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The Coming Atlantic Mega-Tsunami
rbrander writes "It's not news at all that scientists predict an eventual "mega-tsunami" that will sweep across the Atlantic that will still be anything from 60 to 150 ft high when it hits the U.S. Eastern seaboard. This Old News, however, suddenly seems fresh. Like an asteroid hit, it could be millenia away, or tomorrow, that a volcano in the Canary Islands just off Africa drops half a trillion tons of rock into the Atlantic.
A short description of the problem from BBC News and some more graphic descriptions (of up to 100 million dead) and shrewd commentary on the politics of warning from journalist Gwynne Dyer."
As anyone who's seen the video's of the Asian Tsunami at video.contemporaryinsanity.org knows, this is not a pleasant thing to contemplate...
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Here's the Wiki link for a Megatsunami. Here's an excerpt:
"During an eruption that is anticipated to occur sometime within the next few thousand years the western half of the island, weighing perhaps 500 billion tonnes, will catastrophically slide into the ocean. This will inevitably generate a megatsunami which will travel across the Atlantic and strike the Caribbean and the Eastern American seaboard several hours later with a wave possibly 90 meters (300 feet) high, resulting in massive coastal devastation.
I don't think that is true. There are 2 systems in the Pacific but because Tsunamis are very rare in the Atlantic there is no early warning system.
There's some bad science in the post, especially the comment about the wave being 'still' that high. Most tsunamis are very small out in the ocean, most less then a few centimeters tall.
They don't get big until they approach the shore and the depth gets shallow.
The small waves, btw, travel around the speed of a jetliner, hence the lack of warning.
At least in the Atlantic, we have an early warning system for Tsunamis
Untrue. The Pacific has the only dedicated system (although Tsunamis may be inferred from other equipment like tidal gauges.)
I assume this has been contemplated, but couldn't we cause the threatening hunk of rock to slide in a safer direction? Like cutting down a tottering tree?
One man's -1 Flamebait is another man's +5 Funny.
I heard an interview with someone from NOAA with the Pacific Marine Environmental Laboratory in Seatle that described what happens when a Tsunami occurs. He said when the wave travels through deep water it has tremendous speed (hundreds of mile/hour) but is only a few feet high. As it comes into shallow water the wave slows down to 10s of miles/hour and that causes the huge wall of water. So a Tsunami is not really a 100 ft wave as it travels through the ocean only once it nears land.
Just my $.02.
Now I can change my
My God, it's Full of Source!
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Lame. Come on, people. Let's take a look at this with a critical eye before everyone panicks. You post a BBC article from 2000? The BBC ran a more recent article with more recent findings.
Tidal wave thread 'over-hyped'
Summary: Evidence suggests slides on the Canary Islands to happen in small, incremental slides. The huge collapse is sensationalism and the absolute "worst-case scenario"
That's a three foot wave hitting the U.S. Eastern seaboard after a worst case collapse at La Palma. The paper is very detailed and worth a read.
This is what the real experts think about this. The topic of the mega-tsunami is at the end of the FAQ. So
read it and learn something.
Note that one could point to a lot of active oceanic volcanoes and pose a similar threat level if one considers a tens of thousand of years time frame.
Another side note: When I was in grad school, I was the TA for one of the committee members.
6 hours+. Plenty of time to evacuate a lot of people.
A lot, yes. Most, no. Consider New York City. Eight million residents, and millions more day workers. Roads which come to a stop and trains which totally fill just getting the day workers out each evening. People will try to retreat to high buildings and hope the foundations hold (probable, most are attached to bedrock) - but in the outer boroughs homes are mostly just a few stories. Will these folks be welcomed in the skyscrapers even if they get there? Plus, all of Long Island will be trying to evacuate over the same bridges used by the city.
"with their freedom lost all virtue lose" - Milton
[We're] talking trillions of tons of rock off an active volcano, which might even distrub it enough to set it off anyway.
The mechanism of exploding mountains, as discovered when Mt St Helens went "bang" is:
- Pressure builds up, bulging the mountain upward.
- Suddenly the bulging causes the side of the mountain to slide off.
- With the weight suddenly removed, the pressure blasts the remaining portion of the mountain into dust and up into the stratosphere.
So IMHO attempting to remove the loose slab, slowly and gently, from the intermittently-active volcano (which is thus inactive now because the weight above it is enough to keep the lava and gas bottled up) very likely WOULD wake it up. If that happens, the part that isn't moved yet might just go right away.
And given that the slab is already slipping off slowly, disturbing it by trying to disassemble it risks finishing the job of loosening it and precipitating the event you're trying to avoid.
Kinda like defusing a BIG bomb. Or taking apart a large pile of jackstraws without having any of them collapse.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Unfortunately, waves do not travel in straight lines (well, not in the way described). Waves act as if they are recreated at each point in the wavefront, which allows them to turn around corners.
This is highly dependant on wavelength to aperature ratio, which is why you can hear sounds around a corner, but not see around one.
while (sig==sig) sig=!sig;
Perhaps no one hears about these 'mega-tsunamis' much from the media because most scientists agree it could never happen? From http://www.sthjournal.org/media.htm :
....Volcanoes on La Palma ... and Hawaii", George Pararas-Carayannis, in Science of Tsunami Hazards, Vol 20, No.5, pages 251-277, 2002.
Here are a set of facts, agreed on by committee members, about the claims in these reports:
- While the active volcano of Cumbre Vieja on Las Palma is expected to erupt again, it will not send a large part of the island into the ocean, though small landslides may occur. The Discovery program does not bring out in the interviews that such volcanic collapses are extremely rare events, separated in geologic time by thousands or even millions of years.
- No such event - a mega tsunami - has occurred in either the Atlantic or Pacific oceans in recorded history.
- The colossal collapses of Krakatau or Santorin (the two most similar known happenings) generated catastrophic waves in the immediate area but hazardous waves did not propagate to distant shores. Carefully performed numerical and experimental model experiments on such events and of the postulated Las Palma event verify that the relatively short waves from these small, though intense, occurrences do not travel as do tsunami waves from a major earthquake.
- The U.S. volcano observatory, situated on Kilauea, near the current eruption, states that there is no likelihood of that part of the island breaking off into the ocean.
- These considerations have been published in journals and discussed at conferences sponsored by the Tsunami Society.
Some papers on this subject include:
"Evaluation of the threat of Mega Tsunami Generation From
"Modeling the La Palma Landslide Tsunami", Charles L. Mader, in Science of Tsunami Hazards, Vol. 19, No. 3, pages 160-180, 2001.
"Volcano Growth and the Evolution of the Island of Hawaii", J.G. Moore and D.A.Clague, in the Geologic Society of America Bulletin, 104, 1992.
According to this site, a magitude 10 would release some 1 trillion tons equivalent of energy, and would be the equivalent of a "San-Andreas type fault circling Earth."
A magnitude 12 would be 160 trillion tons equivalent, and would "fault Earth in half through center."
You can never go home again... but I guess you can shop there.