1. What are Glaciers?
Masses of ice formed on land by the compaction of snow. 
Factor of glacier movement: gravity (caused by weight of ice)

2. How do they form?
When accumulation of snow in winter (build-up) is greater than ablation (melt) during summer.
White color reflects much of insolation (remember albedo)
Usually form in high latitudes or altitudes

3. For a glacier to grow, the temperature must be low enough for snow and there must be enough moisture in the air for snow to form Usually glaciers will begin as snow builds up in depressions on hillsides If more snow accumulates than melts, over time a glacier will form As the snow grow deeper, its weight will compact the snow beneath it

4. Alternate freezing and thawing will cause the snow to turn more icy It will change from snow to a semi-solid slush called firn Finally the firn will compact into solid ice More snow will then fall on top of the glacial ice, causing the glacier to increase in size and weight

6. Alpine or Valley Glaciers are those that form in mountains and follow river valleys. Glaciers move as they are pulled downslope by gravity. How much they move depends greatly on how much snow has accumulated. If there is too much melting relative to ablation, the glacier can become smaller. This is called retreating.

7. When glaciers are no longer confined to valleys they spread out and create ice sheets known as continental glaciers. These glaciers are large and move very slowly. They are moved by valley glaciers pushing into them. The vast size and weight of continental glaciers means that they can weather a vast amount of materials and transport them large distances.

8. Erosional Processes
Plucking: Water freezes and cracks rocks, and these rock fragments are carried away by the glacial ice Abrasion: Debris interactions with the land. Striations: Scratches in rock caused by abrasion.

10. Plucking

11. Striations

12. Glacial Deposition
Drift is the name for any sediment deposited by a glacier Till is deposits left when glacial ice melts. It is unsorted and unstratified, meaning it is made of rocks and sediments of many sizes Outwash is sediment left by running glacial melt water. It is sorted and stratified, with the largest sediments being deposited first

13. Erosional Features of Alpine Glaciers
Cirque: This is where the snow and ice forming the glacier first accumulates; plucking causes depression in hillside.
Tarn: After glaciation, a cirque may fill with water creating a lake

14. Erosional Features: Cirque

16. Erosional Features
Arête: A steep ridge separating two glaciers eroding the mountain between them.
Horn: Multiple arêtes creating a sharply pointed peak.
Col: A section of the mountain is eroded. Mountain pass is created.

17. Erosional Features: Arête

18. Erosional Features: Horn

20. U-shaped Valley: A glacially eroded valley; also called a glacial trough.
Truncated Spur: Along the valleys of the U-shaped valley where original ridges have been cut off by erosion there are triangular faces
Hanging Valley: Small tributary glacier that connected to main glacier, which after melting leaves high valley remaining often with waterfalls.

21. Erosional Features: Truncated Spur

22. Erosional Features: Hanging Valley