Ch12&13 Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1. What is the epicenter of an earthquake? a. the location along a fault where the first motion of an earthquake occurs b. a seismic wave that travels along the surface of Earth c. the point on Earth s surface directly above the earthquake s focus d. the last place that motion in an earthquake is detected 2. What is elastic rebound? a. the sudden return of deformed rock to its undeformed shape b. the gradual return of deformed rock to its undeformed shape c. the sudden return of undeformed rock to its deformed shape d. the gradual return of undeformed rock to its deformed shape 3. Where does the first motion of an earthquake occur? a. fault c. epicenter b. focus d. locus 4. An area where no direct seismic waves from a particular earthquake can be detected is called a. an inactive fault zone. c. a shadow zone. b. the mesosphere. d. the atmosphere. 5. How does the structure of Earth s interior affect seismic waves? a. It can increase the power of seismic waves exponentially. b. It can send seismic waves into shadow zones and seismic gaps. c. It can affect the speed and direction of seismic waves. d. It can change seismic waves into dangerous earthquakes. 6. Through what type of materials do P waves travel fastest? a. very rigid, brittle materials b. hot lava c. liquids and gases d. very rigid, not easily compressed materials 7. What effect does Earth s interior have on P waves and S waves?
a. It can send them into seismic gaps. b. It can absorb P waves, but not S waves. c. It has virtually no effect, especially on P waves. d. It can affect the speed and direction of the waves. 8. Why do earthquakes usually occur at plate boundaries? a. The rock on the edges of tectonic plates is soft and gives in easily to various pressures. b. Rock in environments near tectonic plate boundaries experience great stress. c. The boundaries between tectonic plates have been seismically active for millions of years d. Rock in environments near tectonic plate boundaries experience little stress. 9. Fault zones form at plate boundaries because a. seismic gaps and shadow zones form there. b. very little rock stress and strain occur there. c. intense stress occurs there when the plates separate, collide, subduct, or slide past each other. d. they have a long geologic history of occurring in the same places. 10. A modern seismograph consists of a. three sensing devices. c. two sensing devices. b. four sensing devices. d. 10 sensing devices. 11. To locate the epicenter of earthquakes, scientists use computers to a. analyze hypotheses and theories. b. perform triangulations based on data from seismograph stations. c. detect vibrations. d. determine magnitude and intensity. 12. When seismologists record arrival times of P waves and S waves at several seismograph stations, they are looking for the earthquake s a. magnitude. c. epicenter. b. intensity. d. focus. 13. Which scale more accurately measures the magnitude of large earthquakes? a. modified Mercalli scale c. moment magnitude scale b. Richter scale d. Mohs scale
14. What happens to tsunamis as they move toward shore? a. The decrease in height. c. They turn into riptides. b. They die out. d. They increase in height. 15. Which of the following is NOT a cause of tsunamis? a. volcanic eruption c. undersea landslide b. tornado d. undersea earthquake 16. What causes tsunamis? a. magnetic pole shifts, seismic gaps, extreme tides during winter b. tornadoes, volcanic eruptions, landslides c. changes in Earth s ozone layer, world climate changes, glaciers d. undersea earthquakes, landslides, volcanic eruptions 17. During a major earthquake, buildings a. always remain standing. c. may sway or collapse. b. do not move. d. are never damaged. 18. Which of the following can affect how a building responds to seismic waves? a. the type of roof the building has b. the type of ground beneath the building c. the type of electrical system the building has d. the type of windows the building has 19. If you are in a car during an earthquake, you should a. drive toward a bridge. c. get out and run. b. stop the car in a safe place. d. park near a tall building. 20. What are food, water, flashlights, and a portable radio needed for? a. measuring surface waves c. finding shadow zones b. preparing for earthquakes d. predicting earthquakes 21. If you are indoors during an earthquake, you should a. stand near a window. c. crouch under a desk.
