Talk:Megatsunami

message: The person who changes information on this page take note: 1. The international system of mass is the METRIC system not pounds or tons, the International unit of measurement is the METRE - NOT Meter which is an instrument used to measure such as electric meter, gas meter. However, the world recognises that the people of the north American continent called "Americans" have developed their own corruption of English as used by the rest of the world. The English word Epicentre is recognised internationally as indicating the point on the surface where an eartquake occurs and is immediately above the "Focus." So whilst you may not understand that 1 x 10^3 kg is 1 tonne - it is the Internationally recognised and scientific method of writing it. Science globally uses the kilogram, metre. The USA Scientific community now also use the same system so get with it and stop using "Yanklish" and use International English. Also leave the editing of this page to the scientists who are monitoring it otherwise you may well find it locked to stop further vandalism by - well we know who.The Geologist (talk) 18:10, 28 March 2008 (UTC)
replies: text: At the risk of sounding "Yankish" ("yanklish" appearing to be a corruption of the English language by the puritanical inhabitants of the soggy isle of Britain), the differences between American English, British English, and so-called International English are negligible and don't warrant this outburst. Scientific articles continue to be published side-by-side in peer-reviewed journals with their regional variants intact. The American scientific community is by no means unanimous in the use of "International English." An abuse of the metric system does warrant immediate rectification, since since mixing the metric and English systems can cause confusion. The spelling of center vs. centre, however, does not.
75.162.68.121 (talk) 05:52, 9 December 2008 (UTC)
thread_title:  Measuring system 

message: The title of the article is "Megatsunami" (without a hyphen), but in the article itself it is spelt "mega-tsunami" (with a hyphen) on all but a couple of occasions. I don't think it matters, myself, which form is used, but it ought to be consistent. What do people think? Ondewelle (talk) 19:44, 2 November 2008 (UTC)
replies: text: As there have been no responses, I have altered the spelling throughout the article (not in the references) to match the spelling in the title. If anyone feels strongly that the change should have been the other way around, then it's easy to revert, although in that case the article title ought to be changed. Ondewelle (talk) 15:14, 10 November 2008 (UTC)
thread_title:  Spelling in the title and the article: megatsunami vs mega-tsunami 

message: Not confusing to me. the article was referring to the last time a megatsunami was s big it took out the coasts of an entire continent. 
"Some are so large that they can devastate the coasts of entire continents. The last such event (that we know of) occurred approximately 4,000 years ago".
Good article.
Claudius
Good article, however, I noticed a claim that the Santorini megatsunami was linked to the Exodus.  I signed up to strike this out as there is no evidence at all that the two events were contemporaneous, that an event in the Mediterranean would have had an effect on the Red Sea, or that the Exodus even occurred (although this last point is perhaps less important in terms of this article).  This was my first try at editing on Wikipedia, so if I'm going about this the wrong way, I'd be happy to hear from other users.
Rob Gentles  —Preceding unsigned comment added by Robgentles (talk • contribs) 18:08, 3 March 2008 (UTC)
thread_title:  Article OK 

message: ::The point is that it's likey much easier for terroists to cause a La Palma megatsunami event than to obtain and explode a nuclear bomb in North America.
I don't know about that, I think it would take some math for that, a lot of math to correctly detonate the correct explosives with the right strength at the right times at the right places. And Zero0000 is right as well, the explosives would need to be detonated deep underground, and we're talking about 5.5 trillion tons (I'm not talking about tonnes) of earth that will be causing this megatsunami.
I agree with the anonymous person who wrote the above. It would be very easy to detonate a nuclear explosion in North America. Only 12 kilograms of plutonium is sufficient to cause a self-sustaining fission reaction; that amount could be carried in a briefcase. The same can't be said for La Palma; it would take a lot of work, as well as substantial geological knowledge, large-scale drilling crews and lots of time. It cannot be done. thefamouseccles 13:53, 1 Feb 2005 (UTC)
thread_title: Math

message: What source said something about 15-25 meters? I found several that said 90 meters (295 ft).  
--Mac Davis 10:51, 1 Jan 2005 (UTC)
thread_title: 15-25 meters?

