Wave description

From GeoClasses

Wave length, height and amplitude

Water waves tend to have peaked peaks and rounded troughs.

• Wavelength: The distance from peak to peak, or trough to trough on a wave.
• Wave height: The total height of the wave from trough to peak.
• Amplitude: Half of the wave height.

Wave motion

Oscilatory motion of water particles at surface of wave.

• The velocity at which a wave travels is its celerity.
• The waves move across the water but water particles, as well as bouys on the surface do not. These particles move in circles. This is why a ship can drop a bouy and expect it to remain in the same spot (except that it can be blown by the wind or moved by currents).

Wave base

• The circular motion of water particles near the surface does not extend very far down. At a depth of half the wavelength the motion is about 4% of the original motion. This depth is called the wave base.
• The small motion that occurs beneath wave base means that waves do not significantly erode below this depth, and that it is only when waves reach water shallower than the wave base do they become affected by the ocean floor.