Skippers beware: Tsunamis in the North Atlantic

[Skybird]

The shrinking ice shield at Greenland has an unpleasant consequence: the landmass of Greenland, until some years ago rising with 0.5-1 cm per year, has quadrupled it'S speed and currently moves upwards with 4 cm per year, increasing. until recently, the mass of the ice has pished Greenland several hundred meters into earth's crust. Also, the glaciers are moving faster and become smaller, increasing the speed at wich the ice is shrinking and Greenland is rising, because streams/tidings of warmer water are observed to drill holes and tunnels into the ice and create vertical "rivers" of warm water into the ice. Where they reach the bottom, they function like sliders on which the ice is moving like a hovercraft on an air cushion, reducing friction and thus increasing their speed, sometimes dramatically.

http://environment.newscientist.com/...sing-fast.html (still free)

Of course this has an impact on the structure of the tectonic tension in the region, which could lead to great ground movements at the bottom of the Atlantic. And since there is water everywhere, this has the potential for creating Tsunamis.

Tsunamis are nothing new in the north Atlantic. The last one took place 8000 years ago, and the sediment layer at the Scottish coast allow the conclusion that it must have hit the european coast with waves as high as 20m. Much higher waves can be imagined and theoretically founded by scenarios. the highest suggestion I ever read abiut was 300 m, but let'S don't get heavy aboiut that number. Scientitst were able to prove that up to 27 Tsunamis must have taken place in the North Atlantic in the past 20000 years,. most of them must have been triggered by the rise of the ocean sea level that took place 15000 years ago.

In the north Atlantic, the continental shelfs steeply fall to depths of several thiusand meters. Rubble and loose sediments are mostly being hold together by being frozen in methane hydrate, like dirt in a snowball. But the average temperature of the water is rising, and to this now additional growing tectonic instability of the greenland landmass must be added. The likelihood that along whole continental coasts, in a chain reaction, masses of rubble and sediments start moving and falling hundreds and thiousands of meter easily can trigger the energy to create waves that match that ebergy potential of the Tsunamis of the past.

http://environment.newscientist.com/...mg19025531.300 (subscription needed)

What it would mean if a Tsunamis offshore of Norway hits Europe, you can read in thrilling visual detail in this very exciting thriller by Frank Schätzing, "The Swarm". It means the total destruction of major parts of central Europe. If you move the centre of the Tsunmai more towars the West, it means nothing else for the coastal region of north America as well. Coastal regions means: up to 300 km, some say even more, into the landmass. Inside this, everything gets devastated.

Some scientists also refer to the high threat potential of the volcano at La Palma. Since it last outbrake after WWII, parts of it have slipped by 4 m, increasing the instability of the whole formation. If it would lose it's stability doe to increased water erosion or tectonic activity (the Greenland rising reaches as far as to the Canary Islands), it would mean that a minimum of 500 km3 would fall into the sea and down to the Atlantic's seabed. This implies the creation of enough energy that it would be sufficient also to trigger a major Tsunami wave.

Denmark, most of Germany up to it'S middle, Netherlands, much of France, and parts of Spain would be waved of the map, literally. Estimations go as high as 150 million people killed within the first day Total population of europe is slightly below 500 million, I think.

Since climate change most likely translates into "warming" for the forseeable future indeed, and many symptoms that have been pointed at by sceptics (for example the short-termed increase of ice at the southern pole) easily can be revealed not to indicate a new cooling, but to be further evidence for warming, if you only look close enough, the growing instability of the sediments and rubble layers at the steep shelfs in the atlantic seem to be a certainty that at some point in the forseeable (= not hundreds of years away) future will go beyond the critical point. So the questions most likely is not if there will be a Tsnuami in the north Atlantic, but when.

[Konovalov]

Originally Posted by Skybird

Tsunamis are nothing new in the north Atlantic. The last one took place 8000 years ago,

Perhaps 'nothing new' from a geological perspective.

Interesting reading. :hmm:

[baggygreen]

I remember reading a novel a while ago where some maniac was trying to send a cruise missile into the side of La Palma. That was the first i'd even heard of the place.

