Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers...
-
Upload
jeffry-franklin -
Category
Documents
-
view
215 -
download
3
Transcript of Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers...
![Page 1: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/1.jpg)
Section 15.2Glacial Movements and Erosion
![Page 2: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/2.jpg)
How do glaciers move?
What are some reasons why glaciers move?
• Heavy snow fall
• Steep slopes
• Temperature increase/summer
What slows glaciers down?
• Friction
![Page 3: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/3.jpg)
Slip and slide on a layer of water (friction)
![Page 4: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/4.jpg)
2 main types of glacial movement
1. Basal slip
2. Plastic flow
![Page 5: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/5.jpg)
1. Basal slip
• Basal slip = immense weight of the glacier puts pressure on the bottom causing grains of ice to partially melt
– creates a slushy layer– glacier “slips and slides” on the slush
![Page 6: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/6.jpg)
2. Plastic Flow
• Due to pressure (weight) of snow above
• Grains of ice actually deform and flatten
• Ice in the interior of the glacier moves forward like a plastic putty
![Page 7: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/7.jpg)
![Page 8: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/8.jpg)
As a glacier moves…Crevasses form
• cracks in the glacier due to increased speed often associated with a steep incline
![Page 9: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/9.jpg)
What happens at the end of a glacier?
If the glacier is below the snowline…
ice front -the ice starts to melt, signifying the end of the glacier
![Page 10: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/10.jpg)
What happens at the end of a glacier?
If the snowline is at sea level…
calving -large pieces of glacier break off of the front (icebergs!)
![Page 11: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/11.jpg)
How do glaciers cause erosion?
Till -breaking down boulders, rocks, pebbles, and small grains into smaller pieces
Moraine -the accumulation of till
![Page 12: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/12.jpg)
The Ransom Moraine is a
large moraine that
cuts diagonally
across Kendall County
![Page 13: Section 15.2 Glacial Movements and Erosion. How do glaciers move? What are some reasons why glaciers move? Heavy snow fall Steep slopes Temperature increase/summer.](https://reader036.fdocuments.us/reader036/viewer/2022070409/56649e905503460f94b94ef7/html5/thumbnails/13.jpg)
Aftermath of glaciers
Striations -occur when the glacial load scratches parallel groves in the underlying bedrock
Roches mountonnees
a distinct pattern of rocks that are often exposed that bare a resemblance to a flock of sheep. “sheep rocks”