Exam 2 HW 8

wave steepness reaches a ratio of 1:7

"Whitecaps" form when _____________________.

1/2 of the wavelength.

A deep-water wave occurs when the water depth is equal to at least:

shallow water wave

A tsunami is considered to be a:

pacific

A vast majority of all large tsunami are generated in the ________ Ocean.

steepness = 1:7.

A wave will begin to break when:

wave reflection

An unintended consequence of the jetty that protects the harbor entrance at Newport Harbor, California is a wave pattern that has crippled and killed many body surfers due to ________.

decreasing speed, increasing steepness

As a wave approaches shore, its characteristics change by _____________________.

increases and its wavelength decreases

As a wave begins to feel bottom near a shoreline, its wave height:

10 seconds

Based on the graph, what is the approximate period of a deep-water wave with a speed of 15 meters per second?

25 meters per second

Based on the graph, what is the approximate speed, in meters per second, of a deep-water wave with a wavelength of 400 meters?

smaller waves

Constructive interference results in larger waves whereas destructive interference produces:

-The raft moves in a circle, and it returns to essentially the same place -The raft's net movement is not toward the shore compared to the surf zone

During a visit to the beach, you get in a small rubber raft and paddle out beyond the surf zone. You become tired, so you stop and take a rest. Describe the movement of your raft beyond the surf zone. Select the two that apply. the two that apply. -The raft will move toward shore along with the water particles underneath the raft. -The raft's net movement is not toward the shore compared to the surf zone. -The raft moves -up and down vigorously due to the breaking of waves that are taller than waves in the surf zone. -The raft moves in a circle, and it returns to essentially the same place.

swell

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern.

through displacement of the seafloor under water

How are tsunamis generated?

Waves with shorter periods have shorter wavelengths.

How are wave period and wavelength related?

Water moves in a circle in the same direction as wave movement.

How does water move as waves pass?

Wave amplitude decreases as depth increases

How does wave amplitude change with depth in water?

Wave refraction at the headland INCREASES EROSION at the headland and causes deposition in adjacent bays

How does wave refraction at headlands affect deposition and erosion?

spilling breakers

If a surfer wishes to have a really long ride, what type of wave should he or she look for?

gravity

In general the restoring force for wind-generated waves is:

300,000

In the open ocean, 1 wave in ________ will be four times as high as the height of the wave average.

23

In the open ocean, 1 wave in ________ will be over twice the height of the wave average.

The assertion is correct, but the reason is incorrect.

Judge the following sentence according to the criteria given below: Many people call tsunami "tidal waves" BECAUSE they are related to the tides.

The assertion and the reason are both correct, and the reason is valid.

Judge the following sentence according to the criteria given below: Transform faults do not generally generate tsunami BECAUSE the side-to-side movement of these faults does not change the volume of the ocean basin.

All of the locations except 9 could produce tsunamis, because all are subduction zones involving at least one oceanic plate.

Look again at the map. Bear in mind that all the earthquake locations that are not inland are on a convergent plate boundary (subduction zone). Which of these statements is true?

winds blowing across the ocean surface.

Most ocean waves form as a result of:

north to south

Most of the year, and most of the time, the movement of sediment and water (longshore current) along the California coast is from __________.

orbital waves

Ocean surface waves are:

orbital

Ocean waves in motion are classified as ______waves.

-A gently sloping, sandy bottom -A gently sloping, rocky bottom

Of the following bathymetric conditions, which one(s) would likely produce spilling breakers? Choose all that apply. -a gently sloping, rocky bottom -a gently sloping, sandy bottom -deep water -adjacent to an abrupt shallow coral reef -a steeply sloping, rocky bottom -a steeply sloping, sandy bottom

-Ocean waves can be described by their period, wavelength, and height. -Ocean waves can be classified by the depth of water in which they move. -Ocean waves can be classified by the way in which they form.

Of the following statements about ocean waves, which is/are true? Choose all that apply. -Ocean waves involve the transport of water across ocean basins. -Ocean waves can be classified by the force that created them. -Ocean waves can be classified by the depth of water in which they move. -Ocean waves occur only at the air/water interface. -Ocean waves can be described by their period, wavelength, and height.

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

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

10

On average how many supertankers or containerships are reported missing each year without a trace?

good, erosion

Refraction causes headlands to be areas of ________ surfing and sites of ________.

atmospheric

Ripple like clouds in the sky are an example of ________ waves.

Africa

Rogue waves are created along the "Wild Coast" off the southeast coast of ________, where the Agulhas Current flows directly against large Antarctic storm waves.

longitudinal

Sound travels as ________ waves.

principle of decreasing orbital motion with depth

Submarines sometimes ride out heavy storms in deep water by submerging. That is a practical application of utilizing the ____________________.

wavelength/2.

The circular motion of water molecules extends to a depth that is equal to:

wave base

The depth below the surface where the circular orbits become so small that movement is negligible is called the ________.

fetch, wind duration, and wind speed.

The height of a wave depends upon:

wavelength

The horizontal distance between wave crest to crest is called the ________.

westerlies

The largest wind-generated waves tend to be associated with the:

fault movement

The majority of tsunami are caused by underwater ________.

wave frequency

The number of wave crests passing a fixed location per unit of time is called the ________.

wavelength

The speed of a deep-water wave is proportional to:

water depth.

