Final answer:
The movement of water in a breaking wave involves forward and turbulent motion as the wave's crest topples over near the shore, contrasting with the circular, up-and-down motion of water particles in an unbroken wave where energy moves through the water but the water itself remains mostly in place.
Step-by-step explanation:
The major difference in the movement of water in a breaking wave compared to the water movement in the same wave before it breaks lies in the motion of the water particles. In an unbroken wave, the water particles move primarily in a circular motion, with energy passing through the water causing a repeating pattern of crests and troughs. This motion is up and down, and the seagulls experience simple harmonic motion as a result. However, as the wave approaches shallow water near the shore, the energy is compressed due to shoaling, which increases the wave height and decreases its stability.
When a wave breaks, the water at the top of the wave moves forward and crashes down, rather than primarily moving in an up and down motion. This is caused by the crest of the wave moving faster than the base due to friction with the shallower sea bed, ultimately causing the wave to topple over.
In summary, before a wave breaks, the water particles exhibit a cyclic, up-and-down motion due to the wave's energy, maintaining their general position. As the wave breaks, the motion becomes more turbulent and forward-moving, indicating a transfer of energy that propels water forward and causes the characteristic breaking of waves near the shoreline.