External Forces of Change Weathering & Erosion

1. Explain the difference b/w weathering & erosion. Weathering breaks down rocks on Earth’s surface into smaller pieces Erosion wears away Earth’s surface (wind, glaciers, moving water)

Physical- breaks rock into smaller pieces 2. Explain the difference b/w physical & chemical weathering; give example. Physical- breaks rock into smaller pieces Water freezes in crack, ice splits rock

Chemical- changes the actual chemical make-up of the rock 2. Explain the difference b/w physical & chemical weathering; give example. Chemical- changes the actual chemical make-up of the rock Water + CO2 destruction of limestone

3. What causes acid rain? Acidic chemicals from pollution (factories, etc) combine w/ precipitation Eats away at buildings, kills fish/plants, etc.

4. What is wind erosion? 5. Benefits & drawbacks? Movement of dust, sand, soil from one place to another Benefits: Mineral-rich soil is deposited creating fertile soil Drawbacks: Good soil can be carried away leaving land barren

Ex: LOESS. Fertile, yellow-gray soil carried by wind throughout the Yellow River leaving the land great for farming

7. How can glaciers cause erosion? Slowly move downhill p.u. soil/rocks destroy forests, carve valleys, alter river course, wear down mtns.

8. What are moraines? Large piles of debris/rocks left behind by glaciers Form long ridges of land or create dams that form glacial lakes

9. Describe the difference b/w sheet glaciers and mtn. glaciers. Sheet: flat, broad sheets of ice (Greenland, Antarctica) Can break off to form icebergs Mtn: found in high mts. (Rockies) Move downhill creating valleys

10. How does water cause erosion? Fast-moving water  cuts into land, wears away soil/rock  creates sediment which grinds away other rocks Waves erode cliffs, beaches, etc.

wind and little water erosion 1. Bryce Canyon, Utah wind and little water erosion

2. Grand Canyon, Arizona water erosion

3. Glacier National Park, Montana glacial erosion

4. Bronze turning green when exposed to elements chemical weathering – acid rain

5. Broken tombstone physical weathering

chemical weathering (carbonic acid) 6. Mammoth Cave, Kentucky chemical weathering (carbonic acid)

7. Grand Tetons, Wyoming glacial erosion

8. Trees atop Mt. Mitchell, North Carolina chemical weathering (acid rain)

9. Capital Gorge, Utah wind and water erosion

The Great Lakes – NE U.S. glacial erosion