message: Several media sources around the world refer to "mega-tsunamis" which the above posts ask about. It is NOT a SCIENTIFIC TERM nor is it used by geologists when discussing tsunamis with each other. It was coined by the BBC - British Broadcasting Corporation for the Horizon programme "Mega Tsunami Wave of Destruction" which was screened by the BBC2 channel and broadcast 12 October 2000. It is of the same non-scientific / geological language that gave us "Super Volcano!" There is no such volcano, but what there is are "Super eruptions." The term is used by the media and geologists to explain the very simple fact that such tsunami or volcanic eruption is beyond our normal understanding and could potentially have serious implications far beyond the local area. As the 26th December 2004 earthquake and resultant tsunami showed, a natural event in one location can cause devastation thousands of kilometres away from the origin. The Geologist (talk) 20:32, 5 March 2008 (UTC)
replies: text: It's also a load of rubbish. Dan100 20:14, Jan 6, 2005 (UTC)
There is a very rude word to describe what you are claiming. The melting Ice Caps will add salt water back into a liquid state. This will not cause a tsunami. The Geologist (talk) 20:32, 5 March 2008 (UTC)
thread_title:  What is a "Mega-tsunami?" 

message: "In modern times, this phenomenon would be made even more likely to occur based upon President George W. Bush's adherence to scripture and disregard of the Kyoto Accords. The sinking of the polar ice caps is likely to follow the abandoment of such environmental accords and create large scale destruction from these giant waves."
This doesn't seem to be a particularly neutral point of view.
--Staz 21:36, 4 Jan 2005 (UTC)
replies: text: It's also a load of rubbish. Dan100 20:14, Jan 6, 2005 (UTC)
There is a very rude word to describe what you are claiming. The melting Ice Caps will add salt water back into a liquid state. This will not cause a tsunami. The Geologist (talk) 20:32, 5 March 2008 (UTC)
thread_title:  NPOV Query 

message: I fully agree with the danger of that terrorists can take advantage of such environmental disasters, what i do not understand is why the collaps of la palma cannot be stopped. I suggest that America should pay every dollar in investigating this problem instead of sending the money to Mars. I'm not a scientist, i think you noticed that,but there seems to be water in the mountain of la palma, that will cause the collapse, maybe they should get this out, again you see i'm not a scientist, but maybe if you put 50 scientists on this problem for 10 years you have a solution and after that we can go to Mars. Why wait for this to happen its stupid. The same with prevention of a hit from a meteor from outer space, because it happens only once in 100.000 years, they put it in nuclear bombs. A meteor is a 1000 nuclear bombs at once! 
by dmx
from Holland
:It takes more than a bit of scaffolding to hold a 5-trillion-ton mountain in place, and any drilling, building or mining that's substantial enough to make a difference might very well be substantial enough to trigger the landslide itself. What we need to do is stop trying to prevent landslides and tsunami and volcanic eruptions, and start understanding what we can do to prevent human death from the effects of these disasters. Early warning systems, for instance. It'd make a lot more economic and environmental sense, plus it's just common sense: to take your meteorite example, how will we stop a chunk of solid rock - sometimes even iron - moving at nearly 40,000 kilometres an hour? And I think that the idea of terrorists causing a landslide like this is just paranoia; I agree with Zero on that. People are too afraid of terrorists; if we fear them, they've already won.   thefamouseccles 13:38, 1 Feb 2005 (UTC)
thread_title:  Terrorists 

message: Not only do we not hve the technology to prevent several trillion tonnes of rock from catastrophically failing or entering the ocean we do not have the technology to produce the carbon fibre in sufficient quantity or thickness. You might as well ask why didn't they stop the 26th December 2004 earthquake? If we had used all the equipment in the world the earthquake would still have happened the tsunami would still have happened because the technology - carbon fibres nano or otherwise cannot contain the kind of forces that are involved. 
We have no more chance of stopping the Cumbre Vieja from failing at some future date than we have of stopping the sun rising tomorrow morning. We are talking of forces beyond anything you can comprehend. The Geologist (talk) 20:33, 5 March 2008 (UTC)
thread_title:  We do not have the technology - simple 

message: "the source of the next large-scale megatsunami is the island of La Palma, in the Canary Islands, ~although further research has dismissed the threat. However,~ recent research has found that a large section of the island will break off into the ocean, causing a megatsunami"
I don't know of what research this paragraph refers to, but as it stands the wording  is somewhat contradicatory and more than a little ugly. So I'm going to cut out the text denoted by tildes, and hope that someone out there with more knowledge on the topic can clarify or re-write. - Whoops sorry I forgot my signature --Tocqueville 17:08, 30 July 2005 (UTC)
thread_title:  La Palma research (grammar) 

