Final answer:
When ocean waves approach the shore, their velocity decreases while their frequency remains constant, resulting in a shorter wavelength. This effect, known as shoaling, leads to higher waves as energy is compressed in shallower water. Unlike with light or sound, the frequency of ocean waves does not change as they slow down because the rate of wave crest arrival at a point remains the same.
Step-by-step explanation:
As ocean waves approach the shore, their velocity decreases due to interaction with the shallower sea floor. This effect is analogous to what happens when light waves travel from air into water, demonstrating a wave principle that the speed of a wave is equal to its frequency times its wavelength. In the case of ocean waves, as they enter shallower water, their velocity decreases, resulting in a decrease in wavelength yet the frequency of the wave generally remains the same because the wave crests do not reach the shore more quickly. This is because the energy of the wave has to be conserved, and as the depth of the water decreases, the energy is compressed into a smaller volume, leading to shoaling where waves become higher.
Due to this conservation of energy, it is essential to clarify that while the wavelength shortens, the frequency of the wave does not increase; it remains constant because the wave crest frequency—how often the wave crests pass a fixed point—does not change. This is a common misconception because in other contexts, such as with sound or light waves, a decrease in wavelength leads to an increase in frequency due to a constant speed (as in the case with light waves in a vacuum).