🌋🧠 EXAM 2 — MULTIPLE CHOICE PRACTICE TEST (75 QUESTIONS)

VOLCANO HAZARDS

1. Which two gases are most abundant in volcanic emissions?
A. CO₂ & SO₂
B. Water & CO
C. Water & CO₂
D. Methane & CO₂
Correct: C

2. What causes melting at subduction zones?
A. Pressure decrease
B. Water addition
C. Temperature increase
D. Magma mixing
Correct: B

3. What causes melting at divergent boundaries?
A. Water addition
B. Temperature increase
C. Pressure decrease
D. Friction
Correct: C

4. Which magma type is least viscous?
A. Felsic
B. Intermediate
C. Mafic
D. Ultramafic
Correct: D

5. Which magma type has the highest silica content?
A. Mafic
B. Ultramafic
C. Intermediate
D. Felsic
Correct: D

6. High‑viscosity magma tends to:
A. Allow gases to escape
B. Produce gentle eruptions
C. Trap gases
D. Form shield volcanoes
Correct: C

7. Which eruption style is least explosive?
A. Plinian
B. Hawaiian
C. Vulcanian
D. Peléan
Correct: B

8. Which eruption style involves magma interacting with water?
A. Strombolian
B. Surtseyan
C. Plinian
D. Hawaiian
Correct: B

9. Which eruption style produces lava fountains and some pyroclasts?
A. Strombolian
B. Vulcanian
C. Peléan
D. Plinian
Correct: A

10. Which eruption style involves a lava dome blocking the throat?
A. Hawaiian
B. Strombolian
C. Vulcanian
D. Surtseyan
Correct: C

11. Which eruption style produces pyroclastic flows named after Mt. Pelée?
A. Peléan
B. Plinian
C. Hawaiian
D. Strombolian
Correct: A

12. Which eruption style produces tall ash columns?
A. Hawaiian
B. Plinian
C. Strombolian
D. Surtseyan
Correct: B

13. Shield volcanoes are composed of:
A. Mafic lava flows
B. Felsic lava
C. Pyroclastic layers
D. Alternating ash and lava
Correct: A

14. Cinder cones are composed of:
A. Mafic pyroclasts
B. Felsic lava
C. Intermediate lava
D. Ash only
Correct: A

15. Composite volcanoes are composed of:
A. Mafic lava
B. Alternating pyroclasts + intermediate lava
C. Felsic domes
D. Pyroclastic flows only
Correct: B

16. Why are lava flows rarely deadly?
A. They are too hot
B. They move too slowly
C. They explode
D. They only occur underwater
Correct: B

17. The deadliest volcanic hazard is:
A. Lava flows
B. Ash fall
C. Pyroclastic flows
D. Gas emissions
Correct: C

18. A lahar is:
A. A lava fountain
B. A mudflow of water + volcanic debris
C. A pyroclastic surge
D. A gas cloud
Correct: B

19. Lahars can occur without an eruption because:
A. They require magma
B. They require earthquakes
C. Rain or snowmelt can mobilize ash
D. They require lava
Correct: C

20. What killed 22,000 people in Armero, Colombia?
A. Lava
B. Pyroclastic flows
C. Lahar
D. Gas cloud
Correct: C

21. What caused the Lake Nyos disaster?
A. Lava flow
B. CO₂ released from magma accumulated in the lake
C. Pyroclastic flow
D. Earthquake
Correct: B

22. What saved Heimaey’s harbor in 1973?
A. Evacuation
B. Explosives
C. Spraying seawater + building barriers
D. Diverting lava with trenches
Correct: C

23. What triggered Eyjafjallajökull’s explosive eruption in 2010?
A. Magma mixing
B. Glacial meltwater entering magma
C. Earthquake swarm
D. Dome collapse
Correct: B

24. First sign of Mt. St. Helens reactivation in 1980:
A. Lava dome
B. Ash plume
C. M3 earthquake swarm
D. Lahar
Correct: C

25. Most earthquake swarms near volcanoes:
A. Always cause eruptions
B. Usually cause eruptions
C. Rarely cause eruptions
D. Never cause eruptions
Correct: C

LANDSLIDES

26. Mass wasting is:
A. Erosion by rivers
B. Movement of material downslope by gravity
C. Wind erosion
D. Glacier movement
Correct: B

27. Relief is created by:
A. Wind
B. Upward and downward displacement
C. Rainfall
D. Vegetation
Correct: B

28. A slope becomes unstable when:
A. Resistance > shear
B. Shear > resistance
C. Normal stress increases
D. Vegetation grows
Correct: B

29. Water destabilizes slopes by:
A. Increasing friction
B. Reducing pore pressure
C. Increasing pore pressure
D. Cooling the soil
Correct: C

30. A small amount of water in sediment:
A. Decreases cohesion
B. Increases cohesion
C. Causes liquefaction
D. Removes friction
Correct: B

31. Saturated sediment fails because:
A. Grains stick together
B. Grains lose contact
C. It becomes heavier
D. It becomes colder
Correct: B

32. Vegetation stabilizes slopes by:
A. Adding weight
B. Breaking rock
C. Roots holding regolith + absorbing water
D. Increasing pore pressure
Correct: C

33. Angle of repose is:
A. Angle of a cliff
B. Steepest angle material can hold
C. Angle of a fault
D. Angle of a dune
Correct: B

