2.a erosional landforms

Question 1

What is a corrie?

Answer 1

A horse shoe -shaped valley which is formed through erosion

Question 2

How is a corrie formed

Answer 2

1. Nirvation causes for a hollow to form where snow accumulates
2. Overtime hollow enlarges and snow compresses to form ice ( due to exta mass)
3. At depth rotational movement the ice gains under its own mass –> deepens hollow
4. Rotational movement also causes for plucking of back wall making it steep - debris falls into crevasse
5. Rock debris abrades the hollow deepening it
6. A lip is formed from moraine deposited

Question 3

FLOW chart of corries formation

Answer 3

Nivation - enlarges hollow - rotational movement - plucking back wall - crevasse- abrades / deepens hollow - lip formed

Question 4

what are the lakes at the base of corrie in post glacial landscapes called?

Answer 4

Tarn

Question 5

What is an Arete ?

Answer 5

A sharp narrow often pinnacled ridge formed as a result of glacial erosions from both sides ( often two corrie bck to back eroded through plucking steepening the back wall)

• During glaciation the corries retreat forming the ridge of the arete between them
• rockfalls occur of the rock

Question 6

What is a pyramidal peak

Answer 6

A steep sided- pyramid shaped peak formed as a result of the backward erosion of corrie glaciers on three or more sides

Question 7

What is a Fjord?

Answer 7

• A long narrow arm of the sea formed as a result of a valley glacier

Question 8

How arw Fjords formed?

Answer 8

Glacier erodes the origional base which has deepened the bottom of the valley.

Question 9

What is a glacial trough?

Answer 9

Often chatactersided by steep sides and a flat bottom

Question 10

What erosion causes a Glacial trough?

Answer 10

Primarilly caused by strongly channeled ice

Question 11

What is a truncated spur?

Answer 11

Areas of land protruding from the river valley side (spurs) are removed by the glacier

Question 12

What is a hanging valley?

Answer 12

Is a result of diffrential erosion between the main glacier and the valley of a tributary ( stream)
1. Tributaory is eroded at a slower rate therefore triburatory valley is left hanging

Question 13

What are striations?

Answer 13

Are scratches or grooves made by debris embedded at the bae of glacier

• boulders gravel which were once frozen in the base erodes the surface of the bedrock

Question 14

How can striations indicate the movement of glaciers?

Answer 14

it will point in the direction of the ice flow

Question 15

What are ellipsodial basins ?

Answer 15

Deep elongated lakes ormed by subglacial activity beneath the ice sheets

Question 16

How is a roche moutonnee formed?

Answer 16

1. As the glacier moves uphill to get over the rock pressure increases due to weight
2. Temperature increases which leads to more meltwater → enables for movement up hill ( Basal sliding)
3. As it moves uphill the sub glacial material ( on the bottom of glacier) abrades(scratches causing striations) the stoss side → makes it smooth and wears away the side of the slope.
4. As the glacier moves over the obstacle the pressure decreases → meltwater refreezes attaching itself to the lee side of the → plucking away material as glacier continues to move
5. Leaving sharp jagged edges on the lee side of the glacier.