Ch. 8

Wind speed, duration, and fetch are the three conditions necessary to produce a fully developed sea. True False

True

Based on the equations for determining the speed of shallow-water waves, which one of the following variables is necessary to determine the speed of shallow-water waves? Select only one answer. Wave height Water depth Period Wavelength It is impossible to determine the speed of shallow-water waves without more information

Water depth

Waves that are breaking along the shore and are forming curling crests over air pockets are called: gravity waves. surf. swells. spilling breakers. plunging breakers

plunging breakers

Submarines sometimes ride out heavy storms in deep water by submerging. That is a practical application of utilizing the ____________________. SOFAR channel for safe navigation principle of constant proportions thermohaline stratification principle of decreasing orbital motion with depth wave refraction in deep water

principle of decreasing orbital motion with depth

The height of a wave depends upon: fetch, wind duration, and wind speed. wind duration. fetch and wind speed. wind duration and wind speed. fetch.

fetch, wind duration, and wind speed.

A tsunami may result from: tectonic activity on the seafloor. an intense storm. a large deep-water wave. a storm surge. constructive wave interference

tectonic activity on the seafloor.

Match the term or person with the appropriate phrase. deep-water wave speed (S) wave height wavelength/2 steepness = 1:7 wavelength/period

wavelength/period

Match the term with the appropriate phrase. orbital waves movement of air across the air-water interface waves at the ocean surface involving longitudinal and transverse waves the energy that causes ocean waves to form movement of water of different densities along a water-water interface movement of different air masses along an air-air interface

waves at the ocean surface involving longitudinal and transverse waves

The largest wind-generated waves tend to be associated with the: westerlies. equatorial doldrums. horse latitudes. polar regions. trade winds.

westerlies.

Wave energy is focused on headlands by wave refraction. True False

True

Calculate the speed (S) in meters per second for a deep-water wave with a wavelength (L) of 351 meters and a period (T) of 15 seconds. 547.5 m/s 8.75 m/s 42.3 m/s 23.4 m/s 0.04 m/s

23.4 m/s

Refer to the figure below detailing wave characteristics. Use the information on the figure to answer the following question. The wavelength is labeled with the number: 1. 2. 3. 4. 5.

3

Of the following offshore ocean conditions, which one(s) would likely produce spilling breakers? A gently sloping rocky bottom A gently sloping sandy bottom A steeply sloping rocky bottom A steeply sloping sandy bottom Deep water adjacent to an abrupt shallow coral reef

A gently sloping rocky bottom A gently sloping sandy bottom

What fault movement beneath the ocean is more likely to create a tsunami—vertical or a horizontal movement? A vertical movement is more likely to cause a tsunami. This movement causes a sudden change in the entire water column. Horizontal movements do not create water displacement. A horizontal movement is more likely to cause a tsunami. This movement causes a sudden change in the entire water column. Vertical movements do not create water displacement and are unlikely to cause a tsunami. Both vertical and horizontal movements are equally likely to cause tsunamis, as they both displace water in the entire column.

A vertical movement is more likely to cause a tsunami. This movement causes a sudden change in the entire water column. Horizontal movements do not create water displacement.

Of the following statements about tsunami, which is/are true? Tsunami always express themselves at the coast as a single rapid surge of water towards the shore. At the coast, a tsunami looks like a suddenly occurring high or low tide, which is why they are misnamed "tidal waves." If you are at a beach and the water suddenly drains out away from shore, it is safe to go explore the newly exposed land. The tsunami warning system uses seismic waves and deep-ocean pressure sensors to detect tsunami. Tsunami have a very long wavelength, so they travel at very high speeds (equivalent to the speed of a jet airplane). Tsunami are undetectable by ships in the open ocean.

At the coast, a tsunami looks like a suddenly occurring high or low tide, which is why they are misnamed "tidal waves." The tsunami warning system uses seismic waves and deep-ocean pressure sensors to detect tsunami. Tsunami have a very long wavelength, so they travel at very high speeds (equivalent to the speed of a jet airplane). Tsunami are undetectable by ships in the open ocean

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Please identify the word and/or phrase that does NOT fit the pattern. Enter only the letter of the answer (caps, no period, and not the full entry) in the field below. A. longitudinal B. orbital C. progressive D. spilling E. transverse

D. spilling

A shallow-water wave must form in water depth less than 100 meters. True False

False

A storm surge might form in association with a seafloor avalanche. True False

False

Internal waves are formed by the movement of water of different densities along an air-water interface. True False

