Talk:Tsunami

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Awa

In the article there is this sentence:

• January 26, 1700: the Cascadia Earthquake (estimated 9.0 magnitude) caused massive tsunamis across the Pacific Northwest and in Awa, Japan

To which Awa does it refer: Chiba or Tokishuma? Does anyone know? If not, then no matter. I only ask for disambiguation purposes. Jaberwocky6669 05:07, Jun 25, 2005 (UTC)

There appears to be a bit of an issue raised at Talk:2004 Indian Ocean earthquake#disambiguation request: "Awa" and fact check. After a bit of search it appears that there was no major tsunami in 1703, and I can't find evidence of massive damage in 1700 either. The response to the article here is supported by this data from the NGDC in which the highest death toll between 1700 and 1703 was 5233 on 31 December 1703 for the Tokaido region. Can anyone offer any more evidence for the large tsunami(s) mentioned here and at 2004 Indian Ocean earthquake? - BanyanTree 01:39, 15 October 2005 (UTC)

I was the one who initially added the Awa references to both this article and the 2004 Indian Ocean earthquake one. After seeing all the additional evidence it does seem that the Awa event was misreported in several sources. It may be worth chasing this down a little more before making the WP edits though; for instance if it was indeed the case that this event was reported erroneously in several reputable sources then that itself may be notable enough to comment on in this article. Terry 13:53, 15 October 2005 (UTC)

I've removed the references to Awa both here and at 2004 Indian Ocean earthquake as no additional information has been given refuting the information above that the info is bad. - BanyanTree 00:56, 20 October 2005 (UTC)

Santorini and flood myths

I took this bit about the Santorini eruption/tsunami out of the article: "and is believed by some scientists to have been the basis of Great Flood accounts which were eventually recorded in Jewish, Christian, and Islamic texts." Both the Babylonian and Sumerian flood myths, which are closely related to the Genesis account, predate the Santorini blast by hundreds of years if not more, and as far as I know this is pretty firmly established (e.g. N.K. Sandars, introduction to Penguin edition of Epic of Gilgamesh). If someone has a source about "some scientists" feel free to put it back: I wasn't able to find anything on Google which specifically mentions scientists believing Santorini to be the basis for the flood myths. (Influencing already existing flood myths might be another thing entirely.) Antandrus (talk) 4 July 2005 14:55 (UTC)

New

I wonder what happened to the idea about putting POV first person accounts into the article, it would give it a great feel. Anyone else like that idea?I seek the heart 07:05, 26 September 2005 (UTC)

That would be a blatant violation of WP:NPOV. -- Arwel 16:50, 26 September 2005 (UTC)

Animal Precognition

Suggest that a section about this intriguing phenomenon, observed before the 2004 Indian Ocean event, would add value to the article. Which animals have this sense and know to act on it? By what means do the animals receive prior warning? How long before the event do they receive it? Why don't humans have this ability? Is this phenomenon observed before other major events, like volcanic eruptions, etc? EdX20 00:42, 22 November 2005 (UTC)

"Precognition" is probably misleading in this case, as it implies that it wasn't the result of their normal senses. In the case of elephants, dogs, etc, it is thought that subsonic rumbling of the approaching tsunami provides warning (much like it does for earthquakes). An article I read back in December suggested that unusual behavior by fish, which presumably could detect the pressure changes and other disturbances in the ocean, caused unusual behavior by the shore birds that feed on them and so on across the ecosystem, well before the effects of the approaching tsunami were noticed by humans. All of this, well referenced of course, would be useful in this article. - BanyanTree 16:16, 22 November 2005 (UTC)

I think this section could be removed. The California Department of Conservation, the agency in charge of earthquake readiness, lists this as a myth. The problem is, how can one tell the difference between odd behavior in animals due to an earthquake vs odd behavior due to any other explanation. This may also be a case where it is just a mental trick we play on ourselves, vs hard scientific evidence. In any case, there should be a hard hournal article to support this contention.--Dr.Worm 15:43, 11 April 2006 (UTC)

Megatsunami

The megatsunami article currently suggests a megatsunami is not a tsunami. However from reading it and from a reading and general understanding ot a tsunami, it appears to me this is qutie incorrect and a megatsunami is simply a media inspired term used to describe particularly large tsunamis, most likely not the result of seismic activity. I have gone into this in more detail in the talk page for megatsunamis. Regardless, the megatsunami article needs to be updated since at the current time, it is either wrong (if I am correct, megatsunamis are tsunamis, unlike what it suggests) or confusing (if megatsunamis are not tsunamis, it does a poor job of explaining the difference) Nil Einne 11:17, 8 January 2006 (UTC)

Magma

Tsunami wave

I did some English-language redaction on the recently added "Tsunami wave", but I'm not sure about the raw information itself. First, do we have a source for any of it? Second, I'm uncomfortable about the "N-wave" statement (again, fixed if we have a source). Finally, I'm concerned about my editing of the business about a "solitary wave". The original was:

The Tsunami is also characterised as a Solitary wave (according to shape) which has only crest and no trough.

