OCE1001 chapter 8 hw
A deep-water wave occurs when the water depth is equal to at least
1/2 of the wavelenght
Based on the graph, what is the approximate period of a deep-water wave with a speed of 15 meters per second?
10 seconds
Based on the graph, what is the approximate period of a deep-water wave with a speed of 25 meters per second?
16 seconds
Based on the graph, what is the approximate speed, in meters per second, of a deep-water wave with a wavelength of 200 meters?
18 meters per second
What is the speed in meters per second of a deep water wave with a wavelength of 3.5 meters?
2.34 meters per second
What is the speed in meters per second of a deep water wave with a wavelength of 5 meters?
2.8 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?
25 meters per second
Based on the graph, what is the approximate period of a deep-water wave with a speed of 5 meters per second?
3.5 seconds
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 2.5 meters and Sea B has wave heights of 3.5 meters, what would be the height of waves resulting from constructive interference?
6 f*ckin meters
Waves from separate sea areas move away as swell and produce an interference pattern when they come together. If Sea A and Sea B have wave heights of 3 meters, what would be the height of waves resulting from constructive interference?
6 meters
What results when two waves, in phase and with the same wavelength, interact?
A wave with an amplitude that is the sum of the amplitudes of the initial two waves.
Rogue waves are created along the "Wild Coast" off the southeast coast of ________, where the Agulhas Current flows directly against large Antarctic storm waves.
Africa
In the figure above, which shows an irregularly shaped shoreline. At which labeled locations would you expect wave energy to be the highest due to wave refraction?
B, D
Why are internal waves usually associated with a pycnocline?
Because a pycnocline is a boundary between two different water masses with different densities.
Why are these types of waves called internal waves?
Because they are internal to the ocean.
Besides where each type of wave is located, what is one of the most obvious physical differences between internal waves and surface waves?
Internal waves have a much longer wavelength as compared to the shorter wavelength surface waves.
Which of the following are names for large ocean waves that can be created by constructive interference?
Superwaves Rogue waves Freak waves
What is the relationship between wave base and wavelength?
The depth of the wave base is one-half the wavelength of the waves.
Why does wave height increase as waves enter shallow water?
The energy of the wave must be contained within a smaller water column in shallow water.
What causes waves to refract as they approach the shore?
The wave base begins to touch the sea floor. They transition from deep-water waves to shallow-water waves.
What triggers a wave traveling across the ocean to finally release its energy?
The wave begins to interact with the sea floor as it moves into shallower water.
What is an interference pattern?
The wave pattern produced when two or more waves interact.
Why do ocean waves bend around headlands?
The waves are moving more slowly just in front of the headland, causing the waves to bend.
Why do ships at sea tend not to notice tsunamis?
Tsunamis in deep water have small wave height and long wavelength.
How does water move as waves pass?
Water moves in a circle in the same direction as wave movement.
How does wave amplitude change with depth in water?
Wave amplitude decreases as depth increases.
Which of the following statements about wave period is most accurate?
Wave period is the inverse of wave frequency.
How does wave refraction at headlands affect deposition and erosion?
Wave refraction at the headland increases erosion at the headland and causes deposition in adjacent bays.
Which of the following statements is/are true regarding wave refraction?
Wave refraction is the bending of waves that occurs when waves approach the shore at an angle. Wave refraction explains why all waves come almost straight in toward a beach, no matter what their original angle was. Refraction occurs when the part of the wave in shallow water slows down and the part of the wave in deeper water moves at its original speed. Wave refraction causes sand to be deposited in bays, where wave energy is lower.
Of the following statements about ocean waves, which one(s) describe wave steepness? Choose all that apply.
Wave steepness is determined by dividing the wave height by the wavelength. Wave steepness cannot exceed a 1:7 ratio, or the wave will break.
What does the term "in phase" refer to?
Waves in phase have identical wavelengths and are aligned peak-to-peak and trough-to-trough
How are wave period and wavelength related?
Waves with shorter periods have shorter wavelengths.
When will perfect destructive interference occur?
When two waves that are 180 degrees out-of-phase interfere.
When will perfect constructive interference occur for waves that are in phase and moving at the same velocity?
When waves with identical wavelengths interfere.
