325px|thumb|right|Wave base diagram.
The wave base, in physical oceanography, is the maximum depth at which a water wave's passage causes significant water motion. At water depths deeper than the wave base, bottom sediments and the seafloor are no longer stirred by the wave motion above.
Process
In seawater, the water particles are moved in a circular orbital motion when a wave passes. The radius of the circle of motion for any given water molecule decreases exponentially with increasing depth. The wave base, which is the depth of influence of a water wave, is about half the wavelength.
At depths greater than half the wavelength, the water motion is less than 4% of its value at the water surface and may be neglected.
For example, in a pool of water deep, a wave with a wavelength would be moving the water at the bottom. In the same pool, a wave with a wavelength of would not be able to cause water movement on the bottom.
Distinctions
There are typically two significant wave bases, the fair weather wave base (FWWB) and the storm wave base (SWB).)
See also
- — above fair weather wave base
- — below fair weather wave base