Waves
Waves are generated by wind blowing over the surface of the ocean. Also generated by earthquakes, volcanic eruptions and landslides.
Wave height: 3 factors affecting it:
- wind speed
- wind stability - winds blowing steadily from the same direction produce bigger waves than variable winds
- Fetch: distanced of open water over which the wind blows to create the winds
Largest waves ever recorded were almost 30m high, and are observed in the Pacific.
Storm waves tend to be choppy and irregular. As the waves move out from the storm, the choppiness is replaced by regular swell.
Wave terminology:
Crest, trough, wavelength and wave period need to be known.
Wave form moves forward, but it is energy that is actually transmitted rather than the water, which moves in circular orbits.
Waves have a finite extent - the circulation dies down eventually - submarines don't feel the disturbances on the surface.
Waves break once the depth of the water drops below half the wavelength.