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Tsunami that devastated the ancient world could return
AFP on Yahoo ^ | 3/9/08 | AFP

Posted on 03/09/2008 7:17:08 PM PDT by NormsRevenge

PARIS (AFP) - "The sea was driven back, and its waters flowed away to such an extent that the deep sea bed was laid bare and many kinds of sea creatures could be seen," wrote Roman historian Ammianus Marcellus, awed at a tsunami that struck the then-thriving port of Alexandria in 365 AD.

"Huge masses of water flowed back when least expected, and now overwhelmed and killed many thousands of people... Some great ships were hurled by the fury of the waves onto the rooftops, and others were thrown up to two miles (three kilometres) from the shore."

Ancient documents show the great waves of July 21, 365 AD claimed lives from Greece, Sicily and Alexandria in Egypt to modern-day Dubrovnik in the Adriatic.

Swamped by sea water, rich Nile delta farmland was abandoned and hilltop towns became ghost-like, inhabited only by hermits.

The tsunami was generated by a massive quake that occurred under the western tip of the Greek island of Crete, experts believe.

Until now, the main thinking has been that this quake -- as in the Indian Ocean tsunami of December 26, 2004 -- occurred in a so-called subduction zone.

A subduction zone is where two of the Earth's plates meet. One plate rides over another plate which is gliding downward at an angle into the planet's mantle.

Subduction zones usually have measurable creep, of say a few centimetres (inches) a year. But as the rock becomes brittle and deformed at greater depths, these zones can also deliver titanic quakes, displacing so much land that, when the slippage occurs on the ocean floor, a killer wave is generated.

The 365 AD quake occurred at a point on the 500-kilometre (300-mile) -long Hellenic subduction zone, which snakes along the Mediterranean floor in a semi-circle from southwestern Turkey to western Greece.

Researchers in Britain have taken a fresh look at this event and have come up with some worrying news.

University of Cambridge professor Beth Shaw carried out a computer simulation of the quake, based especially on fieldwork in Crete where the push forced up land by as much as 10 metres (32.5 feet).

They estimate the quake to have been 8.3-8.5 magnitude and that its land displacement -- of 20 metres (65 feet) on average -- puts it in the same category as the 9.3 temblor that occurred off Sumatra in 2004.

They conclude the slippage occurred along 100 kilometres (about 60 miles) on a previously unidentified fault that lies close to the surface, just above the subduction zone.

The quake happened at a depth of around 45 kilometres (30 miles) -- around 30 kilometres (20 miles) closer to the surface than would have been likely if the slip had occurred on the subduction fault itself.

After the 365 AD quake, the fault is likely to remain quiet for around 5,000 years.

But if the tectonic structure along the rest of the Hellenic subduction zone is similar, a tsunami-generating quake could strike the eastern Mediterranean in roughly 800 years, the scientists estimate.

The last tsunami to hit the eastern Mediterranean occurred on August 8, 1303. According to research published in 2006, a quake off Crete of about 7.8 magnitude hit Alexandria 40 minutes later with a wave nine metres (29.25 feet) high.

"That there has been only one other such event... in the past 1,650 years should focus our attention on the modern-day tsunami hazard in the eastern Mediterranean," the new study, published in the journal Nature Geoscience, warns.

"Repetition of such an event would have catastrophic consequences for today's densely-populated Mediterranean coastal regions."

The UN Educational, Scientific and Cultural Organisation (UNESCO) is setting up a tsunami alert system for the Mediterranean as part of a global network established after the 2004 Indian Ocean disaster.


TOPICS: Foreign Affairs; Miscellaneous
KEYWORDS: 0365; 1303; 130308; 13030808; 365; 36507; 3650721; 365ad; ad365; alexandria; ammianusmarcellus; ancientworld; atlantis; byzantineempire; canaryislands; catastrophism; crete; cumbrevieja; devastated; earthquake; egypt; godsgravesglyphs; lapalma; rome; tsunami; tsunamis; volcano
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To: Man50D
"Yep and no one is paying attention."

And what would they do about it if they were paying attention?

Carolyn

41 posted on 03/10/2008 7:17:52 AM PDT by CDHart ("It's too late to work within the system and too early to shoot the b@#$%^&s."--Claire Wolfe)
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To: Berosus

Global warming will bring the Atlantic coast to your front door.

And the Pacific coast to your back door.


