A tsunami (from Japanese: 津波, "harbour wave"; English pronunciation: /tsuːˈnɑːmi/) , also known as a seismic sea wave, is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions (including detonations of underwater nuclear devices), landslides, glacier calvings, meteorite impacts and other disturbances above or below water all have the potential to generate a tsunami. Unlike normal ocean waves which are generated by wind, or tides which are generated by the gravitational pull of the Moon and Sun, a tsunami is generated by the displacement of water.
Tsunami waves do not resemble normal undersea currents or sea waves, because their wavelength is far longer. Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising tide, and for this reason they are often referred to as tidal waves, although this usage is not favoured by the scientific community because tsunamis are not tidal in nature. Tsunamis generally consist of a series of waves with periods ranging from minutes to hours, arriving in a so-called "internal wave train". Wave heights of tens of metres can be generated by large events. Although the impact of tsunamis is limited to coastal areas, their destructive power can be enormous and they can affect entire ocean basins; the 2004 Indian Ocean tsunami was among the deadliest natural disasters in human history with at least 230,000 people killed or missing in 14 countries bordering the Indian Ocean.
Greek historian Thucydides suggested in his late-5th century BC History of the Peloponnesian War, that tsunamis were related to submarine earthquakes, but the understanding of a tsunami's nature remained slim until the 20th century and much remains unknown. Major areas of current research include trying to determine why some large earthquakes do not generate tsunamis while other smaller ones do; trying to accurately forecast the passage of tsunamis across the oceans; and also to forecast how tsunami waves interact with specific shorelines.

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  1. ATCclears

    Tsunami warning issued for morning of Jan 15, 2022

    https://www.tsunami.gov/ https://www.tsunami.gov/events/PAAQ/2022/01/15/r5qho6/2/WEAK51/WEAK51.txt
  2. ATCclears

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  3. Oathkeeper1775

    Solar Minimum; ice tsunami

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  4. H

    Possibility Or Odds Of Hawiian Mega Tsunami? ...

    Had a bad physical week with recurring nightmares. What are the odds or possibility of a major Hawaiian earthquake shaking loose a huge part of the big island? Particularity the whole coast North of Hilo with the resulting mega tsunami hitting the Pacific Northwest Coast with 100+ meter high...
  5. P7M13

    Tsunami flooding maps from NOAA

    My wife is terrified of "the big one", hence she is regularly searching for more info. She came across this today, thought I'd put it up. At the link, you can download the PDF maps in a zip file. Enjoy, keep your head above water, don't piss on any high tension lines! Of course, they had to use...
  6. CountryGent

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    Well, it is about 4:00 AM in the morning and I just got woke up by the NOAA weather alert radio going off. It looks like there is a tsunami alert due to an earthquake off the coast of Alaska. The BBC has details here. :eek:
  7. CountryGent

    The Next Megaquake (BBC Documentary)

    The BBC put out a documentary on the history of, and potential future event, of a megaquake in the Pacific Northwest. I watched it the other day and the science was pretty interesting, so I am passing it along. Cheers.
  8. IronMonster

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    Upgraded to 7.7! Tsunami alert as powerful quake hits off Russia’s Kamchatka If you are on the coast watch the news, Who knows what this might turn into but best be ready if you are close to the water!
  9. CountryGent

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    The following documentary was produced by National Geographic. It features material related to the 2004 Tsunami in Indonesia. The film also covers a potential tsunami along the Pacific Northwest and has footage on research done in the Cannon Beach and Seaside area. Anyway, I just thought I'd...
  10. CountryGent

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    Considering this is likely the most destructive natural disaster that could impact our region, I thought starting a thread in which we can discuss the eventuality, compare notes, ponder scenarios, and consider what can be done to be more prepared. As some may not be completely familiar with the...
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