Glacial landscapes

Question 1

Corries formation

Answer 1

Form in a hollow where snow accumulates and compresses into ice.
Freeze thaw of the rocky outcrops supply scree to the ice surface.
Water seeping into glacial crevasse and freezing leads to freeze thaw of the back wall.
As weight of the ice moves, it begins to move by rotational slip.
Loose rocks and freeze thaw scrape out hollow through abrasion.
At the snout, ice is thinner so forms a lip as glacier moves out.

Question 2

Arêtes formation

Answer 2

formed between 2 glacial slopes that have formed back to back on the walls of 2 corries.

Question 3

Pyramidal peak formation

Answer 3

A mountain with corries formed on 3 steep sides.

Question 4

U-shaped valley formation

Answer 4

Glacier fills a river valley with ice.
Frost shatter of the arête supplies scree to the ice surface.
Abrasion and plucking erode the floor and side of the valley creating a U-shape.
The glacier moves through interlocking spurs creating truncated spurs and a straight valley as it is unable to flow around.

Question 5

Hanging valleys formation

Answer 5

Tributary glaciers in tributary valleys are less powerful glaciers which fill up the valley with ice.
Plucking and abrasion erode sides and floor of the valley creating straight valley sides.
As they can’t erode down to the same level as main glaciers, valleys are left hanging above the main valleys.
Waterfalls often mark these landforms.

Question 6

Drumlin formation

Answer 6

A drumlin is a stream lined egg shaped hill made of glacial till.

1. Formed beneath ice advancing across a lowland area that is melting
2. Small obstacles encourage deposition which mostly occurs around the upstream end of the obstacle, forming the blunt end
3. The rest of the hill is moulded and shaped by the moving ice to form the tapered and downstream end.

Question 7

Crag and tail formation

Answer 7

A crag and tail is a rock hill with a tapered hill on its lee side.

1. Glacier meets resistant rock and ice is forced to flow around / over it.
2. Plucking & abrasion on the upstream side steepen the slope and make it jagged, forming the crag.
3. In the lee of the crag, velocity and pressure of the ice decrease.
4. If there is a hollow in the softer rock, deposition of glacial till occurs.
5. Deposition decreases the further the glacier is away from the crag, so the tail tapers towards the end.

Question 8

Moraine

Answer 8

rock material transported and deposited by glaciers.

Ice melts when glacier meets lower valley levels as ice thins and is less able to carry material.

Question 9

Ground moraine

Answer 9

Material carried on the base of the glacier which is deposited as glacial till when the glacier melts.
Forms a uneven valley floor

Question 10

Lateral moraine

Answer 10

Scree from freeze thaw fallen from glacier and down the valley sides as the glacier movies through.

Forms a right angle on the edges of the glacier.

Question 11

Medial moraine

Answer 11

Formed in the middle of a glacier when two glaciers meet.

Question 12

Terminal moraine

Answer 12

Ridge of till deposited at the snout of the glacier.