42 posted on 03/10/2008 7:19:26 AM PDT by Larry Lucido
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To: NormsRevenge

later


43 posted on 03/10/2008 7:39:12 AM PDT by Jaded ("I have a mustard- seed; and I am not afraid to use it."- Joseph Ratzinger)
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To: Man50D
The wave height, by some estimations, will be 165 feet by the time it reaches the east coast and move upto 12 miles inland.

A 16-story wave. Like something out of a scifi movie. My office is 10 stories up. As I look down, it's hard to imagine that much water.

44 posted on 03/10/2008 8:05:19 AM PDT by scan59 (Let consumers dictate market policies. Government just gets in the way.)
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To: Man50D
Aside from packing up and moving to the mountains, what would you suggest that people do?

How about sit and worry, that'll fix it!

45 posted on 03/10/2008 8:16:22 AM PDT by Ditter
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To: Caramelgal

Wasn’t California suppose to fall into the ocean? Would this cause a sizeable Tsunami or just taint the water supplies?


46 posted on 03/10/2008 9:59:25 AM PDT by Jaded ("I have a mustard- seed; and I am not afraid to use it."- Joseph Ratzinger)
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To: Larry Lucido

“Global warming will bring the Atlantic coast to your front door.

And the Pacific coast to your back door.”

Darn! Last year the local newspaper had a headline that claimed Berea, KY (a town about 30 miles south of here), will be the safest place to head to, if the world ends in 2012.


47 posted on 03/10/2008 2:50:13 PM PDT by Berosus (Support our troops, bring them home -- from the Balkans.)
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To: Berosus

I had a friend who made Shaker furniture in Berea. My sister is in Lexington. Maybe I should think of getting a plot of land down there, just in case. :-)


48 posted on 03/10/2008 2:53:53 PM PDT by Larry Lucido
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To: NormsRevenge

Hope this doesn’t happen to Gaza and wash everybody out to sea. That would be tragic.


49 posted on 03/10/2008 2:55:42 PM PDT by RightWhale (Clam down! avoid ataque de nervosa)
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To: Larry Lucido

ok I could have been hit by a camel....


50 posted on 03/10/2008 3:12:01 PM PDT by Gone_Postal (We are not interested in the possibilities of defeat)
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To: Wally_Kalbacken

As long as you’re not in Naples you should be OK.


51 posted on 03/10/2008 3:34:26 PM PDT by who_would_fardels_bear
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To: Man50D
EVALUATION OF TSUNAMI FAR-FIELD EFFECTS FROM POSTULATED COLLAPSES OF STRATOVOLCANOES

Dr. George Pararas-Carayannis - Paper published in Science of Tsunami Hazards, Vol 20, No.5, pages 251-277, 2002.

…Thus, these models forecast incorrectly tsunami far field effects. Shallow water effects, which are due to the nonlinear nature of the tsunami, are treated as linear and overestimated. Only waves of much longer wavelength can propagate effectively across ocean basins. Even though local destructive tsunami waves can result from the postulated mechanisms, waves of such short periods will rapidly decay away from the source region with considerable height attenuation….

Subsequent modeling by Mader (2001) confirms this and provides realistic estimates of tsunami far-field effects for the same hypothetical La Palma slide. Using the wave profile output obtained from a high speed (110 meters/second), pneumatic landslide generator of the Swiss Federal Institute of Technology at Zurich, Switzerland (Fritz, 2001), and based on a "worst case" scenario for La Palma (650 meter high, 20 kilometer radius water wave after 30 kilometers of travel), Mader's numerical model treats the resulting tsunami as an intermediate wave of short wavelength and period - taking into account both dispersion and geometric spreading effects. Specifically, the shorter period and wave amplitudes in his model, result in significant wave height attenuation with distance - to less than one-third of the shallow water amplitudes. The upper limit of his modeling study shows that the east coast of the U.S. and the Caribbean would receive waves less than 3 meters high. The European and African coasts would have waves less than 10 meters high. However, full Navier-Stokes modeling of the same La Palma failure, brings the maximum expected tsunami wave amplitude off the U.S. east coast to about one meter.

52 posted on 03/10/2008 3:46:05 PM PDT by Caramelgal (Rely on the spirit and meaning of the teachings, not on the words or superficial interpretations)
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To: yarddog

I also live in the panhandle. If your property taxes are low, it’s because of one of two things...or both.

You either have a crap home, or you’ve been protected by the Florida property tax welfare system, called “Save Our Homes,” which is nothing more than an organized way for long term residents to transfer much of their share of the property tax burden onto the renters, those with second homes in FL, and new FL residents.

Florida’s economy will suffer badly until they throw that unfair and unconstitutional law out and replace it with a property tax system that treats all citizens equally.

