Video Study Guide: Earth Revealed
Episode 22: Wind, Dust, and Deserts
Instructor'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 neglected to emphasize several important issues related to "deserts." The first is in the definition of the term. The popular impression of a desert is a place which is hot and dry. However, as stated in the episode, 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. Furthermore, this is not so much a lack of water, as it is a lack of moisture. I realize that this sounds like the same thing, but the difference is profound. Consider this: A billionaire may be concerned with thousands (millions?) of dollars, but the loss of this amount, while painful, is of no great importance. A poor man, on the other hand, is concerned with dimes and dollars, and any small fluctuation in the available monetary supply can have significant effect! I much prefer the term "arid land" to "desert." In this way, the reality of the influence of moisture (or actually the lack of moisture) is reflected in the name we use to describe these most fragile of lands.
Where are most deserts located?
What is a desert?
Describe how proximity to the equator affects the formation of deserts.
Describe the rain shadow effect and the formation of deserts.
What other factors influence the location and formation of deserts?
Describe the affect of precipitation on the desert.
What are alluvial fans?
Why do most deserts have interior drainage patterns?
How is sand transported by wind?
What are playas?
Describe the formation of desert pavement.
Describe the formation of desert varnish.
How can the removal of vegetation lead to desertification?
How did ranching and farming practices contribute to the Dust Bowl of the 1930s?
How is modern technology contributing to the desertification of sub-Sahara Africa?
Discuss efforts to reduce desertification on a global scale.
Why do you think that desert lands are so fragile?
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