In case you were wondering about FL tsunamis...

[Aessotariq]

The thought crossed my mind as I learned of the horrible tragedy in Asia.

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http://www.miami.com/mld/miamiherald/news/10504353.htm

Posted on Mon, Dec. 27, 2004

COASTAL AREAS

Giant wave possible, but unlikely, in S. Fla.

Scientists say South Florida would be an unlikely target of tsunamis generated by earthquakes, but they say no coastal area is entirely out of danger.

BY MARTIN MERZER

[email protected]

The question comes naturally in low-lying, coastal South Florida: Could it happen here -- could an offshore earthquake or similar phenomenon propel towering tsunamis to, through and over our densely populated beaches and bayfronts?

The answer: It's theoretically possible, but not at all probable. If you must worry, worry about hurricanes, holiday bills, the Dolphins, just about anything but calamitous tsunamis.

''A [9.0-magnitude] earthquake is just absolutely massive and it can cause massive tsunamis,'' said Tim Dixon, a professor of geology and geophysics at the University of Miami. ``It's unlikely we would have such a big earthquake in this part of the world.''

Dixon and other experts said the cascade of events that buried thousands of Asians under walls of ocean water Sunday began with an earthquake in a geologically active area -- known as a ''subduction zone'' -- much more potent than any within range of South Florida.

SHIFTING PLATES

Earthquakes can occur when one ''plate'' of the earth's crust slips beneath or past another. When this happens under the ocean and with great force, tsunamis can roar across the water at speeds greater than 400 mph and, as they approach shore, reach heights greater than 20 feet.

The geological feature that brought wide devastation to coastal Asia is known as the ''sunda'' subduction zone, where the southeastern edge of the Indian Ocean plate is pushing under Indonesia and the continent behind it.

EDGE OF CARIBBEAN

The subduction zone of most concern to South Florida lies on the eastern edge of the Caribbean, about 1,400 miles from Fort Lauderdale and Miami. Marked by the arc of volcanic islands known as the Lesser Antilles, this is where the Atlantic sea floor is creeping under the Caribbean sea floor.

But scientists say this region is older and geologically less volatile than the sunda region, and thus less likely to trigger an earthquake of the magnitude registered near Indonesia. This, in turn, greatly diminishes the chances of disastrous tsunamis.

That is a good thing for South Florida.

If such waves were to originate on the edge of the Caribbean at, say, 1 a.m. and race across the water at 400 mph, they would crash ashore in Miami Beach and Hollywood by 4:30 a.m.

''There's no way, absolutely no way, we'd be able to get warnings out,'' Dixon said. ``There are very few effective tsunami warning systems, because of the speed of the waves.''

NOT A CONCERN

Geologists say the other nearby underwater earthquake zone, in the eastern Pacific near Central America, is relatively active but again not as potent as the Asian zone. In addition, any tsunamis generated in the eastern Pacific would head west, away from South Florida.

At the same time, it must be remembered that no coastal region is entirely immune to the danger, and South Florida is particularly vulnerable to a similar threat -- the tsunami-like ''storm surge'' that a powerful hurricane can generate as it reaches land.

Alas, scientists note another, less predictable danger.

''There is one other good way to generate tsunamis -- underwater landslides,'' Dixon said. ``In principle, these can happen anywhere along the Eastern Seaboard of the United States or along the west coast of Africa.''

But even this is rare and any resulting tidal waves likely would be much smaller than those produced Sunday. They could threaten some Caribbean islands, but would not be much of a threat to South Florida.

''We probably are hit by the odd tsunami every once in a while, but they are so small nobody notices them,'' Dixon said. ``We don't need to be too concerned about tsunamis here.''

[asonj23]

I remember a freak wave that hit Daytona Beach a few years back. The major damage was at the pier and boardwalk. There were boardwalk buisnesses flooded and supposedly a few cars on the beach rolled over. I didn't see any flipped cars (i used to live near the area on the beach side) but there was certainly a lot of debris on the beach and some standing water in a few of the buisnesses along the boardwalk. I have not heard anything on the suspected causes. The funny thing is that it also seemed to only effect that immediate area instead of something a little more widespread.

[miamistreets]

I hope nothing like that happens here (in FloridaI dont think we'd be ready,we would be terminated if that occurs.

But we're not close to where plates collide,so i think we're safe.

[Brickell]

Africa wasn't either, but they got hit by the tsunami. These things will travel thousands of miles before they dissipate.

[miamistreets]

oh crap !!

Wait.(this isnt about tsunamis but its close to it)

I have seen a picture of downtown Miami and a tornado like it was going to hit it or something.I dont know if anyone else has seen it.

Did that really happen?

Everytime I show it to anybody they ask "Did that really happen?" I just tell them,"I think so" ...

[Brickell]

Yes it did.

[Aessotariq]

When I first saw this picture in the paper, the urbanite in me couldn't help but admire the density of the skyline at this angle.

[miamistreets]

If i was in one of those buildings and saw that out the window,I would freak out.

Luckily not many buildings were damaged.I suppose.Because many of those in the picture, are still standing.

[Brickell]

It was a weak tornado (and eventually moved over the water to become a waterspout). It was mostly just trash being blown around. I don't remember any reports of major damage.