Monday, September 06, 2004

Phew

It appears my friend Susan in Palm Coast, Fla., dodged the bullet with Hurricane Frances.
She called last night to report wind damage to their house was minimal, although the canal behind the house which links with the ICW was way up over the seawall and the water level was about 10 feet from their back door with high tide on the way. The were also without electricity and were having to call their friends in the north to get the bigger picture, weather-wise.
I told her it looked like she could expect at least another six hours of rain, but that the wind danger was abating.
Okay, so maybe I overreacted a few days ago when I questioned her decision to stay put. But Frances, like most hurricanes, is/was an unpredictable animal with lots of surprises. Who knew it would slow down, lose intensity and then crawl ashore as a Category 2 hurricane?
But hurricanes aside, there is no doubt in my mind that the east coast of Florida is doomed if and when the volcano at LaPalma in the Canary Islands sheds its western flank.
Here's the story from the BBC website http://www.bbc.co.uk/science/horizon/2000/mega_tsunami.shtml

Scattered across the world’s oceans are a handful of rare geological time-bombs. Once unleashed they create an extraordinary phenomenon, a gigantic tidal wave, far bigger than any normal tsunami, able to cross oceans and ravage countries on the other side of the world. Only recently have scientists realised the next episode is likely to begin at the Canary Islands, off North Africa, where a wall of water will one day be created which will race across the entire Atlantic ocean at the speed of a jet airliner to devastate the east coast of the United States. America will have been struck by a mega-tsunami.

Back in 1953 two geologists travelled to a remote bay in Alaska looking for oil. They gradually realised that in the past the bay had been struck by huge waves, and wondered what could have possibly caused them. Five years later, they got their answer. In 1958 there was a landslide, in which a towering cliff collapsed into the bay, creating a wave half a kilometre high, higher than any skyscraper on Earth. The true destructive potential of landslide-generated tsunami, which scientists named "Mega-tsunami", suddenly began to be appreciated. If a modest-sized landslide in Alaska could create a wave of this size, what havoc could a really huge landslide cause?

Scientists now realise that the greatest danger comes from large volcanic islands, which are particularly prone to these massive landslides. Geologists began to look for evidence of past landslides on the sea bed, and what they saw astonished them. The sea floor around Hawaii, for instance, was covered with the remains of millions of years’ worth of ancient landslides, colossal in size.

But huge landslides and the mega-tsunami that they cause are extremely rare - the last one happened 4,000 years ago on the island of RĂ©union. The growing concern is that the ideal conditions for just such a landslide - and consequent mega-tsunami - now exist on the island of La Palma in the Canaries. In 1949 the southern volcano on the island erupted. During the eruption an enormous crack appeared across one side of the volcano, as the western half slipped a few metres towards the Atlantic before stopping in its tracks. Although the volcano presents no danger while it is quiescent, scientists believe the western flank will give way completely during some future eruption on the summit of the volcano. In other words, any time in the next few thousand years a huge section of southern La Palma, weighing 500 thousand million tonnes, will fall into the Atlantic ocean.

What will happen when the volcano on La Palma collapses? Scientists predict that it will generate a wave that will be almost inconceivably destructive, far bigger than anything ever witnessed in modern times. It will surge across the entire Atlantic in a matter of hours, engulfing the whole US east coast, sweeping away everything in its path up to 20km inland. Boston would be hit first, followed by New York, then all the way down the coast to Miami and the Caribbean.


Another site estimates the wave that will hit Forida at 50 meters (164 ft.) That's why Florida isn't on my list of places I'd like to live.

No comments: