CHAPTER 18 Concept Review

CHAPTER 18 Concept Review

The Human Sphere: Flooding in the World’s Driest Place

Question 18.44

1. Why must Antofagasta guard against flooding when it is in one of the driest places on Earth?

18.1 Desert Landforms and Processes

Question 18.45

2. What single physical characteristic defines all deserts?

Question 18.46

3. What three major physical factors create deserts?

Question 18.47

4. Which is more important in deserts, physical or chemical weathering? Why?

Question 18.48

5. What is rock varnish? How does it form?

Question 18.49

6. What is a petroglyph? On what surface are petroglyphs often made?

Question 18.50

7. What and when was the Green Sahara? What caused it? What is the evidence for it? How were people affected by it?

Question 18.51

8. What is aeolian erosion? What similarities do aeolian erosion and fluvial erosion share?

Question 18.52

9. What is a ventifact and how does it form? In this context, what are pedestal rocks and yardangs?

Question 18.53

10. Describe the main physical aspects of a sand dune and describe how a sand dune migrates.

Question 18.54

11. What are the major types of sand dunes?

Question 18.55

12. Why do some sand dunes “sing”?

Question 18.56

13. What is sand dune stabilization? How does it relate to reversing desertification?

Question 18.57

14. Deserts are dry places. Why, then, is water the most important agent of erosion in deserts?

Question 18.58

15. Give examples of local geographic names for ephemeral desert streams.

Question 18.59

16. Where and how do bajadas form?
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Question 18.60

17. What is a playa lake? A playa? A saline lake? Explain how each forms.

18.2 Desert Landscapes

Question 18.61

18. What is a reg? Compare the formation of lag deposits with the formation of desert pavement.

Question 18.62

19. What is an erg? Where, geographically, are they most common?

Question 18.63

20. What is mesa-and-butte terrain? Explain how it develops.

Question 18.64

21. What are inselbergs? Explain how they develop.

Question 18.65

22. What is basin-and-range topography? Explain how it develops.

Question 18.66

23. What are badlands?

18.3 Geographic Perspectives: Shrinking Desert Lakes

Question 18.67

24. Why do the levels of lakes in internal drainage basins fluctuate easily?

Question 18.68

25. How are people causing large desert lakes worldwide to shrink?

Question 18.69

26. Where was the Aral Sea? What happened to it?

Question 18.70

27. Why are there now toxic dust storms in the Aral Sea Basin?

Question 18.71

28. What do desert lakes in the Great Basin in the western United States have in common with the Aral Sea?

Question 18.72

29. What happened to Owens Lake that nearly happened to Mono Lake? Why are there toxic dust storms in Owens Valley today?

Question 18.73

30. Is Mono Lake’s situation getting worse, stable, or improving? Explain.