Glaciers - Erosional Landforms

Question 1

plucking

Answer 1

glacier freezes onto rock, moves away, pulls rock

Question 2

u-shaped valley formation

Answer 2

1. snow accumulates in mountain hollows -> compresses into neve -> compresses into ice (1 mark)
2. glacier takes path of least resistance along v-shaped valley, moves downhill bc gravity
3. plucking (define) = makes valley sides steeper
4. abrasion (define) = makes deeper
5. weight of glacier widens & deepens valley into U shape w/ flat floor and steep sides
6. interlocking spurs are bulldozed = truncated spurs & crags or steep valley sides
7. original river = misfit stream

Question 3

corrie

Answer 3

1. snow gathers in a north facing hollow (1) snow compresses into neve –> ice (1)
2. ice builds up in a cool climate = more mass = moves downhill under gravity (1) freeze-thaw action loosens rocks at back of hollow (1), = freezes into the glacier & plucked out as ice moves away (1) = steepening of back wall of hollow
3. bottom of the hollow deepened by abrasion (1) bc rocks frozen into base of ice are scraped across the ground. rotary movement of ice erodes middle of hollow deeoest so a shallow lip forms (1)
4. ice melts in warmer climate = large armchair-shaped hollow/corries remains & contains a tarn (1) tarn = trapped water by rock lip = built by moraine (1). EXAMPLE: Coire Cas.
5. 2 corries eroded back to back, this will produce a steep knife edged ridge called an arête (1).
6. 3 or more corries forming back to back produce a pyramidal peak.

Question 4

pyramidal peak

Answer 4

1. snow gathers in a north facing hollow (1) snow compresses into neve –> ice (1)
2. ice builds up in a cool climate = more mass = moves downhill under gravity (1) freeze-thaw action loosens rocks at back of hollow (1), = freezes into the glacier & plucked out as ice moves away (1) = steepening of back wall of hollow
3. bottom of the hollow deepened by abrasion (1) bc rocks frozen into base of ice are scraped across the ground. rotary movement of ice erodes middle of hollow deeoest so a shallow lip forms (1)
4. ice melts in warmer climate = large armchair-shaped hollow/corries remains & contains a tarn (1) tarn = trapped water by rock lip = built by moraine (1). EXAMPLE: Coire Cas.
5. 3=< corries forming back to back = pyramidal peak

Question 5

arete

Answer 5

1. snow gathers in a north facing hollow (1) snow compresses into neve –> ice (1)
2. ice builds up in a cool climate = more mass = moves downhill under gravity (1) freeze-thaw action loosens rocks at back of hollow (1), = freezes into the glacier & plucked out as ice moves away (1) = steepening of back wall of hollow
3. bottom of the hollow deepened by abrasion (1) bc rocks frozen into base of ice are scraped across the ground. rotary movement of ice erodes middle of hollow deeoest so a shallow lip forms (1)
4. ice melts in warmer climate = large armchair-shaped hollow/corries remains & contains a tarn (1) tarn = trapped water by rock lip = built by moraine (1). EXAMPLE: Coire Cas.
5. 2 corries eroded back to back = steep knife edged ridge = arête (1)

Question 6

hanging valley

Answer 6

1. hanging valley is forms in a U shaped valley.
2. snow compresses –> neve –> glacial ice
3. glacier moves downhill bc weight under the influence of gravity.
4. plucking (define) = steeper valley sides
5. abrasion (define) = makes valley deeper.
6. frost shattering (define) steepens valley sides
7. interlocking spurs are cut off by the glacier = steep crags = truncated spurs. 8. truncated spurs are the sides of the U shape valley
8. here there was a tributary river valley reaching the main channel, this is now suspended above the deepened U shaped valley, leaving it “hanging”.
   If a tributary river flows in this valley it will reach the main misfit stream via a waterfall.