False

Rogue waves are generated by destructive interference patterns of ocean swells. True False

False

The speed of a shallow-water wave is a function of wave period. True False

False

Of the following situations involving orthogonals, which one involves the highest energy? Select only one answer. Orthogonals that do not change much as they approach the shore Orthogonals that become oriented parallel to shore as they approach the shore Orthogonals that disappear as they approach the shore Orthogonals that become more closely spaced as they approach the shore Orthogonals that get farther apart as they approach the shore

Orthogonals that become more closely spaced as they approach the shore

What tools does the Pacific Tsunami Warning Center (PTWC) use in creating tsunami warnings? PTWC uses human observers on boats to detect potential tsunamis and tidal buoys to confirm the presence. The PTWC only uses tidal buoys to detect the presence of an abnormal sea height, like a tsunami. PTWC only uses satellites to detect large anomalies (differences from the average) like tsunamis in the ocean surface height. PTWC uses ocean buoys, deep-ocean pressure sensors, and satellites to detect tsunamis.

PTWC uses ocean buoys, deep-ocean pressure sensors, and satellites to detect tsunamis.

What are the beach slope and energy characteristics of surging breakers? Surging breakers occur where the ocean bottom has an abrupt slope change. This results in wave energy being compressed in a shorter distance. Surging breakers occur on moderate to steep slopes. The energy is compressed and is released gradually as the water moves up the shoreline. Surging breakers occur on gently sloped beaches. This gentle slope change results in a gradual release of energy. Surging breakers occur on moderate to steeply sloped beaches. When breaking it has a curling motion where the crest "outruns" the rest of the wave. Surging breakers occur where there is an abrupt slope change. The result is a gradual release of energy as the wave approaches the shore.

Surging breakers occur where the ocean bottom has an abrupt slope change. This results in wave energy being compressed in a shorter distance.

Which of the following statements is correct? The greater the wave height, the faster the wave travels. The greater the wave height, the deeper the wave base. The faster the wave, the greater the wave height. The longer the wave, the faster the wave travels. The longer the wave base, the deeper the wave base.

The longer the wave, the faster the wave travels.

Of the following statements about ocean waves, which one(s) describe wave period? The vertical distance between a wave crest and an adjacent trough The horizontal distance between adjacent wave crests The time it takes for one full wavelength to pass a given point The number of waves that pass a given point in a certain amount of time The inverse of wave frequency Wave height divided by wavelength

The time it takes for one full wavelength to pass a given point The inverse of wave frequency

Of the following physical changes that occur to waves as they move into shallow water, which is/are true? Wave speed increases. The waves touch bottom. Wavelength decreases. Wave steepness increases. Wave height increases.

The waves touch bottom. Wavelength decreases. Wave steepness increases. Wave height increases.

Deep-water waves move faster than shallow water waves because they are not slowed by friction with the ocean bottom. True False

True

What physical changes occur to a wave's wave speed (S), wavelength (L), height (H), and wave steepness (H/L) as the wave moves across shoaling water to break on the shore? Wave speed (S) decreases, wavelength (L) increases, height (H) decreases, and wave steepness (H/L) increases. Wave speed (S) decreases, wavelength (L) decreases, height (H) decreases, and wave steepness (H/L) decreases. Wave speed (S) decreases, wavelength (L) decreases, height (H) increases, and wave steepness (H/L) increases. Wave speed (S) increases, wavelength (L) decreases, height (H) increases, and wave steepness (H/L) increases. Wave speed (S) increases, wavelength (L) increases, height (H) decreases, and wave steepness (H/L) decreases.

Wave speed (S) decreases, wavelength (L) decreases, height (H) increases, and wave steepness (H/L) increases.

Of the following statements about ocean waves, which one(s) describe wave steepness? Wave steepness is defined as wave height divided by wavelength. Wave steepness is the time it takes for one full wavelength to pass a given point. If wave steepness ever exceeds a 1:7 ratio, then the wave breaks. Wave steepness is the vertical distance between a wave crest and an adjacent trough. Wave steepness is the horizontal distance between adjacent wave crests. Wave steepness is depth equal to half the wavelength

Wave steepness is defined as wave height divided by wavelength. If wave steepness ever exceeds a 1:7 ratio, then the wave breaks.

Where are internal waves most likely to form? in areas near coastal glaciers where large icebergs fall into the ocean along areas of rapidly changing density, such as a pycnocline in the nearshore environment where waves begin to "feel" the bottom along areas of rapidly changing temperature in the water column, such as the air-water interface

along areas of rapidly changing temperature in the water column, such as the air-water interface

The first wave that forms when the wind begins to blow across the ocean surface is a: tsunami. reflected wave. capillary wave. seiche. tide.

capillary wave.

