Test Bank Volcanoes And Related Hazards Test Bank Docx Ch6

Chapter 06 Test Bank: Volcanoes and Related Hazards

Multiple Choice Questions

1. The nature of volcanic eruptions is closely related to plate tectonics and magma type. Which of the following best describes basaltic magma?

A. relatively SiO₂ poor and cool

B. relatively SiO₂ poor and hot

C. relatively SiO₂ rich and cool

D. relatively SiO₂ rich and hot

2. Viscosity is the measure of a fluid's resistance to a flow. Which of the following factors affect the viscosity of magmas?

A. elevation and density

B. density and water content

C. temperature and SiO₂ content

D. water and SiO₂ content

E. density and temperature

3. Which of the following factors determine whether a volcanic eruption will be explosive or non-explosive?

A. gas content and rock fractures

B. magma viscosity and elevation

C. depth of magma and elevation

D. depth of magma and rock fractures

E. magma viscosity and gas content

4. Which of the following tectonic settings is the most likely to generate an explosive volcanic eruption?

A. subduction zone

B. fold mountain belt

C. mid-ocean ridge

D. rift valley

E. oceanic hot-spot

5. Which of the following would most likely result in a lava flow that is hazardous to humans?

A. low viscosity andesitic magma

B. high viscosity rhyolitic magma

C. high viscosity basaltic magma

D. low viscosity basaltic magma

E. high viscosity andesitic magma

6. There are two basic types of volcanoes, shield and composite cone. Which of the following best describes composite cone volcanoes?

A. relatively large, erupt andesitic magma, and are non-explosive

B. relatively small, erupt andesitic magma, and are highly explosive

C. relatively large, erupt basaltic magma, and are highly explosive

D. relatively small, erupt basaltic magma, and are highly explosive

E. relatively large, erupt basaltic magma, and are non-explosive

7. Which of the following best explains why some volcanoes erupt so violently?

A. rapid temperature drop as magma reaches the surface environment

B. combustion as nitrogen gas compounds react with atmospheric oxygen

C. rapid decompression of dissolved gases

D. cooling effect of seawater beneath island arc volcanoes

E. all of the answers listed here

8. Which of the following is an example of a hot-spot, or intraplate volcano?

A. Mt. St. Helens

B. the Ring of Fire

C. Hawaiian Islands

D. Mt. Rainier

E. Mt. Fuji

9. Water vapor is often the most abundant dissolved gas within magm

A. What best describes the source of water in gas-rich magmas?

A. all of the answers listed here

B. water-rich sediment in subduction zones

C. heavy rainfall in tropical areas

D. shallow groundwater circulating through continental crustal rocks

E. seepage of seawater into oceanic crustal rocks

10. What best describes the relatively small volcanoes that form when fragments of erupted lava cool and accumulate around a vent?

A. fissure dome

B. lava dome

C. shield volcano

D. composite cone

E. cinder cone

11. Which of the following terms is used to describe a large circular depression that forms after an eruption when a magma chamber becomes empty and collapses in on itself?

A. crater

B. caldera

C. tuff-cone

D. sinkhole

E. lava pit

12. What best describes a pyroclastic flow?

A. hot mudflow

B. volcanic tsunami that makes landfall

C. dense ash fall

D. lava flow that has caught on fire

E. dry avalanche of hot material

13. Which of the following hazards is LEAST likely to be associated with explosive volcanic eruptions?

A. ash fall

B. pyroclastic flows

C. mudflows

D. lava flows

E. tsunamis

14. Which of the following is NOT a common a problem associated with volcanic ash-fall?

A. destruction of crops

B. forest fires

C. disruption of air travel

D. building collapse

E. filling of stream channels

15. What best explains why volcanic mudflows are so dangerous to humans?

A. relatively small, erupt basaltic magma, and are highly explosive

B. relatively large, erupt basaltic magma, and are non-explosive

C. relatively large, erupt andesitic magma, and are non-explosive

D. relatively large, erupt basaltic magma, and are highly explosive

E. relatively small, erupt andesitic magma, and are highly explosive

16. Which of the following volcanoes in the U.S. is most notably for having a history of massive mudflows, which today threatens large numbers of people?

