There was also something about similar non linear wave behavior being observed in fibre optics not too long ago.
Results 21 to 28 of 28
07-11-11, 21:47 #21Guest
Location : London
- Join Date
- Jan 2004
08-11-11, 00:05 #22
I have a curiosity about rogue waves so I did a little research. I have seen large swells that seem random and infrequent and it's a real problem if you're running in a following sea and you don't see them coming. I can't imagine these walls of water some as high as 28 metres (90 feet). It seems freakish and almost mythical, but they happen. Here's an article by Dee White on the subject. Very interesting stuff:
08-11-11, 00:45 #23
I was on a Semi Sub in the North Sea which was heaving 54ft/16.5m. A few years below the accomodation windows on the rig were blown in by a wave and they were 80ft above sea level. Heres a link to the 100fter that hit the Armada platform a few years ago
NiallTheres nowt like the wind, waves and voices yelling how do you flush the bloody TOILET
08-11-11, 17:21 #24Registered User
Location : Back in UK
- Join Date
- Jul 2006
>Therefore, a forecast of 10-foot seas in open waters means a mariner should expect to encounter a wave spectrum with many waves between 6 and 10 feet along with a small percentage of waves up to 16 feet and possibly even as large as 20 feet.
NOAA's explanation of their wave forecasts. Not exactly rogue waves but we've often had those wave heights. The biggest one is usually around every seven waves.
09-11-11, 16:29 #25Registered User
Location : UK when not sailing
- Join Date
- Oct 2002
Not sure if I am really taking this debate further.
It has long been known that waves always come with a range of frequencies and that larger than normal waves occur when two or more wave trains come into phase. The “every 7th wave” being a big one has some statistical support. Just occasionally, waves twice the average will occur purely by chance. I do not know how large a wave can be caused by this effect alone.
Such effects are compounded by wind, really it is swell, against current. The Agulhas current effect becomes really dangerous when a deep low gives a long spell of strong winds opposing the current. Ship captains tell me that ships heading into the big swells go over the crest of a wave and down the other side so fast that they simply carry on diving down into the next wave, especially when it is steep and following closely after its predecessor. Momentum takes over. Whether these are the “holes” that have been mentioned, I do not know.
There are, of course, other reasons for freak waves such as a minor earth tremor leading to a Tsunami type effect. A shock wave type effect can occur when a swell goes through a narrow strait. This is one of the possible causes of seiches around the Balearics. Bottom topgraphy is also, clearly, another factor.
It is probably misleading to look for single answers for freak waves and may be equally so when trying to determine a single reason for one particular wave.
09-11-11, 16:35 #26
[QUOTE=binch;3206357]One of our most scientific instruments were milk bottles half full of liquid jelly. Lowered under a buoy, we could detect something or other from the way the jelly set. (We had oceanographers on board, very earnest young men with beards.)/QUOTE]
10-11-11, 09:43 #27
10-11-11, 09:47 #28