Talk:Tsunami

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Not all Tsunamis are large

The statement 'The soso effects of a tsunami are always devastating due to the immense volumes of water and energy involved.' is 100% false. Tsunamis can be as small as having a wave height of 5ft, and can have no destructive impact what so ever. This fact can be found in most Oceanography textbooks. --67.234.209.142 (talk) 02:40, 5 May 2008 (UTC)

Corrected. Oda Mari (talk) 15:37, 5 May 2008 (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 journal article to support this contention.--Dr.Worm 15:43, 11 April 2006 (UTC)

The paragraph beginning "One of the early warnings comes from nearby animals" seems speculative as there were plently of animals killed by the 2004 tsunami. For example, The Washington Post reported, "In the coastal town of Velanganni ... volunteers wearing face masks drove around in trucks Tuesday, picking up cattle carcasses ...". The (Wikipedia) paragraph also says, "The Lisbon quake is the first documented case of such a phenomenon in Europe." If this is actually true, needs a reference. Instead of "Animal Precognition" I'd suggest a section title such as "Do Animals Know Early?" that discusses the evidence. --Dr Smith 22:29, 22 July 2006 (UTC)

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Tsunami wave

I did some English-language redaction on the recently added "Tsunamiwave", 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)

From Samueldevadoss,

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.

A solitary wave or Solitron is generated by water pressure building up in front of the bow of a ship. Some tsunami are not generated by "N" type disturbances but as at Santorini and Krakatau a "U" shaped disturbance due to the collapse of the magma chamber generating a submarine caldera. Incidentally where - as at Sumatra, the ocean floor is pushed up and down simultaneously the resultant disturbance could be more correctly described by a square root symbol \/ ^----. The Geologist (talk) 19:44, 5 March 2008 (UTC)

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.

However, it must be remembered, at this scale, that even a millimetre rise on the other side would have drastic consequences. Giving the Atlantic's width to be approx 4000km, a 1mm rise in water level on the other side would equate to a tsunami between 100 and 150m high. Obviously such a small rise of 1mm cannot occur on this tiny scale (water tension). --Spark.1.4 11:05, 19 October 2006 (UTC)

You are ignoring the colossal amount of energy that a massive gravitational landlside would contain, which your "large rock" cannot contain unless you lifted it several tens of metres above the ground. The Geologist (talk) 14:41, 14 March 2008 (UTC)

"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 a toy house, sending it crashing into one side of the toy truck, thus sending an enormous rush of blocks -- about 1 foot high -- the short distance to the opposite shore, at such high speed that it ran up the opposite slope to a height of 1 inch. There was no such thing as a wall of blocks twice the height of the arm chair by the kitchen , and there has never been anything like this in the last three seconds

Temper, temper! and actually YOU are very wrong. First there are witnesses who did survive the 1958 Lituya Bay "mega-tsunami." Second the scientific and geological evidence confirmed what they told the US Coast Guard service and others. Third the sesimic record confirmed an earthquake. Fourth more recent investigations showed that the block fell almost intact breaking up as it impacted the water at a terminal velocity of about 54 m s² The force it impacted the waters with was colossal - several millions of Newtons per m² and was sufficient to generate an initial wave of approximately 524 m amplitude. All of which is provable and therefore scientific fact. Lest you think I am some pseudo-scientist I assure you and others too, that I am a geologist and have visited Lituya Bay to examine for myself and my research the evidence. The Geologist (talk) 15:05, 14 March 2008 (UTC)

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 fuck bitch 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.

What causes the wave to "rear up" isn't the drawback, but the physics of wave formation. As a wave comes ashore, the base slows but the upper part continues to travel forward at the same speed - just like a person in a car which is braking hard is forced forwards because they are still travelling at the original speed of the car. In addition to this the water rises BECAUSE the shore area slopes upwards forcing the water upwards. This rearing up causes drawback not the other way round. Photographs taken of the Indian Ocean tsuanmi clearly show the approaching wave rising BEFORE the drawback commenced. I personally have a set which have been extensively studied and analysed by colleagues around the world. Drawback is an artefact of the rearing fuck is an artefact of the tsunami. Simply put you have a tsunami wave which extends from the surface to the sea bed - which is why tsunami waves obey the same rules as shallow waves, this is pushed upwards as it approaches land, causing he wave to rear up and thus generate drawback which often occurs with a tremendous sucking sound. The incoming wave surges ashore and can inundate upto several kilometres inland. The Geologist (talk) 14:56, 14 March 2008 (UTC)

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)

This may well be true (I've no idea), but there are very respectable-sounding people who do argue that landslides can cause tsunamis: [1] Given the inclusion of could and might in the original statement, I think it should stand. Henry^Flower 11:29, 16 May 2006 (UTC)

Sure, and there is also a one-hour documentary touting this pseudo-disaster, in which researchers are shown estimating the size of a surface tsunami over 2,000 miles from its genesis by sliding rocks into a water tank only a few yards long. Debunking sites include http://www.lapalma-tsunami.com/ and http://www.drgeorgepc.com/TsunamiMegaEvaluation.html Drshi 22:01, 17 May 2006 (UTC)

