MathLapse - Wind Generated Waves
The wind forces the water into circular motion, yet it generates waves.
Ever wondered why a ball in the water is not easily pushed forward by the waves? It looks like the ball continuously moves forward-and-backward and up-and-down as the waves pass by it.
It is because the water in wind generated waves exibits a vertical circular motion perpendicular to the waves. Most of this motion happens at or near the water surface. Actually, the water stays almost at the same place, but the peaks of its motion are relayed in the form of waves. This explains why such waves do not push on shore very far - the water itself does not move forward.
Are all waves the same? Well, not. There are other types of waves, too. For example, the tsunami waves are quite different. Their wavelength may reach up to 100 kilometers and even small tsunami waves may have devastating impact on shores. These waves engage all the water, not just the surface layer, and the water itself moves forward.