# Mega-tsunami as terrorist threat **URL:** \ **Category:** Factual Questions\ **Created:** [February 11, 2003, 11:57pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472 "2003-02-11T23:57:13Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Urban\_Ranger](https://avatars.discourse-cdn.com/v4/letter/u/e9c0ed/32.png) [@Urban\_Ranger](https://boards.straightdope.com/u/Urban_Ranger)\ **Post date:** [February 12, 2003, 1:12pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/21 "2003-02-12T13:12:22Z")
> [@](#): > > \*Originally posted by jjimm \* > You can shift very heavy objects with very small forces if they’re precariously balanced. The rocks are not that precariously balanced. Otherwise, a small earth quake would havd had done it already. ---
**Author:** ![jjimm](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@jjimm](https://boards.straightdope.com/u/jjimm)\ **Post date:** [February 12, 2003, 1:22pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/22 "2003-02-12T13:22:12Z")
> [@](#): > > \*Originally posted by Urban Ranger \* > \*\*The rocks are not that precariously balanced. Otherwise, a small earth quake would havd had done it already. \*\* **Urban** , read the article: it’s _a matter or time_. A small earthquake could have done it already, or could do it tomorrow, or in 200 years. It’s not like a potential event will never happen simply because it hasn’t happened yet. ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [February 12, 2003, 2:59pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/23 "2003-02-12T14:59:53Z")
A point of information… While the highest tsunami on record might have occurred in Lituya Bay, Alaska, it was under unusual circumstances in that it was caused by a landslide that created a wave surging up the slope on the opposite side of the narrow bay. These conditions are hardly what you’d find associated with the Canaries. [link](http://www.pmel.noaa.gov/tsunami/Faq/x005_highest) ---
**Author:** ![micilin](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@micilin](https://boards.straightdope.com/u/micilin)\ **Post date:** [February 12, 2003, 5:33pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/24 "2003-02-12T17:33:27Z")
**lieu** , the Lituya Bay tsunami was actually referenced in the program as the inspiration/model for the behaviour of the possible Canaries mega-tsunami. Its also mentioned (indirectly) on the site I linked to above. Admittedly this was a typically hysterical Horizon Chicken-Licken special, but the point of the program is that the circumstances for the Canaries are just those of Lituya bay scaled up. YMM and more than likely will V. Mine does! And **cart** , let sleeping dogs lie! Especially ones that weigh 500,000,000,000 tonnes! ---
**Author:** ![wevets](https://avatars.discourse-cdn.com/v4/letter/w/e9a140/32.png) [@wevets](https://boards.straightdope.com/u/wevets)\ **Post date:** [February 12, 2003, 8:05pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/25 "2003-02-12T20:05:37Z")
I remember watching the program on Discovery a few months ago… I was under the impression that the portions of the program that referred to a single mega-tsunami ‘wiping out the entire Eastern Seaboard’ were somewhat hyperbolic. It appeared that what was done to obtain the information presented in the program was merely to calculate how high a wave could be caused by the collapse of the mountainside, then calculate how much of the US East Coast would be less than that hight above sea level. There are two big problems I have with accepting such a calculation at face value: One is that in the historical past, tsunami events have had much more localized effects, for example the waves caused by the 1964 earthquakes in Alaska did not equally inundate the West Coast. Crescent City, CA suffered 11 deaths, while all of the Oregon coast suffered 4 deaths, and the entire coast south of Crescent City suffered zero deaths. Source: [http://www.ngdc.noaa.gov/seg/hazard/tsudb.html](http://www.ngdc.noaa.gov/seg/hazard/tsudb.html) The other big problem I have is that AFAIK, there’s no geological or biological evidence of a tsunami affecting such a massive area as the entire East Coast. If this sort of mega-disaster does happen from time to time, you’d think such mega-tsunamis would leave a mark that someone would have noticed. Instead we find evidence of tsunamis affecting localized areas (such as the evidence from the forest community around Lituya Bay). So I suspect the Discovery program was a bit over-sensationalized, and that the collapse of the Canary Island volcano would cause a huge disaster: a tsunami, but that it would be unlikely to affect the entire East Coast equally, as was assumed in the scenario presented. Although, I do have to admit that a bigger wave makes for better TV. 😉 ---
