1. External Forces of Change Weathering & Erosion

2.  Weathering breaks down rocks on Earth’s surface into smaller pieces  Erosion wears away Earth’s surface (wind, glaciers, moving water), and then carries materials away 1. Explain the difference between weathering & erosion.

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

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

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

6.  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 4. What is wind erosion? 5. Benefits & drawbacks?

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

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

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

11. 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

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.  Bill Nye

13.  Water Erosion Bryce Canyon, Utah

14. Grand Canyon, Arizona Water Erosion, maybe some wind as well

15.  Glacial Erosion Glacier National Park, Montana

16.  Chemical Weathering Bronze turning green

17.  Physical Weathering Breaking of Tombstones