My version is:

Tsunamis form "solitary waves", or waves with crests but no troughs — more like sand dunes than sine waves.

The problem is that I may have misinterpreted the use of "which" in the original. I thought it meant "a solitary wave which is a wave that has only crests…", but it may have meant "a subclass of solitary waves that have only crests…". Solitary wave is unhelpful, as its explanation is purely mathematical, but Soliton (to which I linked the reference, and which specifically mentions water waves in a tank) suggests solitary waves are a more general class, and that a tsunami-style wave is only a single example. I'd appreciate it if someone more domain-knowledgeable could check and possibly correction my changes. Thanks. ~ Jeff Q (talk) 18:34, 19 February 2006 (UTC)

It is accepted that, I havent't clearly explained about the 'TSUNAMI WAVE' in relation to solitay wave. Solitary waves are not only mathamatical concept but also a real time event (Solibores or just bores are some examples) and can be generated in experimental wave tanks. The name N-wave is used because the intial form of a Tsunami wave resembles the letter 'N'(exactly at the point of generation of Tsuanmi) and with time and distance it grows to solitary wave. Hope, I will add references soon for justification. Thank you.

new interwiki

+ sr:Цунами(What's this? I'm a Newbie) [I don't want to put any of this in the article because I'm still not sure how to identify my edit and post verification.]

RE: "However, an extremely large landslide could generate a megatsunami that might have ocean-wide impacts." The reference here is to shoreline slides.

No amount of land sliding into the sea can create a "megatsunami" or any other kind of tsunami over any appreciable distance. Only a deep-sea slide or tectonic upheaval can generate such a phenomenon. The reason is simple friction. Any wave propagated only on the surface dissipates as it encounters and transfers its energy to all the particles of water in its path, as well as the tremendously heavy air above. This can easily be verified by rolling a large rock -- say a foot across -- into one side of a 100 foot pond. Though at this scale such a rock would represent something about the size of Spain sliding into the Atlantic Ocean, you will see the resulting ripples diminish as they radiate outward, and no change whatsoever in the water at the opposite shore.

"These events can give rise to much larger local shock waves (solitons), such as the landslide at the head of Lituya Bay which produced a water wave estimated at 50 – 150 m and reached 524 m up local mountains."

The following myth is widely circulated about this event "On July 7, 1958 In a narrow Alaskan bay about 250 miles west of Juneau, the highest tsunami ever recorded loomed to a height of 1,700 feet (520 meters) -- almost twice as tall as the Eiffel Tower."

FACT: A powerful earthquake caused the collapse of 40 million cubic yards of earth and glacier overlooking the bay's narrow inlet, sending it crashing into one side of the inlet, thus sending an enormous rush of water -- about 100 feet high -- the short distance to the opposite shore, at such high speed that it ran up the opposite slope to a height of 1,700 feet. There was no such thing as a wall of water twice the height of the Eiffel Tower, and there has never been anything like a "towering wave" in all of recorded history.

Tsunami researchers have got to curtail perpetuation of the myth that a "big" tsunami means a "tall wave." It does not. The public is constantly being haunted by the image of a prodigious "wall of water" suddenly looming over us, and this is utterly impossible, short of impact by a large celestial body. There is no evidence whatsoever that any tsunami traveling an appreciable distance across the ocean can make landfall at some monstrous height above sea level. When such a wave approaches a shore, receding water causes it to rear up temporarily, but then it curls, crashes, and races onto the land in a sloped configuration -- just as a normal wave does -- but it does so at high speed. It's the velocity, not the height of the wave, that causes so much destruction. A massive volume of water traveling at high speed with great inertia, even a few yards above sea level, can exert tremendous force over a great distance inland. Constant reports of towering waves are based upon the height to which such surges have run up inland slopes, NOT the actual height of the waves.

Corroboration: Dear Dr. Shiarella, Thank you for your correct comment. We will see if we can put a description of the actual wave on our web site, and I will make sure this is clearly noted in training presentations. Regards, Laura Kong, Director, International Tsunami Information Center Drshi 23:02, 14 May 2006 (UTC)