Test Bank Chapter 5 The Wrath of Vulcan Volcanic Eruptions

CHAPTER 5: The Wrath of Vulcan: Volcanic Eruptions

LEARNING OBJECTIVES

5A. Distinguish among the different types of volcanoes.

5B. Explain how volcanic eruptions produce such a variety of materials, including lava, pyroclastic debris, and gases.

5C. Explain why some eruptions yield streams of lava while others produce catastrophic explosions.

5D. Describe how the type of eruption reflects the character of lava and the geologic setting.

5E. Assess the many hazards that eruptions pose to life and environment.

5F. Interpret clues to pending eruptions.

MULTIPLE CHOICE

1. In 79 C.E., the citizens of Pompeii and Herculaneum in the Roman Empire were buried by pyroclastic debris derived from an eruption of ________.

2. Viscous lava that accumulates above a vent in a bulbous mass creates a

3. Pele’s hair ________.

4. Ash, cinders, and blocks are all types of ________.

5. A fast-moving wet slurry consisting of a mixture of water and volcaniclastic debris is termed a ________.

6. Volcanic bombs are ________.

7. The textural term for a basaltic lava flow that has a smooth, ropy appearance is ________.

8. Basaltic lavas that have rough, rubbly surfaces are called ________.

9. Basaltic lavas ________.

10. The difference between accretionary lapilli and pumice lapilli is that ________.

11. Columnar joints form when ________.

12. Lithified ash (or ash mixed with pyroclastic fragments) forms a volcaniclastic rock called a:

13. Common volcanic gases include the following:

14. The characteristic “rotten egg” smell of many active volcanoes is derived from ________.

15. ______________ are snowball-like lumps of ash formed when ash mixes with water in the air and then sticks together to form small balls.

16. The pillow basalts in the photo below most likely formed ____________.

17. The vertical features preserved in the basalt flow in the image below formed because the lava ________.

18. Pillow lavas are most commonly associated with ________.

19. Compared to felsic lavas, mafic lavas have a ________.

20. The image below shows a lava dome in Panum Crater, California. What is the most likely composition of the rocks that make up this lava dome?

21. Rhyolite lavas ________.

22. Of the three primary forms of subaerial volcanoes, ________ have the most gently sloping sides, due to the low viscosity of the basaltic lavas that form them.

23. Of the three primary forms of subaerial volcanoes, ________ consist of a cone-shaped pile of tephra often formed in a single eruption.

24. Of the three primary forms of subaerial volcanoes, ________ are large cone-shaped mountains that consist of alternating layers of tephra and solidified lava.

25. As compared to subaerial basaltic lavas, submarine basaltic lavas differ in that they ________.

26. Explosive or voluminous eruptions may cause a volcano to subside or collapse into the now-empty magma chamber, producing a broad depression termed a ________.

27. A mixture of air, hot ash, and pumice lapilli that rushes down the side of a volcano in a scalding avalanche is termed a(n) ________.

28. Whether an eruption will produce lava flows or pyroclastic debris depends on the viscosity of magma and the _______

29. Phreatic eruptions take place when ________.

30. Nonviolent eruptions characterized by extensive flows of basaltic lava are termed ________.

31. A large, violent, explosive eruption is termed a __________________ eruption.

32. A passive eruption that primarily forms lava flows and minor scoria is termed a __________________ eruption.

33. In 1902, a famous pyroclastic flow killed approximately 28,000 people on the Caribbean island of ________.

34. Which of the following magma compositions are most commonly erupted in continental arc settings?

35. What magma properties would most likely lead to the formation of a shield volcano?

36. Volcanism is least likely to occur in which of the following geologic settings?

37. The Columbia River Plateau is an example of a ________.

38. The Hawaiian island chain is an example of a(n) ________.

39. Hot spot volcanoes are associated with which geologic feature?

40. Volcanism in Iceland is occurring as a result of ________.

41. Which volcanic hazard poses the greatest threat to humans?

42. What was unusual about the 1986 volcano-related disaster near Lake Nyos in Cameroon?

43. The average time between eruptions is called a(n) ________

44. If a volcano lies along a convergent boundary but has not erupted in over 100,000 years, the volcano is considered ________.

45. Increases in heat flow, gas emissions and nearby earthquakes are all signs that a volcano _______.

46. The largest known volcanic eruption in the last million years occurred at ________.

47. A map that shows homes, businesses, roads and other infrastructure that lie in the path of potential volcanic hazards is called a ________________.

48. How do volcanic eruptions affect global average temperatures on the Earth?

49. Olympus Mons, the largest known volcano in our Solar System, is an example of a ________.

50. The Moon’s lunar maria are believed to be ancient __________.

1. Describe how felsic and mafic magma differ in composition, temperature, and viscosity, and how this affects the rate of flow of each type.

2. Describe how explosive eruptions occur. Make sure to address viscosity, gas content, and the process for building pressure.

3. Contrast the shape, size, eruptive style and lava composition of the three main types of volcanoes: shield volcanoes, cinder cones, and stratovolcanoes.

4. What is a caldera? How is a caldera different from a stratovolcano?

5. What is the fundamental difference between an explosive and an effusive eruption? What variables are important in determining whether a volcano “flows” or “blows”?

6. The style of eruption depends on the plate tectonic setting in which the volcano is situated. Compare the different eruption styles you could observe at a divergent versus a convergent plate boundary. Make sure to address the roles that composition, viscosity, and gas content play in your answer.

7. List and describe two volcanic hazards, including both a description of the hazard and the possible effects of the hazard.

8. Recurrence intervals are often used as estimates of when the next eruption might occur. Explain what a recurrence interval is and how it is calculated. Why is a recurrence interval not the most useful means of forecasting eruptions?

9. Is it possible for scientists to predict eruptions? What are two ways in which geoscientists look for possible volcanic activity in the short term?

10. Describe how an explosive volcanic eruption can create a global cooling event.