Fiction

Tsunamis are giant walls of water.

Fact

Tsunamis do not necessarily make their final approach to land as a series of giant breaking waves. They more likely resemble a very rapidly rising tide with the cycle occurring in just 5 to 60 minutes instead of 12 hours with potentially much greater height. Occasionally, tsunamis can form walls of water (known as tsunami bores) but tsunamis normally have the appearance of a fast-rising and fast-receding flood.

Fiction

A tsunami is a single wave.

Fact

A tsunami is a series of waves. Often the initial wave is not the largest. In fact, the largest wave may not occur for several hours. There may also be more than one series of tsunami waves if a very large earthquake triggers local landslides, which in turn trigger additional tsunamis.

Fiction

Boats should move to the protection of a bay or harbor during a tsunami.

Fact

Tsunamis are often most destructive in bays and harbors, not just because of the waves but because of the violent currents they can generate in local waterways. Tsunamis are least destructive in deep, open ocean waters.

Fiction

A Tsunami Warning will alert me if a tsunami is on the way.

Facts

There will not always be enough time to issue a warning because a local tsunami can attack shorelines within minutes of an earthquake or underwater landslide.  Recognize natural warning signs for a tsunami, such as strong or unusually long earth shaking, and/or water receding from the shoreline, and if you feel and see them, move quickly inland and to higher ground.

Fiction

A tsunami is the same thing as a tidal wave.

Facts

Tsunamis are not tidal waves.  Tidal waves are regular ocean waves, and are caused by the tides. These waves are caused by the interaction of the pull of the moon’s gravity on the earth. A “tidal wave” is a term used in common folklore to mean the same thing as a tsunami, but is not the same thing.

Fiction

You can surf a tsunami wave.

Fact

We have already established a tsunami is a series of waves - not a single wave.
Furthermore, tsunami waves travel much faster than other waves (around 10-30 mph at the shore, in excess of 500 mph at the earthquake epicenter) and pulls a great deal of debris from the ocean bottom in addition to crushed homes, cars, and shipping containers from the land, which makes surfing a deadly game.

Fiction

Only earthquakes can trigger a tsunami.

Fact

A tsunami is a series of large waves generated by a sudden displacement of water on the ocean floor that can result from an earthquake, an underwater landslide, a volcanic eruption or - very rarely - a large meteorite strike.