Posted on 07/23/2004 1:25:25 AM PDT by Rebelbase
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
Predicting rouge waves would be invaluable.
My squadron had a ship head into Japan to have repairs done, and two sailors went to the stern to do some maintenance. Rogue wave came, the railing didn't keep 'em onboard. They retreived one sailor with a broken arm. We spent two days searching, but never found the other.
This is very interesting.
Apparently it defied the "conventional scientific wisdom" and wasn't believed, until now, when they have irrefutable proof.
I wonder what is causing them.
Cowabunga, Dude!
Old salts talk about a Devils' Wave at Monterey. The waters are calm. Then, out of the blue, a giant wave appears and destroys fishing ships. There are mysteries in the sea yet uncovered. FReegards....
One possible cause is underwater earthquakes. Gasses could cause pressures. Large, deep underwater caves could cause periodic pressures as the water streams around inside them at different lunar cycles. And God-knows-what.
To see them from Satellites they must be huge.
"Wonder what's causing them.."
I recall an article in Reader's Digest about 30 years ago..
A cadet training vessel, a sailing ship, was capsized at sea by what was believed to be a rogue wave..
The theory has been around a long time that it is "convergence", that waves can meet, and add their strength together..
With the proper conditions, the additive affects create these big boomers..
Another article I read on this subject noted the large waves that precede hurricanes, and pointed out that ocean currents and even weather fronts can contribute to abnormally large waves.
Still plenty to learn about the world we live in, let alone the universe..
Isn't that what you get when Tammy Faye Baker entered a room?
Normal waves in the ocean are caused by when wind blows across the water's surface. The wave height is determined by wind speed, fetch, duration, and the water's depth.
Here is a wave machine. Play with it to see how high you can make a wave.
http://www.pbs.org/wnet/savageseas/multimedia/wavemachine.html
The prevailing theory holds that freak waves can result when strong, high storm waves slam headlong into a powerful current traveling in the opposite direction. The interaction can push together the storm swells, so that their frequencies superimpose, creating one tremendously powerful wave that can reach a height of 100 feet or more.
http://www.pbs.org/wnet/savageseas/neptune-side-waves.html
97 feet was my best effort.
Yeah, that is as high as it goes. I wish it would let you have more variablility in the wind speed. Like increasing it to 75 knots or so. Similiar to Hurricane strength winds.
The theory of singular waves has been around for many decades. This article points out more observations (more that can be seen from ships, that is.)
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