The most common cause of tsunamis is from undersea earthquakes on the ocean floor. Submarine landslides and volcanic eruptions also cause tsunamis. On very rare occasions, a meteorite impact in the ocean results in a tsunami. Any event that displaces a significant amount of water in a short period of time can cause a tsunami.
Not all undersea earthquakes cause tsunamis. The quake must cause part of the crust to lift up like a gigantic paddle, displacing a large volume of water. If the quake happens deep in the crust or the crust is not displaced significantly, then a tsunami is not likely to occur. Strong, shallow quakes produce more tsunamis. Tsunamis are difficult to detect on the open ocean since the wave does not rise very far above the ocean's surface. As the tsunami approaches shallower water, the water piles up and causes a much taller wave.
Volcanic eruptions also cause tsunamis, such as the waves produced when the Indonesian volcano Krakatoa erupted in 1883. Superheated gas and rock from the volcano flowed into the sea, which displaced a huge volume of water and caused tsunamis. These waves were felt as far away as South Africa. Many villages were destroyed by these waves, and more than 36,000 people died.Learn More
A tsunami begins above an undersea earthquake, landslide or volcanic eruption along the ocean floor, explains Lisa Gardiner of the National Earth Science Teachers Association. In the case of an earthquake, when the movement along a fault moves the seafloor upward, water also pushes upward and becomes a tsunami wave.Full Answer >
Tsunamis happen when earthquakes, landslides or volcanic eruptions disturb the ocean floor. Most tsunamis occur when there are earthquakes at tectonic plate boundaries. When the ocean floor at the boundary rises or falls, it moves the water above and creates the huge waves that become tsunamis.Full Answer >
Tsunamis do not get names like hurricanes and typhoons, but some of the most famous and devastating tsunamis include the Indonesian tsunami on December 26, 2004, the tsunami that hit Japan on March 11, 2011, and a tsunami that hit Portugal on November 1, 1755. Tsunamis show how powerless the general population is at the hands of mother nature.Full Answer >
According to National Geographic, tsunamis can be caused by underwater landslides or volcanic eruptions, and are generated from the epicenter of the shift. The movement of tectonic plates causes water displacement, which creates a rolling wave that can travel over water at up to 500 miles per hour.Full Answer >