Noun

1. A large and sudden rise and fall in the tide.
2. A large, sudden, and disastrous wave of water caused by a tremendous disturbance in the ocean; a tsunami. (See Usage notes below.)
   • The last tidal wave here killed twenty and left thousands homeless.
3. A sudden and powerful surge.
   • 2003, Michael Moore, Dude, Where’s My Country, chapter 3
     • But this is no stream, folks. This will be a tidal wave that can swamp our democracy.
   • As the doors opened, a tidal wave of people flooded into the room.
   • I was overcome by a tidal wave of emotions.
4. A crest of ocean water; a wave.
5. A crest of ocean water resulting from tidal forces.

Usage notes

• For some time now, it has been common to correct the use of tidal wave that refers to a disastrous wave caused by a disturbance in the ocean, with the term tsunami suggested in its stead. In scientific publications, tsunami has become the standard term for this phenomenon, though in the mass media and elsewhere, they are used interchangeably and frequently, tsunami seeing more usage on the whole.

• The sense of tidal wave that is synonymous with tsunami has long been in the English language, and relates to the uncommon sense of tidal that refers to any rise and fall in the water level of any large body of water, and not just the daily rising and falling caused by the moon (see storm tide, hurricane tide, and tidal flood). While there is nothing that is strictly speaking ‘incorrect’ with regard to this usage of tidal wave, many people believe that the term should simply not be linked with the term tide at all, to avoid the possibility of any confusion as to the cause of a tidal wave.

• Tsunami was at one point strongly associated with scientific use, and many people would have considered it pedantic in ordinary conversation, but its prevalence in mass media and popular media has most likely reduced or eliminated this association. Currently it is a (mostly) non-contentious term that can be used in place of the more contentious and oft-corrected tidal wave.

Quotations

See also Tidal wave on sister project wikiquote

• The Atlantic tidal wave arrives after approximately a day in the English Channel area of the European coast and needs another day to go around the British islands in order to be effective in the North Sea.

  - 2003: Tide - Wikipedia, the free encyclopedia. Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Tide#Types_of_tides (accessed 2 January, 2005)

• A tidal wave is a crest of water that moves around the earth with the tide.

  - 2002?: Tides. Sir Francis Drake High School. http://drake.marin.k12.ca.us/stuwork/rockwater/wavetide/tides.html (accessed 2 January, 2005)

• Currents on this coast are greatly affected by the prevailing winds, and a tidal wave higher than that ordinarily produced by the moon is sent up the whole shore of Uruguay before a southwest gale, or lowered by a northeaster, as may happen. One of these waves having just receded before the northeast wind which brought [Slocum's sloop] the Spray in left the tide now at low ebb, with oyster-rocks laid bare for some distance along the shore.

  - 1899: Joshua Slocum, Sailing Alone around the World. Internet: Project Gutenberg, 2004

• A Belfast couple who were caught up in a huge tidal wave in Thailand have said they are lucky to be alive.

  - 2004: NI couple caught in tidal wave. BBC NEWS. http://news.bbc.co.uk/1/hi/northern_ireland/4125863.stm (accessed 3 January, 2005)

• But governments insisted they did not know the true nature of the threat because there was no international system in place to track tidal waves in the Indian Ocean — an area where they are rare — and they can’t afford to buy sophisticated equipment to build one.

  - 2004: Scientists fault warning efforts on tidal waves. MSNBC (From a special report: Asia's Deadly Tsunami). http://www.msnbc.msn.com/id/6756409/ (accessed 3 January, 2005)

• Tsunamis are tidal waves formed by underwater earthquakes or, much less frequently, by volcanic eruptions - meteor impacts - or underwater landslides. They that can exceed 400 miles per hours in the deep ocean.

  - 2002?: Tsunamis - Tidal Waves - Flooding. Ellie Crystal's Metaphysical and Science Website. http://www.crystalinks.com/tsunami.html (accessed 3 January, 2005)

• They leapt into the air and clutched the brass pole as if it were the last vantage point above a tidal wave passing below, and then the brass pole, to their dismay, slid them down into darkness, into the blast and cough and suction of the gaseous dragon roaring to life!