message: The first paragraph contains two comments regarding the definition of a megatsunami, which seem to contradict each other.
#"A megatsunami is a form of displacement wave, related to tsunamis in name only."
#"the term generally refers to tsunamis with waves from 40 metres (131 feet) to over 100 metres (328 feet) tall."
The first seems to indicate that a megatsunami is not a type of tsunami, the second indicates that a megatsunami is a type tsunami. Can anybody clarify this, please? Cheers TigerShark 15:41, 4 September 2005 (UTC)
replies: text: Whups, true !! Will do ! FT2 08:25, September 8, 2005 (UTC)
A so called "mega-tsunami" is just a BIG tsunami and the term was coined by the BBC and is used by the media not geologists - I am a professional geologist and volcanologist. The Geologist (talk) 20:39, 5 March 2008 (UTC)
thread_title:  Definition 

message: I took the image entry out; it should be on the tsunami page.  A megatsunami is caused by landslips falling into the ocean, not landslips beneath the ocean.  An illustration for this article would best be of Lituya Bay or whichever it was in Alaska which had the 5000'er back in the 1950s; there's images of the debris path, i.e. the wiped-out trees up to the elevation of the wave.Skookum1 08:03, 8 February 2006 (UTC)
thread_title: Image added is not of Megatsunami but Tsunami 

message: Anyone have any info about how high the waves were after the comet that killed the dinosaurs hit?--Threedots dead 22:50, 4 March 2007 (UTC)
thread_title:  Chicxulub Megatsunami 

message: This is only peripheral to the subject(s) of this discussion, but there is no geohazard article, which I find strange; is tehre something else those are called that could be redirected to?  As far as mega/tsunami geohazards, there are three specific ones in my part of the world (BC) - the conseuqnces of what's called The Barrier letting go into Daisy Lake and unlesashing a debris wave into Howe Sound, the potential/probable subsidence of Richmond, British Columbia in the even of "The Big One", and a chunk of Mount Breakenridge at the upper end of Harrison Lake, which like the Barrier could cause devastation far from the location of the event itself in that case, potentially as far as Bellingham Bay....).  Anyway no doubt there's no "potential megatsunami" section (or potential avalanche-caused wave or whatever); there must be a catalogue of such hazards somewhere; List of geohazards?? Maybe??Skookum1 (talk) 19:30, 2 March 2008 (UTC)
thread_title: [[Geohazard]]?

message: A list of geohazards includes "Tsunamis," but not "Mega-tsunamis." That is because scientifically and geologically there is no such thing. Since it does not exist scientifically or geologically it cannot present a hazard in any shape or form. The term "Mega-tsunami" was coined by the media - and the British Broadcasting Corporation was the first to use the term when they broadcast the Horizon programme "Mega Tsunami - Wave of Destruction" BBC2 12th October 2000. The fact that certain geologists / scientist have been recorded as using the term is because they are trying to ensure that the ordinary person (who is generally not scientifically literate), understands that "we" are talking about a tsunami of incredible proportions. The wave from a tsunami will vary in amplitude depending upon many factors and the most important of these is the amount of energy that generates the initial disturbance. The greater this energy the larger the initial amplitude of the wave. Lets assume for a moment that the initial disturbance inputs 20 x10^20 joules of energy into the wave. This will dissipate according to the inverse square root law which states that at a distance from the origin the energy will be dissipated by half. It works like this:
At the origin 2.2x10^25 joules (which is about 6x10^27 watts) were forced into the ocean. If the ocean is about 5000 km wide how much energy will hit the distant coastline?  E = ( P / 4 pi D^2 ) where E = the Energy at the distant point in watts per metre squared, P = the original power, pi = 3.142 and D = the distance in metres. By substitution it can be shown that at 5,000,000 metres (5000 km) the energy which will hit the coastline is in the order of 2.0E+07 or 20,000,000 Watts per metre square.
Just as there is no "mega-tsunami" there is no such thing as a "super volcano." Volcanologists refer to super-eruptions to indicate VEI 7 or 8 but again it is media generated and not all volcanologists use it. Also think of how many times you will have heard the term "Tidal wave" used when in actual fact the phenomena being reported was a tsunami and nothing to do with the tides. The Geologist (talk) 20:35, 5 March 2008 (UTC)
thread_title:  That is because it is already dealt with 

