Tsunamis can be generated when the sea floor hurriedly deforms and vertically displaces the overlying water. Tectonic earthquakes are a certain kind of earthquake that are associated with the earth’s crustal deformation; when these earthquakes occur beneath the sea, the water above the deformed area is relocated from its equilibrium position.

Waves are formed as the displaced water mass, which acts under the pressure of gravity, attempts to regain its equilibrium. When large areas of the ocean floor elevate or subside, a tsunami can be created. Huge vertical movements of the earth’s crust can occur at plate boundaries.

Plates act together along these boundaries called faults. Around the margins of the Pacific Ocean, for instance, denser oceanic plates slip under continental plates in a process known as subduction. Subduction earthquakes are mainly effective in generating tsunamis.