The speed of a shallow-water wave is proportional to:

period

The time between two successive waves is called the:

wave period

The time it takes one full wave to pass a fixed position is called the ________.

internal

Tidal movement, turbidity currents, wind stress, and even passing ships at the surface create ________ waves.

the bending of waves

Wave refraction is __________.

wavelength divided by period.

Wave speed is equal to:

orbital

Waves at the ocean surface are ________ waves.

wave refractions

Waves converge on headlands due to:

5 meters

Waves from separate sea areas move away as swell and produce an interference pattern when they come together. If Sea A has wave heights of 1.5 meters and Sea B has wave heights of 3.5 meters, what would be the height of waves resulting from constructive interference?

3 meters

Waves from separate sea areas move away as swell and produce an interference pattern when they come together. If Sea A has wave heights of 2 meters and Sea B has wave heights of 5 meters, what would be the height of waves resulting from destructive interference?

plunging breakers

Waves that are breaking along the shore and are forming curling crests over air pockets are called:

the steepness of the beach slope

What causes the three different types of breakers?

The part of a wave in shallow water slows down, causing the wave to bend and line up nearly parallel to the shore.

What causes wave refraction?

storm-generated winds that blow across the surface

What disturbing force is responsible for most ocean waves that eventually break on shore?

Waves in phase have identical wavelengths and are aligned peak-to-peak and trough-to-trough

What does the term "in phase" refer to?

a series of water waves that travel away from a fault in all directions at high speed

What is a tsunami?

The wave pattern produced when two or more waves interact

What is an interference pattern?

the bending of waves due to a change in wave velocity

What is refraction?

the highest part of the wave

What is the crest of a wave?

The depth of the wave base is one-half the wavelength of the waves

What is the relationship between wave base and wavelength?

1.53 meters per second

What is the speed in meters per second of a deep water wave with a wavelength of 1.5 meters?

2.34 meters per second

What is the speed in meters per second of a deep water wave with a wavelength of 3.5 meters?

2.8 meters per second

What is the speed in meters per second of a deep water wave with a wavelength of 5 meters?

the lowest part of the wave

What is the trough of a wave?

the lower limit of wave-induced motion in the water

What is the wave base?

the distance between the highest and lowest part of the wave

What is the wave height?

the time it takes for one wavelength of a wave to pass a particular point

What is the wave period?

the distance between consecutive wave crests or troughs

What is the wavelength?

mixed interference

What occurs more often, pure destructive, pure constructive, or mixed interference?

A wave with an amplitude that is the sum of the amplitudes of the initial two waves

What results when two waves, in phase and with the same wavelength, interact?

The wave begins to interact with the sea floor as it moves into shallower water.

What triggers a wave traveling across the ocean to finally release its energy?

surging breakers

What type of breaker would pose the most danger to people playing or swimming in the surf zone?

convergent plate boundaries

What type of plate boundary are most tsunamis associated with?

When waves with identical wavelengths interfere

When will perfect constructive interference occur for waves that are in phase and moving at the same velocity?

pacific

Which ocean is associated with most tsunamis?

freak waves, rogue waves, superwaves

Which of the following are names for large ocean waves that can be created by constructive interference? Choose all that apply. Havoc waves Shipwrecker waves Freak waves Rogue waves Superwaves

forms on moderately sloped shorelines to create curling crests

Which of the following best describes a plunging breaker?

Scientists cannot predict when exactly an earthquake will occur, but they can identify tectonically active areas that are likely to produce earthquake activity and let the public know they are in an earthquake-prone area.

Which of the following best describes how scientists help the public prepare for an earthquake event?

fault movement

Which of the following caused the Indian Ocean tsunami of 2004?

Meteorite impacts

Which of the following is the least frequent cause of a tsunami in recent centuries?

Wave period is the inverse of wave frequency.

Which of the following statements about wave period is most accurate?

water depth

Which one of the following variables is necessary to determine the speed of shallow-water waves? Select only one answer.

surging breaker

Which type of breaker forms waves the present the greatest challenge to body surfers?

surging breaker

Which type of breaker forms when the waves build up and break right at the shoreline?

Plunging breaker

Which type of breaker has a curling crest that moves over an air pocket?

Spilling breaker

Which type of breaker is a turbulent mass of air and water that runs down the front slope of the wave as it breaks?

The waves are moving more SLOWLY just in front of the headland, causing the waves to bend.

Why do ocean waves bend around headlands?

Tsunamis in deep water have small wave height and long wavelength.

Why do ships at sea tend not to notice tsunamis?

In shallow water, the energy of the tsunami must be contained within a smaller water column.

Why does the wave height of a tsunami increase as the tsunami enters shallow water?

The energy of the wave must be contained within a smaller water column in shallow water

Why does wave height increase as waves enter shallow water?

This is likely, because Sumatra is near many ocean trenches.

Will Sumatra experience another tsunami like the destructive one of December 2004?

10.14 hours

You live on an island in the Pacific. An earthquake of magnitude 8.5 off the coast of Japan, 8000 km away, generates a tsunami with a wavelength of 200 km. The average water depth between your island and Japan is 4900 m. If a tsunami warning is issued for your island, how many hours will you have before the waves arrive?

longitudinal

________ waves also known as push-pull waves.

transverse

________ waves also known as side-to-side waves.