I don't pretend to understand the physics/geology/whatever of the matter; all I (or anyone at Wikipedia) can do is to look at what reputable sources say. Some say that a landslide could cause a tsunami, while some don't. Unless one side concedes, it's not for us to take sides. Henry^Flower 22:07, 17 May 2006 (UTC)

An underwater landslide has been blamed for the July 17 1998 Papua New Guinea tsunami (which killed approx 2200. I'm concerned that wikipedia doesn't appear to have a page on it) by some scientists, yes - [1 http://www.sciencenews.org/pages/sn_arc99/8_14_99/fob2.htm] [2 http://earthguide.ucsd.edu/seafloorscience/slopes/slopes_story.html] --Spark.1.4 11:05, 19 October 2006 (UTC)

Investigations showed the same scaring on the surface of sediments off the coast of Papua New Guinea (Tappin, D; 2001. Local tsunamis. Geoscientist. 11-8, 4-7),as are seen at the site of the Grand Banks and Storegga slumps. The Geologist (talk) 14:56, 14 March 2008 (UTC)

Well, though as of now this site does not represent an "us" to me, it seems that when two legitimate sides to an issue exist, both should be equally represented. To my mind, it does not take a physicist or geologist to see the patent absurdity of a shallow landslide of any size propagating a tsunami over the surface of a sea for thousands of miles. A tsunami is NEVER a surface phenomenon, as verified above by Laura Kong. Those who have lept to such conclusions have done so on the basis of geological evidence found in remote areas that suggests a possible link to other areas far afield at which such slides have ocurred. Not exactly incontrovertable. Drshi 14:36, 18 May 2006 (UTC)

I certainly agree that both sides should be equally represented. Bill McGuire, a professor at a very respectable university, [2] does not think the idea is patently absurd. We should say that some people think it could happen, and some people think it couldn't. Henry^Flower 14:51, 18 May 2006 (UTC)

Of course, we don't know whether or not the positions of McGuire and other pro-tsunami researchers have been modified since the subsequent proffering of opinions and evidence to the contrary, do we? Drshi 16:51, 21 May 2006 (UTC)

I certainly don't. But the idea can hardly be as absurd as you make out if they believed (and, AFAIK, believe) it. Henry^Flower 18:26, 21 May 2006 (UTC)

My previous comment states that the supposition is absurd "to my mind"; it does not proclaim absolute absurdity. However, I am certainly not without credentialed support in my belief, and history is replete with virtually universal scientific opinions that have since proved dead wrong, even absurd. I did my own research in my backyard pond, as described in my initial entry, and I feel that any person with a reasonable intellect and imagination should be able to conclude that, in the case of a non-stagnant, 100' pond of any depth and shoreline slope, it would take a landsliding mass about the relative size of Europe to cause any effect at all on the opposite shore. Sometimes the most simple observations are far more telling than complex scientific extrapolations, as famously illustrated on TV by Caltech physics professor Richard Feynman, when he placed a small O-ring into ice-cold water and showed its loss of pliability before an investigative committee on the Challenger space-shuttle disaster. With all due respect, it's beginning to sound to me as if you hold some kind of stock in the tsunami theory, otherwise your investment here might be more productive were it aimed at assisting this newcomer in inserting the equally valid opposing view into the attendant article. ;-)

PS It also seems to me that you are too eagerly taking the findings of establishment researchers at face value, as though they are operating in some sort of academic ivory tower. The way this whole issue got started was that some researchers applied for grants on the basis of a possible tsunami devastating the coasts of Great Britain and America. Of course such a hypothesis would prove attractive to funding sources; but what would be the odds of such a grant being extended were a researcher to report a first year finding that there was no solid support for such a hypothesis? Unfortunately, scientific theories are seldom without bias of one sort of another, while those who debunk such theories are usually independent mavericks with no special ax to grind other than maintaining the purity of scientific method. Drshi 11:53, 24 May 2006 (UTC)

I don't know where some of you get or got your information as written above. Lituya Bay DID cause a wave with an amplitude of 524 m - that is documented. It was not a "splash." Volcanic edifice failure "... Will cause the western flank of the Cumbre Vieja on La Palma to fail and generate a so called "mega-tsunami ..." Will it? There is a lot of evidence to support the claim that the flank will not fail en-masse, but rather in a series of sector collapses. Consider this the Cumbre Vieja is about 25 km long and in 1949 an eruption occurred which was accompanied with an earthquake. This earthquake is considered by some to indicate that the volcano is about to collapse - so run for the hills! Well the section that opened in 1949 is about 2.5 km long or about 10% of the total length of the Cumbre Vieja. The sector moved about 2 m vertically and about 1 m horizontally. Hardly a precursor to imminent failure. However, the hypothesis cannot be proved UNTIL it undergoes sufficient eruptions to cause failure and it may then generate a massive tsunami - the so called "mega-tsunami!" As a volcanologist and a geologist who lives and works in the Canary Islands I am involved in ongoing research into the potential falure.

