Rogue Waves - or Freak Waves - are you scared of them?

[The Batt?sai]

Originally posted by: BW86
I've never encountered one while out in the ocean. I would probably sh!t my pants if I saw one.

i doubt u would. it would probably be a few feet high at the best. waves get bigger as their energy gets compacted by the land. well tidal waves do this . and yes i know thats not the scientific name for them

 

[The Batt?sai]

Originally posted by: Specop 007
I worry about rogue waves about as much as I worry about crashing into a tanker truck full of acid and being dissolved.

Its a concern, but I dont lose any sleep over it either.

 

[AccruedExpenditure]

I'd hit it

 

[Jzero]

Depends what you'd mean by "scared." Yeah, the thought of getting barrelled over by a giant wave scares me.

But it's not going to stop me from going out to sea.

 

[sao123]

http://www.bbc.co.uk/science/horizon/2002/freakwave.shtml


Also from Wikipedia

Freak waves, also known as rogue waves or monster waves, are relatively large and spontaneous ocean surface waves which can sink even large ships and ocean liners. In oceanography, they are more concisely defined as waves that are more than double the significant wave height (SWH), which is itself defined as the mean of the largest third of waves in a wave record.

Once thought to be only legendary, they are now known to be a natural (although relatively rare) ocean phenomenon. Anecdotal evidence from mariners' testimonies and damages inflicted on ships suggested they occurred; however, their scientific measurement was only positively confirmed following measurements of a freak wave at the Draupner oil platform in the North Sea on January 1, 1995. During this event, minor damage was inflicted on the platform, confirming that the reading was valid.

In the course of the Project MaxWave, researchers from the GKSS Research Centre, using data collected by ESA satellites, identified a large number of radar signatures that may be evidence for freak waves. Further research is underway to verify the method that translates the radar echoes into sea surface elevation.

Freak waves are a likely source of the sudden inexplicable disappearance of many ocean-going vessels.

Contents [hide]
1 History
2 Occurrence
3 Causes
4 Encounters
5 See also
6 References
7 External links
7.1 MaxWave report and WaveAtlas
7.2 Other



[edit]
History
This rare photo of a rogue wave was taken by first mate Philippe Lijour aboard the supertanker Esso Languedoc, during a storm off Durban in South Africa in 1980. The mast seen starboard in the photo stands 25 metres above mean sea level. The wave approached the ship from behind before breaking over the deck, but in this case caused only minor damage. The mean wave height at the time was between 5-10 metres. Credits: Philippe Lijour
It is common for mid-ocean storm waves to reach 7 metres (23 feet) in height, and in extreme conditions such waves can reach heights of 15 metres (50 feet). However, for centuries maritime lore told of the existence of vastly more massive waves ? veritable monsters up to 30 metres (100 feet) in height (approximately the height of a 12-story building) ? that could appear without warning in mid-ocean, against the prevailing current and wave direction, and often in perfectly clear weather. Such waves were said to consist of an almost vertical wall of water preceded by a trough so deep that it was referred to as a "hole in the sea"; a ship encountering a wave of such magnitude would be unlikely to survive the tremendous pressures of up to 100 tonnes/m2 (980 kPa) exerted by the weight of the breaking water, and would almost certainly be sunk in a matter of seconds. Usual ship design allows for rounded storm waves up to 15 m and pressures around 15 tonnes/m2 (147 kPa) without damage, and up to twice that if some deformation is allowed for, which is about a wave of twenty metres.

Scientists long dismissed such stories, asserting that mathematical models indicated that ocean waves of greater than 15 metres in height were likely to be rare "once in 10,000 years" events. However, satellite imaging has in recent years confirmed that waves of up to 30 metres in height are much more common than mathematical probability would predict based on a linear model of wave size. In addition, pressure readings from buoys moored in the Gulf of Mexico at the time of Hurricane Katrina also indicate the presence of such large waves at the time of the storm. In fact, they seem to occur in all of the world's oceans many times every year. This has caused a re-examination of the reason for their existence, as well as calling into serious question many long-accepted principles of maritime engineering.

Note: The localized freak waves discussed here are not the same as tsunami, formerly called "tidal waves". Tsunami are displacement waves which travel at high speed and are more or less unnoticeable in deep water; they only become dangerous as they approach the shoreline. In the deep sea, tsunami do not represent a threat to shipping. Freak waves, in contrast, are localized short-lived water phenomena that most frequently occur far out to sea.

