Glaciation

1. Glaciation Mt. Robson by Lawren Harris http://www.groupofsevenart.com/

2. Processes that erode:

3. Water Processes that erode:

4. Water Wind Processes that erode:

5. Water Wind Ice Processes that erode:

6. Glaciation The Glacier by Arthur Lismer http://www.bertc.com/subtwo/lismer15.htm

7. Glaciation is a Glacial Period or Ice Age The earth has experienced several ice ages • 2 billion years ago • 600 million years ago • 250 million years ago (Pangea) • 1 to 2 million years ago • Most recent was 100,000 years ago, ending 6,000 years ago • Ice sheets covered almost all of Canada, up to 4 km thick • Due to cold climate, enormous amounts of water were frozen in ice sheets causing the level of oceans to fall • Ice sheet is a mass of ice larger than 50,000 km²

8. Glaciation is a Glacial Period or Ice Age The earth has experienced several ice ages • 2 billion years ago • 600 million years ago • 250 million years ago (Pangea) • 1 to 2 million years ago • Most recent was 100,000 years ago, ending 6,000 years ago • Ice sheets covered almost all of Canada, up to 4 km thick • Due to cold climate, enormous amounts of water were frozen in ice sheets causing the water level of oceans to fall. • Ice sheet is a mass of ice larger than 50,000 km²

9. The Water Cycle http://classroom.aws.com/lessons/EarlyYears/images/WaterCycle.jpg

10. What is a glacier? • A glacier is a large, slow moving piece of ice, formed from compacted layers of snow, that slowly deforms and flows in response to gravity.

11. What is a glacier? • A glacier is a large, slow moving piece of ice, formed from compacted layers of snow, that slowly deforms and flows in response to gravity.

12. Glacier Formation • Earth’s climate is cool • Snow that falls does not completely melt • Over many years, the snow gets deeper and becomes hundreds and thousands of metres thick. • Tremendous weight of snow on top causes the bottom layers to turn to ice that is very dense. • This pressure causes glaciers to move…in different ways

13. Glacier Formation • Earth’s climate is cool • Snow that falls does not completely melt • Over many years, the snow gets deeper and becomes hundreds and thousands of metres thick. • Tremendous weight of snow on top causes the bottom layers to turn to ice that is very dense. • This pressure along with gravity causes glaciers to move…in different ways

14. Two types of glaciers: • Alpine Glaciers • Continental Glaciers

15. Alpine Glaciers • Are found in mountain regions • Move under the force of gravity • Sharpen the upper portions of the mountain • Scrape away the valley walls to produce U-shaped valleys • Moraine is formed from the debris • Oak Ridges Moraine http://geology.about.com/library/bl/images/blglacierval.htm http://www.flickr.com/photos/davejglaves/1191311285/

16. Alpine Glaciers • Are found in mountain regions • Move under the force of gravity • Sharpen the upper portions of the mountain • Scrape away the valley walls to produce U-shaped valleys • Moraine is formed from the debris • Oak Ridges Moraine http://geology.about.com/library/bl/images/blglacierval.htm http://www.flickr.com/photos/davejglaves/1191311285/

17. The Columbia Icefield http://www-mtl.mit.edu/~fana/Alaska_trip/Icefield_pwky/columbia_01_medium.jpg

18. The Columbia Icefield http://www-mtl.mit.edu/~fana/Alaska_trip/Icefield_pwky/columbia_01_medium.jpg

19. The Columbia Icefield http://www-mtl.mit.edu/~fana/Alaska_trip/Icefield_pwky/columbia_01_medium.jpg

20. The Columbia Icefield http://www-mtl.mit.edu/~fana/Alaska_trip/Icefield_pwky/columbia_01_medium.jpg

21. Continental Glaciers • Cover large areas of land • Move under own weight • Spread outward from center or zone of accumulation • Edge or margin of glacier can advance, retreat or stay in one place. • Smoothes the landscape by eroding high points and filling in lower areas http://www.uwsp.edu/geo/faculty/ritter/images/lithosphere/glacial/glacier_zones.jpg http://www.swisseduc.ch/glaciers/glossary/icons/glacier-advance.jpg

22. Continental Glaciers • Cover large areas of land • Move under own weight • Spread outward from center or zone of accumulation • Edge or margin of glacier can advance, retreat or stay in one place. • Smoothes the landscape by eroding high points and filling in lower areas http://www.uwsp.edu/geo/faculty/ritter/images/lithosphere/glacial/glacier_zones.jpg http://www.swisseduc.ch/glaciers/glossary/icons/glacier-advance.jpg

23. Continental Glaciers continued • This erosion can expand existing river valleys, making them deeper and wider • U-shaped Valleys • Can also make lakes deeper and wider • The Great Lakes were formed this way • Once covered and shaped the Canadian Shield but today they only exist in Greenland and Antarctica. http://www.novaspace.com/POSTERS/PHOTO/GreatLakes.jpeg

24. Continental Glaciers continued • This erosion can expand existing river valleys, making them deeper and wider • U-shaped Valleys • Can also make lakes deeper and wider • The Great Lakes were formed this way • Once covered and shaped the Canadian Shield but today they only exist in Greenland and Antarctica. http://www.novaspace.com/POSTERS/PHOTO/GreatLakes.jpeg

25. Questions • How are glaciers formed? • How do glaciers move? • What are the main differences between an Alpine and Continental Glacier? • Where can we find glaciers today? • Which areas of Canada were shaped by Glaciation? • How were the Great Lakes formed?