Jay Manifold reminds us of the potential for a much larger tsunami than the one that hit this past weekend. Patricia and I were wondering last night what we would do if we heard about a Canary collapse. It might be sufficient to get out to the west county. If we have to go further than that, we might be SOL, because there are only a couple roads that head into the Everglades here, and they'd probably be jammed once people figured out what was happening. Though I wonder if the Bahamas would take the brunt of it, and much of the energy.

Of course, it wouldn't be just Florida that gets hit. The entire eastern seaboard would likely be wiped out, all the way up into Canada.

My understanding of the facts are that you'd have about 6-8 hours of warning, and only have to get 2-3 miles inland. Drive as far as you can then hoof it!

Though I wonder if the Bahamas would take the brunt of it, and much of the energy.

Actually, islands can act as lens for waves. The waves move slower in the shallower water around and island and turn inward. The two wavefronts from either side of the island then lead to an interference pattern. Where the wave forms cancel out things are calmer but where they are additive the waves will be twice as large. The interference pattern would be on the scale of the wavelength of the tsunami, which usually is more than fifty miles.

On the bright side for Florida the bahamas is not a single island but a cluster and that would tend to dissipate energy.

Get a PPL and have a nearby Cessna or Piper. Then you can avoid the traffic jams and maybe return home once the damage is done.

Learn how to fly a two man ultralite. Keep it in the garage. If the unthinkable happens, drive to an open area like a high school football field assemble and scoot.

A quick trip to Google shows that you would have plenty of warning, if you're paying attention:

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 metre high waves - higher than Nelson's column in London, some 8 to 9 hours after the landslide. 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.

The ultralight sounds like a good idea, until the flying cars get here.

Although it's a antidotal now, by the end of the week we will have stories of those who ran and lived, telling of others that were warned as the water was drawn out to sea and simply stood their and watched the phenomenon. It sad but true we live in a society that has no memory of such events and no practical knowledge of how the physics of large waves work.

Here's an animation of the wave propagation of the recent tsunami you will see it reflects around islands.

I gather that an eruption in 1949 pretty much cracked the island in half and that the suspense is about when the loose half is going to fall into the drink. The paper cited didn't seem to come right out and say so, but it looks like the danger may be decades or even centuries off. You have to watch geologists carefully when they throw around terms like "frequent." Evidently it takes more than a garden-variety eruption to do the deed as there was another eruption in the same area in 1971 and the loose bit didn't budge. Unlike earthquakes, major volcanic eruptions usually advertise themselves in advance. In a worst case scenario, the Atlantic Basin nations could buy off each then-current resident with a spanking new condo on one of the other Canaries and take down the whole island, piecemeal, before it had a chance to go all at once and make that inconvenient splash. With a few years in hand, the job could even be done with conventional explosives (ANFO). If haste was essential, tactical nukes might be preferable. Of course, by the time this event is likely to be imminent, available technology might offer other alternatives. Maybe JSA could put up a really big blimp and hold the loose half of the island up with carbon nanotube cables until it could be nailed or superglued back onto the sound half. Hell, if we get 200 years to work with we can probably just say a suitable magic word and make the volcano mind its manners - Clarke's Law.

See this article on

the Tsunami potential in Florida. Bottom line: vastly exaggerated.

Interesting analysis Chuck. While the probability may be lower, risk assesment must also take into account the potential dammage that such an event would cause. While it's likely that fewer people would actually die in such an event because of timely notice and the fact that hurricane evacutaion routes could double to move people from coastal areas, the dollar value of dammages from the event would be similar to that of a storm surge from a hurricane. These dammages would be magnified by the fact that residents did not have the three or four day notice to prepare like they presently do for hurricanes. Did you merge the Caribbean data with the Atlantic data? The rim of most of the Atlantic is pretty inactive geologicaly. What most people don't realize is that per mile of shoreline the Caribbean Sea has the highest tsunami risk in the planet. Over the past 500 years there has been something like 75+ tsunami events recorded within the basin. The fact that there has not been a significant event in over half a century combined with the human apptitude for not grasping the significance of events that haven't happened in their lifetime means that the risk is relatively unknown. As was mention in the article, there is one gentleman that has been pushing NOAA for an early warning system for the east coast similar to what the west coast has. His name is Dr. George Maul and he's with the Florida Institute of Technology. Though his efforts may not have been sucessful, the University of Puerto Rico has established a monitoring center, though it's not manned 24-hours a day. Rand, the next time you're in the Melbourne area you may wish to look him up. I corresponded with him while I was student at Florida State and was working on a Urban & Regional Planning paper that addressed tsunami risk for the state. You'd be surprised to know that the state's Emergency Planning policy (as of 1999) didn't even address the risk of tsunami. I have no idea if they've added that risk to their planning documents since though the article Chuck posted seems to imply that they're at least considering the threat. The point I'm trying to make is don't assume that you'll have eight hours notice. If you focus on the Canaries you may be caught looking in the wrong direction when the next one occurs.

The analysis Mark Johnson and I just completed for the state of Florida Department of Community Affairs analyzed the tsunami risk equally with other hazards (hurricane, tornado, earthquake, etc.). In an average year, a typical house in West Palm, for example, has 1 in 10 chance of being wrecked by a hurricane, 1 in 120 for tornado, and about 1 in 500 for a tsunami. Of course, the damage swath for a hurricane is usually only 50 to 100 miles in width. A big tsunami, as we have seen, can blast thousands of miles of shoreline. Our event total damages for hurricanes rarely topped $50 billion, while our tsunami events, while rare, frequently hit $1 Trillion dollars. For Florida casualties, hurricane projections again rarely top 1000 (given modern warning and evacuation). Tsunami events often exceed 50,000. We looked at tsunami risk from four sources: coastal sediment slumping, seismic, volcanic, and impact. Tsunami's are just in a class by themselves for potential damage.

This analysis seems to indicate that the Cumbre Vieja threat is much overblown. I must confess I can't make heads or tails of the math.

Get a Tsunami ejection system for your house. It would be able to launch a family of four into LEO and then land you in Oklahoma.