The waves are greatly exaggerated compared to water depth. The rock holds this new shape. The rock movement pushes and pulls a column of water from the floor to the surface of the sea. See Figure 1. The buckled floor has moved an entire column of water into a trough-first waveform.
Waves emanate from the disturbance just as they do when a rock hits a lake.
The local tsunami travels trough-first. They travel in widening circles across the oceans of Earth for thousands of miles nearly as fast as a jet airliner. When the waves hit the shore, they hit hard with almost all of their initial energy. The wave pattern changes upon reaching shallow waters near the shore. As a result of this jumbling, a crest of a local tsunami may occasionally reach land before the trough.