FORMATION
A tsunami, is, like volcanoes, a result of tectonics, or plate movement.
AS A RESULT OF EARTHQUAKES
Tsunamis can be generated when the sea floor abruptly deforms and vertically displaces the
overlying water. When earthquakes occur beneath the sea, the water above the area is
displaced from its equilibrium position. Waves are formed as the displaced water mass,
which acts with influence of gravity, attempts to regain its equilibrium. When large areas
of the sea floor elevate or subside, a tsunami can be created. Large vertical movements of
the earth's crust can occur at plate boundaries. Tsunamis usually form from earthquakes in
the subduction zones.
AS A RESULT OF OTHER TECTONIC PROCESSES
A tsunami can be generated by any disturbance that displaces a large water mass from its
equilibrium position. In the case of quake generated tsunamis, the water column is
disturbed by the uplift or subsidence of the sea floor. A violent volcanic eruption can
create an impulsive force that uplifts the water column and generates a tsunami. On the
other hand, supermarine landslides and cosmic-body impacts disturb the water from above,
as momentum from falling debris is transferred to the water into which the debris falls.
Generally speaking, tsunamis generated from these mechanisms, unlike the Pacific-wide
tsunamis caused by some earthquakes, dissipate quickly and rarely affect coastlines
distant from the source area.