Any tsunami requires the WHOLE water column to be disturbed - not just the surface and massive gravitational landslides may have the ability. Submarine seismic activity of high enough magnitude will - Chile 1960, Alaska 1964, Sumatra 2004. Bolides impacting the ocean will also if of sufficient mass generate a tsunami. Landslides and submarine slumps may cause localised tsunami - Grand Banks 1929, Papua New Guinea 1998. Massive volcanic explosions will (if they affect the water column), generate a tsunami - Santorini about 3615 BP, Krakatau 1883. As the Sumatra earthquake showed sesmically generated tsunami have the ability to travel transoceanic distances.

Whether a volcanic edifice failing would generate a transoceanic tsunami or so called "mega-tsunami" is the subject of ongoing research. The Geologist (talk) 19:36, 5 March 2008 (UTC)

Here is something hot out of the laboratory! A recent experiment involving a tank 100 m long 15 m deep and 5 m wide was undertaken. It also used a slope inclined at 15 degrees (and this was varied between 10 and 25 degrees) and 25 m³ of sand and gravel. When the sand and gravel slid into the water it generated a "tsunami" which came surged over the distant end. The height of the wave was almost 24 m. SO - perhaps there may be some basis of Day et al; 1999, and Ward and Day; 2001, work. Research continues and watch this space! The Geologist (talk) 17:39, 18 March 2008 (UTC)

Video

Is this appropriate: Rare footage of the 2004 Tsunami its a video entitled 'funny tsunami' i have been reverting it, but i'm just checking that i'm doing the right thing by stopping it?

I don't think there is anything funny about that or any other tsunami. Only a sick mind could think it funny to loose your friends or family. The Geologist (talk) 19:13, 5 March 2008 (UTC)

Magnitude

Does anyone have any information in which a minimum magnitude is associated with a tsunami. This could prove useful knowledge for those who live in tsunami prone areas. 21:29 28 August 2006 (HST)

I don't believe that there is a 'minimum magnitude' as such, as a fairly moderate earthquake (say a 5 or 6) could cause an underwater landslide which could be just as devestating as a 9 or 10.--Spark.1.4 10:51, 19 October 2006 (UTC)

Almost any seismic disturbance can initiate a tsunami. However a low Magnitude earthquake at depth would not. I believe that in Japan any sesimic activity of Magnitude 4 or greater can initiate a local tsunami. For this reason people in coastal areas of Japan are very aware of the risks and have well rehearsed procedures and routes to evacuate low lying coastal areas. Perhaps someone from the Japanese scientific community might like to comment. The Geologist (talk) 19:12, 5 March 2008 (UTC)

question

can anyone explain how the tsunami wave appears to sometime cause water to retreat from the shore at first?Edxguy 14:24, 3 December 2006 (UTC)

research waves in general, have you ever been to the beach? before every wave, the water goes out. if it didn't ever go out all the water would be on the land and not in the ocean.

The above reply is not correct. A tsunami has two phases - as does any wave. A positive peak and a negative peak in respect to the original sea level. Which are due to the manner in which sea floor disturbances disrupt the water column. The section that pushes upwards - positive direction pushes the water column upwards, whilst the part that in effect moves downwards - negative draws the water column downwards. The disturbance then radiates outwards - the positive section will literally arrive as an overflowing - Banda Aceh and similar areas on 24th December 2004 were suddenly inundated without any warning. This was due to the positive peak arriving without any indication. Other areas saw the sea recede - the drawback due to the arrival of the negative peak.

It is difficult to decide which is the more dangerous in respect of the fact that people invariably investigate why the sea suddenly withdraws ( many survivors of tsunamis mention a "sucking sound,") because when the sea "returns" it rushes in faster than you can run. Yet if you keep your wits about you that drawback will give you valuable time to run to high ground or get above the third or fourth floors of high rise buildings.

The sudden inundation is dangerous for many obvious reasons. There is no warning you are suddenly engulfed in several tonnes of water moving at speeds close to 1000 km hour and to give you some idea of the force involved the velocity of the wave (m per second squared x the mass will give the force). The wave will arrive with a velocity of about 280 m per second. Sea water has a density of 1.1 x 10³ kg m³, hence each cubic metre of sea water hit had an approximate force of

280² x 1100 = 8.61 x 10⁷ N m² or the equivalent force of 86 million tonnes per square metre. Please note that this is not the actual force that the wave exerted as it came ashore. This is because as it came ashore its velocity reduced, but the energy present didn't. In arriving at an actual value several factors have to be taken into consideration not least the distance travelled - the energy dissipated according to the inverse square root theorem rule. The Geologist (talk) 19:11, 5 March 2008 (UTC)

Stats

The article Great Chilean Earthquake has a different fatality figure than this article. -- Beland 02:09, 31 December 2006 (UTC)

The earthquake article mentions earthquake fatalities; the tsunami article talks about tsunami fatalities - I don't think there's any contradiction - apples and oranges. SandyGeorgia (Talk) 05:44, 9 January 2007 (UTC)

Anyway, since it's not clear, I added the referenced number from the CRED database. SandyGeorgia (Talk) 05:47, 9 January 2007 (UTC)

You might also like to read an account by Houron Tazieff called "When the Earth Trembles," which contains a graphic account of the earthquakes and tsunami. The Geologist (talk) 19:10, 5 March 2008 (UTC)

Funny Tsunami?

