Chapter 9: Waves and Water Dynamics Study Guide
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The largest wind-generated waves tend to be associated with the westerlies.
The highest portion of a wave is called the wave crest.
The lowest part of the wave is called the wave trough.
The vertical distance between the crest and the trough is called the wave height.
The horizontal distance between two successive crests or two successive troughs is called the wavelength.
The ratio of wave height to wavelength is called the wave steepness.
The time between two successive waves is called the period.
Water waves are orbital waves.
Wave speed is equal to wavelength divided by period.
Storm surges are generated by intense low pressure systems.
The circular motion of water molecules extends to a depth that is equal to wavelength/2.
The diameter of a wave orbital at the surface is equal to wave height.
A deep water wave occurs when the water depth is equal to 1/2 of wavelength.
All of the following are shallow water waves near shore wind generated waves, surf, tides, and tsunamis.
The speed of a shallow water wave is proportional to water depth.
The speed of a deep water wave is proportional to wave period.
The height of a wave depends upon fetch, duration, and wind speed.
The fetch refers to the distance over which wind blows without interruption.
An internal wave might form at a density boundary within the ocean.
As a wave begins to feel bottom near a shoreline, its wave height increases and wavelength decreases.
Constructive interference results in larger waves while destructive interference produces smaller waves.
A wave will break when water depth = wavelength/20.
Waves that are moving faster than local wind and are sorted out by wavelength are called swells.
Waves that are breaking along the shore and are forming a curling crest over an air pocket are called plunging
breakers.
If a surfer wishes to have a really long ride, they should look for spilling breakers.
Waves converge on headlands due to wave refraction.
The following represents the typical order of formation of waves from earliest to latest: sea, swell, surf
Rogue waves tend to occur where storm waves moves against strong surface currents.
Standing waves may be caused by wave reflection.
A tsunami may result from tectonic activity on the seafloor.
A tsunami is considered to be a shallow water wave.
Tides are examples of forced waves.
The orbital motion of water molecules in a wave goes down to a depth equal to the wavelength divided by two.
A wave train is caused by wave energy moving more slowly than individual waves.
Swells are examples of free waves.
Wave energy is focused on headlands due to wave refraction.
A standing wave is caused by wave reflection.
Know Figure 9-3, p.267; Figure 9-9, p.273; Figure 9-14, p.277; and Figure 9-17, p.281
Essays: You are to pick two. The answers must be typed. Three Paragraphs for each (beginning, middle, end).
1. Describe the formation of water waves from a still ocean surface.
2. Compare and contrast wind-generated waves and internal waves. Include in your answer a discussion of the forces
that generate each wave type and the properties of each wave type (size, period, wavelength, etc.).
3. Describe the relationship between the following: wave height, wavelength, wave speed, and wave steepness.
4. The R/V Spartina is cruising off the Georgia coast taking water and sediment samples when she encounters a
storm. The ship's captain asks you to assist him by calculating the frequency of the waves and the wavelength.
The wave speed is measured at 4 meters per minute. The wave period is determined to be 12 seconds. What is the
wavelength of the storm swells encountered by the R/V Spartina?
5. Compare and contrast shallow and deep water waves.