"Monster Wave" folklore was right all along

[richardm]

ESA satellites have the evidence that humungous waves up to 25m tall are more common than you'd think.


Over the last two decades more than 200 super-carriers - cargo ships over 200m long - have been lost at sea. Eyewitness reports suggest many were sunk by high and violent walls of water that rose up out of calm seas.

But for years these tales of towering beasts were written off as fantasy; and many marine scientists clung to statistical models stating monstrous deviations from the normal sea state occur once every 1,000 years.

...

Around 30,000 separate imagettes were produced by the two satellites during a three-week period in 2001 - and the data was mathematically analysed.

Esa says the survey revealed 10 massive waves - some nearly 30m (100 ft) high.

"The waves exist in higher numbers than anyone expected," said Dr Rosenthal


Scary stuff, really. Although the oceans are big, and presumably the chances of meeting one of these waves must be small, or we'd have had the proof sooner than this (unless most people who see 'em get drowned, of course)

Giant squid, and now monster waves. What's next? Mermaids? ;)

[BPSCG]

Originally posted by richardm

quote:
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Over the last two decades more than 200 super-carriers - cargo ships over 200m long - have been lost at sea. ...

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Citation? Link? Something smells like rotting fish here. Super-carriers sinking at the rate of one every five weeks for twenty years?

[richardm]

Originally posted by BPSCG
Citation? Link? Something smells like rotting fish here. Super-carriers sinking at the rate of one every five weeks for twenty years?

Oops - Full story (http://news.bbc.co.uk/1/hi/sci/tech/3917539.stm) .

A recent Horizon programme: (http://www.bbc.co.uk/science/horizon/2002/freakwave.shtml)


The world's oceans claim on average one ship a week, often in mysterious circumstances.


An aside, speaking of losing one ship per week. Recently, someone accidentally set fire to his 30 ft wooden yacht off Islay, and had to abandon ship. He watched from his rubber dinghy as it burned down to the waterline then sank, while the lifeboat homed in (he was easy to find, because of the useful smoke plume).

The name of the yacht? "The Spark (http://www.yachtingmonthly.com/auto/newsdesk/20040607100946ymnews.html)". You couldn't make it up.

[Psi Baba]

Another link:
http://www.sciencedaily.com/releases/2004/07/040721084137.htm
This one has someone quoted as saying: " two large ships sink every week on average."

[pgwenthold]

Originally posted by richardm
Scary stuff, really. Although the oceans are big, and presumably the chances of meeting one of these waves must be small, or we'd have had the proof sooner than this (unless most people who see 'em get drowned, of course)
)

How would you avoid such a thing? It's not crazy to say that if you see one, you are going to get hit by it, so I don't think it is unreasonable to figure they are mostly dead.

OTOH, this reminds me a lot of the story about tornados (or water spouts, if you prefer) over the ocean. Every once in a while you will hear that tornados can't form over the ocean. The problem is, if one does, how will you know? You don't have a lot of people around to see them. In fact, there _are_ ship captain logs that do report seeing tornados at such and such a time in such and such a location. Not surprisingly, the number of sighted tornados in the ocean is pretty small.

OTOH, we do know that certain weather conditions that often result in tornados on land are also found over the oceans. Therefore, it is expected that there should be plenty of tornadic activity. You just don't have many tornado chasers out there.

[Khonshu]

I've seen a waterspout off the Georgia coast. Watched it form - neat stuff. Funny thing was all the birds flying around it & diving into the water at the edges of the spout. They didn't seem to be alarmed by the whole thing. Of course, I had left the camera in the room.

So yeah, I know it's ancedotal, but I've seen it. I can provide a witness as well.

[c0rbin]

Water Spout Images from Google (http://images.google.com/images?hl=en&ie=UTF-8&q=waterspout&spell=1)

Of course some are faked, but not all.

Reagrding surviving a 100 foot wave--the only solution I could think of would be to turn away and gun it if on the open ocean--ride it like a surfer would until it runs its course.

You may have to back-track, but at least you have saved the cargo, the boat, and your lives.

[Correa Neto]

OK, the evidence is good, and the phenomena is proven to exist. But this raises a number of questions...

I wonder why there are no reports of these monsters hitting shores... Could the continental shelves decrease their height? Continental shelves attenuating such waves would perhaps generate occasional surf breakers very far from the shore that probably would also have been sighted. OK, depending on shelf slope, perhaps the waves would loose energy slowly.

If this is so, why there are no reports from areas where there is no huge shelf protecting the shores, such as oceanic islands as Hawaii? Or could shield volcanoes's morphology (small slope angle over a broad area) also decrease them?

I remember hearing about huge (above 5 m tall) waves coming from nowhere in clear blue sky with little wind and calm seas at Trindade island (oceanic island 1500km off Brazillian coast). Could these be "monster waves" attenuated by the island's underwater topography?

Edited to add- depht meters from submarines would also be able to detect such fast changes in the water collumn above the vessel, would`nt they?

[Dragonrock]

Originally posted by Correa Neto
I remember hearing about huge (above 5 m tall) waves coming from nowhere in clear blue sky with little wind and calm seas at Trindade island (oceanic island 1500km off Brazillian coast). Could these be "monster waves" attenuated by the island's underwater topography?

I believe these are commonly referred to as "rogue waves." One theory says that they are basically a "wave harmonic." The idea being that several small waves all traveling in generally the same direction stack up for a short time creating one large wave.

Superstitious sailors view rogue waves as bad luck. This may be due to the idea that they are more common around the edges of storms.

[Virgil]

Originally posted by Correa Neto

Edited to add- depht meters from submarines would also be able to detect such fast changes in the water collumn above the vessel, would`nt they?



Maybe not...


Virgil

[BPSCG]

Originally posted by Psi Baba
Another link:
http://www.sciencedaily.com/releases/2004/07/040721084137.htm
This one has someone quoted as saying: " two large ships sink every week on average." Jeeze... Sounded crazy to me, but...

I ain't never going on a ship again.

[BPSCG]

Originally posted by Dragonrock
I believe these are commonly referred to as "rogue waves." One theory says that they are basically a "wave harmonic." The idea being that several small waves all traveling in generally the same direction stack up for a short time creating one large wave.

Superstitious sailors view rogue waves as bad luck. This may be due to the idea that they are more common around the edges of storms. You mean a wave ten stories high that can turn your ship upside down in a heartbeat is bad luck?

What a silly superstition!

[Dragonrock]

Originally posted by BPSCG
You mean a wave ten stories high that can turn your ship upside down in a heartbeat is bad luck?

What a silly superstition!

No, the smaller giant waves, the ones that are just 15 or 20 feet high. The only real danger is getting washed off of the deck.

[Diogenes]

Originally posted by Dragonrock

Superstitious sailors view rogue waves as bad luck. ..


Is this anything like the superstition among soldiers regarding rogue RPG's?

How do the ones who are not superstitious view them. Providing they are able to tell the story?

[Goshawk]

Apparently these rogue waves only occur out in the open ocean. Somehow they must dissipate their energy before they hit the land at 100 feet high. Current theory says that underwater topography probably has something to do with it.

More info on giant rogue waves here.

http://www.gi.alaska.edu/ScienceForum/ASF2/225.html
http://www.glerl.noaa.gov/res/Task_rpts/2002/ppliu02-3.html
http://www.science-frontiers.com/sf066/sf066g14.htm

[davidhorman]

One theory says that they are basically a "wave harmonic."

The Horizon documentary mentioned something about it being related to quantum mechanics. Can anyone shed any light on that? Because wave harmonics are pretty classical, aren't they?

David