**Author:** ![Thaumaturge](https://avatars.discourse-cdn.com/v4/letter/t/858c86/32.png) [@Thaumaturge](https://boards.straightdope.com/u/Thaumaturge)\ **Post date:** [February 12, 2003, 9:43pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/26 "2003-02-12T21:43:55Z")
Well, as far the claim that there is no evidence of large waves affecting large areas goes, there is evidence in Australia of a 1000 foot wave washing up on large sections of the coast thousands of years ago. The likely cause of the Wave was one of the many Hawaiian landslides that have occurred, and that were recently discovered via advanced seafloor mapping. On the southeast side of the Big Island of Hawaii, there is a large crack opening up, and someday that whole section of land will fall into the sea. There is evidence on the seafloor of dozens of these landslides occuring all along the Hawaiian archipeligo over millions of years. Apparently volcanoes in the ocean don’t build the most stabile of foundations. My theory is based on the way that lava forms rock underwater. It forms rounded “pillow rock”, that stacks upon itself in a loose manner. Add to this relatively unstable base the expansion and contraction that volcanoes undergo, and you have perfect conditions for a large landslide. Underwater volcanoes are giant rubble piles waiting for an excuse to fall. ---
**Author:** ![cart](https://avatars.discourse-cdn.com/v4/letter/c/3ec8ea/32.png) [@cart](https://boards.straightdope.com/u/cart)\ **Post date:** [February 13, 2003, 11:40am UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/27 "2003-02-13T11:40:39Z")
> [@](#): > > \*Originally posted by micilin \* > \*\*And **cart** , let sleeping dogs lie! Especially ones that weigh 500,000,000,000 tonnes! \*\* What? I was just looking. 🙂 [drops chisel] ---
**Author:** ![Urban\_Ranger](https://avatars.discourse-cdn.com/v4/letter/u/e9c0ed/32.png) [@Urban\_Ranger](https://boards.straightdope.com/u/Urban_Ranger)\ **Post date:** [February 13, 2003, 12:10pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/28 "2003-02-13T12:10:04Z")
> [@](#): > > \*Originally posted by jjimm \* > **Urban** , read the article: it’s _a matter or time_. A small earthquake could have done it already, or could do it tomorrow, or in 200 years. It’s not like a potential event will never happen simply because it hasn’t happened yet. I didn’t say that. I merely pointed out volcanic eruptions are frequently accompanied by small earthquakes. ---
**Author:** ![newcrasher](https://avatars.discourse-cdn.com/v4/letter/n/b3f665/32.png) [@newcrasher](https://boards.straightdope.com/u/newcrasher)\ **Post date:** [February 13, 2003, 12:44pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/29 "2003-02-13T12:44:23Z")
> [@](#): > > \*Originally posted by jjimm \* > \*\*I watched a documentary recently about the natural danger posed by the Canaries - I’ll answer a few comments based on my recollections of the program. \*\* Its a sad, sad day when the fear mongers have us discussing saving ourselves from little yellow birds… ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [February 13, 2003, 1:05pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/30 "2003-02-13T13:05:24Z")
> [@](#): > > Its a sad, sad day when the fear mongers have us discussing saving ourselves from little yellow birds… If the event is inevitable, as they say, sooner or later the amount of energy needed to trigger it will pass through the range that a little yellow bird can deliver by landing on a bush. I say we should take pre-emptive action and kill all these little yellow birdies. 😉 ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [February 13, 2003, 3:45pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/31 "2003-02-13T15:45:50Z")
Go here– [http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=162871](http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=162871) BLAST IT!!! Everybody in this thread read the link!!! :mad: ---
**Author:** ![NurseCarmen](https://avatars.discourse-cdn.com/v4/letter/n/5daacb/32.png) [@NurseCarmen](https://boards.straightdope.com/u/NurseCarmen)\ **Post date:** [February 13, 2003, 4:01pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/32 "2003-02-13T16:01:58Z")
> [@](#): > > \*Originally posted by Zagadka \* > \*\*Unless Osama shaves his head, gets a furless cat and starts wearing quasi-futuristic clothing, I think this is a pretty goddamned unlikely scenario :-p \*\* I hate to point out that UBL _no longer shows up on videotape!_ In the audio tape recently released, technicians are fairly certain that some of his mispronunciations are due to his pinky being placed at the corner of his mouth. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 13, 2003, 4:24pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/33 "2003-02-13T16:24:24Z")
It’s not an tsunami, but a global catastrophe is caused by a strategically placed atomic bomb in [Mother of Storms, by John Barnes](http://www.amazon.com/exec/obidos/tg/detail/-/0812533453/ref=cm_cr_dp_2_1/103-3312852-0368660?v=glance&s=books&vi=customer-reviews). ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [February 13, 2003, 4:30pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/34 "2003-02-13T16:30:53Z")
