Deck 10: Waves

Question 1

Why does wave refraction occur?

A) Wave lines approach shore and enter into different depths
B) The density of the wave alters in shallow water
C) Waves break perpendicularly to the shore
D) Waves stack up on shore and bend

Answer 1

A
The variation in depth causes the waves to not break simultaneously. Sections of the wave line that enter shallow water first slow down, but segments still in deeper water keep their original speed. Information can be found in the section Deep-Water Waves Change to Shallow-Water Waves As They Approach Shore.

Question 2

What type of wave is categorized as a deep-water wave?

A) Capillary wave
B) Seiche wave
C) Tsunami wave
D) Tides

Answer 2

A
Only capillary waves and wind waves can be deep-water waves. The wavelength of the other types waves listed are too large. They will never be in water that is deeper than half its wavelength. Information can be found in the section Contemporary Oceanography Makes Use of Modern Technology.

Question 3

What is a fetch?

A) The undulation of dispersed waves across the surface of the ocean
B) The maximum wave size theoretically possible for a specific wind strength and duration
C) The uninterrupted distance over which wind blows
D) A progression of swells with the same origin

Answer 3

C
The fetch is one factor in the development of wind waves. The wind speed, duration and direction over the fetch are crucial in the creation of wind waves. Information can be found in the section Wind Blowing Over the Ocean Generates Waves.

Question 4

What kind of waves occur at the boundary between two fluid media?

A) Seiche waves
B) Orbital waves
C) Transitional waves
D) Tidal waves

Question 5

What determines the characteristics of ocean waves?

A) The wavelength and wave period
B) The wave height and wave frequency
C) The wavelength and water depth
D) The wave period and wave frequency

Question 6

What maintains a forced wave?

A) Wavelength
B) Wind
C) Disturbing force
D) Restoring force

Question 7

What is an ice quake?

A) The force of that creates a wave
B) Ice that is smashed and ground together to form pressure ridges
C) The force that determines a wave's size
D) An ice shear zone where waves collide

Question 8

When does a wave begin to interact with its bottom?

A) When the bottom is deeper than ½ the wavelength
B) When the bottom is shallower than ½ the wavelength
C) When the bottom is deeper than twice the wavelength
D) When the bottom is shallower than twice the wavelength

Question 9

Why is a storm surge not considered a progressive wave?

A) It is formed by low pressure.
B) It is very short lived.
C) It is only a crest rather than a whole wave.
D) It is enhanced by high tides.

Question 10

What is the relative ratio of height to wavelength in a tsunami?

A) It is extremely high.
B) It is incalculable.
C) It is extremely low.
D) It is calculated based on the seismic forces

Question 11

What occurs when waves hit an obstacle straight on?

A) Wave refraction
B) Wave diffraction
C) Wave dispersion
D) Wave reflection

Question 12

What is a wave period?

A) The horizontal distance between two successive crests or troughs
B) The number of waves passing a fixed point per second
C) The time for a wave to move the distance of one wavelength
D) The end of a wave train

Question 13

What is a characteristic of a tsunami?

A) Deep-water waves
B) Long wavelengths
C) Standing waves in the open ocean
D) Oscillations near coastal areas

Question 14

What is not true of a rogue wave?

A) The constructive interference of many wavelengths
B) A wave much larger than the theoretical maximum wave sustained by a fully developed sea
C) A freak, unpredictable wave
D) A predictable but large wave

Question 15

What type of ocean wave has a disturbing force of sudden changes in atmospheric pressure?

A) Seiche waves
B) Capillary waves
C) Wind waves
D) Tidal waves

Question 16

What is the process of wave separation?

A) Swells
B) Wave trains
C) Fully developed sea
D) Dispersion

Question 17

What kind of flow is important in driving the ocean surface currents?

A) Wave frequency
B) West Wind Drift
C) Progressive waves
D) Stokes drift

Question 18

Standing waves are important in the physics of what kind of wave?