Has anyone seen the funny tsunami video? Is it appropriate to link to it? hi lol fun

NO it is not appropriate to link to it. A tsunami IS NOT FUNNY to those who survive one or loose friends and family. Use that thing that keeps your ears apart

1755 - Lisbon, Portugal

This section is confusing (to me at least):

"Tens of thousands of Portuguese [...] were killed by a tsunami which followed a half hour later."

"The earthquake, tsunami, and many forest fires killed more than 1,000 of Lisbon's pre-quake population of 275,000."

Either that's mistyping, or it's saying that tens of thousands of Portuguese were killed, but only 1,000 of them were actually from Lisbon.

217.194.34.103 10:17, 6 March 2007 (UTC)

The Portuguese Wikipedia says in the article about the 1755_Lisbon_Earthquake at http://pt.wikipedia.org/wiki/Terramoto_de_Lisboa (my translation): "From a population of 275 thousands in Lisbon, it's believed that 90 thousands died." In a remark about this claim, the article also says (my translation) "There are sources citing 30,000 mortal victims." Jayme 18:42, 29 May 2007 (UTC)

Japanese legend

I removed the statement It, in Japanese legend, is thought to be caused by a giant fish-god swimming around under the ocean, causing a tsunami because the legend is (at least in every reference I dug up) that earthquakes, and not tsunami, are caused the giant catfish's writhing. I know it sounds kind of nitpick-y, but since not all tsunami are caused by earthquakes, the line isn't completely accurate. Mary quite contrary 05:07, 16 March 2007 (UTC)

Really?

"ca. 1600 B.C.: The Israelite crossing of the Red Sea has been linked by some researchers to a tsunami following the volcanic explosion of the Greek island of Santorini."
Which serious researcher would come to the idea that a volcanic eruption in the Mediterranean would spark a tsunami in the Red Sea? Is this an attempt by some creationist to infiltrate the "science" of the christian religious texts into science again?
That should be deleted as it is complete nonsense.
—The preceding unsigned comment was added by 85.3.187.12 (talk) 15:57, 27 March 2007 (UTC).

No, this is an attempt by some non-religious scientist to explain what religious people regard as supernatural. It was referred to by Dr Iain Stewart on the BBC programme "10 things you didn't know about tsunami" which aired recently. Moonraker12 (talk) 12:43, 19 January 2008 (UTC)

this is a really good site and helps you alot with all of the work you might need fopr school. —The preceding unsigned comment was added by 24.239.67.53 (talk) 01.16, 29 March 2007 (UTC).

There is an agreement that the Israelites did not cross the "Red Sea," but the "Reed Sea" which is documented as existing in the southeastern corner of the Mediterranean Sea and was still in existence at the time the Suez Canal was constructed. There is strong probability therefore, that "Red" is a misinterpretation of "REED" and I am certainly not a "Creationist" I do happen to be a geologist and a volcanologist and deal with provable facts to what some consider to be stories. I believe that the bible contains a history of the Jewish people, and as such it has recorded many natural events which the writers were only able to explain as "Acts of God." There is a time difference between the radiocarbon dating of the Santorini explosion and the archaeological date of the Exodus of 300 years, but you must bear in mind that there is also uncertainity about the date of the Exodus plus it is highly unlikely that the description wasn't written immediately and the writer may have confused the pharoah.

If the Reed Sea was the place where the Israelites crossed the sea "dry shod," then their crossing may have coincided with a drawback of the Santorini tsunami. The armies of pharoah were drowned in the returning surges. It is plausible but is not provable at the present time, though a search is under way for the tsunamite - deposits made by a tsunami. The Geologist (talk) 18:26, 5 March 2008 (UTC)The Geologist

Bounce-back tsunami

"These tsunami were so large that they caused landslides on the opposite coast triggering another massive tsunami, or "bounce back" tsunami. An example today would be a landslide equivalent to everything west of Portland, Oregon falling into the Pacific Ocean, resulting in a tsunami that would then hit the Chinese coast with enough force to erode the coast, triggering a landslide large enough to send a tsunami that would in turn inundate the U.S. West Coast and would wipe out Portland."

I'm not sure how even a very large tsunami alone could cause a landslide large enough to generate another ocean-wide tsunami. This sounds implausible, and I've never heard of anything like it before. Added to which, the scenario of everything west of Portland "falling" into the ocean is ridiculous and not sensible for inclusion in a serious encyclopedia. But hey, if someone has a reference, let's have it in there. —The preceding unsigned comment was added by 203.173.58.133 (talk) 16:47, 1 April 2007 (UTC).

