Sverdrup Chapter 8 The Waves Verified Test Bank

Investigating Oceanography, 3e (Sverdrup)

Chapter 8 The Waves

1) A ________ is a wave generated by a submarine earthquake.

2) Waves that form beneath the surface on the pycnocline are called ________ waves.

3) Shallow-water waves will change direction as they approach shore in a process called ________.

4) Water particles in deep-water waves move in ________ orbits.

5) Water particles in shallow-water waves move in ________ orbits.

6) When deep-water waves travel away from a storm, the longer waves move faster than the shorter waves. This process is called sorting, or ________.

7) The restoring force for ________ waves is surface tension.

8) The restoring force of a capillary wave is gravity.

9) The diameter of deep-water wave orbits decrease with depth.

10) A 10 m long wave will have elliptical orbits in water that are 50 m deep.

11) Wind waves in the open sea have wavelengths and speeds that are defined by the wave period.

12) The speed of a shallow water wave changes with depth, but the length of a wave does not change.

13) Waves that travel through each other tend to cancel each other out and cease to exist on the far side of the passing zone.

14) A tsunami is a shallow water wave.

15) A tsunami, or seismic sea wave, travels at a speed determined by the size of the earthquake that forms it.

16) Internal waves are always standing waves.

17) The equation C = gT/2л is appropriate to determine the speed of a deep-water wave.

18) Water particle orbits of shallow-water waves change only their vertical dimension with depth.

19) Storm waves in the open sea are likely to be less steep and break less often than waves in the surf zone.

20) More than half of the tsunami warnings issued in the last 50 years have been false alarms.

21) The period of a wave never changes.

22) There is no vertical motion at the antinode of a standing wave.

23) There are three antinodes in a double-node standing wave.

24) When the water depth is between L/2 and L/20, the wave speed is constant.

25) Internal waves are faster and have shorter periods than most wind waves.

26) Because of dispersion, the distribution of waves from a single storm changes with time and distance from the storm center.

27) Constructive interference between waves increases the height of the resulting wave.

28) The most common generating force for water waves is wind.

29) Wavelength is the distance from the crest to the trough of the same wave.

30) The wave frequency is the time it takes for two subsequent wave crests to pass a location.

31) The diameter of wave orbitals increases with increasing depth.

32) Tsunami are always deep-water waves.

33) Shorter period waves travel faster than longer period waves.

34) On a standing wave, the maximum vertical movement occurs at the node.

35) The restoring force of a fully developed wind wave is ________.

A) gravity

B) solar heat

C) density

D) surface tension

E) viscosity

36) The maximum diameter of a water particle orbit of a deep water wave is defined by wave ________.

A) steepness

B) height

C) length

D) period

E) speed

37) The orbital motion of a deep-water wave extends to a depth equal to ________.

A) twice the wavelength

B) the wave's height

C) one-half the wavelength

D) one-half the wave's height

E) the seafloor depth

38) The speed of a surface gravity wave is described by the ________.

A) wavelength times the period

B) wave period divided by wavelength

C) wavelength divided by wave period

D) square of the depth

E) Earth's gravity

39) If a surface water wave has a wavelength of 200 m and a 5-second period, its speed is ________.

A) 4000 cm/sec

B) 400 cm/sec

C) 40 cm/sec

D) 100 m/sec

E) 10 m/sec

40) A group of waves is propagated at a speed that is ________ the speed of the individual waves in deep water.

A) twice

B) the same as

C) one-half

D) one-quarter

E) one-tenth

41) The speed of a shallow water wave varies with ________.

A) its height

B) the depth of the water

C) its steepness

D) its period

E) its amplitude

42) The speed of a shallow water wave is computed using ________.

A) C = the square root of gD

B) C2 = gL/2л

C) C2 = L/T

D) C = L × T

E) C = LT/g

43) Water particle orbits for a shallow water wave are ________.

A) elliptic and flatten with depth

B) elliptic and enlarge with depth

C) circular and extend halfway to the seafloor

D) circular at the surface and elliptical at the sea floor

E) circular and extend to the seafloor

44) The refraction of waves tends to concentrate wave energy ________ and disperse energy ________.

A) in bays; on headlands

B) on headlands; in bays

C) along coasts; behind breakwaters

D) along coasts; on headlands

E) along coasts; in bays

45) Water protected from direct wave influence behind a breakwater can be placed in motion by wave ________.

A) diffraction

B) refraction

C) reflection

D) All of these are correct.

E) None of these is correct.

46) Waves occurring at the interface between layers of seawater and fresh water are called ________.

A) freshwater waves

B) interference waves

C) density waves

D) internal waves

E) surface waves

47) Water transported shoreward in the surf zone is returned seaward by ________.

A) shallow water waves

B) reflected waves

C) refracted waves

D) rip currents

E) internal waves

48) Waves moving against a current will ________.

A) increase their height

B) decrease their speed

C) shorten their wavelength

D) All of these are correct.

E) None of these is correct.

49) In a standing wave, the positions where there is maximum vertical motion are called ________.

A) antinodes

B) nodes

C) wave gaps

D) troughs

E) surges

50) In a closed basin, a single-node standing wave oscillation tends to have a wavelength that is ________ the basin length.

A) one-quarter

B) one-half

C) the same as

D) twice

E) four times

51) The amplitude of a wave is about ________ the wave height.