message: I found an an online cite and date for the Seton Portage slide; I'm searching for any geographic or geological or glciation studies which may detail it further; I left the cite tag because the comaprison toe he size of Lituya needs numerical/citation verification, though if you saw the valley/slide it's pretty clear there could not NOT have ben a slide; that could be better worded in teh aricle and hopefully te cite will do away with tneed for speculative langauge - once i find the cite(s).  Teh smaller one alogn Anderson I think I've got a shot of ,though from a distance; the conical fan into the lae has 60-degree sides from about 500' up the mountainsde, th reverse chtue at hte topc of the mountain is fiv e times its size; it alsocannotnot have made a wave......Skookum1 (talk) 02:22, 26 October 2008 (UTC)
thread_title: Seton Portage additions

message: A megatsunami caused by volcanic eruption devastated Crete around 1450 BC, destroying much of Minoan power and causing the Atlantis myth. This should be included. (Source: http://news.softpedia.com/news/A-Mega-Tsunami-Could-Strike-Mediterranean-Anytime-80609.shtml, among others.) —Preceding unsigned comment added by 69.90.50.237 (talk) 06:27, 8 April 2009 (UTC)
thread_title:  Minoans 

message: Should the  tsunami  caused by  that   volcanic  island that  exploded the entire     island  be a megatsunami as the  force from that  explosion would  most likely easily cause one.--83.70.105.68 (talk) 19:55, 17 August 2010 (UTC)
replies: text: I do believe the Krakatoa explosion would have rated on a scale approximate to that of a mega-tsunami (41 meter waves, if I recall rightly), however the term megatsunami is rather loosly defined. 174.29.238.192 (talk) 21:27, 18 April 2011 (UTC)
thread_title:  explosion 

message: Is there any chance that   the country im living in Ireland  be   hit by a    megatsunami    and has they ever been one   and   where would one come from and  what would  cause   it. --83.70.105.68 (talk) 19:58, 17 August 2010 (UTC)
thread_title:  question 

message: Reading the section on Hawaii, it suggests a wave traveling inland on the island 16 miles.
The island is 30 miles by 44 miles... Depending on the fine print (direction) a wave could only travel 15-22 miles inland before it was then proceeding back to the ocean -- on the far side of the island.  I don't suppose there is any elaboration of what is actually expected of such a wave?  174.29.238.192 (talk) 20:11, 18 April 2011 (UTC)
thread_title:  Hawaii and submersion 

message: The article starts with the phrase, "(also known as iminami (斎波, "purification wave"))" with a reference to  Brockway, Robert. Everything Is Going to Kill Everybody http://en.wikipedia.org/wiki/Megatsunami#cite_note-Brockway-0. It seems true that this book states "The Japanese call it iminami, which means "the purifying wave."". Still, I recommend to find Japanese citations for the use of the word "iminami", or to simply remove this phrase within the parentheses because, as a native Japanese speaker, I've never heard of the word "iminami". It sounds a non-word to me. I'm born and raised in Tokyo, and currently I'm a graduate student in computer science at a university of Tokyo.
As far as I can recall, both "iminami" and "斎波" have never been used in Japanese TV programs and Japanese newspapers.  I searched this word in Japanese Google, but I could not find any Web sites using this word to refer a big tsunami. Suspecting use in English, I searched "iminami" in both English Wiktionary and Urbandictionary.com, but none hits. Moreover, the character "斎" does NOT have the reading "imi" and the meaning "purifying", while the character "波" reads "nami" and means a wave or waves.
When referring to big tsunamis, we simply says "大津波", or "ootsunami" where "oo" means big. However, I think a "megatsunami" is not "ootsunami" as "ootsunami" is mainly used for big tsunamis in historic events. In contrast, this page defines a megatsnami as  "A megatsunami is meant to refer to a tsunami with an initial wave amplitude (height) measured in several tens, hundreds, or possibly thousands of meters". In my understanding, all the tsunamis of this scale that took place so far are prehistoric ones, not historic. Therefore, "ootsunami", the Japanese word for big historic waves, is not "megatsunami". If so, I think there's no word corresponding to "megatsunami" in the Japanese language. That's why I recommend to simply remove the phrase within the parentheses rather than to replace it to another Japanese term.121.3.142.72 (talk) 20:18, 9 August 2012 (UTC)
replies: text: After searching around a bit, I agree that this doesn't seem a common usage at all. So whether or not it exists, it shouldn't be in the article and I've removed it. Mikenorton (talk) 22:58, 9 August 2012 (UTC)
thread_title: Iminami, does this word really exist?