[edit]
Occurrence
The MaxWave project studied the ocean surface with radar over a 3-week period in 2001. They took 30,000 images each of a 10 x 5 km section of ocean in that time, a total area of 1.5 million km2. Giant waves were detected in 10 of these, or one per 150,000 km2. A short-lived wave in a section of ocean this size is an extremely rare occurrence in its own right.[1]

[edit]
Causes
Merchant ship labouring in heavy seas as huge wave looms astern. Huge waves are common near the 100-fathom curve on the Bay of Biscay. Published in Fall 1993 issue of Mariner's Weather Log. Credits: NOAA Photo LibraryThe phenomenon of freak waves is still a matter of active research, so it is too early to say clearly what the most common causes are or whether they vary from place to place. The areas of highest predictable risk appear to be where a strong current runs counter to the primary direction of travel of the waves; the area near Cape Agulhas off the southern tip of Africa is one such area. However, since this thesis does not explain the existence of all waves which have been detected, several different mechanisms are likely, with localised variation. Suggested mechanisms for freak waves include the following:

Diffractive focusing by, perhaps, coast shape or seabed shape
Constructive interference - In this theory, several smaller wave trains meet. Their crest heights combine to create a freak wave.[2]
Focusing by currents - Storm forced waves are driven into an opposing current. This results in shortening of wave frequency causing oncoming wave trains to compress together into a freak wave.[3]
Nonlinear effects (similar to solitons) - According to research in the area of quantum physics, it is completely feasible to have a freak wave occur by natural, nonlinear processes from a random background of smaller waves.[4] In such a case, it is hypothesised, an unusual, unstable wave type may form which 'sucks' energy from other waves, growing to a near-vertical monster itself, before becoming too unstable and collapsing shortly after. This is modelled by a wave equation known as the nonlinear Schrödinger equation (NLS), in which a normal and perfectly accountable (by the standard linear model) wave begins to 'soak' energy from the waves immediately fore and aft, reducing them to minor ripples compared to other waves. Such a monster, and the abyssal trough commonly seen before and after it, may last only for some minutes before either breaking, or reducing in size again.
Normal part of the wave spectrum - Freak waves are not freaks at all but are part of normal wave generation process, albeit a rare extremity.[5]
It is important to note that the spatio-temporal focussing seen in the NLS equation can also occur when the nonlinearity is removed. In this case, focussing is primarily due to different waves coming into phase, rather than any energy transfer processes. Further analysis of freak waves using a fully nonlinear model by R.H. Gibbs (2005) brings this mode into question, as it is shown that a typical wavegroup focusses in such a way as to produce a significant wall of water, at the cost of a reduced height.

There seem to be three categories of freak waves:

"Walls of water" travelling up to 10 km through the ocean
"Three Sisters", groups of three waves (Endeavour or Caledonian Star report March 2, 2001, 53°03'S 63°35'W)
Single, giant storm waves, building up to fourfold the storm's waves height and collapsing after some seconds (MS Bremen report Feb 22, 2001, 45°54'S 38°58'W)
A comprehensive paper describing the ways that freak waves could form, complete with layman descriptions, photos and animations, can be found here.

[edit]
Encounters
Draupner wave (North Sea, 1995): first recorded evidence
RMS Queen Elizabeth 2 (North Atlantic, 1995)
Bremen (South Atlantic, 2001)
Caledonian Star (South Atlantic, 2001)
Norwegian Dawn, (off the coast of Georgia, 16 April 2005): media report, another report
Norwegian Spirit, (off the coast of Tortola, January, 2006)
Aleutian Ballad (Bering Sea, 2006) : from television show "Deadliest Catch".
The least commom places of impact for rogue waves is the mid-atlantic, oceanographers have compiled all the data and came to the conclusion that the mid Atlantic and the waters off Bermuda are very tranquil compared to other ocean points.

 

[Rubycon]

Originally posted by: sao123

Also from Wikipedia

Norwegian Spirit, (off the coast of Tortola, January, 2006)

That incident was more of a series of large waves from a low pressure in the north Atlantic. Also the ship was not off the coast of Tortola as reported, the position was much further north - off the coast of the Carolinas.

 

[Dubb]

I love rogue wave. Awesome band.

 

[Molondo]

would rogue waves have anything to do with that movie poseidon?