Young high school and college grads have little if any chance of being able to enjoy the “American Dream” if they remain residents of Florida.


53 posted on 03/10/2008 4:20:00 PM PDT by RavenATB
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To: yarddog
“I am an eleventh generation Floridian. Florida has lower than average taxes. “

By the way, I suggest that if you truthfully believe that property taxes are low in the FL panhandle that you pull up the Okaloosa County assessor's web page and take a look at the property taxes paid for some of those 3,000 sq/foot waterfront homes purchased 15-20 years ago in Fort Walton Beach, Niceville, Valporaiso, and compare what those residents are paying in property taxes to someone who owns a similar sized home that purchased it in 2005 or 2006.

Look at some of those nice early ‘80s homes along the waterfront on Bayshore in Niceville that are worth upwards of $1.5-$2Million but are paying property taxes on a an assessed value of less than $400K. Then look at any off-water home in Bluewater Bay, Swift Creek, Rocky Bayou Country Club Estates, or across the bridge in Destin and Sandestin that was purchased in 2005 or 2006. I can show you instances where homes on the water in Okaloosa county are taxed on an appraised value that's less than 1/4 of their current actual value, while many homes in the newer subdivisions I mentioned that were purchased in the last few years are taxed at 100% of current-day value or more.

The reason you use the word “average” to apply it to the tax level is that you have to average the thousands of residents who paying the property taxes for hundreds of thousands of long-term FL homeowners who turned their property tax system into another form of wealth redistribution.

Florida is NOT a low tax state for anyone thinking of renting or moving her from out of state, or anyone who made the mistake of moving to Florida in the past five years.

54 posted on 03/10/2008 4:36:35 PM PDT by RavenATB
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To: Caramelgal
Mega-tsunami to devastate US coastline

A tsunami wave higher than any in recorded history threatens to ravage the US coastline in the aftermath of a volcanic eruption in the Canary Islands, UK and US scientists will report today. Locations on both African and European Atlantic coastlines - including Britain - are also thought to be at risk.

The new research, a collaboration between Dr. Simon Day of the Benfield Greig Hazard Research Centre at UCL and Dr. Steven Ward of the University of California, reveals the extent and size of the mega-tsunami, the consequence of a giant landslide that may be triggered by a future eruption of the Cumbre Vieja volcano.

Previous research by Simon Day and colleagues predicted that a future eruption would be likely to cause a landslide on the western flank of Cumbre Vieja. A block of rock approximately twice the volume of the Isle of Man would break off, travelling into the sea at a speed of up to 350 kilometres per hour. The disintegration of the rock, this earlier study predicted, would produce a debris avalanche deposit extending 60 kilometres from the island. The energy released by the collapse would be equal to the electricity consumption of the entire United States in half a year.

The new model - which provides further insights into the consequences of the collapse - predicts that the landslide would create an exceptionally large tsunami with the capability to travel great distances and reaching speeds of up to 800 kilometres per hour. Immediately after Cumbre Vieja's collapse a dome of water 900 metres high and tens of kilometres wide will form only to collapse and rebound. As the landslide continues to move underwater a series of wave crests and troughs are produced which soon develop into a tsumani 'wave train' which fuels the waves progress. After only 10 minutes, the model predicts, the tsunami will have moved a distance of almost 250 kilometres.

The greatest effects are predicted to occur north, west and south of the Canaries. On the West Saharan shore waves are expected to reach heights of 100 metres from crest to trough and on the north coast of Brazil waves over 40 metres high are anticipated. Florida and the Caribbean, the final destinations in the North Atlantic to be affected by the tsunami, will have to brace themselves for receiving 50 kilometre high waves - higher than Nelson's column in London, some 8 to 9 hours after the landslide. Towards Europe waves heights will be smaller, but substantial tsunami waves will hit the Atlantic coasts of Britain, Spain Portugal and France.

For tsunamis striking flat-lying coastline regions such as Florida, calculating the inundation distance - the extent to which water penetrates inland taking the form of fast moving floods after waves break - is crucial to assessing potential damage. Dr. Day and his colleagues estimate inundation distances in the region of several kilometres from the coast. Accurate estimates of the scale of economic loss are yet to be made but are thought to be in the multi-trillion USD range.
55 posted on 03/10/2008 7:25:09 PM PDT by Man50D (Fair Tax, you earn it, you keep it!)
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To: Man50D

Maybe it will hit while the Democrats are re-doing their primary voting...

It’s Bush’s fault!


56 posted on 03/10/2008 8:13:34 PM PDT by RavenATB
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