On further consideration, this may be a confusion with tsunamis being reflected, which may well (does?) happen so far as I know, though obviously with a large loss of energy. References would be handy, and until then I suggest leaving more extreme paragraphs like this out. And sticking to realistic geological examples.

Whilst it is possible that a tsunami could trigger landlsides on distant shores, it is extremely unlikely that the landslide could then trigger a further tsunami. This is because the incoming energy present in the waves would be inundating the shore, massive damage would result and the energy that a landslide would impart into the incoming tsunami would be absorbed and dissipated locally. Reflection of the waves may give the impression that a fresh tsunami was being generated. The Geologist (talk) 19:08, 5 March 2008 (UTC)

The Word Tsunami

Why is the word tsunami in italics all over this article? 65.92.176.38 01:31, 2 April 2007 (UTC)

Who knows. It's fixed now 206.47.141.21 16:25, 2 April 2007 (UTC)

2004 Indian Ocean Tsunami

I found this line in the article surprising, and hard to believe: "The American recording stations in Hawaii detected the tsunami within a few minutes of it starting, but as it posed no danger in their locality they did not publish a warning." According to: http://www.noaanews.noaa.gov/stories2004/s2358.htm they detected the earthquake- but not the tsunami, because they don't have any buoys in the Indian Ocean, and they did send out warnings. I think this line should be deleted or cited.

Athenastreet 18:47, 4 April 2007 (UTC)

no name for sue nommy

The TSW sation in Hawaii and other seismic observatories around the world recorded the SEISMIC WAVES from the earthquake within minutes of the earthquake occurring. They DID NOT record the tsunami It was several hours later it was recorded and then only as a small disturbance on tide gauges outside the Indian Ocean. The Geologist (talk) 19:03, 5 March 2008 (UTC)

Plural of tsunami

According to Merrian-Webster, the plural of tsunami can be either tsunami or tsunamis. Personally, I prefer the former simply because I’m accustomed to it, but most NES (native English speakers) might prefer the latter, which could lead to edit wars over this. Any suggestions for averting such silliness, such as perhaps a notice or footnote stating that either is correct, but we’ve (“Who’s we?” is the obvious retort, of course) settled on one or the other? Jim_Lockhart 02:36, 13 April 2007 (UTC)

I've thought about this as well. My instinctual reaction is, we don't automatically add "s" to pluralize every English word, so why should we do it - inappropriately - to a word from another language? My more logical reaction is to look at other Japanese words ending in "i" that have made their way to us and how WP treated them. For instance, according to the dictionary, it's an acceptable to pluralize origami with an "s", but our WP article doesn't use this version. A better argument is "sushi", which nobody in their right mind would call "sushis".

Then again, having lived in Japan, I have a little personal bias and definitely get itchy when I hear or read "tsunamis". But I'm not sure what the consensus is/was/would be here. --Mary quite contrary ^(hai?) 03:33, 13 April 2007 (UTC)

As a geologist and a volcanologist the scientific community uses the singular - "Tsunami", whilst the media sometimes uses the plural - tsunamis. The Geologist (talk) 18:34, 5 March 2008 (UTC)

Inappropriate remark?

Since not all tsunami occur in harbors, however, that term is equally misleading, although it does have the benefit of being misleading in a different language.

I fail to see where's the benefit in that; looks completely non serious to me, any reason to leave it in? Perseguidor 13:59, 15 April 2007 (UTC)

To clarify: actually I do see the very practical benefit of that (it isn't as misleading an error to the general public), but the remark strikes me as badly worded. I wanted to know whether I'm just being culturally oversensitive because of the fact that english is not my first language. Perseguidor 14:04, 15 April 2007 (UTC)

The comment could be worded better. Also, the "Signs of an approaching tsunami" section needs work. Could "disgustingly fat wave" be vandalism? Has a tsunami ever washed "over an entire country"? The last sentence in the section, "Although in the 2004 tsunami in the Indian Ocean the sea receding was not reported on the African coast or any other western coasts it hit, when the tsunami approached from the east" doesn't seem to fit in that section at all, and is not a complete sentence, in addition to being very poorly worded.

Additionally, the section on the 2007 Solomon Islands tsunami is written using some present tenses (it is not timeless, as all wikipedia articles should be) and also needs to be updated with conclusive data. --Cromwellt|talk|contribs 19:46, 30 April 2007 (UTC)

Well the scientific community worldwide know what a tsunami is and so do most people who live in vulnerable areas. The Geologist (talk) 19:05, 5 March 2008 (UTC)

Gas bubble image

I've commented out the "Gas bubble" image (Image:Tsunami5.JPG) pending a reference for this. Maybe gas bubbles cause tsunami, but I'm a bit skeptical. Ref. please. Vsmith 01:38, 24 May 2007 (UTC)

Scepticism in this case is justified. A gas bubble would cause a sudden localised disturbance which might resemble a tsunami in the immediate vicinity, but it would not be large enough or powerful to generate a tsunami. The Geologist (talk) 19:07, 5 March 2008 (UTC)

Tsunami in Mexico in 1932

Different sources talk about a Tsunami in Cuyutlán town in Mexico, on June 22, 1932. I listed this Tsunami, as "Possible Tsunami" in the section of North America and Caribbean Tsunami, refering a news that also refers newspapers from 1932 and interviews. EliminatorJR eliminated this addition, but considering that it was written under "Possible Tsunami" section, and sourced, it should be kept.