34. Rounded sand has an angle of repose of:
A. 10°
B. 20°
C. 30–37°
D. 60°
Correct: C

35. Angular gravel has an angle of repose of:
A. 20°
B. 30°
C. 45°
D. 60°
Correct: C

36. Slopes are most unstable when layers are:
A. Perpendicular to slope
B. Parallel to slope
C. Random
D. Vertical
Correct: B

37. Creep is:
A. Fast
B. Medium speed
C. Slow
D. Instantaneous
Correct: C

38. Signs of creep include:
A. Straight trees
B. Tilted poles
C. Fresh lava
D. Ash layers
Correct: B

39. Solifluction occurs in:
A. Deserts
B. Permafrost
C. Volcanoes
D. Rivers
Correct: B

40. A slump moves along a:
A. Flat plane
B. Curved surface
C. Vertical cliff
D. Fault
Correct: B

41. A debris flow contains:
A. Only mud
B. Only rocks
C. Water, mud, and large rocks
D. Only water
Correct: C

42. A rockfall is:
A. Sliding
B. Rolling
C. Free‑fall
D. Flowing
Correct: C

43. Natural triggers of landslides include:
A. Earthquakes
B. Rain
C. Undercutting
D. All of the above
Correct: D

44. Human triggers include:
A. Removing vegetation
B. Over‑steepening slopes
C. Adding weight
D. All of the above
Correct: D

45. What caused the Lituya Bay megatsunami?
A. Earthquake uplift
B. Rockfall from strike‑slip fault
C. Volcanic eruption
D. Storm surge
Correct: B

TSUNAMIS

46. Tsunamis are caused by:
A. Wind
B. Tides
C. Sudden displacement of water
D. Hurricanes
Correct: C

47. Most tsunamis occur at:
A. Divergent boundaries
B. Transform boundaries
C. Convergent boundaries
D. Hot spots
Correct: C

48. Tsunami wavelength:
A. 10 m
B. 100 m
C. 200–500 km
D. 1 km
Correct: C

49. Tsunami period:
A. 5 seconds
B. 20 seconds
C. 10 minutes–2 hours
D. 24 hours
Correct: C

50. Tsunami speed in deep water:
A. 10 mph
B. 50 mph
C. 200 mph
D. 435 mph
Correct: D

51. Tsunamis are harmless to ships because:
A. They are too slow
B. They have small amplitude in deep water
C. They break early
D. They only occur near land
Correct: B

52. As tsunamis approach shore, they:
A. Speed up
B. Slow down and grow taller
C. Disappear
D. Split
Correct: B

53. Drawback is:
A. First wave
B. Water receding before tsunami
C. Last wave
D. A type of erosion
Correct: B

54. Run‑up elevation is:
A. Horizontal distance
B. Vertical height reached
C. Wave speed
D. Wave period
Correct: B

55. Inundation limit is:
A. Vertical height
B. Horizontal distance inland
C. Wave speed
D. Wave depth
Correct: B

56. Is danger over at the inundation limit?
A. Yes
B. No
C. Sometimes
D. Only in deep water
Correct: B

57. Tsunami waves bend around islands due to:
A. Reflection
B. Refraction
C. Diffusion
D. Absorption
Correct: B

58. Tsunami interference patterns are caused by:
A. Refraction
B. Reflection
C. Both A and B
D. None
Correct: C

59. Tsunamis arrive as:
A. One wave
B. Two waves
C. Wave trains
D. Storm surges
Correct: C

60. DART stations detect:
A. Wind
B. Pressure changes on seafloor
C. Temperature
D. Salinity
Correct: B

ATMOSPHERE

61. Most abundant atmospheric gas:
A. Oxygen
B. Nitrogen
C. CO₂
D. Argon
Correct: B

62. Weather occurs in the:
A. Stratosphere
B. Troposphere
C. Mesosphere
D. Thermosphere
Correct: B

63. What warms the stratosphere?
A. CO₂
B. Ozone absorbing UV
C. Methane
D. Water vapor
Correct: B

64. Why is the mesosphere cold?
A. No ozone
B. Too much ozone
C. High pressure
D. Low pressure
Correct: A

65. Why is the thermosphere hot?
A. Greenhouse gases
B. Absorbs high‑energy radiation
C. Thick atmosphere
D. Cloud cover
Correct: B

66. Weather is:
A. Long‑term
B. Short‑term
C. Seasonal
D. Geological
Correct: B

67. Climate is:
A. Short‑term
B. Long‑term
C. Daily
D. Weekly
Correct: B

68. Warm air rises because:
A. It is heavier
B. It expands and becomes less dense
C. It contracts
D. It cools
Correct: B

69. Cold air sinks because:
A. It expands
B. It becomes less dense
C. It contracts and becomes denser
D. It heats up
Correct: C

70. Relative humidity measures:
A. Total water vapor
B. How close air is to saturation
C. Temperature
D. Pressure
Correct: B

71. Which air holds more water?
A. Cold
B. Warm
C. Both equal
D. Neither
Correct: B

72. Wind is caused by:
A. Coriolis only
B. Pressure differences
C. Temperature only
D. Humidity
Correct: B

73. Coriolis deflects air in the Northern Hemisphere:
A. Left
B. Right
C. Up
D. Down
Correct: B

74. Clouds form when air:
A. Sinks
B. Warms
C. Rises and cools
D. Moves sideways
Correct: C

75. The jet stream is:
A. A surface wind
B. A high‑altitude fast wind
C. A hurricane
D. A cold front
Correct: B