They seem to have left me to finish off.
You could try to create your own Tsunami. In a tank of water drop a pebble and look at the small waves that are created. Then (in an area where water on the floor is not a problem), drop a brick into the tank and look at what that creates. This movement of water becomes larger when the wave reaches the shallow areas (beaches) of the surrounding area. It gets bigger, faster and more powerful. Look at the excellent video below.