What is a Tsunami?

A tsunami is a series of large waves caused by the sudden movement of a large amount of water, usually due to powerful natural events like earthquakes, volcanic eruptions, or landslides under or near the ocean.

How Does a Tsunami Form?

Underwater Earthquakes

This is the most common cause. When tectonic plates shift and one plate moves suddenly, it can push the sea floor up or down. This movement forces water to move too, creating waves.

Volcanic Eruptions

Explosions or collapses from volcanic activity can displace large amounts of water.

Landslides

If a large chunk of rock or earth suddenly falls into the ocean, it pushes water out of the way and creates waves.

Meteor Impacts

Rare, but a large meteor hitting the ocean could create a massive tsunami.

How Do Tsunamis Behave?

In deep water, a tsunami can travel as fast as a jet plane—up to 800 km/h (500 mph).

The wave is often less than a meter high in the open ocean, making it hard to detect.

As it approaches land, the wave slows down but grows much taller—sometimes over 10 meters or more.