1. Glaciation Presentation

2. Glaciation
Standard Grade
Geography
Alan Doherty Linlithgow Academy

3. Climate Change is not new!
From “Glaciers” by John Gordon
Colin Baxter Publications, 2001

4. Interglacial periods Glacial periods From “Glaciers” by John Gordon
Colin Baxter Publications, 2001

5. Snow collects in hollows
Snow builds up during the winter (accumulation) and melts during the summer (ablation)
If accumulation is greater than ablation the snow builds up in layers
Pressure gradually turns the snow into ice
When the critical mass of ice is reached, the ice begins to move downhill
A glacier is born!

6. Snowflakes are compressed and squeezed into ice crystals
n.b. the colour changes from white to blue!

7. How does ice flow?
With difficulty!

8. 1.SNOW BUILDS UP IN HOLLOWS IN THE HILLSIDE
GLACIATION
1.SNOW BUILDS UP IN HOLLOWS IN THE HILLSIDE
2. THE SNOW COMPACTS INTO ICE
3. THE ICE “FLOWS” DOWN THE MOUNTAINSIDE
4. THE GLACIER PUSHES FORWARD AND MELTS BACK

9. Valley Glaciers
nasa
Denali, in Alaska

10. Ice Sheets
From “Earth from Above” by Yann Arthus-Bertrand

11. If the ice covers the whole area then the mountain tops are rounded e
If the ice covers the whole area then the mountain tops are rounded e.g. Scotland
If the mountain tops remain above the ice then frost action makes them “jaggy” e.g.the Alps

12. Past and Present Ice Limits
From “Earth Story”
By Lamb and Sington

13. GLACIATION
GLACIERS ERODE 
TRANSPORT
and DEPOSIT

14. Glacial Erosion Glaciers erode in two ways
Abrasion - this occurs when stones embedded in the bottom of the glacier scrape across the ground
Plucking - this occurs when the bottom layer of ice freezes on to the ground when the ice is stationary. When the glacier begins to move, bedrock material may be torn from the ground.

15. Glacial Erosion Cirque = Corrie = Cwm
From “A2 Geography for AQA specification A” by Bowen, A & Pallister, J. Reprinted by permission of Harcourt Education
Cirque = Corrie = Cwm

16. Aretes or sharp ridges arete corrie corrie tributary glacier
main glacier

17. A corrie is a hollow in the hillside
arete
End moraine
Corrie or cirque
Lochan or tarn
Mountain top

18. Aretes and pyramidal peaks
Arete ridge

19. U-shaped valley

20. U-shaped valley
Hanging
valley
Misfit stream

21. Ribbon Lake

22. Transportation
Material which is carried along by the ice is called moraine.
Large stones which are dropped as the ice melts are called erratics.

23. Transportation

24. Transportation
From “A2 Geography for AQA specification A” by Bowen, A & Pallister, J. Reprinted by permission of Harcourt Education

25. by water: fluvio-glacial
Deposition
by ice: moraine
by water: fluvio-glacial

26. by ice: moraine (boulder clay)
Deposition
by ice: moraine (boulder clay)
by water: fluvio-glacial (sands & gravel)

27. Glaciation
End of part one
Standard Grade
Geography