-
'Rogue waves'
i probably shouldn't post this, my g/f being a travel agent and all but its just to dam fasinating
http://news.yahoo.com/news?tmpl=stor..._sea&printer=1
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.
-
There is a 'Hot Spot' off the south eastern coast of South Africa, here the warm waters of the Indian Ocean are hit by the extremely cold waters from the Antarctic. The resultant clash generates enormous waves, several have been seen in excess of the mythical 30m / 100 ft height.
No danger to me, as I get nauseous in a frothy bath :D
Although if you are unfortunate enough to be caught at sea in a storm, I've heard that the best way to avoid seasickness is to get your body in equilibrium with the sea, and the ONLY way to do that = :drink: :D
-
Good Day,
Rogue Waves are frequently encountered however we may not recognize them as such unless they are large. They can be caused by a multitude of reasons and the most common are obviously disturbances below the ocean's floor, earthquakes near the ocean, and a faster wave overtaking and combining with a slower wave. All non-seismic waves are wind generated over a multitude of miles, the stronger the wind the larger the waves. If you have ever been surfing or boating and witnessed one or more waves larger than the rest, then you have encountered a rogue wave.
The Rogue Waves that are devastating and get all the press are obviously caused by larger faster waves combining with large slower waves. And thus we have the sailor's nightmare.
cheers
:cool:
-
Interesting,
It is a long time since I studied meteorology, but I seem to recall being told that one wave in around 5000 will have an amplitude of 4 times the average. On a shoreline, this isn't a great problem as such waves would break sooner, but out in the mid-ocean it is a different story.
:eek:
-
:) Having been in boats and out on the water for 20 years or so, this is really
interesting. I have mostly been in bays not oceans, so the force and height of
the waves i am used to are far less than what is out in the wild blue beyond.
Swells come in sets of usually three(when there is a sea running) and occasionally
there will be an extra one behind them created by the momentum of the leading set.
Also there can be a rogue wave created by a passing ship, even if the water is flat.
I have seen some huge swells created this way when the water was like glass.
Too often inexperienced people go out in boats and ignore this danger, out of pure
ignorance and are usually in the news headlines with sad outcomes.
this site has some interesting
stuff on underwater waves of huge size (170 meters) tall.
Check out the pics on this site
The damaged caused to the ship is awsome, and just shows the power of the sea.
cheers TidaL.....
-
Quote:
Originally posted here by tiDaLfAze23
:) Having been in boats and out on the water for 20 years or so
Quote:
Originally posted here by tiDaLfAze23 :)
I have mostly been in bays not oceans
It's time you came over to Scotland, you would just love Loch Lomond (would ensure you did not come anywhere near Mark Boyle) :D
-
:) How have you been jm459? I would prolly like that, only me worry that it may be a one way boating ride. :eek7:
-
Wow that is different...lol