b. stand on top of a desk. d. get outdoors fast. 22. Which of the following rules should be followed before and after an earthquake? a. stay cautious, follow instructions c. panic, clean up quickly b. be prepared, be cautious d. move outdoors, buy supplies 23. Which method is NOT used to predict earthquakes? a. detect changes in rock c. assess building damage b. monitor natural gas seepage d. record foreshocks 24. A foreshock is a. a major earthquake. c. another name for seismic gap. b. a small earthquake. d. a precursor to a tsunami. 25. Which of the following do scientists study in their efforts to forecast earthquakes? a. seismic gaps, rock changes, foreshocks b. bird migration, animal behavior patterns, human behavior patterns c. the solar system, air testing, rock samples d. barometric pressure, rock alignment, prevailing winds 26. When the temperature of rock rises above its melting point, a. magma will form. c. magma will not form. b. the melting point will increase. d. the melting point will decrease. 27. Any activity that includes the movement of magna to Earth s surface is called a. a vent. c. volcanism. b. a volcano. d. lava. 28. Which of the following is NOT a major volcanic area? a. boundaries of tectonic plates c. central continental plains b. mid ocean ridges d. subduction zones 29. This area is both a major earthquake zone and volcano zone. a. Pacific Ring of Volcanoes c. Oceanic Ring of Fire b. Pacific Ring of Fire d. Pacific Island Arc
30. When an underwater volcano erupts, the magma cools quickly, forming a. pillow lava. c. fissures. b. island arcs. d. vents. 31. What forms on the ocean floor in a subduction zone? a. hot spot c. lithosphere b. mantle plume d. trench 32. Which of the following is NOT a tectonic setting where volcanoes form? a. boundaries of tectonic plates c. mid ocean ridges b. glacier formed crater lakes d. subduction zones 33. When oceanic lithosphere subducts beneath oceanic lithosphere, a. a fissure will form. c. an island arc forms. b. aa lava is produced. d. more lithosphere is produced. 34. Pillow lava forms a. along a tectonic plate. c. below a caldera. b. on a mid ocean ridge. d. on a cinder cone. 35. What island is cut by a fissure breaking it into two parts? a. Japan c. Iceland b. Hawaii d. Grand Cayman 36. The three primary tectonic settings are zones near convergent and divergent tectonic plates, subduction zones, and a. mid ocean ridges. c. oceanic plates. b. island arcs. d. trench zones. 37. An area of volcanic activity far from a tectonic plate boundary is called a(n) a. hot spot. c. island arc. b. cone. d. mantle plume.
38. Large plutons that can cover an area as large as 100 km 2 are called a. dikes. c. batholiths. b. necks. d. igneous. 39. Magma or igneous rock that is rich in magnesium and iron and that is generally dark in color is called a. felsic. c. mafic. b. ash. d. pyroclastic. 40. When lava cools rapidly, a crust forms on the surface of the flow. If the flow continues, the crust wrinkles and forms volcanic rock known as a. aa. c. blocky lava. b. pahoehoe. d. lapilli. 41. Magma or igneous rock that is rich in feldspar and silica and is generally light in color is called a. mafic. c. composite. b. felsic. d. cinder. 42. Pyroclastic material less than 0.25 mm in diameter is called a. a volcanic bomb. c. volcanic ash. b. a volcanic block. d. volcanic dust. 43. Volcanic ash, dust, blocks, bombs, and lapilli are all a. felsic lava. c. mafic lava. b. pyroclastic materials. d. pahoehoe. 44. The eruption of Mount St. Helens was a. an oceanic volcano. c. an explosive eruption. b. a quiet eruption. d. a stratovolcano. 45. Composite volcanoes are also known as a. stratovolcanoes. c. craters. b. cinder cones. d. shield volcanoes. 46. Which of the following is NOT a major volcano cone type?
a. cinder cone c. shield b. composite d. mantle plume 47. A large depression formed by the collapse of a volcanic cone is called a a. crater. c. pluton. b. caldera. d. trench. 48. Which of the following does NOT signal a volcanic eruption? a. increase in thunderstorms near the volcano b. changes in earthquake activity c. bulging of volcano surface d. changes in the amount and composition of volcanic gases 49. Volcanic eruptions may be signaled by a. a change in earthquake activity. c. a change in wildlife behavior. b. a sudden weather change. d. volcanic dust in the air. 50. Three events that might signal a volcanic eruption are changes in earthquake activity, volcano surface bulges, and a. the appearance of vents. c. heavy thunder clouds. b. a sulfuric odor. d. a change in gases emitted.
