Balance

Answer 6

Accumulation Zone: adding mass
Ablation Zone: mass being lost (calving = breaking off) it can break off, melt off or sublimate
Sublimation: turning directly into water vapor

Question 7

What is the Equilibrium Line?

Answer 7

things are being added at the same time that they are being worn away (retreat vs. advance)

Question 8

Glacial Movement

Answer 8

steeper slope = faster glacial movement
faster accumulation = faster glacial movement
-ice at the bottom of the glacier becomes plastic (mailable) = friction at bottom not completely transferred up to the top. (crevices opening ans shutting down during movement)

Question 9

Plucking vs Abrasion

Answer 9

Plucking: ice eroding landscape
Abrasion: solids being moved by the ice denuding stuff

Question 10

Describe Plucking

Answer 10

-pressure differences at base from uneven terrain
-base melts with high pressure, refreezes with lower pressure
-material picked up as water refreezes around it
-speed of movement does not interfere with denuding
PLUCKING = CARRIED AWAY

Question 11

Describe Abrasion

Answer 11

Dropping big and little stuff all together (not sorted by size)
Glacial Till

Question 12

What are the 2 broad types of glaciers?

Answer 12

Alpine and Continental

Question 13

Alpine Glaciers

Answer 13

• occur in the mountains
• snow accumulation due to altitude (high elevation)
• no mass wasting

Question 14

Continental Glaciers

Answer 14

• occur outside of mountains
• due to high latitude
• wide, spread out glaciers (now only in Greenland and Antarctica)

Question 15

Alpine: What does a V-shaped valley mean?

Answer 15

shaped by streams

Question 16

Alpine: What does a U-shaped valley mean?

Answer 16

shaped by glaciers

Question 17

Continental: What does it look like?

Answer 17

area that glacier moved across = flat

Question 18

Glacial Transportation

Answer 18

• material from plucking, abrasion and mass movements
• glaciers retain transported material until the glacier melts/ no longer “is”
• Moraines

Question 19

Moraines

Answer 19

Glacial Deposition:

• Lateral: along side of valley
• Medial: ridge of material
• End: at the end of glaciers
• Terminal: end at farthest extent
• Recessional: end as glaciers recede
• Till: was underneath glacier
• Out wash: outside path