Posted on 01/05/2002 6:49:34 PM PST by aculeus
GERMAN scientists claim to have explained the mystery behind so-called monster waves - the term given by oceanographers for near-vertical breaking seas up to 120ft high. Such seas are thought to have sunk more than 200 supertankers and container ships without trace during the past two decades.
Often dismissed as sailors' yarns, monster waves have terrified seafarers for centuries and provided the raw material for countless novels and films including Sebastian Junger's recent best-seller The Perfect Storm.
Yet until now scientists and oceanographers had been unable to determine exactly what formed such gigantic "one-off" seas that are capable of breaking a 600ft-long ship in half and sending it to the bottom within seconds.
A team of oceanographers at the Technical University in Berlin has now managed to explain the phenomenon with the aid of computers and by simulating monster waves in a tank.
"Our wave experiments have proved for the first time that monster waves are physically possible and that they really do exist," said Prof Gunther Clauss, who led the team of scientists.
"This represents a breakthrough for the shipping and oil industries because we can now start to design structures that can cope with these monsters," he added.
Using a computerised, hydraulically powered wave-making machine in a specially designed tank supplied by oceanographers at Hanover University, Prof Clauss's team has established that monster waves can occur with little or no warning.
The waves are created in a storm when slow-moving waves are caught up by a succession of faster waves travelling at more than twice their speed. "What happens then is that the waves simply pile up on top of each other to create a monster," said Prof Clauss.
"The result is an almost vertical wall of water which towers up to 120ft in height before collapsing on itself. Any vessel caught by one of these has little chance of surviving."
Photographs of the experiments show the monster wave building into a vertical wall of water before exploding into an uncontrollable boiling mass as it collapses on itself.
"Even in the tank the effect was awe-inspiring," said Prof Clauss. "The exploding wave was so powerful that it broke through the ceiling of the building in which the tank is located," he added.
Monster waves are thought to have caused the loss of at least 200 "super carriers" or ships measuring more than 600ft in length on the world's oceans over the past 20 years. The unexplained disappearance of many smaller vessels including trawlers and yachts could put the total number of losses much higher.
Yet accounts by seamen who have witnessed such waves are comparatively rare. One, dating from 1995, was when the QE2 was hit by a hurricane on a crossing to New York.
She survived what was estimated to be a 95ft high wave which the ship took directly over her bow. Her captain, Ronald Warwick, described the phenomenon as "like going into the White Cliffs of Dover".
One of the few small-boat sailors to survive a monster wave was the British yachtsman, Brigadier Miles Smeeton, who did so twice. His 50ft ketch, Tzu Hang was dismasted twice by such waves while attempting to round Cape Horn in the 1950s - once after being "pitchpoled", toppled stern over bow.
In Germany, the horrors of monster waves have been brought right up to date after revelations about the near-sinking of the German Antarctic cruise liner Bremen in the south Atlantic last year. The ship with 137 passengers aboard was hit by a 114ft wave in March while heading towards make Rio de Janiero after an Antarctic cruise.
The impact smashed windows on the bridge and cut the ship's electricity supply. The vessel drifted engineless for more than half an hour heeling at an angle of 40 degrees in huge seas whipped by hurricane-strength winds.
"I have been at sea for 48 years, but never have I experienced such a wave," said the Bremen's captain, Heinz Aye, 65, who is now retired.
Prof Clauss said that his team's research would help naval architects in their efforts to construct ships and oil platforms that were capable of withstanding such freak wave forces.
"In many cases it is as simple as building a bridge on a ship that is not slab-sided but rounded, so it can cope with being hit by a monster wave. Most ships plying the oceans right now are not built along these lines," he said.
The team also hopes that its research will help in the development of radar that is specifically designed to warn of sea conditions that could produce the monster-wave phenomenon.
"This could help the captains of ships to steer clear of a danger area, but the truth is we can do nothing to prevent monster waves. They are a product of nature," Prof Clauss added.
He also said that the Fitzgerald either had a stress fracture or had bottomed on a reef earlier and that was the proximate cause of the sinking.
Regards,
And the researchers checking out the stats.
Lake Superior, off Whitefish Point.
Some of the Fitzgerald crew were from my area (northeast Wisconsin).
And this happened on which Great Lake?
The Fitzgerald was 675" long, no evidence exists about what sunk her, and if you know your Indian Lore, the lake was the Gitcheegoomie
It's the big lake that is superior to all others. The Fitz went down before she could reach the shelter of Whitefish Bay.
The Fitzgerald weighted 13,632 tons and was 729 feet long. In 1958, when it was first launched, it was the largest carrier on the Great Lakes, and remained so until 1971. The Fitzgerald was labeled "The Pride of the American Flag". In 1964 it became the first ship on the Great Lakes to carry more than a million tons of ore through the Soo Locks. On November 9, 1975 she departed from Superior, WI with approximately 26,000 tons of ore bound for Detroit MI. Shortly after leaving, the Fitzgerald made contact with the Arthur M. Anderson bound, on a similar route, for Gary IN.
Eaker
That's almost inconcieveable. Moving water is nothing to mess around with.
"seiche
n.
From Swiss-French. A natural, standing wave in the water of a lake, bay, etc., caused by changes in atmospheric pressure, seismic disturbances, winds, waves, tides, etc.: it continues after the generating force stops."
These are different from "soliton" waves, which are another story altogether.
--Boris
Yup, we got in the capsule the next morning and made a tour of the legs and the hull bottom.
One of the legs had a small crack in it, but it could have been there all the time.
We were back to drilling the same day we got back on board.
Seems to me I remember reading about Hamilton (the Irish math dude) seeing some huge wave in a canal, coming out of nowhere, not dispersing at all, passing off into the sunset, adn somebody called them solitons.
Do you guys know the reference for this German study?
I believe 'Rogue waves' have been around for a long, long, time, as a part of seagoing lore.
The sea gives me the heebie-jeebies.
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