Ch12&13 Test Answer Section MULTIPLE CHOICE 1. ANS: C PTS: 1 DIF: 1 REF: 1 2. ANS: A PTS: 1 DIF: 1 REF: 1 3. ANS: B PTS: 1 DIF: 1 REF: 1 4. ANS: C PTS: 1 DIF: 1 REF: 1 5. ANS: C PTS: 1 DIF: 1 REF: 1 6. ANS: D PTS: 1 DIF: 1 REF: 1 7. ANS: D PTS: 1 DIF: 1 REF: 1 8. ANS: B PTS: 1 DIF: 1 REF: 1 9. ANS: C PTS: 1 DIF: 1 REF: 1 10. ANS: A PTS: 1 DIF: 1 REF: 2 11. ANS: B PTS: 1 DIF: 1 REF: 2 12. ANS: C PTS: 1 DIF: 1 REF: 2 13. ANS: C PTS: 1 DIF: 1 REF: 2 14. ANS: D PTS: 1 DIF: 1 REF: 3
15. ANS: B PTS: 1 DIF: 1 REF: 3 16. ANS: D PTS: 1 DIF: 1 REF: 3 17. ANS: C PTS: 1 DIF: 1 REF: 3 18. ANS: B PTS: 1 DIF: 1 REF: 3 19. ANS: B PTS: 1 DIF: 1 REF: 3 20. ANS: B PTS: 1 DIF: 1 REF: 3 21. ANS: C PTS: 1 DIF: 1 REF: 3 22. ANS: B PTS: 1 DIF: 1 REF: 3 23. ANS: C PTS: 1 DIF: 1 REF: 3 24. ANS: B PTS: 1 DIF: 1 REF: 3 25. ANS: A PTS: 1 DIF: 1 REF: 3 26. ANS: A PTS: 1 DIF: 1 REF: 1 27. ANS: C PTS: 1 DIF: 1 REF: 1 28. ANS: C PTS: 1 DIF: 1 REF: 1 29. ANS: B PTS: 1 DIF: 1 REF: 1 30. ANS: A PTS: 1 DIF: 1 REF: 1
31. ANS: D PTS: 1 DIF: 1 REF: 1 32. ANS: B PTS: 1 DIF: 1 REF: 1 33. ANS: C PTS: 1 DIF: 1 REF: 1 34. ANS: B PTS: 1 DIF: 1 REF: 1 35. ANS: C PTS: 1 DIF: 1 REF: 1 36. ANS: A PTS: 1 DIF: 1 REF: 1 37. ANS: A PTS: 1 DIF: 1 REF: 1 38. ANS: C PTS: 1 DIF: 1 REF: 1 39. ANS: C PTS: 1 DIF: 1 REF: 2 40. ANS: B PTS: 1 DIF: 1 REF: 2 41. ANS: B PTS: 1 DIF: 1 REF: 2 42. ANS: D PTS: 1 DIF: 1 REF: 2 43. ANS: B PTS: 1 DIF: 1 REF: 2 44. ANS: C PTS: 1 DIF: 1 REF: 2 45. ANS: A PTS: 1 DIF: 1 REF: 2 46. ANS: D PTS: 1 DIF: 1 REF: 2
47. ANS: B PTS: 1 DIF: 1 REF: 2 48. ANS: A PTS: 1 DIF: 1 REF: 2 OBJ: 5 49. ANS: A PTS: 1 DIF: 1 REF: 2 OBJ: 5 50. ANS: D PTS: 1 DIF: 1 REF: 2 OBJ: 5