Tuesday , June 22 2021

The continuing mystery of the rising ocean waves



At 15:00 on New Year's Eve in 1995, work stopped at the deck of the Norwegian oil platform, Draupner, which was isolated in the midst of the stormy North Sea. The wind became too strong, the waves moved, and it was no longer safe to be outside.

But one wave pressed the rest. It measures a height of 84 feet – about two and a half times the height of the telephone pillar – and is then called the "Draperner Wave". Fortunately, the monstrous elevation did not reach the platform.

Draunner's wave was the first scientific proof of a rare wave of scammers or freaks that appeared suddenly and was at least twice as high as surrounding waves. It is believed that these short-lived, colossal phenomena are possible culprits for the still inexplicable sinking of ships in the open ocean.

Although there is still considerable uncertainty about the shape of the fraudulent waves, a team of engineering scientists successfully simulated a way in which the waves can suddenly rise from the sea. Researchers recreated a (smaller version) of Draunner wave in a simulation pool and published their research in Journal of Fluid Mechanics,

"There's a lot of heated debate about the physical mechanisms for shaping these things," said Mark McAllister, a mechanical engineer at Oxford University and co-author of the study. "We have shown the conditions that can support such a wave."

<img class = "" data-credit-name = "University of Oxford / University of Edinburgh
"data-credit-provider =" user type "data-caption =" Left: simulated wave. To the right: Hokusai's "Great Wave" (early 1930s). "Title =" Left: Simulated Wave. Right: Hokusai's "Great Wave" (early 1830s). "Src =" https://mondrian.mashable.com/uploads%252Fcard%252Fimage%252F922828%252F6338a4f9-3572-488f-a39b-4dc9867ed5c5.jpg%252Ffit-in__1200x9600. jpg? signature = ZImDdwMoTv353wVRYmyhkDLH9_g = & source = https% 3A% 2F% 2Fblueprint-api-production.s3.amazonaws.com "alt =" Left: Simulated Wave. Right: Hokusai's "Great Wave" (early 1830s). "Data-fragment =" m! 2917 "data-image =" https://mondrian.mashable.com/uploads%252Fcard%252Fimage%252F922828%252F6338a4f9-3572-488f -a39b-4dc9867ed5c5.jpg% 252Foriginal.jpg? signature = GA_DKfPGMATb0plF5fh_9byu3y4 = & source = https% 3A% 2F% 2Fblueprint-api-production.s3.amazonaws.com "data-micro =" 1 "/>

To the left: simulated wave. Right: Hokusai's "Great Wave" (early 1930s).

Photograph: The University of Oxford / The University of Edinburgh

This simulation, carried out in the 82-foot diameter test tank conducted by the University of Edinburgh, has shown that when a series of waves intersect at large angles (about 120 degrees), a wave will be formed.

"This is an important part of the puzzle," said Gunther Steinmeier, a physicist at the German Institute for Nonlinear Optics and Short Impulse Spectroscopy Max Bourne.

Still, he stressed that there are still many things we do not know about these little-seen waves, even more than two decades after Draunner's famous event.

"Approximately 20 years later, we firmly believe they exist, but there are so many explanations," said Steinmeier, who had no role in the study. "They are so rare.

"If you ask three scientists in the area, you will probably hear four different stories and everyone is sure that all other explanations are completely wrong," he added.

To create Drawner, engineers spent about two days sending waves to each other at different angles until they found the right combination. The wave was very much like the famous "Great Wave of Kanagawa" from the early 1930s by artist Hokusai.

"The similarity to Hokusai's Great Wave was quite an accident, but a very pleasant surprise," said Samuel Draykot, an Edinburgh University engineer and co-author of an e-mail survey.

"Only a few months later I read the theories that Hawksay's big wave could actually depict the so-called deceptive wave," Drake added.

Detected waves have been reported both in the open ocean and near the coast, Drake said. Accordingly, understanding when a wave of fraudsters may occur may help sailors or people working at sea know when conditions are ripe for a cheater like two storms coming from different angles.

Draunner's simulated wave, about 1 meter high.

Draunner's simulated wave, about 1 meter high.

Photo: OXFORD UNIVERSITY / UNIVERSITY OF UNIQUE

"There are theories that say it's accidental," says McAllister. "And others say that if you have specific conditions, waves will grow."

Still, there are probably a lot of chances to play with any deceptive wave, Steinmeier noted.

Weather conditions must be correct (maybe violent). Waves coming from different directions also have to collide right at the right time and with the right angle just like they did to the Draperner platform.

"Statistically, this is quite a small number," Steinmeier said. However, he noted that some ship captains, who had been in the sea for decades, reported that Draunner was experiencing huge waves.

At the very least, Draunner's 1995 wave allowed workers to descend in the midst of the stormy North Sea, but unharmed.

"Fortunately, the platform was high enough so the wave did not hit the deck," McAllister said. "If it was lower, it could have been quite disastrous.

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