Posted on 07/22/2004 11:14:14 AM PDT by Strategerist
PARIS (AFP) - European satellites have given confirmation to terrified mariners who describe seeing freak waves as tall as 10-storey buildings, the European Space Agency (ESA) said.
"Rogue waves" have been the anecdotal cause behind scores of sinkings of vessels as large as container ships and supertankers over the past two decades.
But evidence to support this has been sketchy, and many marine scientists have clung to statistical models that say monstrous deviations from the normal sea state only occur once every thousand years.
Testing this promise, ESA tasked two of its Earth-scanning satellites, ERS-1 and ERS-2, to monitor the oceans with their radar.
The radars send back "imagettes" -- a picture of the sea surface in a rectangle measuring 10 by five kilometers (six by 2.5 miles) that is taken every 200 kms (120 miles).
Around 30,000 separate "imagettes" were taken by the two satellites in a three-week project, MaxWave, that was carried out in 2001.
Even though the research period was brief, the satellites identified more than 10 individual giant waves around the globe that measured more than 25 metres (81.25 feet) in height, ESA said in a press release.
The waves exist "in higher numbers than anyone expected," said Wolfgang Rosenthal, senior scientist with the GKSS Research Centre in Geesthacht, Germany, who pored over the data.
"The next step is to analyse if they can be forecasted," he said.
Ironically, the research coincided with two "rogue wave" incidents in which two tourist cruisers, the Bremen and the Caledonian Star, had their bridge windows smashed by 30-metre (100-feet) monsters in the South Atlantic.
The Bremen was left drifting without navigation or propulsion for two hours after the hit.
In 1995, the British cruise liner Queen Elizabeth II (news - web sites) encountered a 29-metre (94.25-feet) wall of water during a hurricane in the North Atlantic.
Its captain, Ronald Warwick, likened it to "the White Cliffs of Dover."
In the next phase of research, a project called Wave Atlas will use two years of "imagettes" to create a worldwide atlas of rogue wave events and carry out statistical analyses, ESA said.
The goal is to find out how these strange, cataclysmic phenomena may be generated by ocean eddies and currents or by the collision of weather fronts, and which regions of the seas may be most at risk.
Finding out could help ship architects and the designers of oil rigs and their operators to skirt the menace.
Funny. Scientists are discovering what mariners have been reporting for centuries.
I suspect a Cheney/Halliburton connection to surface soon.
Actually a good example of bad reporting, as I've followed the whole rogue wave thing for a while, and the idea that most marine scientists said they didn't exist is simply a load of BS; there have been studies and theories about them for a long time.
The thing about general-media science articles is they love to overplay the "scientists shocked" or "scientists change mind" thing to create a more dramatic story.
During WWII the QEI took a rogue wave on a troop run that rolled her to within 2* of her ultimate stability.
Solid water broke out all the bridge windows, 100 feet above the waterline.
She was making a fast unescorted transit (normal for fast liners), and if she had rolled at 30 knots, she would have driven under in a couple of seconds, and been assumed lost to a submarine.
So9
Wow. Did the wave actually break, pitch over like a breaking wave on the beach, or did it boil at the crest? I've always wondered, because normal waves have to 'feel bottom' before they can break.
Yeah, I knew that . . . I presume most marine scientists go out on the water themselves.
Solitons have had a good mathematical backing for decades. (Even a journal.) I don't know if the rogue waves are solitions, but it wouldn't be surprising.
I've seen "rogue" waves hit between sets of waves. Sometimes two waves would come together and double rather than nullifying each other, (mind you the ones I've seen have been small, generally less than 10').
I got picked up by one and dropped on a reef in Hawaii while scuba diving once, (about a 8-10' wave). It hurt when it happened and it hurt that night when I scrubbed all the abrasions with hydrogen peroxide. I tried to attenuate the pain of the scrubbing my consuming large quantities of Seagrams 7 and 7-Up. About halfway through I gave up on the 7-Up.
Semper Fi
'Surface acceleration' I assume refers to water being drawn up into the wave as it builds...
Absolutely. Wave addition occurs when two or more wave crests occupy the same place at the same time. With a Rouge wave, this could mean many more than two waves. That's why they appear as monsters out of nowhere.
About wave addition: A few years ago a tsunami was heading for a south pacific island ,(I don't recall which one). Because the islanders had ample warning they moved to the far side of the island. The tsunami hit dead on, the wave split and wrapped around the island,(due to bottom conditions caused by the coral reef that surrounded the island), and doubled up on the backside of the island, killing most of the islanders as I recall.
I lost a shipmate to a rogue wave on Oct 31, 1989. A 30-foot (9 meter) wave washed over the aircraft elevator he was working on. We never did find his body, but two guys washed over with him were rescued.
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