Why Do Waves Break?
Waves break as they encounter shallow water because the “bottom” portion of the wave hits either the nearshore shelf or reef while the “top” portion of the wave continues to move forward and ultimately steepens and falls over. The condition for wave breaking is when a wave reaches the shore and enters water that is approximately 1.3 times as deep as the wave is high. At this depth the wave becomes unstable and crest is thrown forward into what we observe as white water and turbulence. The reason a wave breaks is that the wave becomes overly steep, particularly at the peak of its crest. This over steepening is due to the water particles in the wave crest exceeding the velocity of the wave form. In this situation the the crest surges ahead resulting in the breaking wave. Three “Types” of Breaking Waves • Spilling Breakers – Very flat nearly horizontal beach • Plunging Breakers – Steep beach • Surging Breakers – Very steep beach The Gulf of Mexico and specifically Texas barrier island bea
Waves in the deep parts of the sea move like ripples on the surface of the water. When they near land and enter shallow water, they slow down, because deep water always moves faster than shallow water. Waves also grow higher as they near a shore, for in effect the sea bottom is “rising” as the water gets shallower, pushing the c
Because when a wave hits shallow water, there is drag at the bottom of the wave from the reef or sand it passes over. This drag causes the lower part of the wave to move slower than the top part of the wave, and eventually, the top part of the wave overtakes the bottom part of the wave and causes the wave to break. A wave will break differently depending on the shape of the reef or sand bottom it passes over.