  - 1953: Ray Bradbury, Fahrenheit 451.

• [A] severe earthquake was felt ... a second severe quake was felt ... a terrible roaring sound was heard followed almost immediately by a very heavy blow against the side of the building, and about 3 inches of water appeared ... broadcast a priority message stating that we had been struck by a tidal wave and might have to abandon the station ...

  - 1946: Memorandum kept by Chief Radio Electrician Hoban B. Sanford, U.S. Coast Guard. SEMper PARatus PACarea. http://www.semparpac.org/ScotchCap.pdf (accessed 7 January, 2005)

• The popular inclinations resemble a tidal wave; if the current once commences in your favour, it will go on of its own force to the end.

  - 1877: William Carew Hazilitt in Essays of Michel de Montaigne, by Charles Cotton, edited by William Carew Hazilitt, Letter XIV. Internet: Project Gutenberg, 2004

• The railroad became clogged with freight, a tidal wave of men broke over the town.

  - 1922: Rex Ellingwood Beach, Flowing Gold. Internet: Project Gutenberg, 2004.

Summary of BNC search results

The British National Corpus contains 87 usages of tidal wave. Of a random sample of 50:

• none used the term in the strict oceanographic sense
• eight referred to the literal sense of a surge in the tide (see below)
• a few referred to floods or in one case "a tidal wave of powder snow"
• a few were fragments (tidal wave alone or tidal wave disaster)
• two asserted that tidal wave and tsunami are synonymous
• one may have used the oceanographic sense figuratively (!): But will John Major and the Government go down with the sun-Saturn boat or be swept away by the sun-Pluto tidal wave on the 14th? (from Today. London: News Group Newspapers Ltd, 1992 BNC reference CEK)
• the rest (dozens) were various figurative senses (a tidal wave of crime; swept over her like a tidal wave etc.)

Here are a few of the "surge in the tide" examples. These imply specifically that a tidal wave can be driven by the wind:

• The Vets were not evacuated when the hurricane struck and Hemingway reports on the wind and the tidal wave that killed hundreds of them. (BNC reference CG3: Creative writing. A practical guide. Casterton, Julia. Basingstoke: Macmillan Publishers Ltd, 1992)
• A cyclone and tidal wave in Bangladesh leave 10,000 dead. (BNC Reference HH3: New Internationalist. u.p., n.d)

These mention seismic or volcanic causes:

• This tidal wave is a product of the combined efforts of the jostling of the crustal plates and the behaviour of the deep Ocean through which the resulting shock waves are transmitted: a small nudge in southern Chile can set up a wave that streaks across the entire Pacific in a matter of hours, with unimaginably enormous force. (BNC reference CJD: The Pacific. Winchester, Simon. London: Arrow Books Ltd, 1992)
• The dying ripples of its massive tidal wave lapped up the English Channel, and the volcanic debris, wreathing the planet, altered weather and harvest patterns around the world for years afterwards. (BNC reference FNP: Ring of fire. Blair, Lorne. London: Bantam (Corgi), 1988)

These don't mention a cause specifically (though the rest of the account may provide context):

• We could just see the hazy point where, in that August of 1883, the Dutch administrator of south Sumatra and his family had observed the tidal wave rise inexorably 150 feet right up to the veranda of his residence, pause, and withdraw again, taking some of his flowerpots, half the hillside, and the entire town with its population of some 800 people. (BNC reference FNP: Ring of fire. Blair, Lorne. London: Bantam (Corgi), 1988)
• Just over half an hour later, the tidal wave swept up to the Over bridge on the outskirts of Gloucester. (BNC reference K1E: [Central News autocue data.] u.p., n.d.)
• The 6ft tidal wave flipped the dinghy over and threw the two families into the icy water. (BNC reference K1F: [Central News autocue data.] u.p., n.d)

This one distinguishes a tidal wave from a wind-driven innundation, but doesn't say what a tidal wave might be:

• Perhaps because of the coral reefs, as now, there had been no tidal wave but the force of the wind had driven the sea inland, thirty feet deep in Belpan City. (BNC reference AMU: Alistair MacLean's golden girl. Gandolfi, Simon. London: Chapmans Publishers Ltd, 1992)

Additional citations