Progressive waves are waves that move forward across the surface. Slide 5 of 25 Progressive waves are waves that move forward across the surface. As waves pass, wave form and wave energy move rapidly forward, not the water.
Water molecules move in an orbital motion as the wave passes.
Diameter of orbit increases with increasing wave size and decreases with decreasing water depth. Wave base is the depth to which a wave can move water. If the water is deeper than wave base, orbits are circular and there is no interaction between the bottom and the wave, but if the water is shallower than wave base, orbits are elliptical and become increasingly flattened towards the bottom.