Splitting article?

The section of notable tsunamis is large, perhaps we could create List of notable tsunamis and simply link to it here? - 2-16 17:22, 6 June 2007 (UTC)

A Tsunami does not have to be 'on a massive scale'

A tsunami (soo-nah-mee; IPA: /tsʊˈnɑːmi/) is a series of waves created when a body of water, such as an ocean, is rapidly displaced on a massive scale

This should read:

A tsunami (soo-nah-mee; IPA: /tsʊˈnɑːmi/) is a series of waves created when a body of water, such as an ocean, is rapidly displaced

Or something simmilar, could someone please confirm

69.156.99.171 17:46, 30 June 2007 (UTC)

A tsunami is generated when a large body of water - usually oceans but sometimes in lakes and inlets or fjords, is suddenly displaced by vertical displacement of the ocean or lake floor. Large bodies - asteroids, massive landslides etc., falling into the ocean or lake can also have the same effect The Geologist (talk) 18:57, 5 March 2008 (UTC)

Missing name

Under Tsunami#Causes, third paragraph:

In the 1950s it was discovered by that larger tsunami than previously believed

Who discovered this?

Geologists working for oil companies and the USGS!

Split

What about to move a Historic tsunami section into a new article? It is quite long now and it looks ugly here. Miraceti 14:12, 25 July 2007 (UTC)

Removed content

I have removed the following (unreferenced etc.) section from the article:

---

Samui Kaze Desu,( Cold Wind Query) a Japanese expression, meaning ' Isn't that The Cold Wind?' - a small cold wind from the sea that often preceeds the tsunami.

It seems that when a vast volume of sea water is thrown into the air, a similar volume of air is displaced, and consequently a wave of air flows outward from the eruption.

This wave of air travels faster than the wave of water, and is cold by the time it comes ashore because it travels across the surface of the water. It may arrive seconds or minutes before the tsunami,depending how far out the eruption is, or maybe not at all ( perhaps if the first onslaught of the tsunami is a recession of water ?).

Experienced Japanese leave the shore immediately.

---

Mike Rosoft 14:12, 30 September 2007 (UTC)

"Fillius Sum Sunamus"

Arrant nonsense in the opening graf. Argh. 128.2.247.61 07:01, 12 November 2007 (UTC)...

Pronunciation

Both the Oxford English Dictionary and American Heritage Dictionary only list the "tsunami" pronunciation. They do not even have a "sunami" pronunciation therefore the "tsunami" pronunciation is first. Azalea pomp (talk) 17:00, 26 December 2007 (UTC)

I removed the 'sunami' pronunciation. It's incorrect. Oda Mari (talk) 18:24, 26 December 2007 (UTC)

Most English text books - as used in the English speaking world clarify the pronunciation as "Sue - nar - me" which may seem strange but it emphasises the syllabuls and tries to ensure correct pronunciation. The only time I have seen tsunami spelt incorrectly as "sunami" was on here. It isn't spelt that way - it is spelt "TSUNAMI." The Geologist (talk) 18:52, 5 March 2008 (UTC)

Tidal Wave Vs. Tsunami

I would like someone to explain to me why "Tsunami" and not "Tidal Wave". I know the second is caused by the tides of the moon, but considering Tsunami is mentioned as meaning "Harbor Wave", I cannot see why use it except political correctness. If I'm wrong, okay. Thank you.--65.24.61.74 (talk) 23:58, 15 February 2008 (UTC) STRodgers

Sorry, it is not "Political Correctness" that we use the term "Tsunami", but it like many other terms used in science has been taken in general usage. For example what about Strombolian, Vulcanian, Plinian to describe explosive eruptions of increasing intensity, or hurricane - named after the Carib god "Hurakan or Huriken." What about "Lahars" to describe volcanic mudflows - it is an Indonesian word, or Nuee Ardente to mean "Glowing clouds" it's French. The list is endless. The Geologist (talk) 18:41, 5 March 2008 (UTC)

OK - this 'The use of the term "tidal wave" to describe a tsunami is wrong because IF NO wind were to act upon the sea, then as the tide flooded (rose) or ebbs (drains) solely under the influence of the Moon and Sun, the water would rise and fall without any wave. Non-tsunami waves form by the action of wind on the upper surface of the sea.'

