Why do waves break toward the shore instead of away from it?
Think of the normal beach environment where the water depth goes from shallow to deep as you move away from the beach. As the wave moves into the shallow water, the bottom of the wave is slowed down from the intereaction with the bottom. This is why the waves get higher in the shallow beach areas. Out in the ocean the same amount of water is spread out over a greater area. The waves are longer and lower. When they come into shallower water, they are slowed and build up in height. As the wave moves into even yet shallower water the taller wave begins to lean forward until the top gets ahead of it’s base and it topples forward. This is the same procedure seen with the Tsurnami waves that devastated some coastal areas recently. The Tsunami waves are hard to observe and detect out at sea because they are very long in duration and not very high. You can’t even sense they are passing. But, when they get into shallower areas the waves grow to be huge.
