I've planned this blog for a while, I hope you find it interesting. Just a warning however, this is all facts, I have not made up a single part of this blog, and to be honest, it may prove to be disturbing to some, and to me, the latter parts are particularly frightening to contemplate.
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First, an introduction as to what is a tsunami:
A tsunami is a series of water waves caused by a large displacement of water. Disturbances above and below water level including volcanic eruptions, earthquakes, mass movements, ocean impacts and underwater explosions all have the potential to generate a tsunami, an act of nature that to be put simply, is uncontrollable, and unthinkable, because of the destructible force it can cause to coastal regions.
While everyday wind waves have a wavelength (crest to crest) of about 100 metres, and a height of roughly 1.5 metres, a tsunami has a wavelength of roughly 200 kilometres, and can travel at 500mph. As a tsunami approaches the shore, or shallow water, a 'drawback' is noticeable. This means all the water is drawn away from the shore, exposing normally submerged areas. When the tsunami enters shallow water, it slows down, and its height increases to make a literal wall of water. Incredibly, tsunami's are unnoticeable in deep waters, and a boat would rarely feel anything but a slight 2 metre bump.
A normal wave instantly 'breaks' as it comes to the shore, but a tsunami doesn't break, despite rearing up extremely high. Because of the large displacement of water, the water follows behindthe wave, which makes it particularly devastating because you cannot see what's behind it until it's too late.
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2004 Indian Earthquake and Tsunami
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I'm sure many of you would have heard of this devastating event that occurred on boxing day 2004. What caused this tsunami was an undersea megathrust earthquake, which took place40km under the ocean, and the 9.3 magnitude earthquake, was so big, it shook the entire world by 1cm for several seconds.
It killed approximately 230,000 people in 14 countries, the largest affected was Indonesia, followed by Sri Lanka, India and Thailand. The poor people had no idea what was about to hit them. especially since that poor part of the world didn't have tsunami detectors in the area to warn the general public. Areas affected in below pic:
The megathrust earthquake was unusually large in geographical and geological extent. An estimated 1,600km of fault surface ruptured about 15m (50ft) along the subduction zone where the India Plate slides (or subducts) under the overriding Burma Plate. The slip did not happen instantaneously but took place in two phases over a period of several minutes. The wholesea bed rose vertically by several metres along one side of the tectonic plate- this is what caused the tsunami, the large displacement of water (13km cubed approx.). The energy released by the earthquake is more than the entire WW2 bombings, and equivalent to 1502 times morethe energy releasedin theHiroshima Atomic bomb. The shift of mass and massive release of energy very slightly altered the Earth's rotation.
The first sign was the shakes caused by the earthquake, which lasted for a few minutes. Shortly after, the tide began to drawback. Unfortunately people didn't realise what was about to happen, and instead of turning and running, they merely went closer to observe. The first wave was large, but never proved life threatening.
A second wave occurred minutes after the first, slightly bigger, and moving inland. But it was the third wave that hit, which was most destructive, and tsunami specialists later revealed that the wave height was about 30 metres high.
Times that by 3, and that was the size of the tsunami that caused so many billions worth of damage, ended generations, and is one of the deadly natural disasters recorded in history.
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But that isn't the main part of my blog, what I'm about to tell will undoubtably sound... untrue, but I can tell you, it is the truth.
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.
The mega tsunami
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 Réunion. 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 futureyears 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. Using exceptional equipment, the wave size predicted was extremely disturbing - the size of the wave will be the height of roughly 650 metres. The eruption is already overdue, meaning it could occur anytime within the next few hundred years, but its not a matter of "if" this event will happen, its simply a matter of "when" :?
Basically what it would look like when it does eventually happen. A frightening thought no doubt, whether it will happen in our lifetime is another question, but when that landslide does happen, the east coast of America will have just 6 hours to prepare itself before this monstrous tsunami strikes it.
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I'm not trying to frighten anyone intentionally by the way :P
I'm simply extremely interested in tsunami's, tidal waves and rogue waves, and I got all of this information from a programme about it, which I must say, was extremely interesting and disturbing to even contemplate the consequences of that landslide occurring in our lifetime. I mean, can you imagine a 650 metre wave? When things like this happen in movies, you know its not real, but this will eventually happen, and I certainly find it horrifying to imagine such an unthinkable and unstoppable natural disaster.
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That took me 2 hours to type up :o Hope you found this interesting I certainly think so, and another reminder, this is not a load ofrubbish I'm telling you. Google it if you must. But I hope you enjoyed it :)
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