A. Mt. Shasta, California

B. Mt. St. Helens, Washington

C. Mauna Loa, Hawaii

D. Mt. Spur, Alaska

E. Mt. Rainier, Washington

17. Which of the following is NOT a tool that scientists use to predict volcanic eruptions?

A. seismic monitoring

B. monitoring topographic changes

C. monitoring geophysical and groundwater changes

D. deep drilling and magma sampling

E. volcanic gas sampling

True / False Questions

18. Volcanic tsunamis can form around volcanic islands during large explosive events or massive landslides.

True / False

19. Volcanic ash forms when rock particles and lava droplets are ejected skyward.

True / False

20. Attempts at predicting volcanic eruptions have largely been unsuccessful.

True / False

Multiple Choice Questions

21. Volcanoes found in the interior of plates are associated with which plate tectonic feature?

A. Divergent boundary

B. Convergent boundary

C. Transform boundary

D. A hot spot

22. Where are basaltic magmas generated?

A. In the upper crust

B. In the lower crust

C. In the upper mantle

D. In the lower mantle

23. Oceanic crust is comprised of which kind of rock?

A. Basalt

B. Andesite

C. Rhyolite

D. Diorite

24. Which kind of magma has the lowest viscosity?

A. Granite

B. Rhyolite

C. Andesite

D. Basalt

25. Which is the dominant volcanic gas found in andesitic magma?

A. Oxygen

B. Carbon dioxide

C. Water

D. Hydrogen

26. What is the cause of volcanic earthquakes?

A. Increased viscosity due to cooling

B. Decreased viscosity due to cooling

C. Fluid pressure from the magma

D. Movement of tectonic plates

27. What causes volcanic explosions?

A. Escaping volcanic gases

B. Increased melting due to high water content

C. Breaking of rocks during an earthquake

D. Collisions between tectonic plates

28. What is the name for pulverized rock that is explosively ejected along with magma?

A. Lava

B. Pillow basalt

C. Flood basalt

D. Pyroclastic material

29. Where is the Columbia River flood basalt located?

A. In southern California

B. In Oregon and Washington

C. In New Mexico

D. In Florida and Georgia

30. Shield volcanoes are produced from which type of magma?

A. Basalt

B. Andesite

C. Rhyolite

D. All of these choices are correct

31. Which type of volcano is characteristic of the Andes Mountains of South America?

A. Shield volcano

B. Caldera

C. Stratovolcano

D. Cinder cone

32. All of the following are volcanic hazards except

A. lava domes.

B. mudflows.

C. landslides.

D. tsunamis.

33. Which type of magma produces lava flows which travel the fastest and farthest?

A. Andesite

B. Basalt

C. Rhyolite

D. Granite

34. Which type of eruption often generates tsunamis?

A. Caldera formation by collapse

B. Pyroclastic flow

C. Continental flood basalt

D. Steam explosion

35. What was unusual about the 1980 eruption of Mt. St. Helens?

A. A flank eruption occurred

B. A lateral blast

C. The small size of mudflows that were formed

D. The thickness of lava flows produced

36. What does the collapse of the rising eruption column often produce?

A. Volcanic mudflows

B. Pyroclastic flows

C. Lateral blasts

D. Tsunamis

37. What destroyed the Roman town of Pompeii in 79 AD?

A. A landslide

B. A mudflow

C. An enormous lava flow

D. A pyroclastic flow

38. Which geologic hazard can be triggered by a volcanic landslide?

A. Earthquake

B. Steam explosion

C. Pyroclastic flow

D. Tsunami

39. What do magmatic earthquakes (harmonic tremors) indicate?

A. An eruption may be imminent.

B. Tectonic plates are colliding.

C. A hot spot is forming.

D. The volcano is extinct and safe.

40. What can changes in the composition of volcanic gases indicate?

A. Where valuable mineral resources are located

B. Magma rising toward the surface

C. How much lava will be produced

D. Whether or not volcanic mudflows can occur