Earthquakes that generate tsunamis most often happen where Earth\’s tectonic plates converge, and the heavier plate dips beneath the lighter one. Part of the seafloor snaps upward as the tension is released. The entire column of seawater is pushed toward the surface, creating an enormous bulge. As the water flattens out, giant ripples race outward. Landslides, Volcanic Eruptions, Meteorites
Submarine landslides, which often occur during a large earthquake, can create a tsunami. During a submarine landslide, the equilibrium sea level is altered by sediment moving along the sea floor.
Gravitational forces then propagate the tsunami given the initial perturbation of the sea level. Similarly, a violent marine volcanic eruption can create an impulsive force that displaces the water column and generates a tsunami. Above water landslides and space borne objects can disturb the water from above the surface. The falling debris displaces the water from its equilibrium position and produces a tsunami.
Unlike ocean-wide tsunamis caused by some earthquakes, tsunamis generated by non-seismic mechanisms usually dissipate quickly and rarely affect coastlines far from the source area. Come and visit the Pacific Tsunami Museum to learn more about the science of tsunamis! [ On May 22, 1960 a magnitude 9. 5 Mw earthquake, the largest earthquake ever instrumentally recorded, occurred in southern Chile. The series of earthquakes that followed ravaged southern Chile and ruptured over a period of days a 1,000 km section of the fault.
The number of fatalities associated with both the earthquake and tsunami has been estimated to be between 490 and 5,700. Reportedly there were 3,000 injured and intitially there were 717 missing in Chile. The main shock generated a tsunami that was not only destructive along the coast of Chile, but also caused numerous casualties and property damage in Hawaii and Japan, and was noticeable along shorelines throughout the Pacific Ocean area. NOAA image.