Read the questions first. Then answer them while watching this episode of "Earth Revealed". If you miss it in class you are still responsible for the viewing this segment and answering the questions. The video is available online at http://www.learner.org/vod/video.html?sid=78&po=22 . The index for these programs is online at http://www.learner.org/resources/series78.html# . If you do not have an internet connection at home, view it after school or during study hall in the media center. Each segment is 30 minutes long.

Teacher's note: In most cases, I feel that the Earth Revealed series does an excellent job of describing the topic covered by the episode. However, it is my opinion that they have somewhat missed the point about "deserts." First is in the definition of the term. The popular impression of a desert is a place which is hot and dry. However, even by their own admission, a desert is classified by the absence of water, and has nothing to do with temperature. Therefore, Antarctica and Point Barrow can be considered deserts, just as easily as the Mojave or Sahara. A desert is dry, no matter where it is located.

1. Where are most deserts located?
2. What is a desert?
3. Describe how proximity to the equator affects the formation of deserts.
4. Describe the rain shadow effect and the formation of deserts.
5. How does plate tectonics affect the formation of deserts?
6. What other factors influence the location and formation of deserts?
7. Describe the affect of precipitation on the desert.
8. What are alluvial fans?
9. Why do most deserts have interior drainage patterns?
10. How is sand transported by wind?
11. What are playas?
12. Describe the formation of desert pavement.
13. Describe the formation of desert varnish.
14. What is desertification?
15. How can the removal of vegetation lead to desertification?
16. How did ranching and farming practices contribute to the Dust Bowl of the 1930s?
17. How did modern technology contribute to the desertification of sub-Sahara Africa?
18. Discuss efforts to reduce desertification on a global scale.
19. Why do you think that desert lands are so fragile?