**Bosda** , what’s your problem today? Nobody’s running screaming from the thread and grabbing their water wings. They’re discussing the technical merits of the possibility this may someday occur and whether or not the results would have a widespread effect. Calm down. ---
**Author:** ![NurseCarmen](https://avatars.discourse-cdn.com/v4/letter/n/5daacb/32.png) [@NurseCarmen](https://boards.straightdope.com/u/NurseCarmen)\ **Post date:** [February 13, 2003, 4:37pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/35 "2003-02-13T16:37:25Z")
> [@](#): > > \*Originally posted by Urban Ranger \* > \*\*The rocks are not that precariously balanced. Otherwise, a small earthquake would have done it already. \*\* On the documentary they show the geologist walking along a fissure that was created during an eruption several decades ago. The fissure was a couple meters wide. The cause of it was the different rock types on the island, and the reaction of those types to super-heated steam. The steam actually caused one large chunk of the island to slip and slide on top of the main portion of the island, which caused that separation. An A-Bomb wouldn’t create the same type of situation. Instead of getting a large mass to slide into the ocean, it would vaporize a big chunk, and strew debris over a large area. Not to say that this wouldn’t cause some problems in itself as water came rushing back in to fill the void. It just wouldn’t be as effective at mega-tsunami creation as some good old fashion steam. The US navy should keep their eyes out for several \*\*Stanley Steamer Carpet Cleaner[sub]TM[/sub] \*\*trucks headed for the Canaries. ---
**Author:** ![tanstaafl](https://avatars.discourse-cdn.com/v4/letter/t/ba8739/32.png) [@tanstaafl](https://boards.straightdope.com/u/tanstaafl)\ **Post date:** [February 13, 2003, 5:07pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/36 "2003-02-13T17:07:22Z")
> [@](#): > > _Originally posted by newcrasher_ > **Its a sad, sad day when the fear mongers have us discussing saving ourselves from little yellow birds…** > [@](#): > > _Originally posted by Squink_ > \*\*If the event is inevitable, as they say, sooner or later the amount of energy needed to trigger it will pass through the range that a little yellow bird can deliver by landing on a bush. I say we should take pre-emptive action and kill all these little yellow birdies. \*\* \ \ Just wanted to point out that the Canary Islands are actually named for dogs, not birds. Their original Latin name is _Insularia Canaria_ which means “Island of the Dogs”. We now return you to your originally scheduled thread… \ \ ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [February 13, 2003, 5:22pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/37 "2003-02-13T17:22:56Z")
Are you suggesting that dogs migrate? ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [February 13, 2003, 5:38pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/38 "2003-02-13T17:38:38Z")
So you’re saying is that we should planning to kill all the little yellow dogs too ? :dubious: ---
**Author:** ![wevets](https://avatars.discourse-cdn.com/v4/letter/w/e9a140/32.png) [@wevets](https://boards.straightdope.com/u/wevets)\ **Post date:** [February 13, 2003, 9:20pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/39 "2003-02-13T21:20:12Z")
> [@](#): > > \*Originally posted by Thaumaturge \* > Well, as far the claim that there is no evidence of large waves affecting large areas goes, there is evidence in Australia of a 1000 foot wave washing up on large sections of the coast thousands of years ago. The likely cause of the Wave was one of the many Hawaiian landslides that have occurred, and that were recently discovered via advanced seafloor mapping. I hadn’t heard of it. I’m surprised they didn’t mention it in the Discovery program, as it would shore up a big hole in their case. Could you point us to a site, or other cite, for the evidence? ---
**Author:** ![wevets](https://avatars.discourse-cdn.com/v4/letter/w/e9a140/32.png) [@wevets](https://boards.straightdope.com/u/wevets)\ **Post date:** [February 13, 2003, 9:35pm UTC](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472/40 "2003-02-13T21:35:58Z")
Ah, I found it. [http://atlas-conferences.com/cgi-bin/abstract/caiq-39](http://atlas-conferences.com/cgi-bin/abstract/caiq-39) > [@](#): > > The modern world appears secure in its knowledge of hazards. However tsunami today occur at a frequency and magnitude that is less than the prehistoric record. The size of some of these past events in the Australian region, as shown by geological evidence, is beyond the capability of earthquakes, _while their regional extent rules out submarine landslides_. This evidence consists of dump deposits on headlands 40-130 m in height, boulders 6 m in diameter stacked in aligned piles in front of cliffs at sheltered locations, bedrock sculptured into forms similar to those carved by catastrophic floods from ice sheets, and deposition of strandlines up to 35 km inland. Only meteorite or comet impacts with the ocean can generate tsunami big enough to produce these features. Radiocarbon dating along the Southeast Coast of Australia indicates that these events have occurred at a periodicity of around 400-500 years throughout the Late Holocene. (Italics mine) Perhaps I should have been more clear. I believe the Discovery program was being excessively alarmist about the mega-tsunamis generated by landslides, both coastal and submarine. I have no difficulty believing that the impact of an asteroid or comet would create a wave of devastating proportions, but that’s a very different threat than the one emphasized in the program. I should probably also note that Dr. Bryant’s interpretation of the evidence is not accepted by all geologists. [Previous page](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472.md?page=1) [Next page](https://boards.straightdope.com/t/mega-tsunami-as-terrorist-threat/154472.md?page=3)