The potential damage if La Palma fell is in my opinion higher than what Sky predicts. I dont know enough about they way tsunamis travel, but i woulda thought denmark and germany woulda been alright in the event of a wave, with nations more directly in the line of fire so to speak at risk - Spain as mentioned, Portugal, England, Ireland, western Africa. Not to mention Iceland, Greenland, the US's eastern seaboard, much of central and southern america...

The potential for devastation is almost unfathomable. I just hope it doesnt happen in my lifetime, that and the aftermath is one thing i DONT want to see.

[Linton]

Not a Tsunami but problems in the North Sea:
http://www.telegraph.co.uk/news/main.../nstorm208.xml

[Skybird]

Originally Posted by Linton

Not a Tsunami but problems in the North Sea:
http://www.telegraph.co.uk/news/main.../nstorm208.xml

there the government calls the probably rise of 10 ft (3 m) already the "worst flooding in 50 years". Imagine what a tsunami wave of 20 m (60 ft would do, with the far stronger energy by which it travels. and much higher tsunami waves are possible.

Also, a tsunami comes in several waves. The arriving wave is what shatters the land, and destroy objects, but the backflow of thr water can produce even greater suction. During the small tsnumai two years ago many peopple died not when the water arrived, but when it left again, becasue they saw the water had come to a standstill and believed the danger would be over, so the left their safe havens and shelters - too early. Waves after the first would maybe have less energy, but they would collide with a land that is already flattened and freed by much objects and features that had somewhat broken a little the first wave, so they could be as devastating because they meet smaller resistance, or friction. Not that by then there would be much life left in the theatre anyway.



Baggygreen,

remember physics lessons at school. we talk of waves, no linear rays. Waves "bend around" corners and obstacles, and they also bend around landmasses. That'S why germany and denmark are very much in danger as well, even if the UK is the first obstacle a Tsunami may hit, depending on the direction. Much of the Netherlands is below sealevel, and the North of Germany, up to the middle of it, is an incredibly flat piece of land, so is Denmark - monster waves could run here for an eternity before running out of energy. If it is coming from the Northwest, over the North Sea, it even hits the Netherlands and Northern Germany directly. It is estimated that even a Tsunami originating from the area of La Palma, probably would cause major havoc even along - the Norwegian coast!

BTW, I did not "predict" it. According to scientific models, and sediment analysis from past times, it is a realistic and reasonable scenario that could happen even during our lifetime, thus we must take it into account as a possible future reality. - The above mentioned areas also would be amongst the first dissappearing under water if the sealevel rises above a certain mark. You could scratch the land several hundred kilometers away from the coast off the map, then. Much of England, Denmark, germany, scandinavia'S south-east etc would not be existent anymore, but would be flooded.

Nothing man-made ever matches the power of nature.

[baggygreen]

Thanks sky,

i actually didnt do physics past the age of 14, never could stand it.

Yeh, if the waves can get through the channel of even over the top of scotland(?) then i see why denmark and Germany are at risk too...

Just makes me not want to see it even more!

[Letum]

This just isn't as funny as wastegates thread on the subject.

[micky1up]

the problem with this post is tsunamis very rarely damage ships in open ocean they only get distructive when they approach land thats when they grow in size and power but i take it geography wasnt your strong point

[Jimbuna]

Originally Posted by micky1up

the problem with this post is tsunamis very rarely damage ships in open ocean they only get distructive when they approach land thats when they grow in size and power but i take it geography wasnt your strong point

Very true....all they feel out at sea is a kind of rippling/vibrating notion. Same can't be said for divers/frogmen though in the gas and oil fields.

[Skybird]

Originally Posted by micky1up

the problem with this post is tsunamis very rarely damage ships in open ocean they only get distructive when they approach land thats when they grow in size and power but i take it geography wasnt your strong point

Thanks for your kind heads-up, but as a matter of fact I knew that. but the boring truth of ships at high sees seeing nothing would not have made for such a sensational headline.

And to be even more precise than your "correction", it is not the nearness of land being the critical factor, but the rise of the sub-oceanic ground. The steeper it is, the closer to the landmass a tsnunami on the surface becomes visible.

Next time try to make your point in a less offensive way (that geography part). Opposite to what you may have been told, it's not so difficult, you know.