As mentioned in the latter point, Earthquakes are a great cause of tsunamis. In order for an earthquake to originate a tsunami the ocean floors must be shifted vertically abruptly, so the ocean is driven off its normal balance. When this immense mass of water attempts to regain its balance, waves are generated. The size of the tsunami is determined by the magnitude of the vertical deformation of the oceanic floor. Not all earthquakes generate tsunamis, only those of considerable magnitude, that happen under the marine bed and are capable of deforming it.

While any ocean may experience a tsunami, they take place more often at the Pacific Ocean, whose origins are most commonly the setting of considerable earthquakes (especially the coasts of Chile, Peru and Japan.) Besides the type of fault between the South American and Nazca plates, called of subduction (a plate sliding under another), favor the ocean’s floor deformation and, thus, tsunamis.

Despite everything mentioned before, devastating tsunamis have been reported at the Atlantic and Indic Ocean, as well as the Mediterranean Sea. A great tsunami came along the earthquakes of Lisbon in 1755, Puerto Rico in 1918 and Canada in 1929.

Avalanches, volcanic eruptions and submarine explosions may cause tsunamis that are usually triggered quickly, without causing damage in their continental boundaries.

Regarding meteorites, there are no reliable records of their occurrence, but the expansive wave that they would cause when entering the ocean or impact at the marine floor in case they fall in a shallow area, are factors that could be the eventual cause of a tsunami, especially if the meteorite in question is quite large.