 

[shoRunner]

i lose sleep every night because of rogue waves...i am terrified of them...:roll:

 

[NTB]

Originally posted by: quasarsky

Originally posted by: BW86
I've never encountered one while out in the ocean. I would probably sh!t my pants if I saw one.

i doubt u would. it would probably be a few feet high at the best. waves get bigger as their energy gets compacted by the land. well tidal waves do this . and yes i know thats not the scientific name for them

A current, moving the opposite way of water closer to the surface, could do the same thing.

Nate

 

[ballmode]

no

 

[notfred]

Originally posted by: sao123

Originally posted by: notfred
No. I've spent thousnads of hours on the beach and in the ocean and never seen one.

Its not a beach wave...
Its an open ocean wave of heights 50-200 feet, up to as tall as 20 story building.

I've been reading up on them recently, lemme find my bookmarks and ill post some info.

Well, I don't hang out in the middle of the ocean a whole hell of a lot. I'm not afraid of being eaten by a lion either, simply because I don't wander around African grasslands.

 

[Linflas]

We went through a severe storm when I was onboard the USS Independence crossing the Atlantic from Norfolk to the Med. We were locked inside the ship for 3 days and there are pictures in the cruisebook of waves breaking over the flightdeck. I was never worried at all about the ship sinking during the storm. When it was over and we went back out on deck we found that the catwalk that runs along side the flight deck was gone from the bow back to the angle deck on the port side and back to around the forward jet blast deflector on the starboard side.

 

[Vich]

I actually had a dream (nightmare) of gigantic tidal waves hitting a place where i was. ANd ppl were running from it and it was like a mile high.


I remember watching some show about meteors and how if one hit the ocean we would have a gigantic tidal wave that was over a mile high hitting the coastlines.

 

[raildogg]

Originally posted by: Vich
I actually had a dream (nightmare) of gigantic tidal waves hitting a place where i was. ANd ppl were running from it and it was like a mile high.


I remember watching some show about meteors and how if one hit the ocean we would have a gigantic tidal wave that was over a mile high hitting the coastlines.

Wow, that sounds scary. A huge force like that would have a huge impact and would create a tsunami. A tidal wave is high but does not last that long. A tsunami lasts longer. I think Deep Impact was a decent movie.

But to clarify, a rogue wave is something that occurs far out to sea. It usually comes out of nowhere, a wall of water as high as 100ft or higher. I think a rogue wave hit one of the ships in the show on Discovery Channel, the one with the Alaskan crab fishing. Forget the name.

That wave turned the ship on its side but luckily, the ship corrected itself. But it did knock out its computer system.

 

[Rapidskies]

Happens more often than first thought

 

[FoBoT]

i live in Missouri


not so many waves here

 

[potato28]

Freak waves would scare me sh!tless...

 

[NTB]

Originally posted by: FoBoT
i live in Missouri


not so many waves here

Nope. We only have to worry about earthquakes, floods, and tornadoes

Nate

 

[Buck Naked]

I spend hours out on the water every week, and I'm not to worried about rogue waves.
I doubt I'll ever see one in the puget sound.

 

[holden j caufield]

I surf and rogue waves pretty rare (as in I haven't seen one). You'll see set waves at ~certain intervals but rogue wave when the size is between 1-12ft just doesn't happen. When the interval or period or whatever is over 20 seconds then you might see something big. At a few big wave spots like Mavericks I've heard of near 100ft waves on a 50 ft day. Also there was a pic of a wave that actually crashed over the bow of a huge naval ship. Something like 100ft.

 

[WildHorse]

No.

If a giant wave hits here I'll be dead so fast there'll be no time to worry (walking distance to beach).

The last one that hit here was in the 1800's, so its such a rarity it's not worth thinking about.

That 1800s wave carried a big sailing ship way up a canyon just a few miles from me.

All the drunk & otherwise impared drivers are far more likely to impact our lives than falling meteors or giant waves.

 

[sao123]

somehow i dont think most of these people understand what a rogue wave is...

its a giant wave out in the middle of the ocean.
Its not a tsunami, it will never make landfall, or come anywhere near within a hundred miles of the coast. This is a deep ocean wave which is created by constructive interference (non linear shroedinger wave theory) which can feed off of other nearby waves. It lasts only for minutes and travels only a few miles. then it dissipates.

The only way youll ever see one, is (trans?)oceanic cruise, or a deep water oil drilling platform.