1. External Forces of Change Weathering & Erosion

2. 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)

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

4. 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 Water + CO2  destruction of limestone

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

6. 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 Benefits: Mineral-rich soil is deposited creating fertile soil Drawbacks: Good soil can be carried away leaving land barren Drawbacks: Good soil can be carried away leaving land barren

7. 6. Define LOESS.  Fertile, yellow-gray soil  carried by wind throughout the Yellow River leaving the land great for farming

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

9. 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 Form long ridges of land or create dams that form glacial lakes

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

12. 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.