1. a large sea wave, often a series of long and high waves, produced by violent undersea activity such as a seaquake, volcanic eruption or underwater landslide. Tsunamis can travel over hundreds of miles, moving about as fast as an airplane, and can create terrible devastation when they touch land, wiping across coastal areas in a matter of minutes.
2. an overwhelming amount of something, such as information, arriving all at once.
The term is relatively new, entering English only in 1896. From the Japanese kanji 津, tsu, meaning “harbor,” and 波, nami, meaning “wave.” The literal translation of the term as “harbor wave” shows that the emphasis has always been on the impact of the waves upon land and communities, not the waves themselves.
According to the National Oceanic and Atmospheric Administration, the islands of Japan have been hit by 367 tsunamis since the first record of a tidal disaster was made in the year 684.
“On the evening of June 15, 1896, the northeast coast of Hondo, the main island of Japan, was struck by a great earthquake wave (tsunami), which was more destructive of life and property than any earthquake convulsion of this century in that empire.”
—Eliza Ruhama Scidmore, “The Recent Earthquake Wave in Japan,” The National Geographic Magazine, September 1896
“With years of preparation for the Big One — a Cascadia Subduction Zone earthquake and tsunami — Seaside kids are well-versed in evacuation and shelter aspects of the plan. Students’ “You can’t stop this wave” campaign helped raise tsunami awareness throughout the community and spurred passage of the 2015 bond for a new campus in the Southeast Hills out of the inundation zone.”
— R.J. Marx, “Southern Exposure: A too-timely presentation on school safety,” The Daily Astorian, May 28, 2018