How do Glaciers Effect the Land?

1. How do Glaciers Effect the Land? By erosion & deposition

2. Glacial erosion forms when glaciers sculpt, carve and carry away the land beneath them. • Glacial deposition is created by deposition, or what a glacier leaves as it retreats or melts away.

3. Glacial Erosion • A glacier's weight and movement, can re-shape the landscape. (this takes hundreds or thousands of years) • The ice erodes the land surface and carries the broken rocks and soil debris away.

4. Types of Glacial Erosion Glacial Valleys Horns Fjords Cirques Aretes

5. Glacial Valleys Yo • trough-shaped, with steep vertical cliffs where entire mountainsides were removed by glacial action. • Ex: Yosemite National Park. glaciers sheared away mountainsides, creating deep valleys with vertical walls. 

6. Hanging Valley • Forms when small tributary glaciers join larger glaciers • Since small glaciers are unable to erode down into the landscape very far a hanging valley formed. • The larger the glacier, the deeper the valley it can erode.

7. Look at the hanging valley!

8. Fjords • Long, narrow coastal valleys with steep sides & rounded bottoms. • Fjords form when a glacier erodes the land below sea level. When the glacier melts, the ocean water fills in the valley floor.

9. Created when glaciers erode backwards into mountainsides, creating rounded hollows shaped like shallow bowls. Cirques

10. A tarn is a mountain lake or pool, formed in a cirque after the glacier melts. Tarn Lake

11. Jagged, narrow ridges created where the back walls of two cirque glaciers meet, eroding the ridge on both sides. Aretes Arete 

12. Created when several cirque glaciers erode a mountain until all that is left is a steep, pointed peak with sharp, ridge-like aretes leading up to the top. Horns Matterhorn in Switzerland

13. Types of Glacial Erosion

14. Glacial Deposition • Landforms are also created by deposition, or what a glacier leaves as it retreats or melts away. Kettle LakesKames Moraines Till Drumlins Erratic Boulders

15. Till • Material that is deposited as glaciers retreat, leaving behind mounds of gravel, small rocks, sand and mud. • It is made from the rock and soil ground up beneath the glacier as it moves.

16. Moraines • Material a glacier picks up or pushes as it moves. • They form along the surface and sides of the glacier. • As a glacier retreats, the ice melts away from underneath the moraines, leaving long, narrow ridges that show where the glacier used to be. • Glaciers don't always leave moraines behind, because sometimes the glacier's own meltwater carries the material away.

17. Types of Moraines

18. Medial Moraine

19. Kames • Small steep-sided mounds of soil and gravel that form adjacent to the glacier. • They form from streams flowing out of the glacier that carry rock and soil.

20. Kettle lakes • Form when a piece of glacier ice breaks off & becomes buried by glacial till or moraine deposits. • Over time the ice melts, leaving a small depression in the land, filled with water. very small, more like ponds than lakes.

21. Erratic Boulders • Glaciers pick up rocks as they slowly move along. The glaciers carry the rocks far away from their source. • When glaciers melt they leave behind anything they pick up along the way (huge rocks, called erratic boulders)

22. Drumlins • long, streamlined tear-drop-shaped formations. • They form when a glacier deposits material as it is flowing and then moves over it. • Because they are deposited and shaped by glacier movement, all the drumlins left by a particular glacier will face the same direction. • Often, groups of several thousand drumlins are found in one place, looking very much like whalebacks when seen from above.

23. Drumlins

25. Glacial Striations • are scratches or gouges cut into the bedrock by process of glacial abrasion.