Is ... useless in the context of this article, not to mention that the first sentence is poorly constructed and doesn't make any sense. It should just be deleted - It is sufficient to say that a tsunami may be called a tidal wave by some but that it is discouraged because a tsunami is completely unrelated to tides. (which is already said by the sentence preceding and following the aforementioned flotsam) 67.167.185.45 (talk) 21:38, 12 April 2008 (UTC)

Where did my picture go? Everyone, please warn people if you are going to replace their pictures...

Hi everyone:

File:Tsunamihazardzonesign.jpg

My photo

File:IMG 5028.jpg

Allison's photo

I looked at this article for the first time in about a year today and noticed that my photo was gone. I traced the history and figured out what happened. At this edit on 16 March 2007, User:Allison Stillwell replaced the first photo on the right (mine) with the second photo (hers) without any warning.

I don't think this was a good idea. Although both photos share a common deficiency (sun is not to photographer's back), here is why my photo is superior:

• Mine is straight on at the subject; hers is from a very sharp oblique angle and below.
• Mine is illuminated by a flash for superior contrast; hers appears to not have any flash (or was not taken with a strong enough flash).
• Mine is cropped so as to make the sign fill the frame; in hers, there are significant background objects that do not contribute any additional relevant information.

Okay, do we have a consensus to go back to my image? If no one responds, I'm changing the article in a week. --Coolcaesar (talk) 08:39, 24 February 2008 (UTC)

I prefer yours to hers. Because the warning is legible. Oda Mari (talk) 09:41, 24 February 2008 (UTC)

I prefer hers. better quality photograph overall, is not "false coloured" (flash in daylight shooting? what?), hers looks like a photograph you might see in a professional article, yours looks kinda not so good and lopsided and off centre and has things reflected in the sign and is just pretty terrible. also i prefer hers because she's not in here after a YEAR going "wah, MY PHOTOGRAPH." you're not supposed to have "pet articles." not yours. 82.8.49.243 (talk) 03:27, 26 February 2008 (UTC)

oh, i see by your talk page this isn't the first time you've thrown your toys out of the pram over someone daring to touch one of your photos. 82.8.49.243 (talk) 03:44, 26 February 2008 (UTC)

I'm sorry you feel this way, but the reason I replaced the photo is that yours has odd reflections and has a bit of a fisheye to it. I think that mine is a little more professional in terms of composition and colouring, and in the year since it was posted, no one has complained about it. I really, really think you're overreacting here. --Allie (talk) 03:41, 26 February 2008 (UTC)

Well, I am aware of the problem with the flash reflection and the fisheye issue (actually barrel distortion, a common problem with most Olympus "prosumer" cameras). This was back while I was still developing my photography skills.

But the main issue is that the entire point of the photo is to show the content of the sign -- namely, that it's a "tsunami warning sign." This is not like photographing, say, a natural landmark or a building, where there are a huge number of possible angles in three-dimensional space, many of which are attractive. In this case, either the sign is readable or it is not. I'm not sure if you realize that most Wikipedia readers don't have the time, curiosity, or bandwidth to follow links from thumbnails to see the images in full, so it's important that the thumbnail versions of images are easily understandable when seen in articles. You make a rather conclusory statement that your image is more "professional" in terms of composition and coloring without providing any explanation; I simply can't agree. This is not a fancy art image; this is about displaying the content of a sign. Besides the issues I already raised, yours is much harder to read in that it is sharply offset and rotated on all three spatial axes (X, Y, and Z) relative to the subject. --Coolcaesar (talk) 07:55, 27 February 2008 (UTC)

If you want to replace a picture, then do it. Believe it or not, you don't actually have to alert every single person who ever edited that you're replacing their content -- if we had to do that, nothing would ever end up being updated on Wikipedia. I stand by my statement that you're absolutely overreacting here -- it's a picture for God's sake, a single picture. If you react like this, so something that is so insignificant, I find myself terrified that you're ever representing someone in the courtroom. I think you're also being rather haughty about this and that maybe you should consider how you talk to people, but I see from reading your talk page that this has been a constant problem for you. I hope that for both your health and your career you learn to calm down. There are some times when things just aren't worth getting upset over, and one of those things is edits on Wikipedia. It's a website, not some deeply personal thing that people are going around and changing to insult you.

And if you realise that there are problems with composition, why don't you go take another picture of the sign? I'm only in California a few times a year, but you live where there are tsunami warning signs everywhere. It seems to me that if you've been improving your photography skills, you can take a rather nice picture of the sign now, one without the flash reflection and barrel distortion. You seem to like taking photos of anything, so why not just skip over to the coast and take another picture? I'm typically a portrait photographer and inanimate objects tend to bore me to no end, but you appear to love such things, so embrace them... with a better picture. --Allie (talk) 16:41, 27 February 2008 (UTC)

it's not to show the content of the sign, it's to show the general appearance and whereabouts of the sign. the article is for the content. you are being a prissy butt. 82.8.49.243 (talk) 04:30, 28 February 2008 (UTC)

