Thursday, April 1, 2010
The moving orbs of energy beneath the waves
Above is a crude illustration showing how waves are "powered". Far out at sea, wind and tides acting upon the water causes orbs of stored energy to roll beneath its surface. These orbs move below the surface of the water and are elliptically shaped. As they roll forward, the water passes over them like a slippery skin. The orbs don't really carry the water forward but move smoothly beneath it, lifting it as they pass beneath the surface. A toy boat thrown onto the surface of the water will be lifted and then pass over the back of the wave rather than being moved decidedly forward by it.The same happens with the smaller wavelets (called secondarys ) on their surface, which are lifted with the skin of water and then ride up and then over the backs of the waves. In between the rolling orbs are the troughs of the waves.
These orbs lean forward at the top as they move. As these orbs of energy near land and their bottoms touch the sea floor, they lean evermore forward and rise higher in the water. As their bottoms are slowed by the contact with the sea floor their leading edge becomes even further ahead of their bottoms and the water on their backs rushes over their tops as a breaker. More on that next.
Waves out on the open ocean don't break like they do at the shore, but carry the foam on their tops and often pass under it, and leave their crests of foam behind, trailing it down their backs. Out on the open ocean they are often called rollers. Rollers become breakers at the shore in shallow water.