A) one-fourth

B) one-half

C) the same as

D) twice

E) four times

52) Two different wave groups with the same height travel together in the same direction. The wavelength of one group is twice as long as the wavelength of the other group. A combined wave of extra height will be produced ________.

A) every wave

B) every other wave

C) every third wave

D) every fifth wave

E) every seventh wave

53) The fetch of a moving storm system ________ on the side of the storm where the wind is blowing in the ________ direction as the storm is moving.

A) decreases; same

B) decreases; opposite

C) increases; same

D) increases; opposite

E) Both decreases; opposite and increases; same are correct

54) The average energy of a wave is related to the square of its ________.

A) height

B) wave length

C) period

D) speed

E) All of these are correct.

55) If a wave is a capillary wave, the force that causes the water to return to its undisturbed level is ________.

A) gravity

B) wind

C) seismic forces

D) surface tension

E) All of these are correct.

56) Swell is more regular than waves in the wind-generated area because ________.

A) waves have been sorted by dispersion

B) some small waves have been damped out by friction

C) packets of swell are all at the same depth at the same time

D) waves have been sorted by dispersion and some small waves have been damped out by friction

E) waves have been sorted by dispersion, some small waves have been damped out by friction, and packets of swell are all at the same depth at the same time

57) When waves arrive at monitoring stations set up long distances from a storm center, which waves arrive first?

A) Long-period waves

B) Short-period waves

C) Steeper waves

D) Internal waves

E) Capillary waves

58) Wave height of wind waves depends on ________.

A) wavelength

B) wind speed and duration

C) fetch

D) wavelength and wind speed and duration

E) wind speed and duration and fetch

59) The average energy of a wave is determined by the wave's ________.

A) speed

B) length

C) period

D) All of these are correct.

E) None of these is correct.

60) A wave with a height of 4 feet will have ________ as much energy as a 2-foot wave.

A) two times

B) four times

C) six times

D) eight times

E) ten times

61) A water wave reaches an unstable breaking point when the steepness ratio, H/L, reaches ________.

A) 1:10

B) 1:8

C) 1:7

D) 1:5

E) 1:2

62) A long wave with a period of about 15 minutes will travel across the oceans at a speed of approximately ________.

A) 2 m/sec

B) 20 m/sec

C) 200 m/sec

D) 2 km/sec

E) 20 km/sec

63) If the wave height of 1500 waves is recorded, significant wave height will be the average of the highest ________ waves.

A) 15

B) 150

C) 300

D) 500

E) 750

64) A wave breaks when ________.

A) h/L = 1/7

B) L/h = 1/7

C) h = 3 m

D) L = 3 m

E) L/h = 3/7

65) Wave refraction results in ________.

A) wave energy concentrating in bays

B) wave energy decreasing in bays

C) wave energy focusing on headlands

D) wave energy concentrating in bays and wave energy focusing on headlands

E) wave energy decreasing in bays and wave energy focusing on headlands

66) A typical wavelength of a tsunami is ________.

A) 1 to 2 m

B) 10 to 20 m

C) 100 to 200 m

D) 100 to 200 km

E) 1000 to 2000 km

67) The speed of shallow water waves is controlled by the ________.

A) height

B) steepness

C) celerity

D) wavelength

E) water depth

68) A wave period that is representative of a tsunami wave is ________.

A) 5 seconds

B) 10 seconds

C) 15 seconds

D) 1 minutes

E) 20 minutes

69) The correct order of these wave types from fastest (highest) to slowest wave speeds is ________.

A) wind waves – Tsunami – Tides

B) wind waves – Tides – Tsunami

C) tides – Wind waves – Tsunami

D) tides –Tsunami – Wind waves

E) tsunami – Wind waves – Tides

70) Which of the following features of a wave may change during its existence?

A) Height and speed

B) Period

C) Speed

D) Height

E) Wavelength

71) Which of the following relates wave height (H) and wave amplitude (A)?

A) H = A/3

B) H = A/2

C) H = A

D) H = 2A

E) H = A2

72) As a wave moves to shallower water it stops being a deep-water wave when the depth equals (where L = wavelength) ________.

A) L/0.2

B) L/2

C) L/20

D) L/200

E) L/g

73) A deep-water wave is traveling with a speed of 13 m/s. Its period is ________.

A) 1.2 seconds

B) 1.3 seconds

C) 8.3 seconds

D) 13 seconds

E) None of these is correct.

74) A deep-water wave is traveling with a speed of 13 m/s. Its wavelength is ________.

A) 130 m

B) 108 m

C) 13 m

D) 8.3 m

E) 1.3 m

75) A shallow-water wave has an L of 7 m. At which one of the following heights would it break?

A) 0.1 m

B) 0.4 m

C) 0.7 m

D) 0.9 m

E) 1.1 m

76) The speed of a shallow-water wave at a depth of 5 m is ________.

A) 0.2 m/s

B) 0.4 m/s

C) 0.5 m/s

D) 7 m/s

E) 7.8 m/s

77) A small island in the open ocean is receiving swell coming from the southeast. Yet, waves break all around its shores, not just the ones facing southeast. The process responsible for this phenomenon is ________.

A) refraction

B) erosion

C) reflection

D) diffraction

E) isostasy