The first photograph may have failings but legibility of the information is not one of them. The second one shows that the sign is positioned on a post - but here is the crucial thing - it is illegible! I also consider it bad manners to remove someones postings just because you don't like it - unless it is libellous, wrong or illegal. A better solution would have been to leave the original photograph and add the second to show the position. Flash is regularly used in daylight - go and read a book on photography. Also many automatic cameras do not offer the user the option of flash on or off. Before criticising make sure of your facts. Incidentally I am a professional geologist and volcanologist and photography plays a BIG part in my observations and I don't always get the shot I really would like. The Geologist (talk) 18:48, 5 March 2008 (UTC)

How about this picture? Oda Mari (talk) 14:55, 11 March 2008 (UTC)

Oh, I like that one a lot! Good shot! --Allie (talk) 02:52, 16 March 2008 (UTC)

Hi Oda Mari, Pics OK too. Might have been enlarged or cropped but it is legible and that is what matters. The Geologist (talk) 15:19, 14 March 2008 (UTC)

Just got caught up on what's going on. I have been too busy with working at the firm, attending social functions, finishing my tax return and taking online traffic school to work on Wikipedia. I agree that the photo brought in by Oda Mari is a well-composed and acceptable compromise. Oda, feel free to put that photo into the article any time. --Coolcaesar (talk) 06:24, 16 March 2008 (UTC)

For whatever it's worth, this is the same sign design, clearly visible, from Laguna Beach, CA. WarBaCoN (talk) 08:02, 16 March 2008 (UTC)

Why not use all the images? As a gallery, it will need monitoring to ensure that rubbish images are not used. However, if the image is clear and legible, then fine, but lets use a bit of common sense. We don't need a gallery of signs showing "This is the sign on XYZ street" The Geologist (talk) 15:04, 16 March 2008 (UTC)

No need for sarcasm. I noticed a lot of people were going on about various issues with all of these pictures, and this one cleared up a lot of the complaints. If an ideal image was found, the rest could be eliminated as the issue would then be resolved. Sounds like common sense to me. WarBaCoN (talk) 17:39, 16 March 2008 (UTC)

Well I'm NOT being sarcastic as you seem to imply. As a scientist - I am a professional geologist, it is my duty and any one else presenting information to ensure it is correct, legible and easily identifiable. If you go in to the world you will see that different countries present tsunami warning signs in different ways - and strangely not all the signs in one country are the same - unless they have changed them in the last 48 hours! The country? Why its that big blob that sits beneath Canada and above Mexico - alias the USA! The Geologist (talk) 18:33, 17 March 2008 (UTC) b

FYI, "Sarcasm, A form of irony in which apparent praise conceals another, scornful meaning". Anyway, I am not even sure what you are trying to say. I think we all know that different countries use different signs. In fact, where I am from we have NO tsunami warning signs at all, as many others around the world may not while skimming this article. I offered what appeared to be the best photo of the sign in question, that everybody was discussing, in a clear, straight on, and legible picture. I have zero interest in distracting you from your discerning scientific work (in more important areas, I am sure). WarBaCoN (talk) 21:50, 18 March 2008 (UTC)

Oh dear WarBaCon you seem to get annoyed at anything which is not to your liking or suits your opinion. I would like to know where you are from as my own travels around the Pacific Rim I know of only two locations where there is no Tsunami waring signs and both of them sign themselves as US or USA! Comprende. Yes my work is scientific and discerning and truthful. If you can't take criticism then go and play somewhere else not where the adulst are trying to educate ignorant pseudo-scientists who take umbrage when they are proved wrong! The Geologist (talk) 17:21, 30 March 2008 (UTC)

edits for Warnings and prevention

The previous writing of the section not only has errors, but also doesn't use the usual variable letters in some cases. I suggest the following changes be made to bring them in line with normal variable usage.

Here's the before:

F = Gdh

where F = the overlying force or pressure in Newtons per metre square, G is the acceleration due to gravity, d = the density of the water and h = the height of the water column.

G = 9.8 m s², d = 1.1 x 10³ kg m³ and h is the depth of water in metres

Hence for a water column of 5,000 m depth the overlying pressure is equal to 9.8 x 1.1 x 10³ x 5 x 10³ or about 5.4 x 10 7 N m² or about 5.7 Million tonnes per metre square.

Here's the after:

$\,\!P=\rho gh$

where
P = the overlying pressure in Newtons per metre square,
$\rho$ = the density of the seawater= 1.1 x 10³ kg/m³,
g = the acceleration due to gravity= 9.8 m/s² and
h = the height of the water column in metres.

Hence for a water column of 5,000 m depth the overlying pressure is equal to 1.1 x 10³ x 9.8 x 5 x 10³ or about 5.4 x 10 7 N m² or about 5.7 Million tonnes per metre square. —Preceding unsigned comment added by Talldave (talk • contribs) 05:20, 1 June 2008 (UTC)

How about a more accurate term?

Why don't we call these waves "thalassoseismic waves"? --  Denelson83  21:08, 6 June 2008 (UTC)