Why is it incorrect to call tsunami a tidal wave?

Answer 1

A tsunami is often incorrectly called a tidal wave or a storm surge. They can also be incorrectly called a rogue wave. Rogue waves are single waves that are very large, tsunami involve multiple large waves.

The word tsunami is a Japanese term. Japan is one of the most common locations for tsunami. The literal translation in English is "wave harbor" meaning "harbor wave". This name came from the fact that they only become visible as huge waves after arriving in shallower waters near shores and harbors, and therefore, they were originally believed to have originated in the harbor. The word tsunami has been used long enough that it has been adopted into most languages rather than being translated.

The Japanese word does not have a plural form and tsunami is used both for singular and plural in English in many locations. However, it has become accepted over time to say "tsunamis" for the plural in English.

Many early geological, geographical, and oceanographic texts refer to tsunami as "seismic sea waves."

They are sometimes mistakenly called "tidal waves," but tsunami have no relationship to the tides other than looking similar but smaller and generating some similar effects on land with flooding and devastation.

Tsunami are also sometimes incorrectly called "storm surges", which are also different wave phenomena. Tsunami have no relationship to weather. They are not caused by storms, cyclones, hurricanes, or high winds.

Answer 2

At one time the phenomena we now call tsunamis were called tidal waves. However, that tended to cause confusion because in some places a high wave accompanies the change of tide. The size of that wave is known and is predictable. Thus, if an announcement is made that a tidal wave is approaching, a person might expect a 3 meter wave (a 10 foot tall wave). If on the other hand, an announcement is made that a tsunami is approaching, a person might expect a 10 meter high wave (a 33 foot tall wave). Places that have both high tides and tsunamis need to distinguish between the two.