What effect does slowing down in speed have on the height of tsunami waves close to shore?
To expand a little: Ordinary ocean waves are movements only of the top layers of water, and if you were diving a few meters below the surface, you would not feel the effects of even rather strong waves. Tsunamis, however, involve the movement of truly huge amounts of water amounting to the entire “column” of water from the ocean floor to the surface. This is another way to see why the above explanation increases tsunami height. We’re not talking about bigger and bigger “surfing” waves, but a huge volume of water crowding up on itself as it moves over the rising ocean floor.
