Glaciation Revision

Question 1

What is the process of snow accumulation in a corrie?

Answer 1

Snow accumulates in a north facing hollow, which is shaded from the sun, allowing snow to accumulate.

Question 2

How is glacial ice formed in a corrie?

Answer 2

Accumulated snow compresses to form glacial ice.

Question 3

What causes ice to move downhill in a glacier?

Answer 3

Ice moves downhill due to gravity.

Question 4

What is plucking in glacial erosion?

Answer 4

Plucking steepens the backwall, where ice freezes onto rocks and pulls them out as the glacier moves.

Question 5

What is abrasion in glacial erosion?

Answer 5

Abrasion occurs when rocks embedded in the ice scrape away at the base.

Question 6

What is freeze-thaw weathering?

Answer 6

Freeze-thaw weathering is when water enters cracks in rocks, freezes, expands the cracks, and causes rocks to break apart.

Question 7

What is a bergschrund crevasse?

Answer 7

A bergschrund crevasse may open up at the back of the corrie, allowing meltwater and rocks to reach the base of the glacier.

Question 8

What is an example of a corrie?

Answer 8

An example is Brown Cove.

Question 9

How is an arete formed?

Answer 9

An arete is formed when two corries erode towards each other, creating a sharp-ridged edge.

Question 10

What is an example of an arete?

Answer 10

An example is Striding Edge.

Question 11

How is a pyramidal peak formed?

Answer 11

A pyramidal peak is formed when three or more corries erode towards each other, turning a rounded peak into a pointed one.

Question 12

What is an example of a pyramidal peak?

Answer 12

An example is the Matterhorn.

Question 13

How is a U-shaped valley formed?

Answer 13

Former interlocking spurs may be cut off by the glacier, creating truncated spurs.

Question 14

What is a misfit stream?

Answer 14

A misfit stream runs along the floor of a U-shaped valley as it no longer fits the width of the valley floor.

Question 15

What is an example of a U-shaped valley?

Answer 15

An example is Glen Coe.

Question 16

How is a ribbon lake formed?

Answer 16

A ribbon lake is formed when softer rock is eroded deeper than surrounding hard rock.

Question 17

What can create a dam for a ribbon lake?

Answer 17

Terminal moraine can create a dam.

Question 18

What is an example of a ribbon lake?

Answer 18

An example is Loch Muick.

Question 19

How is a hanging valley formed?

Answer 19

A hanging valley is formed when tributary valleys are filled with smaller glaciers that have less erosive power.

Question 20

What characterizes hanging valleys?

Answer 20

These valleys are suspended above the main valley and are usually categorized by waterfalls.

Question 21

What is terminal moraine?

Answer 21

Terminal moraine is a ridge across a valley made up of till/boulder clay.

Question 22

How does terminal moraine form?

Answer 22

As the glacier moves, it pushes sediment in front of its snout, and when the glacier melts, it deposits material.

Question 23

What does terminal moraine mark?

Answer 23

Terminal moraine marks the furthest point the glacier has traveled.

Question 24

What is a drumlin?

Answer 24

Drumlins are elongated mounds made up of unsorted material, including till and boulder clay.

Question 25

How do drumlins form?

Answer 25

Drumlins form when a glacier becomes overloaded with sediment and deposits it while still moving.

Question 26

What are the characteristics of a drumlin?

Answer 26

The steep ‘stoss’ side faces up-valley, while the gently-sloping ‘lee’ side faces down-valley.

Question 27

What is an esker?

Answer 27

Eskers are meandering ridges formed by meltwater streams either within or underneath the glacier.

Question 28

What materials make up an esker?

Answer 28

Eskers are made up of meltwater sands and gravels, sorted by size.

Question 29

How are stones in an esker deposited?

Answer 29

Larger stones are deposited first by flowing water, and they tend to be more rounded due to erosion.