How does that darn ocean keep these waves commin':
( A shout out to all ya surfers who've been keepin 'it real)
Sitting in the ocean on our boards, waiting for the next set, we don't usually think at these types of moments where that swell came from, instead we're too busy kicking our boards around and paddeling like crazy until the wave sucks us back and we dance with the continuous power of the ocean. Even though many lovers of the ocean don't care about where the waves we ride on come from, it is still an interesting aspect to know. _---(Malia Jones)
Its time to get stricktly scientific. Ocean waves, those crescent shape forms we pray for every day to roll on in, are created by disturbing forces. Wind blowing across the ocean surface provides the "disturbing force" for wind waves. The arrival of a storm surge or seismic sea wave in an enclosed harbor or bay or a sudden change in atmospheric pressure may be the disturbing force for a resonant rocking of water known as a seiche. Landslides, volcanic eruptions, or faulting of the seafloor associated with earthquakes are the disturbing forces for seismic sea waves, also known as tsunamis. The disturbing forces for tides are changes in the direction of gravitational forces amoung the Earth, moon, and sun combined with the Earth's rotation.
There is only one of these four waves, wind wave, seiche, seismic sea wave, and tides, which can occur in deep water and that is the wind waves. When a wind wave eventually finds their way to the shore, it begins the transition process of changing from a deep-water wave to an intermediate-depth water wave. Below is an outline of the events leading to the break of the wind wave:
1. The wave train, or a progressing group of swell with the same origin and wavelength, moves toward shore. When the water is less than half the wavelength in depth, the wave "feels" bottom.
2. The circular motion of water molecules in the wave is interrupted. Circles near the bottom flatten to ellipses. The wave's energy must now be packed into less water depth, so the wave crests become peaked rather than rounded.
3. Friction with the bottom slows the wave. Waves behind it continue toward shore at the original rate. Wavelength therefore decreases, but period remains unchanged.
4. The wave becomes too high for its wavelength.
5. As the water becomes even shallower, the part of the wave below average sea level slows because of friction with the bottom. When the wave was in deep water, molecules at the top of the crest were supported by the molecules ahead ( thus transferring energy forward). This is now impossible because the water is moving faster than the wave. As the crest moves ahead of its supporting base, the wave breaks. The break occurs at about a 3:4 ratio of wave height to water depth. (That is a 3-meter wave will break in 4 meters of water.) The turbulent mass of agitated water rushing shoreward during and after the break is known as surf (Right on bro). The surf zone is the region between the breaking waves and the shore ( I think I know where that is !).
Here are some extra terms that might come in handy in your daily conversations:
Deep-water waves are waves moving through water deeper than one-half their wavelength.
Shallow-water waves are waves in water shalower than 1/20 their original wave-length.
Intermediate-depth water waves, or transitional waves, travel through water deeper than 1/20 their original wavelength, but shallower than one-half their original wavelength.
(These three different types of waves refer to the changing of wave form when approaching shore in the 5 steps above.)
Wind waves are gravity waves formed by the transfer of wind energy into water.
Swell is mature wind waves of one wave-length that form orderly undulations of the ocean surface. (We like a good one of those)
Wave trains are progressing groups of swell with the same origin and wavelength. (Those aren't bad either)
There are three factors (extremely important) affecting wind wave development out there:
Wind strength is the mean speed of the wind.
Wind duration is the length of time the wind blows.
Fetch is the uninterrupted distance over which the wind blows without significant change in direction.
Three different ways waves break against the shore, depending in part on the slope of the bottom:
Plunging waves (or better known to us as barrels common to breaking beaches such as Pipline), form when waves approach a steeply sloping bottom. - - - example of: grom in a barreling wave
Spilling waves ( your regular run of the mill type of wave), a milder wave which is generated when there is a more gradual sloping bottom.
Surging waves ( or bammer white wash), occur when an abrupt beach slope prevents a proper break and water simply rushes ashore.
Wave refraction is the slowing and bending of waves in shallow water.
Wave diffraction is the bending of a wave around an obstacle.
Wave reflection is the rflection of progressive waves by a vertical barrier. Reflection occurs with little loss of energy. - - - - - - - - - - - - - - - - - - - - - - - - -getting some air with high style points
I must finish with giving a shout out to Don Alexander, (who keeps ripping it everyday and still has time to inspire us wannabe oceanographers), without him, this stylin page would not be in existence for all ya kind souls.
Thankx, talk to ya later . . . .