Of the following bathymetric conditions, which one(s) would likely produce spilling breakers? Choose all that apply.
a gently sloping, sandy bottom a gently sloping, rocky bottom
What is a tsunami?
a series of water waves that travel away from a fault in all directions at high speed
Of the following waves, which one has the deepest wave base? Select only one answer.
a wave with a 2-meter wave height and a wavelength of 1000 meters
A tsunami watch is issued by the Pacific Tsunami Warning Center when _______________________
an earthquake with a magnitude greater than Mw = 6.5 occurs beneath the ocean
The first wave that forms when the wind begins to blow across the ocean surface is a:
capillary wave
As a wave approaches shore, its characteristics change by ____________________
decreasing speed, increasing steepness
What common office item is used in this video to demonstrate internal waves?
desktop ocean
Conditions for the development of wave energy are least optimal along ________ shores in the ________ Hemisphere
eastern; Northern
The height of a wave depends upon:
fetch, wind duration, and wind speed.
Which of the following best describes a plunging breaker?
forms on moderately sloped shorelines to create curling crests
Refraction causes headlands to be areas of ________ surfing and sites of ________.
good;erosion
In general the restoring force for wind-generated waves is:
gravity
As a wave begins to feel bottom near a shoreline, its wave height:
increases and its wavelength decreases
The movement of sea water at a pynocline creates ________ waves.
internal
________ waves also known as push-pull waves.
longitudinal
Which of the following is the least frequent cause of a tsunami in recent centuries?
meteorite impacts
What occurs more often, pure destructive, pure constructive, or mixed interference?
mixed interference
Ocean surface waves are:
orbital waves
Which type of breaker forms on moderately steep beach slopes?
plunging breaker
Waves that are breaking along the shore and are forming curling crests over air pockets are called:
plunging breakers
Submarines sometimes ride out heavy storms in deep water by submerging. That is a practical application of utilizing the ____________________.
principle of decreasing orbital motion with depth
A tsunami is considered to be a:
shallow water wave
Which type of breaker has a longer life span and give surfers a longer ride than other breakers?
spilling breaker
What disturbing force is responsible for most ocean waves that eventually break on shore?
storm-generated winds that blow across the surface
Which type of breaker forms when the ocean bottom has an abrupt slope?
surging breaker
Which type of breaker forms when the waves build up and break right at the shoreline?
surging breaker
What type of breaker would pose the most danger to people playing or swimming in the surf zone?
surging breakers
Waves that are moving faster than local wind and are sorted out by wavelength are called:
swell
What is refraction?
the bending of waves due to a change in velocity
What is the wavelength?
the distance between consecutive wave crests or troughs
What is the wave height?
the distance between the highest and lowest part of the wave
The fetch refers to:
the distance over which the wind blows without interruption
What is the crest of a wave?
the highest part of a wave
What is the wave base?
the lower limit of wave-induced motion in the water
What is the trough of a wave?
the lowest part of a wave
What causes the three different types of breakers?
the steepness of the beach slope
What is the wave period?
the time it takes for one wavelength of a wave to pass a particular point
How are tsunamis generated?
through displacement of the seafloor under water
Why does the wave height of a tsunami increase as the tsunami enters shallow water?
through displacement of the seafloor under water
Energy travels at right angles to the direction of the vibrating particles in ________ waves.
transverse
________ waves also known as side-to-side waves.
transverse
The uplift or downdropping of large areas of the sea floor creates ________ waves.
tsunami
Which of the following caused the anomalously large tsunami in Papua New Guinea in 1998?
underwater landslide
Which of the following caused the tsunami at Krakatau in 1883?
volcanic eruption
What determines the speed of shallow-water waves?
water depth
The depth below the surface where the circular orbits become so small that movement is negligible is called the ________.
wave base
Which one of the following variables is necessary to determine the speed of shallow-water waves? Select only one answer.
wave depth
The slight forward movement caused by the circular orbit of waves is called ________.
wave drift
The number of wave crests passing a fixed location per unit of time is called the ________.
wave frequency
The time it takes one full wave to pass a fixed position is called the ________.
wave period
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 ________.
wave reflection
Standing waves may be caused by:
wave reflection
Waves converge on headlands due to:
wave refraction
"Whitecaps" form when _____________________.
wave steepness reaches a ratio of 1:7
The circular motion of water molecules extends to a depth that is equal to:
wavelenght/2
The longer the ________, the faster a deep-water wave travels.
wavelength
The speed of a deep-water wave is proportional to:
wavelength
Wave speed of deep-water waves depends only on ________.
wavelength
What determines the speed of deep-water waves?
wavelength
Waves usually arrive nearly parallel to the shore because ____________________________.
waves are refracted toward shallow water
The largest wind-generated waves tend to be associated with the:
westerlies
Which of the following generates most ocean waves?
wind blowing across the surface
Most ocean waves form as a result of:
winds blowing across the ocean surface