1. Unscramble the words! Zefere Twah Sibarano Gnkpulic Enimroa Llubzngido
Freeze thaw
Abrasion
Plucking
Moraine
Bulldozing

2. Erosional Features CORRIE (Cirque, Cwm)
Arête, Pyramidal Peak, Tarn
Glacial Trough (U-Shaped Valley)
Hanging Valley, Truncated Spurs, Ribbon Lake

3. What does a pre-glacial landscape look like?

4. What does a glacial landscape look like?

5. What does a post-glacial landscape look like?

6. Corrie – Helvellyn Use the processes mentioned so far to describe the formation of the corrie and tarn lake
Freeze-Thaw
Plucking
Abrasion

7. Corrie & Tarn
Animation

8. How is a Corrie formed?
Snow collects in a natural hollow on the side of a mountain. Over time, further snow collects in the hollow. This extra weight compresses the snow underneath, turning it into ice.
The hollow is deepened and widened by the corrie glacier through the processes of abrasion and plucking.
This over-deepening leads to an ‘armchair’ shape characteristic of a corrie and causes a ‘rock lip’ to be formed.

9. Inputs – avalanches, precipitation (snow)
Store – ice
Outputs – meltwater, evaporation
Processes of erosion – abrasion and plucking must be described fully. Definitions are usually worth 2 marks each.

10. Inputs – avalanches, precipitation (snow)
Store – ice
Outputs – meltwater, evaporation
Processes of erosion – abrasion and plucking must be described fully. Definitions are usually worth 2 marks each.

11. Explain how is a Corrie formed
Inputs – avalanches, precipitation (snow)
Store – ice
Outputs – meltwater, evaporation
Processes of erosion – abrasion and plucking must be described fully. Definitions are usually worth 2 marks each.

12. A Corrie in pictures! Cwm Idwal
Steep back-wall
Inputs – avalanches, precipitation (snow)
Store – ice
Outputs – meltwater, evaporation
Processes of erosion – abrasion and plucking must be described fully. Definitions are usually worth 2 marks each.
Bowl-shaped corrie
Tarn

13. Aretes are “knife-edged” ridges formed between two corries
Inputs – avalanches, precipitation (snow)
Store – ice
Outputs – meltwater, evaporation
Processes of erosion – abrasion and plucking must be described fully. Definitions are usually worth 2 marks each.

14. Pyramidal peaks are formed when three or more corries cut backwards into the same mountain.
Arête
Tarn
Corrie
Inputs – avalanches, precipitation (snow)
Store – ice
Outputs – meltwater, evaporation
Processes of erosion – abrasion and plucking must be described fully. Definitions are usually worth 2 marks each.

15. Label the Pyramidal Peak Diagram
Inputs – avalanches, precipitation (snow)
Store – ice
Outputs – meltwater, evaporation
Processes of erosion – abrasion and plucking must be described fully. Definitions are usually worth 2 marks each.

16. Arêtes & Pyramidal Peaks
When two corries form next to each other, and their adjacent walls are eroded backwards until they meet, a narrow and pointed rock ridge is formed.
When three or more corries erode backwards we get a pyramidal peak
Examples
Arête – Striding Edge (Lake District)
Pyramidal Peak - Matterhorn

17. Corrie Steep back wall caused by freeze-thaw and plucking
Arm chair shaped hollow that snow and ice accumulate in, carved by a glacier
Rock lip at the edge of the corrie formed by deposits as the glacier rotated out of the basin
Tarn formed in the deepest part of the corrie as it was scooped out by erosion (abrasion)

18. Corrie on Maps

19. Steep back wall created by freeze-thaw and plucking
Corrie
An arm chair shaped hollow widened and deepened by a glacier.
Arete
Sharp knife edged ridge between TWO corries.
Formed as two corries are eroded and weathered backwards.
Named example
Striding Edge on Helvellyn in the Lake District

20. Striding Edge - Matterhorn

21. Crib Goch - Snowdonia

22. Pyramidal Peak: Steep mountain formed as three corries retreat backwards
Corrie back-wall steepened by freeze-thaw and abrasion

23. Arêtes and Pyramidal Peak

24. Corrie Begins as a patch of permanent snow
Snow accumulates, becomes ice
Begins to flow due to gravity
Below the ice there is a scouring action produced by the rotational movement of the ice as it moves down hill, and abrasion from the rock debris held in the ice
The rocks embedded in the ice scrape away at the underlying surface, slowly producing a curved hollow.
As the ice moves, plucking occurs on the backwall
As ice moves, cracks (bergschrunds) occur, allowing water to enter and freeze-thaw to take place
Freeze thaw occurs at the very top part of the glacier

25. This shouldn’t take you long – 15 minutes!
Homework task!
Your task is to produce a 1 page document showing photographs of each of the features you have learnt about – and some information to accompany them!
This shouldn’t take you long – 15 minutes!