Erosion & Glaciers

1. Erosion & Glaciers World Geography 3200/3202 October 2010

2. Glaciers Introduction In this lesson you will: • 1.4.1 Define the terms outwash plain, terminal moraine, erratic, drumlin, and esker. (k) • 1.4.2 Examine evidence for the direction of movement of a continental glacier. (a) • 1.4.3 Define the terms cirque, arête, hanging valley, lateral moraine, and terminal moraine. (k) • 1.4.4 Define the term fiord. (k)

3. Continental vs. Alpine • Continental glaciers : Glaciers thatcover parts of continental land masses like Greenland & Antarctica • Alpine glaciers : Glaciers that are found high in mountain valleys, above the snow-line

4. Glaciers of the world Continental glaciers Alpine Glaciers

5. Continental vs. Alpine: Differences • Location; Alpine glaciers are only found on mountain tops whereas continental glaciers are only found at the earth's poles regardless of elevation. • Size; Alpine glaciers are smaller compared to Continental glaciers.

6. Alpine Glaciers Alpine glaciers are like very slow moving rivers of ice flowing down high mountain valleys They typically erode the mountain beneath them into a u-shaped valley with steep sides. Some alpine or valley glaciers are 1000m thick and up to 160 km long, though most are only a few km in length.

7. Continental vs. Alpine: Similarities • Both move and cause erosion (gravity & friction) • Both change the landscape by weathering & deposition • Both create land forms • Both developed in constantly cold temperatures below freezing. (< 0) • Video Overview

8. Features of Continental Glaciers

9. Features of Continental Glaciers • Use your textbook to create profiles of the following concepts related to continental glaciers • outwash plain • terminal moraine • Erratic • Drumlin • esker

10. Features of Alpine Glaciers

11. Features of Alpine Glaciers • Use your textbook to create profiles of the following concepts related to alpine glaciers • Cirque • Arête • hanging valley • lateral moraine • terminal moraine • fiord

12. Evidence of Glacier Movement • The gently-sloped end of drumlins point in the direction of glacier movement. • The terminal moraine marks the furthest extent of the glacier. • The layers of silt in an outwash plain can indicate direction of glacier movement. (fine particles would be at the leading edge while larger particles would have been closer to the glacier)

13. Review Activities • Assigned Readings • "Glaciers as Agents of Erosion" on pages 32-34 of your text book. • Assigned Activities • Complete Question # 12 on page 33 of your text book.

14. Review Questions • Where are continental glaciers found? • Where are alpine glaciers found? • Many land forms are created by continental glaciers. Which one is very similar to a river delta? • Many land forms are created by continental glaciers. Which one is created by a river running under the glacier?

15. Review Questions • Many land forms are created by continental glaciers. Which one is a large boulder that looks out of place in its surroundings? • Many land forms are created by continental glaciers. Which one marks the furthest extent of the glaciers movement? • Many land forms are created by continental glaciers. Which one is an egg-shaped hill? • Which end of a drumlin indicates the direction of glacier motion?

16. Review Questions • Where are continental glaciers found? THE POLES OF EARTH • Where are alpine glaciers found? HIGH IN MOUNTAIN VALLEYS • Many land forms are created by continental glaciers. Which one is very similar to a river delta? OUTWASH PLAIN • Many land forms are created by continental glaciers. Which one is created by a river running under the glacier? ESKERS

17. Review Questions • Many land forms are created by continental glaciers. Which one is a large boulder that looks out of place in its surroundings? ERRATICS • Many land forms are created by continental glaciers. Which one marks the furthest extent of the glaciers movement? TERMINAL MORAINE • Many land forms are created by continental glaciers. Which one is an egg-shaped hill? DRUMLIN • Which end of a drumlin indicates the direction of glacier motion? POINTY

18. Alpine Glaciers • Alpine glaciers are like very slow moving rivers of ice flowing down high mountain valleys • They typically erode the mountain beneath them into a u-shaped valley with steep sides. • Some alpine or valley glaciers are 1000m thick and up to 160 km long, though most are only a few km in length.

19. Features of Alpine Glaciers

20. Features of Alpine Glaciers • Use your textbook to create profiles of the following concepts related to alpine glaciers • Cirque • Arête • hanging valley • lateral moraine • terminal moraine • fiord

21. Review Activities • Assigned Readings • "Alpine Glaciation" on pages 34-36 of your text book. • Assigned Activities • Do Question # 14 on page 36.

22. Review Questions • What alpine glaciation feature consists of a circular hollow cut into the bedrock. • What alpine glaciation feature consists of a knife-like edge between adjacent cirques? • What alpine glaciation feature consists of a valley that abruptly ends as the main valley is at a much lower level? • What alpine glaciation feature consists of deposits along the side of the glacier. • What alpine glaciation feature is formed when a valley glacier reaches the ocean and eventually melts back.

23. Review Questions • What alpine glaciation feature consists of a circular hollow cut into the bedrock. CIRQUE • What alpine glaciation feature consists of a knife-like edge between adjacent cirques? ARETE • What alpine glaciation feature consists of a valley that abruptly ends as the main valley is at a much lower level? HANGING VALLEY • What alpine glaciation feature consists of deposits along the side of the glacier. LATERAL MORAINE • What alpine glaciation feature is formed when a valley glacier reaches the ocean and eventually melts back. FJIORD