1. Chapter 7
Practice Test

2. #1
Which of the following is most likely to occur in an area of the asthenosphere where surrounding rock exerts less-than-normal pressure?
a. violent volcanic eruptions
b. magma formation
c. plate subduction
d. caldera formation

3. #1
Which of the following is most likely to occur in an area of the asthenosphere where surrounding rock exerts less-than-normal pressure?
b. magma formation

4. #2 Most magma forms in a. continental crust. b. the lithosphere.
c. the asthenosphere.
d. oceanic crust.

5. #2
Most magma forms in
c. the asthenosphere.

6. #3 Great pressure in the asthenosphere keeps the rock there mostly
a. felsic.
b. molten.
c. solid.
d. gaseous.

7. #3 Great pressure in the asthenosphere keeps the rock there mostly
c. solid.

8. #4
An opening in the earth’s surface through which molten rock flows is called a
a. vent.
b. caldera.
c. mantle.
d. fault.

9. #4
An opening in the earth’s surface through which molten rock flows is called a
a. vent.

10. #5
What happens when a plate with oceanic crust meets a plate with continental crust?
a. The continental plate is subducted.
b. New crust forms over a hot spot.
c. The oceanic plate is subducted.
d. New crust forms under a hot spot.

11. #5
What happens when a plate with oceanic crust meets a plate with continental crust?
c. The oceanic plate is subducted.

12. #6 A string of volcanoes that forms along a trench is called
a. an island arc.
b. a fissure.
c. a mid-ocean ridge.
d. a subducted plate.

13. #6 A string of volcanoes that forms along a trench is called
a. an island arc.

14. #7 Iceland was formed over a a. mid-ocean ridge. b. subduction zone.
c. convergent boundary.
d. caldera.

15. #7
Iceland was formed over a
a. mid-ocean ridge.

16. #8 What usually happens to magma after it forms in the earth’s mantle?
a. It spreads out sideways.
b. It sinks deeper down.
c. It stays where it forms.
d. It rises through cracks.

17. #8 What usually happens to magma after it forms in the earth’s mantle?
d. It rises through cracks.

18. #9
An opening on the earth’s surface through which molten rock flows and the material that builds up around the opening together form a
a. subduction zone.
b. trench.
c. convergent boundary.
d. volcano.

19. #9
An opening on the earth’s surface through which molten rock flows and the material that builds up around the opening together form a
d. volcano.

20. #10
As a result of the subduction of oceanic crust under a continent, magma is most likely to erupt from
a. an oceanic ridge.
b. an oceanic trench.
c. an island arc.
d. a volcano.

21. #10
As a result of the subduction of oceanic crust under a continent, magma is most likely to erupt from
d. a volcano.

22. #11
Magma that erupts under water often forms rounded formations called
a. aa lava.
b. pillow lava.
c. volcanic bombs.
d. pahoehoe lava.

23. #11
Magma that erupts under water often forms rounded formations called
b. pillow lava.

24. #12 The type of lava that is rich in silica, iron, and magnesium is
a. pillow.
b. felsic.
c. mafic.
d. aa.

25. #12 The type of lava that is rich in silica, iron, and magnesium is
b. felsic.

26. #13
The easiest way to distinguish between volcanic ash and volcanic dust particles is to compare their
a. color.
b. weight.
c. diameter.
d. density.

27. #13
The easiest way to distinguish between volcanic ash and volcanic dust particles is to compare their
c. diameter.

28. #14 What is formed when a magma chamber empties and collapses?
a. a crater
b. a fissure
c. a caldera
d. a vent

29. #14 What is formed when a magma chamber empties and collapses?
c. a caldera

30. #15
Seismographs can be useful in predicting volcanic eruptions because they measure
a. changes in surface bulging.
b. changes in gas composition.
c. temperature increases.
d. earthquake activity.

31. #15
Seismographs can be useful in predicting volcanic eruptions because they measure
d. earthquake activity.

32. #16 What type of lava usually flows out of oceanic volcanoes?
a. felsic
b. aa
c. mafic
d. pahoehoe

33. #16
What type of lava usually flows out of oceanic volcanoes?
c. mafic

34. #17
Which volcanic material would most likely be produced by a violent eruption?
a. pyroclastic material
b. pillow lava
c. aa
d. pahoehoe

35. #17
Which volcanic material would most likely be produced by a violent eruption?
a. pyroclastic material

36. #18 Pillow lava is most commonly found a. in calderas.
b. along deep trenches.
c. in stratovolcanoes.
d. along mid-ocean ridges.

37. #18
Pillow lava is most commonly found
d. along mid-ocean ridges.

38. #19 Cinder cones are generally formed when volcanoes eject
a. thin lava.
b. solid fragments.
c. pillow lava.
d. gases.

39. #19 Cinder cones are generally formed when volcanoes eject
b. solid fragments.

40. #20
Which of the following generally results from a quiet lava eruption?
a. cinder cone
b. surface bulge
c. shield volcano
d. stratovolcano

41. #20
Which of the following generally results from a quiet lava eruption?
c. shield volcano

42. #21
The catastrophic volcanic eruption that caused a series of tsunamis and a drop in global temperatures happened in
a. Japan.
b. Hawaii.
c. Krakatau.
d. Iceland.

43. #21
The catastrophic volcanic eruption that caused a series of tsunamis and a drop in global temperatures happened in
c. Krakatau.

44. #22 Before a volcanic eruption, seismic activity seems to
a. increase in frequency and decrease in intensity.
b. decrease in both frequency and intensity.
c. decrease in frequency and increase in intensity.
d. increase in both frequency and intensity.

45. #22 Before a volcanic eruption, seismic activity seems to
d. increase in both frequency and intensity.

46. #23 What causes bulging in the surface of volcanoes?
a. build up of volcanic blocks
b. upward movement of magma
c. changes in volcanic gases
d. eruptions of pyroclastic material

47. #23 What causes bulging in the surface of volcanoes?
b. upward movement of magma

48. #24 Where is the volcano Olympus Mons located? a. Io b. the moon
c. Saturn
d. Mars

49. #24
Where is the volcano Olympus Mons located?
d. Mars

50. #25
Which of the following is probably the most volcanically active body in the solar system?
a. the earth
b. Io
c. the moon
d. Mars

51. #25
Which of the following is probably the most volcanically active body in the solar system?
b. Io