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thread_title:  External links modified (January 2018) 

message: I have edited the last section to say 
Previously the text said they were in "sharp disagreement" with the original authors. But there is no continuing debate in the academic literature of the type that a "sharp disagreement" would suggest. I think the new text more fairly summarizes the current status, even the original authors agree their study was based on worst case assumptions - and detailed papers since then have showed those assumptions don't apply to the Canary Islands in its current geological state. Also although a megatsunami is possible locally in the distant future, probably over 10,000 years in the future, with some geological evidence that it happened in the past, there is no evidence of such a megatsunami crossing the Atlantic. Outside of the mid Atlantic islands it would be a normal height tsunami according to recent modeling. This new material summarizes the Cumbre Vieja#Criticism section and uses cites from that section. Robert Walker (talk) 17:41, 29 June 2018 (UTC)
thread_title:  Canary Islands update 

message: I've updated this section also. Current opinion of volcanologists and geologists is that the megatsunami scenario is impossible except very locally. I cite a fact check article for National Geographic that interviewed an expert volcanologist and a geologist.  Robert Walker (talk) 17:59, 29 June 2018 (UTC)
thread_title:  Hawaii section update 

message: Global warming is causing increased melting of glaciers, and I have seen video of huge chunks of ice breaking off (calving?) and falling into the water.  Could this be big enough to cause a local megatsunami?  T bonham (talk) 20:06, 9 July 2018 (UTC)
thread_title:  Glacial melting cause? 

message: It seems that recently there's been some dispute on giant landslide driven tsunamis in Hawaii. While there is no convincing evidence that such an event is likely in the near future, it shouldn't be dismissed. I don't know why the community is so confused on this issue. So let me clear up a few things.
1. Giant and catastrophic flank failures happen on Hawaii. Anyone can pull up a google earth and see the remnants of giant landslides that clearly were not gradual or multistage events (https://en.wikipedia.org/wiki/Nu%CA%BBuanu_Slide). 
2. There are tsunami deposits from these landslides that are plastered up to 1000 feet up the sides of the islands. http://www.soest.hawaii.edu/SOEST_News/PressReleases/Megatsunami/ So they produce giant waves that devastate the islands. It's unknown and probably unlikely that they propagate outward and destroy distant shorelines. They haven't been observed so its difficult to say. 
3. They are extremely rare events and they're the favorite subject for scaremongers who spread confusion about the the true nature of these events. 
Conclusion: Giant tsunamis happen on Hawaii and they're caused by flank collapses. This is evidenced by deposits and observing the remains of landslides. They're extremely rare and probably don't destroy distant shorelines.  If you'd like to learn more, here's a PDF explaining the mechanics of a landslide. 
https://pubs.usgs.gov/pp/1801/downloads/pp1801_Chap4_Denlinger.pdf  — Preceding unsigned comment added by AndrewT2. (talk • contribs) 01:01, 29 December 2018 (UTC)
thread_title:  Megatsunami Evidence and disputes 

message: The important paper by Miller cited in footnote 6 (Miller, D.J. 1960. Giant waves in Lituya Bay Alaska. United States Geological Survey Professional Paper 354-C, pp. 51-86.) had been sourced to a web archive of a no-longer-present University of Wisconsin website which had a clunky translation of the paper into html. I have changed the source to the doi of the original paper, rather than the html version. In doing so, I've gotten a template error message. The footnote and link look okay and seem to work, so I'm uncertain what the error is. Perhaps an editor with more experience with formatting footnotes could discern my error and correct it. Thanks! MayerG (talk) 11:55, 9 November 2022 (UTC)
thread_title:  Miller's 1960 paper on Lituya Bay, Alaska