What is a Tsunami?

A tsunami is an extremely large and tall sea wave. Tsunamis can be extremely dangerous and can wash away houses or other buildings on the coastline.

How are Tsunamis Formed?

Tsunamis can be formed by any disturbance in or under the water, such as an earthquake, landslide, meteorite, or a volcanic eruption.

If an earthquake happens underwater, a tsunami might form. The vibrations of the earthquake can create large waves that could eventually turn into tsunamis. Earthquake-generated tsunamis are most common and most destructive. Earthquakes underwater can even cause undersea landslides, which also cause tsunamis.

Tsunamis can also be formed by undersea landslides. When the landslide occurs, the vibrations and motions caused by the landslides could cause a tsunami to occur. The energy in a landslide gets transferred to the water, forming large waves. These waves grow larger and larger until hitting a shore.

Volcanic eruptions can cause tsunamis. Although they do not happen as often as earthquake-generated tsunamis, volcanic tsunamis can still be deadly when the occur. When volcanoes happen, much debris is blown off by the impact of the magma. When the debris hits the water with lava flowing into the water afterward, the disturbance can cause tsunamis. Tsunamis can also be caused if underwater volcanoes explode. The pressure of the underwater volcano can create huge waves that turn into tsunamis.

Meteorites can land in the ocean and create tsunamis.  When a meteorite crashes into the ocean, it takes up space where water used to be. The energy in the moving meteorite gets transferred into the water. This water is forced outward as waves. The waves gradually turn into tsunamis.

How are Tsunamis Measured?

Tsunamis are measured by their wavelength, velocity, and height. The wavelength of a tsunami is how long the wave will be. The velocity is the speed of which the wave is travelling. The height of the wave is how tall it is. Tsunamographs are used to measure tsunamis. Tsunamographs lie underwater, recording changes or disturbances in water pressure.