As a wave approaches shore, its characteristics change by _____________________. decreasing speed, increasing steepness decreasing speed, decreasing steepness decreasing speed, steepness is unchanged increasing speed, decreasing steepness increasing speed, increasing steepness

decreasing speed, increasing steepness

The celerity (speed) of a deep-water wave with a wavelength of 9 meters, relative to that of a deep-water wave with a wavelength of 1 meter, will be ______________. faster slower the same determined by water depth determined by wave height

faster

In general the restoring force for wind-generated waves is: wind. gravity. seismic activity. surface tension of water molecules. cohesion of water molecules

gravity

As a wave begins to feel bottom near a shoreline, its wave height: increases and its wavelength decreases increases and its wavelength remains the same. decreases and its steepness decreases. decreases and its wavelength increases. increases and its frequency decreases

increases and its wavelength decreases

A disadvantage shared by wave, solar and wind energy is that ___________________________. the energy tends to be concentrated in areas of high latitude and is not readily available to tropical countries it is not available on demand, and there currently is no viable way to store the energy installations must be protected from the very energy that they collect governments are unwilling to subsidize renewable forms of energy the power produced must be transmitted long distances from where it is produced to where it is consumed

it is not available on demand, and there currently is no viable way to store the energy

Match the term with the appropriate phrase. what generates most ocean waves movement of different air masses along an air-air interface the energy that causes ocean waves to form waves at the ocean surface involving longitudinal and transverse waves movement of water of different densities along a water-water interface movement of air across the air-water interface

movement of air across the air-water interface

Match the term with the appropriate phrase. internal wave waves at the ocean surface involving longitudinal and transverse waves movement of air across the air-water interface the energy that causes ocean waves to form movement of water of different densities along a water-water interface movement of different air masses along an air-air interface

movement of water of different densities along a water-water interface

The time between two successive waves is called the: period. frequency. height. trough. crest.

period.

A tsunami is considered to be a: shallow water wave. reflected wave. deep-water wave. capillary wave. refracted wave.

shallow water wave.

Constructive interference results in larger waves whereas destructive interference produces: capillary waves. rouge waves. tsunamis. smaller waves. swells.

smaller waves.

If a surfer wishes to have a really long ride, what type of wave should he or she look for? swells plunging breakers surf spilling breakers gravity waves

spilling breakers

Match the term or person with the appropriate phrase. ratio of wave height to wavelength at which waves break wavelength/period wavelength/2 wave height steepness = 1:7

steepness = 1:7

A wave will begin to break when: distance from shore < wavelength. wavelength < wave height. steepness = 1:7. water depth = wavelength/20. water depth = wave height.

steepness = 1:7.

The fetch refers to: a type of wave-cut platform. the distance between the trough of a wave and the still water level. a method of shoreline erosion control. the circular pattern made by water particles when a wave passes. the distance over which the wind blows without interruption.

the distance over which the wind blows without interruption.

The speed of a deep-water wave is proportional to: water depth. wave frequency. wave speed or celerity. wavelength. wave height.

wavelength.

The speed of a shallow-water wave is proportional to: wave height. wavelength. wave period. wave frequency. water depth.

water depth.

The diameter of a wave orbital at the surface is equal to: wave height. wavelength/wave period. wavelength. wave period. wave height/wavelength

wave height

Waves converge on headlands due to: wave refraction. wave diffraction. constructive interference. destructive interference. wave reflection.

wave refraction.

"Whitecaps" form when _____________________. a wave train overtakes another wave train water depth is greater than 1/2 the wavelength waves are reflected off an obstruction wave steepness reaches a ratio of 1:7 waves approach the shore at an angle

wave steepness reaches a ratio of 1:7

Wave speed is equal to: wavelength divided by period. wavelength divided by fetch. wave height divided by frequency. wavelength divided by frequency. wave height divided by period

wavelength divided by period.

Rogue waves tend to occur: in coastal areas with weak sea breezes. in upwelling zones. where storm waves move against strong surface currents. in areas where wind belts converge. only in the southern ocean below 60°S latitude

where storm waves move against strong surface currents.

Most ocean waves form as a result of: seismic events. density differences between water layers. Earth's rotation. landslides. winds blowing across the ocean surface.

winds blowing across the ocean surface.