Megatsunami

Does anybody know how far you have to be away from the coast when a megatsunami of lets say 500 meters height hits the shore?

Is there any formula to calculate this?

[edit on 12-9-2007 by Terrapop]

[edit on 12-9-2007 by Terrapop]

It would it would be different from location to location. I mean off the top of my head, I can think of several factors that would make for a complex formula. You've got elevation, you've got vegetation, you've got type of soil, you've got other geographical features. It's not so clean cut.

Edit: It, not I...

[edit on 12-9-2007 by Beachcoma]

Not sure anyone's ever worked out any formula. But the only way we'd get a tsunami like that would be as a result of a massive meteorite impact which frankly, would not leave the world as a nice place to live .....

It is not the height of mega tsunami - because it does not just splash on the shore, but it travel 20 miles inland.

Where could the next Mega Tsunami come from

A volcano named Cumbre Vieja on the island of La Palma in the Canary Islands of North Africa is where geologists suspect the next tsunami could begin. The reason for the concern... In 1949 during a volcanic eruption part of the island slid into the ocean before ending its descent. Should another large eruption of the Cumbre Vieja occur, the western side of the island is likely to collapse into the Atlantic.

Predicting the next eruption isn't a likely happening; geologists cannot say whether or not the next eruption will be the one to make the island shed its western shore. Until then, we have to watch and wait.

500 billion tons of rock creating five thousand trillion, (that's fifteen zeros), joules of kinetic energy, that is transferred and converted to a 600 to a thousand meter tall wave with excessive speeds. Ten minutes and it will have traveled 250 kilometers, all the while powered by the underwater landslide.

Fantastic film here: Mega Tsunami // Discovery Channel

Well, I was not looking for an exact formula, but just wanted to know if you live say 100km away from the coast, what roughly must hit the shore to affect you...?

[edit on 12-9-2007 by Terrapop]

It depends on where you are. The height of the tsunami is determined by how shallow the coastal waters are, and how far it travels inland obviously depends on whether it's hitting a low lying area or a mountainous one.

Asa rule, if you live a few hundred feet above sea level you'll be safe except form the sort of tsunami which you probably wouldn't want to survive.

reply to post by Terrapop


It's still hard to say. I watched a show about the Boxer Day Tsunami, and they showed that in some places that were closer to the source of the wave the body water travelled further inland because the soil there was the type that tends to be silty and muddy. So it sort of created a lubricating action for the wave to travel further in.

In other areas the wave was higher, but because the coast was lined with mangrove, it created a sort of water break and slowed the impetus. Still in another location, the land inclination was higher but because there wasn't much to stop the waves it just rolled over the little hill.

In your case, I think you only have to worry about a comet hitting just off shore. 100km inland sounds far enough to avoid most earth-movement based tsunami. Maybe.

Originally posted by Terrapop
Does anybody know how far you have to be away from the coast when a megatsunami of lets say 500 meters height hits the shore?

For a tsunami that high it takes an asteroid that killed the dinosaurs. Getting to high ground will be just one of your insurmountably high number of problems. Some result of tsunami simulations for meteor impact and inland propagation:

www.challenge.nm.org...

Tsunamis above 100m height are possible though without requiring such radical events, just a massive landslide and something like a closed bay area suffice. Those are very local events though.