Here's a breakdown:
* Circular Motion: In deep water, particles move in nearly perfect circles. As the wave passes, the particles rise and fall, rotating clockwise (or counterclockwise depending on the wave direction).
* Elliptical Motion: In shallower water, the circular motion becomes more elliptical. The diameter of the circle in the vertical direction (up and down) remains the same, but the diameter in the horizontal direction decreases as the water becomes shallower. This is because the wave encounters the seabed and its movement is restricted.
Key points:
* The particles themselves don't travel with the wave. They move up and down and back and forth, but they return to their original position after the wave passes.
* The energy of the wave is what travels, not the particles themselves.
* The size of the circles or ellipses decreases as the depth of the water decreases.
Visualizing it:
Imagine a buoy floating on the water surface. As a wave passes, the buoy bobs up and down, moving in a circular or elliptical path. It doesn't move forward with the wave, it just moves in place.
This is why surfers ride waves, not the water itself. The wave provides the energy to propel the surfboard forward, but the surfer is actually riding on the surface of the water, not within the wave itself.
