Ocean Waves
Feb 23, 2016
Ocean Waves
Anatomy of a WaveA wave is the motion of a form
that carries energy from one place to anotherThe form is what moves, the
material that the wave moves through does not move much.
The wave form is characterized by: Amplitude, measured from
midline Wavelength, measured between
identical points of motion Frequency, a count of how many
wavelengths pass a fixed point in 1 second
Anatomy of a WaveThe speed of most waves is
determined by the material that the wave is moving through.
The speed is calculated using:
Wherev is velocity, in m/sf is frequency, in Hzλ is wavelength, in m
Anatomy of a WaveOcean waves are generated when wind flows
over waterThe wind drags across the water, starting the
formation of a waveIf the wind is fairly continuous, then the wave built
will be largerA group of large wave is called a Swell
Wave SizeFactors that affect the size of a
wave:Wind speed
Faster wind kicks up larger wavesDuration of wind
Long duration, stead winds create larger waves
Fetch Distance available for the wind to
work over Large fetches produce large
waves
Waves and the ShoreAs waves reach
shallower water they begin to break upBottom of wave
scrapes along seafloor, and slows down
Top continues to move forward quickly, and begins to curl over
Once top is too far ahead, the wave breaks
Waves and the ShoreAfter the wave breaks,
the water is drawn back away from shore by undertow currents
If the waves are large enough, the undertow currents can develop into rip currentsVery strong undertows
that pull water directly back into the sea
Strong enough to break through incoming waves
Waves and the ShoreAs waves approach the shore,
they nearly always bend to head straight into shore
This bending causes water beneath the waves to flow parallel to the shoreline. This can create longshore currentsLongshore currents help to
straighten out shorelines, develop sandbars, and barrier islands