A) Seismic sea waves
B) Capillary waves
C) Seiche waves
D) Progressive waves

Question 19

What can not initiate a seiche?

A) Tides
B) Storm surge
C) Seabed displacement
D) Internal waves

Question 20

How fast do wave trains travel in relation to individual waves in that train?

A) One-third as fast
B) One-fourth as fast
C) One-half as fast
D) Twice as fast

Question 21

Orbitals of wind waves close to shore have elliptical orbits due to the proximity of the bottom.

Question 22

What remains unchanged regardless of depth?

A) Wavelength
B) Wave height
C) Wave period
D) Wave shape

Question 23

The circulation motion of water particles at the surface continues underwater at orbits of decreasing diameter.

Question 24

The tsunami that struck northern Japan in March 2011 began when a rupture along a submarine fault uplifted the sea surface by as much as 6 meters.

Question 25

Giant internal waves can move down the side of submerged mountains and are detected by temperature differences between water layers.

Question 26

What occurs as a tsunami's circumference expands?

A) The wave height increases
B) The energy dissipates
C) The period increases
D) The period decreases.

Question 27

The tidal waves portrayed to the general public are not true tidal waves.

Question 28

What generates internal waves?

A) Wind energy
B) Tidal energy
C) Ocean currents
D) All of these choices

Question 29

What is not an important factor for the development of wind waves?

A) Wind speed
B) Tides
C) Wind direction
D) Fetch

Question 30

The longer the wavelength is on a wave, the slower the wave energy moves through the water.

Question 31

The restoring force for capillary waves, like most ocean waves, is gravity.

Question 32

How often do destructive tsunamis strike somewhere in the world?

A) Approximately once a year
B) Approximately one every two years
C) Approximately once every decade
D) Approximately a few times per year

Question 33

What drives a storm surge ashore?

A) Frontal storms
B) Wind
C) Gravity
D) Currents

Question 34

Internal waves occur at the boundary between water layers of two different densities.

Question 35

What do tsunami warning networks use to monitor the sea surface?

A) Sonar
B) Electromagnetic field detectors
C) Seismometers
D) Slocum gliders

Question 36

How deep would a submarine need to dive to feel no motion from surface waves with a wavelength of 200 meters ?

A) less than 50 meters
B) less than 100 meters
C) below 50 meters but above 100 meters
D) below 100 meters

Question 37

Multiple wave trains exist at the same time and can interact with each other.

Question 38

What causes ocean waves to form?

A) Energy from the wavelength
B) Energy from the disturbing force
C) Energy from the restoring force
D) Energy from the Stokes drift

Question 39

Another term for a storm surge is a storm seiche due to the amount of water forced ashore.

Question 40

What happens when a tsunami approaches the shore?

A) Its velocity drops rapidly.
B) Its period remains the same.
C) Its wave height increases
D) All of these choices

Question 41

What factors are needed in wind wave development? What occurs after these waves develop?

Question 42

Wind waves retain the most amount of energy.

Question 43

What causes a tsunami? Compare the losses due to the Indonesian (2004) and Japan (2011) earthquakes. How could the loss of life and property have been minimized?

Question 44

The destruction of the 2004 tsunami near Indonesia came from a series of waves rather than a single seismic wave.

Question 45

The water mass moving through a seismic sea wave can reach speeds of 760 kilometers per hour.

Question 46

Tsunamis are shallow-water waves because their wavelengths are so long that they will never be in water deeper than 1/2 its wavelength.

Question 47

What are the five different types of waves discussed in this chapter? Which waves are considered to be deep-water waves? Include the disturbing and restoring forces of these waves.

Question 48

How do wave trains travel? How do they interact with each other?

Question 49

When tsunamis begin to break ashore, they have very high wave crests.

Question 50

What is the difference between a storm surge and a seiche? What are the behaviors and causes of each?