Tsunami

Tsunami is occur when a major fault under the ocean floor suddenly slips. The displaced rock pushes water above it like a giant paddle, producing power water at the ocean surface. The ocean waves spread out from the vicinity of the earthquake source and move across the ocean until they reach the continental shelf, the part of the Earth’s crust that slopes, on rises, from the ocean floor up to the land.
Tsunami wash a shore with often disastrous effects such as severe flooding, loss of lives due to drowning, and damage to property.
A tsunami is very large sea wave that is generated by a disturbance along the ocean floor. This disturbance can be an earthquake, a landslide, or a volcanic eruption. A tsunami as undetectable far out in the ocean, but once it reaches shallow water, this far- traveling wave grows very large.