Glaciated Landscape Development

Question 1

What is a corrie and how is it formed? (E)

Answer 1

• Armchair-shaped rock basin found on the N and E slopes of mountains
• Snow is compacted in a hollow and erodes the hollow through nivation, abrasion, plucking and rotational slip

Question 2

What is an aréte and how is it formed? (E)

Answer 2

• Steep knife-edged ridge formed between two corries
• The backward erosion of two conjoined corries through plucking forms steep back walls

Question 3

What is a pyramidal peak and how is it formed? (E)

Answer 3

• Angular, sharply-pointed summit
• Three or more corries meet back-to-back and their back walls are eroded by plucking

Question 4

What is a glacial trough and how is it formed? (E)

Answer 4

• Straight, wide U-shaped valley
• Glaciers move over existing V-shaped river valleys and cause glacial scouring due to their massive erosive power

Question 5

What is a hanging valley and how is it formed? (E)

Answer 5

• Small tributary U-shaped valley
• The tributary valley glacier does not have a large enough erosive power to erode to the valley floor and is left hanging, often with a waterfall

Question 6

What is a truncated spur and how is it formed? (E)

Answer 6

• Ridge that descends to the valley floor found in a glacial trough
• Glaciers erode interlocking spurs from an existing river valley and remove areas of land

Question 7

What is a roche moutonée and how is it formed? (E)

Answer 7

• A rock mound with a smooth stoss side and a jagged lee side
• Plucking and abrasion erode areas of resistant rock as a glacier moves over it

Question 8

What is a Bergschrund and how is formed? (E)

Answer 8

• A large crevasse in a glaciated landscape
• A glacier moves and separates from the back wall of a corrie

Question 9

What is a ribbon lake and how is it formed? (E)

Answer 9

• A lake formed within a glacial trough
• A glacier moves over alternating bands of soft and hard rock, eroding the soft rock at a higher rate and leaving a rock basin which fills with rainwater

Question 10

What is a fjord and how is it formed? (E)

Answer 10

• Steep coastal cliff in a glaciated landscape
• Glacial erosion occurs below sea level and sea water fills the valley floor as the glacier retreats

Question 11

What is a drumlin and how is it formed? (D)

Answer 11

• A smooth, elongated mound of unsorted till with a steep stoss side and a gentle sloping lee side
• A glacier slows down as it moves over a resistant obstacle and causes deposition behind it

Question 12

What is an erratic and how is it formed? (D)

Answer 12

• A large boulder in a glaciated landscape
• Carried by the glacier and deposited in an area of completely different geology

Question 13

What is a till plain and how is it formed? (D)

Answer 13

• A large expanse of flat relief covered in glacial sediment
• Formed as a large section of ice detaches from a glacier and melts, causing deposition of unsorted till

Question 14

What is a moraine? (D)

Answer 14

A ridge of deposited glacial sediment.

Question 15

What are the five types of moraine?

Answer 15

• Lateral
• Medial
• Terminal
• Recessional
• Push

Question 16

What is a lateral moraine? (D)

Answer 16

A moraine found at the side of a glacier formed by freeze-thaw weathering on the valley sides providing debris to the glacier.

Question 17

What is a medial moraine? (D)

Answer 17

A moraine found between two glaciers formed through the merging of two lateral moraines.

Question 18

What is a terminal moraine? (D)

Answer 18

A moraine that is deposited at the maximum advance of a glacier.

Question 19

What is a recessional moraine? (D)

Answer 19

A moraine found behind a terminal moraine formed by deposition during a temporary standstill in glacial retreat.

Question 20

What is a push moraine? (D)

Answer 20

A moraine with sediment that is tilted upwards formed during temporary glacial advance as sediment is pushed into an existing terminal moraine.

Question 21

What is a meltwater channel? (F)

Answer 21

Meltwater streams within a glacier which deposit material when there is a decrease in discharge.

Question 22

What is a kame and how is it formed? (F)

Answer 22

• A mound of partially sorted sand and gravel formed at the side of a glacier
• A collection of material in a supraglacial hollow is left on the valley floor when the glacier melts

Question 23

What is a kame terrace and how is it formed?

Answer 23

• A relatively flat, elongated deposit of fluvioglacial sediment
• Formed when multiple kames occur in the same area

Question 24

What is an esker and how is it formed? (F)

Answer 24

• A long ridge of stratified sand and gravel
• Sediment in meltwater channels is deposited in the direction of the glacier’s flow as the glacier melts

Question 25

What is an outwash plain and how is it formed? (F)

Answer 25

• A large expanse of fluvioglacial deposits infront of a glacial snout
• Meltwater channels lose hydrostatic pressure as it leaves the snout, causing deposition

Question 26

What are braided channels and how are they formed? (F)

Answer 26

• Meltwater streams that cross each other on an outwash plain
• Streams try to find a more efficient route around the material deposited during low discharge which causes resistance

Question 27

What is a kettle hole and how is it formed? (F)

Answer 27

• A depression found in an outwash plain
• Dead ice is left on the outwash plain as ice calving breaks it off from the glacial snout, before being buried in fluvioglacial sediment and melting

Question 28

What is patterned ground and how is it formed? (P)

Answer 28

• Geometric patterned ground found in periglacial environments
• Frost heave causes the upward movement of stones to the soil surface which then move sideways due to the slope

Question 29

What is an ice wedge and how is it formed? (P)

Answer 29

• Narrow crevasse in the upper layers of the ground
• Water enters cracks in the frozen soil and expands on freezing before repeating, widening the crack

Question 30

What is an open-system pingo and how is it formed? (P)

Answer 30

• Dome-shaped mound of earth found in areas of discontinuous permafrost
• Water moves through unfrozen ground, known as talik, forming an expanding ice lens which pushes upwards

Question 31

What is a closed-system pingo and how is it formed? (P)

Answer 31

• Dome-shaped mound of earth found in areas of continuous permafrost
• An ice lens forms underneath a draining lake in a layer of talik, causing frost heave and upward expansion

Question 32

What is a blockfield and how is it formed? (P)

Answer 32

• A large expanse of angular boulders
• Freeze-thaw weathering forms these boulders in-situ

Question 33

What is a solifluction lobe and how is it formed? (P)

Answer 33

• A tongue-shaped lobe of soil found on slopes
• Active layer becomes waterlogged in summer which saturates the soil, allowing it to slowly move downslope

Question 34

What is a terracette and how is it formed? (P)

Answer 34

• Narrow steps of land with a small tread
• Frost heave pushes the ground upwards, however vegetation prevents soil slumping (solifluction)

Question 35

What is a thermokarst and how is it formed? (P)

Answer 35

• An expanse of land characterised by depressions filled with meltwater
• Caused by the melting and collapse of permafrost