Tsunami Risk Of Asteroid Strikes Revealed

New Scientist ^ | 5-12-2006 | Jeff Hecht

[null and void]

Something like 80% of the world's population lives within 200 ft of sea level

[null and void]

It would be like the Boxing Day Tsunami - on steroids.

At it's worst that one went a few miles inland. I'd guess an event as big as the ones we're contemplating would sweep in 10's of miles to max low hundreds of miles.

OTOH, all the falling ejecta, live steam, continent wide fires and blast might make it moot.

Sweet dreams...

[timer]

At 3000' elevation I must be doing something right. Are you in the "high and dry" real estate business? If so, you might want to let prospective buyers know that 80%/200' factoid.

[timer]

Ah, come-on, that's an ugly potato you dug out of your garden, right? Really though, in the movie : INDEPENDENCE DAY the defsec asked "Why not just nuc it?" "What? And turn a big asteroid into a million small asteroids that will still hit the earth?" The (1908)Tunguska meteorite was most probably a BLACK burnt out comet nucleus. Being COAL BLACK astronomers wouldn't even see it before impact. But the usual tsunami wave is caused by common earthquakes, not rarer meteorites, and the possible La Palma Island landslide would devastate the east and gulf coasts. Even with 8 hours notice you couldn't get everyone out to high ground, and every coastal city would be down to bedrock. Over the last 100 years Hawaii has gotten hit with a tsunami about every 10 years on the average, it's been 30 years since the last one...

[SunkenCiv]

Thanks.

[Robe]

If anyone is interested....

My wife found the book (paperback)at a place in ROCK Hill,SC called the BOOK RACK, they specialize in out of print and hard to find books...they are a major supplier to Amazon I'll be happy to research the Phone # if anyone is interested

Robe

[null and void]

Nah, I got my ex's house (she got mine). It's on a flood plain, in a high earthquake risk area, on a main drag, 100 years old, and on a frickin' Super Fund site.

Worth it to get rid of her, though...

[timer]

She probably says the same thing, and now if only an earthquake would come and swallow him...

[null and void]

I think she's holding off on that until the child support expires...

[USFRIENDINVICTORIA]

I was only being half serious about the "live on high ground" answer. I live about 20 feet above sea level, so I'm obviously not taking my own advice. However, "move to high ground" (or make the ground higher) would be the best answer for most people living in river flood-plains, or places like New Orleans.

Other posters have mentioned the obvious alternative solution for rouge asteroids -- nuke 'em, or nudge them out of the way.

There are so many potential deadly or costly scenarios that we could try to protect against -- we could easily expend all of the world's resources in a futile attempt to do so. The so-called "precautionary principle" tossed around by global warming fear-mongers as a rationale for dismantling the world's economic system "just in case" is an example. No matter how much lipstick is put on that pig, it remains nothing more than a very expensive and untried insurance policy, for an unproven risk.

If an asteroid hit an ocean, and if the barrier worked, then the price might be worth it. Those are big ifs. The energy in a wave varies as the square of the wave's height. A barrier that could stand up against a 300 ft high wave would have to be at least 100 times as strong as one that could withstand a 30 ft. wave.

[timer]

Yes, saw a poster somewhere once, listing dangers from many different causes. Chicken little(the eco-fear mongers), is obviously one extreme; naively bumbling through life is the other. A prudent man takes prudent precautions. Noah built a 3 layer log raft in his orchard, his neighbors laughed...and got washed away in the storm surge(15 cubits deep)of a 4 day hurricane. He got washed out to sea, and survived. His descendents jazzed up the story a bit and a young pakistani boy named ABRAM swallowed the myth whole....So, are YOU going to take prudent precautions(your own "raft")or, at 20' above sea level, get washed away with the rest of them? They don't want to take prudent precautions(a flood road)? Fine. As a SURVIVOR you get to inherit the now washed-clean coastline...Two basic lessons from katrina(ala Rush Limbaugh) : siltation over 300 years and the self-reliant survived, those who waited for government "help" suffered and died. Also, look at the pictures of the buoyant concrete road sections sitting askew on top of the pylons of the freeway that runs across the lake.

[timer]

Child support? Well, as the earthquake or tsunami swallows you, be "comforted" that you won't have THAT burden to bear any longer.

[USFRIENDINVICTORIA]

Of course, Noah had advance warning from a very reliable source -- the source even provided detailed engineering specifications.

Some sort of coastal protection system (such as a buoyant road) could be useful for any city near the Juan de Fuca plate; as protection against the tsunamis created by the inevitable major earthquakes. The tsunami advance warning system in place now is also very sensible -- it won't prevent property damage; but it will save lots of lives.

However, the thread was discussing impacts from giant asteroids -- possibly producing 300 ft high waves. Nothing man-made, and affordable on a coastal scale would be able to withstand waves that large.

[RegulatorCountry]

From what I can tell, the velocity of at least the initial tsunami would be a factor, too. A 300 foot wave moving at something like 200 mph or more would be geography-altering. I can't think of too many manmade structures that wouild endure it. The Great Pyramids or something akin to them might, but not much else.

[devane617]

This is one of those situations that nobody believes until it happens. I have no basis for my guess, but major, catastrophic disaster is probable.

[null and void]

I don't mind the child support. I resented alimony.

[USFRIENDINVICTORIA]

Tsunamis slow down as they build up height; but a 300 ft. wave would still be moving rapidly enough to alter the geography. From where I live, if I had about 20 minutes notice, I could get to high enough ground to be safe -- provided that no one else knew this, so the streets wouldn't be gridlocked. Otherwise, I might as well try surfing.

[timer]

Yup, after 2 wives, finally figured it out : women cost MONEY. Been a happy bachelor since 1979. Funny statistic : if a guy makes it into his 80s there's 8 women for every guy, why wasn't it that way in HIGH SCHOOL?

[timer]

The Juan De Fuca straight between the olympic peninsula and vancouver island : perfect funnel for a tsunami wave to slam into whidbey island/discovery passage. I built a mansion for my sister in 1986-7 200' above the skagit valley, right in the path of that funneled tsunami wave(discovery passage is directly to the west). So if the WAVE doesn't get them they'll have a ring side seat to all those skagit valley tulips washing out to sea...Yes, good point, you could do a flood road for river floods, hurricane storm surges but a MAJOR tsunami? At that scale it's just nature's roll of the dice, if your number is up....And too, the 20 comet fragments that impacted Jupiter in 1994; if that had happened to the EARTH, we would have been GONE 12 years ago...cosmically **** DOES happen.

[RegulatorCountry]

Well, maybe I'm misinterpreting the graphic at the top of this thread, but time lapsed is four hours, and some level of inundation is shown in the Mississippi Valley beyond the extent of the frame, which I am guesstimating to be at least 600 miles. That distance in four hours is 150 mph on average, and it seems to me that forward momentum would be greatly reduced, the further inland it goes. That's why I was, and might still be, under the impression that tsunami generated by asteroid impact, as modelled in the article, is going to be moving at a speed and at a scale that is not exactly comparable to an earthquake generated tsunami.