Posted on 12/09/2006 2:24:21 PM PST by Lessismore
It's a terrifying vision: A violent eruption of Italy's Mount Etna triggers a massive collapse of one flank of the volcano, sending 35 cubic kilometers of debris--the equivalent of 10,000 Cheops pyramids--hurtling at 400 kilometers an hour into the Ionian Sea. The Big Splash unleashes a 50-meter-tall wall of water that, within a few hours, wipes out coastal settlements across the Mediterranean. This catastrophe happened 8000 years ago--and a Mediterranean monster of similar magnitude could happen again.
That's the scenario invoked in an analysis in last week's Geophysical Research Letters. "It was an extraordinary event, probably the largest tsunami unleashed in the Mediterranean in the past several millennia," says co-author Maria Pareschi of the National Institute of Geology and Volcanology (INGV) in Italy, whose team announced its findings at a press briefing in Rome on 5 December.
The paper may solve a long-standing puzzle about the cause of an ancient, devastating tsunami known from sea-floor sediments. "This is a very careful and reasonable work," says Stéphan Grilli, an ocean engineer at the University of Rhode Island, Narragansett. Not everyone agrees. The INGV model has fatal flaws, argues Costas Synolakis, a top tsunami modeler at the University of Southern California in Los Angeles. "The lost tsunami is yet to be discovered," he says.
The Mediterranean basin is a crucible of killer waves. More than 300 tsunamis have been recorded in the last 3300 years, with volcanic activity known to have triggered a dozen in the last 2 millennia. The most recent occurred in December 2002, when a colossal chunk of the Stromboli volcano slid into the Aeolian Sea, creating a 10-meter-high tsunami that snapped moorings of oil tankers in Milazzo harbor 100 kilometers away but did little other damage.
That was a kiddy wave compared to one that left a trail of sediment between Sicily and North Africa. The leading suspect has been a collapse of the Santorini volcano in the Aegean Sea some 3600 years ago. However, INGV's simulations suggest that the Santorini event was largely confined to the Aegean.
The INGV researchers fingered Etna, a highly active volcano on Sicily, as a likely culprit. They carried out seismic surveys and found telltale debris from a landslide spreading 20 kilometers off Sicily. The team carbondated the debris to about 8000 years ago. Next, they mapped similarly aged mudslides that flowed hundreds of kilometers, from the Ionian Sea all the way to the Sidra Gulf off Libya. Corroborating evidence comes from an excavation at Atlit-Yam, a coastal village in present-day Israel, which appears to have been abandoned suddenly 8 millennia ago.
Synolakis is unconvinced. He says INGV's model uses "unrealistic" initial conditions, including an impossibly fast underwater velocity of the Etna collapse. Pareschi counters: "Even taking the slowest speed that we considered, the tsunami would occur."
Not in dispute is the notion that volcanism could spawn future megatsunamis. Sicily, Stromboli, and other volcanic islands should be monitored closely, says Grilli. But the worst nightmare may be spawned farther afield. Last year, scientists warned that a massive collapse of Cumbre Vieja, a volcano in the Canary Islands, would trigger a towering tsunami that could pummel coasts on both sides of the Atlantic. Such a collapse could be 10 times larger than the Etna slide--an "immense geological event," says Pareschi. Forget Atlit-Yam: Such a doomsday wave could overwhelm settlements with familiar names, like New York, Miami, and Lisbon.
Jacopo Pasotti is a writer in Basel, Switzerland.
GGG Ping
IT COULD HAPPEN TOMORROW!!!
Even though the short term risk is small the potential damages are enough to justify funding a few geologists to properly study this. If the risk seems real they should run computer models on just how big a splash this volcano would produce, then repeat the computer run with all the above sea level material digitally removed. That should shrink the tsunami somewhat and might reduce it a lot. If the risk seems imminent, say in the next 50 years, then why don't we just strip mine the offending mountain part down to sea level. It would take some time and money, but the technology to do it exists and if these catastrophic projections are correct than it should be much cheaper than a natural splash. However if the purely underwater portion of the collapse is enough to cause a catastrophe then our choices are more limited. I doubt current underwater mining technology is adequate to remove the problem. At best we could prophylactically throw W into the volcano as the MSM will blame him anyway for the massive loss of blue voters that follows.
Thanks for the link. I searched for "cataclysm" :-(
http://www.freerepublic.com/focus/f-news/1751083/posts
could this be related to that?
already pinged - thanks
It turns out poor quality simulation was done and the size of a possible tsunami from Cumbre Vieja was wildly exaggerated, and it poses little to no danger to the United States. Also there isn't actually the slightest indication it's about to suffer a large slide.
The MSM has been allergic to reporting anything other than the original scare stories, however.
Science are good.
A lot have carefully studied Cumbre Vieja and many people have roundly debunked the scare stories which fostered a bunch of sensationalistic documentaries - however,
1) while scientific journals have reported on this, the MSM has not
2) a lot of people on the internet got off so much about fantasizing about Cumbre Vieja wiping out the East Coast they don't bother to look at any of the counter-evidence.
http://www.sthjournal.org/media.htm
http://www.lapalma-tsunami.com/
The collapse of Cumbre Vieja and the subsequent tsunami has a far higher propability of coming true than Global Warming does. We would be far better off directing the billions currently being spent to reduce CO2 emissions to doing as you propose, strip mining the sides of that mountain and using the rock to expand the island. The locals would benefit, and think of the all the condos that could be built on the new land.
Thanks for good links. It's nice to know responsible geologists have already done the appropriate work.
Thanks for the ping; alas, I'll have to not ping, and just add to the catalog(s). ASAVet posted the link to the original topic here:
http://www.freerepublic.com/focus/f-news/1751074/posts?page=4#4
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Mt. Etna ping
Prehistoric forest discovered off Key West -- on sea bed (under 40 feet of water)
Keynews.com West -- on sea b^ | Wed., Nov 13, 2002 | Mandy Bolen
Posted on 11/15/2002 7:34:31 PM EST by jimtorr
http://www.freerepublic.com/focus/f-news/789935/posts
"pine cones, tree branches and charred limbs -- thought to be about 8,400 years old -- were an unexpected and intriguing treasure awaiting archaeologist Corey Malcom, who spent much of the summer underwater in search of the remains of the Henrietta Marie, a British slave ship that sank 35 miles off Key West in 1700."
After all, is anyone going to tune into the documentary about how an eruption there won't cause a tsunami?
It's no different than the constant scare mongering over Yellowstone.
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