Investigating Rogue/Freak Waves and Chaos Theory

[xeon]

I am doing a resurch project at the moment about rouge/freak waves. It will be mainly on chaos theory as that seems to be the only logical explanation for them. I was just wondering if anyone had any ideas thoughts etc. Many thanks.

 

[meteor]

ummm... what has it to do with quantum theory? Anyway, you should know that rogue waves have been detected recently by satelitte
http://www.esa.int/esaCP/SEMOKQL26WD_index_0.html
don't know about the origin. Could they be a consequence of the eruption of some submarine volcano?

 

[Nenad]

I think it all just a random coincidence and a result of wave superposition. At certain times, waves are perfectly in phase to constructively interfere and cause a 'freak' wave.

 

[HallsofIvy]

I worried about this for some time until I realized you meant "rogue" waves rather than "rouge" waves!

 

[xeon]

But if It was just constructive interfernece then at least 3 or more waves would be needed exsactly in phase which with water waves i think is very unlikely compared to how often they happen

 

[jcsd]

Logically this has nothing to do with quantum mechnaics - but as a matter of fact it does!

It was noticed that waves of incredible size in the ocean where occurring at a frequency that simply could not be explained by the standard model of waves in the ocean i.e. they could simply not be the results of freak superpostions (thois very fact led some to doubt that such waves existed in the first place).

Waves in the ocean are an enirely classical phenoumna, but someone noticed that these freak waves come naturally out of the model if you choose to model the wves with the (time dependent I assume) Schroedinger equation of quantum mechanics. I don't think anyone knows why the Schroedinger equation provides a useful model for physically real water waves (as opposed to the probailty amplitude it normally models), but I suggets you google for 'rogue waves' and the 'Schroedinger equation'.

 

[Tide]

i think is very unlikely compared to how often they happen

What's your basis for saying that?

Ocean waves are sufficiently incoherent that they qualify as noise (in the general sense). As far as I know rogue waves are relatively rare and it is the nature of noise to produce fluctuations - roughly half are above the mean and half are below the mean in amplitude. The frequency of occurrence will depend on the spectrum of that noise and the physical extent of the oceans which is rather vast.

 

[jcsd]

What's your basis for saying that?

Ocean waves are sufficiently incoherent that they qualify as noise (in the general sense). As far as I know rogue waves are relatively rare and it is the nature of noise to produce fluctuations - roughly half are above the mean and half are below the mean in amplitude. The frequency of occurrence will depend on the spectrum of that noise and the physical extent of the oceans which is rather vast.

There is a basis for saying that, the conventional model simply fails to explain their size and observerd frequency.

 

[jcsd]

A little serach tells me it is infact the non-linear Schroedinger equation that's used to model ocean waves!

 

[Tide]

Thanks, jc. I replied to xeon's post before I read your subsequent one. Does the "conventional model" take into account the variable depth of the oceans?

 

[jcsd]

Thanks, jc. I replied to xeon's post before I read your subsequent one. Does the "conventional model" take into account the variable depth of the oceans?

I imagine so, but modelling waves is not something I know a lot about, anyway I dug up this paper:


http://www.oceanweather.com/7thwave/Papers/Gunson_Magnusson.pdf

 

[davescha76]

rogue waves

Just by instance,

I thought of this today about the rogue waves that are being produced in the atlantic.

When a wave bounces off land the waves on the surface cancel each other out. But what about under the water. The tiny ripples go out like a sonar. Now think when these sonar waves colide into one another is it possible for them to push upward and make a wall of water 10 times higher then the other waves.

Just a thought to think about.

 

[Danger]

I worried about this for some time until I realized you meant "rogue" waves rather than "rouge" waves!

I thought that it had something to do with the Red Sea until I started reading it.

 

[MadScientist 1000]

I thought that it had something to do with the Red Sea until I started reading it.

I get it

By the way, didn't a rouge wave sink the Posieden in the movie Posieden?

And do they really pack that much of a punch sometimes?

 

[Danger]

I have no intention of ever watching the remake. In the original 'Posieden Adventure', it was called a rogue wave IIRC. I haven't seen it since it came to the theatres in the early 70's, so my memory might lack a bit.
From my little knowledge of marine activities, though, I find it odd that such a huge wave would capsize a ship. I would expect something with that frequency/amplitude ratio to simply lift it on the leading edge and lower it again on the trailing edge. On the other hand, I'm surprised that the damned thing could remain afloat at all with Shelly Winters on board.
As for the power, remember that we just lost essentially an entire country to one. A tsunami is a rogue, usually.

 

[rcgldr]

Posieden Adventure

No cruise liner or any large ship has ever been capsized by a large wave. Large waves have done damage though, breaking windows as high up as the helm. If the weather is really bad and creating huge waves, the crew on an oil rig have to abandon it into small unsinkable watertight pods that are pulled away from the rig via cables, and they wait it out in the pods (which have water and food) for a rescue ship also designed to be unsinkable. Most water craft that travel into open oceans are unsinkable, with air tight holds and weight distribution that cause them to refloat and right themselves even if completely engulfed in water. Coast Guard cutters are one of the smallest of such craft (assuming kayaks don't count). Millitary vessels are designed likewise. Cruise ships are simply too big and stable to be capsized. You have to put a big hole in one with a weapon or iceberg to sink one.

 

[billiards]

Rogue waves? I'm not familiar with this term, are these like tsunamis or storm surges?

 

[Integral]

No cruise liner or any large ship has ever been capsized by a large wave.

I do not recall the ships name but one of the LARGEST European freight ships was lost with no known explanation. The current assumption is a rogue wave.

I cannot believe that the contours of the ocean bottom are of significance. A large rouge wave is 90m, this is still very small in comparison to the depth of blue water ocean. Rouge waves are a surface phenomena. The old wave models were linear, therefore did not and CANNOT predict highly nonlinear behavior such as a rouge wave.

 

[Bystander]

http://arjournals.annualreviews.org/eprint/ntKxUcsyXeywpgFQRASc/full/10.1146/annurev.fluid.36.050802.122118?cookieSet=1