Megatsunami. The word accurately describes what it means. Where tsunamis are big, megatsunamis break all limits. Tsunamis are regular surfing waves compared to these guys. They can rise up to be 200 meter high wall of water, destroying everything on its path. Time to take a closer look.



On the subject tsunamis, Nathan posted this explanation:

(read it here)

There is no scientific definition of a megatsunami, but informally the term has been used for tsunamis with waves of height from 40 m to over 100 m. They are a local effect, either occurring on shores extremely close to the origin of a tsunami, or in deep, narrow inlets. The largest waves are caused by a very large landslide, such as a collapsing island, into a body of water. They can potentially reach 20 km inland in low-lying regions.

However: there are some exceptions. For instance La Palma.



La Palma is a small island in the Atlantic Ocean near the 'head' of Africa. It's part of the Canary Islands. At first site this island may seem small and unimportant, but looks deceive the eye. This little island could change the earth drastically.

La Palma is a highly volcanic island, with quite some vulcanoes still active. The structure of the ground is that of a specific kind of hardened lava. It is very porous, and water can easily find its way through there. And what, ladies and gentlemen, can water do what clubs and axes etc. can't? Split stone in two. Even the egyptians knew that; they used this technique to break large rocks in two for better handling (in short: crack in stone, wooden wedge in crack, water over wooden wedge, stone splits due to expanding wedge). But it's also the water that hollows out a granite stone. Put this ingredient into a cauldron and mix it with two-three active vulcanoes, connected to each other underground, ensuring they will erupt at the same time. Now light it.

See the catastrofe? Tons of debris, destabilized by the water slowly grinding out the vulcanic rock, have slid into the water, pushing thousands of liters of water away. This water will form into a wave. A wave that grows and grows until...



...it hits the US. That means that cities like Boston, New York, Philadelphia, Washington DC, Miami, but also Toronto, Pittsburgh are destroyed completely. Not to mention small islands in the Atlantic. Furthermore there will be earthquakes, weatherchanges (such as heavy rain, etc.). Thousands of people will be killed. The world economy, which is currently heavily depending on the US will collapse.

Not very nice eh?

Of course, this is the so-called 'worst-case scenario'. Happily, according to this article, the threat is exaggerated. They argue that instead of one big landslide, there will be ten much smaller landslides. These will create waves of course, but not even close to a tsunami.

The question remains a mystery. Of course we hope that this will never happen, but who knows? The best solution I can think of is that the American Government will take precaution measurements (like evacuation plans, bunkers, etc.) to save the people, and start researching ways of how to make buildings survive this mighty blow.

Some interesting articles:
http://news.bbc.co.uk/2/hi/science/nature/3963563.stm -- "Tidal wave threat 'over-hyped'"
http://archives.cnn.com/2001/TECH/science/08/29/tidal.wave/ -- "Scientists warn for massive wave"

WOW! That sounds insane. Getting hit with a water balloon can hurt, can't imagine what a 300 ft. wave traveling at 155 mph would feel like (hopefully wouldn't feel it at all). In your research of this, did you find an estimate of when this could happen? If Pittsburgh would be destroyed, it would be close to making it to me (Ohio). That would be a crazy distance for a wave to travel inland before being stopped. The way I'm visualizing it, the wave would be something like the one on a movie I saw, I just can't remember it's name.

It's the movie where a huge meteor is planned to hit the Earth, so they send out a team of astronauts to land on the meteor's surface and plant explosives in it to destroy it. They plant some explosives, but they only blow it into two meteors instead of one, causing more havoc! In the end, the astronauts decide to risk their own lives to destroy the meteor and save the world, but there was a huge wave that went a tremendous amount inland after part of the meteor hit the ocean. Anyone remember the name of that movie?

Back to the megatsunami. Would the volcanoes erupt sometime in the next decade, century, millenium? I'm hoping it never happens at all, because it take the lives of so many people. Like you also said, our economy would be in shambles from that. New York, Boston, probably all of the east coast cities would be destroyed.

I can't imagine the magnitude of something that could cause that, hopefully I never get the chance to see it either.

I've read somewhere they're planning to use controlled explosions in order to break the part of the mountain in to little pieces. I just hope it doesn't work out like the astronauts in that film (two waves, -ouch-). It is still active, that volcano, so if it doesn't go to sleep in the next century, I wouldn't have high hopes.

As long as the US government recognises the danger in time, the damage could be limited, or even prevented. It is important that people need to know that this danger is something that could really do something mean.

Hmmm I see a movie production here. Do we have any producers in the forum?
This is the way producers make chart busting movie, by exaggerating the reality of something that’s possible but not that catastrophic.

Remember “The day after”?

Well, as a matter of fact, I do make movies with my friend. And I stated alreaduy that this is the 'worst-casescenario'

i dunno about this island but i have read somewhere that the Yellowstone National Park in america is a volcano that is 60 years overdue.......when this volcano erupts (which could be anytime now) it will be worse than a full fledged nuclear attack on America and the results would be lethal

Yep, the film is called Deep Impact, released in May 1998. Its strange that you should bring it up, I was thinking about that film recently (ooh, ESP ). Anyway, more info about the film here - http://www.imdb.com/title/tt0120647/ and http://en.wikipedia.org/wiki/Deep_Impact_%28movie%29


A while ago Horizon (BBC Science Program for those of you outside the UK) had a program about megatsunamis, it was pretty interesting. They said about the island mentioned earlier, and showed pictures from after the tsunami hit; the whole side of the island had the trees torn off it. It would be terrifying to have something like that happen somewhere populated, although I doubt there are large enough land forms to create a landslide big enough to do that sort of thing, so I think we'll be okay.

That's pretty scary.. I live on a little island.. But it's at the bottom of Australia and we're just above the Roaring Forties or whatever those Southern winds are called. Seeing a huge thing like that over half the horizon would be horrifying. I think my parents have this huge fear of something like a megatsunami happening, so our house has always been either very much inland and landlocked or on top of some kind of mountain/hill thing. Though there's no real worry of anything like that happening, as our city is on the bank of a very deep river which narrows as it goes, so the damage and impact would be kept to a fairly thin line down in the waterfront.

The geography of places is really complicated, and I recently read a book called The Day the Sky Fell: In Search of Atlantis (by Rand & Rose Flem-Ath) which says something like a huge tsunami caused by a thing called crust displacement could have caused the burial of the city of Atlantis under Antarctican ice and may also have caused or been a catalyst of ice ages.

A couple of months after the tsunami in Southeast Asia I read about this mega-tsunami in a Dutch magazine called Quest. I didn't really find it scary. Well, the Netherlands aren't really in the line of the tsunami, so that makes sense. I don't think you should really do anything against these kind of things. They happen. And I think all the attention to these things is a bit exaggerated. People need something to fear. That volcano that's 60 years overdue (I wouldn't be surprised if it were 600 years overdue, nature has no schedule) is going to blow anyway. Always remember that fear leads to consumption. And I'm not saying that a volcano that erupts is just tough for the people that are struck, but what are you going to do? Evacuate all places on Earth that might threaten life? In that case I hope NASA starts building a colony on Mars, soon. But nevertheless I hope the megatsunami-scenario will never really come true. That it stays a scenario.

man that's scary as hell! it sucks for the people who'll get to experience this, that's if that's how threatening it is as it sounds... you guys should check out Yellowstone Park. i saw that on Discovery Channel. really scary!