Dei'ah veDibur - Information & Insight
  

A Window into the Chareidi World

11 Tishrei 5767 - October 3, 2006 | Mordecai Plaut, director Published Weekly
NEWS

OPINION
& COMMENT

OBSERVATIONS

HOME
& FAMILY

IN-DEPTH
FEATURES

VAAD HORABBONIM HAOLAMI LEINYONEI GIYUR

TOPICS IN THE NEWS

HOMEPAGE

 

Produced and housed by
Shema Yisrael Torah Network
Shema Yisrael Torah Network

 

 

 

 

 

 

 

 

 

 

Observations


Observations: Giant Waves Occur Every Day — But Scientists Thought They Were Myths Until 1995
by Mordecai Plaut

Whoever thinks that the physical world is fully explored should consider the story of rogue waves.

On January 1, 1995, a huge wave hit an oil platform in the North Sea near Norway. The platform was equipped with a measuring and recording device that kept a careful record of every ocean wave that passed by. It showed that the wave had reached a height of 61 feet. It was the first measured and recorded rogue wave.

Enormous waves that sweep the ocean are traditionally called rogue waves, implying that they are a rarity. Until about ten years ago, skeptical oceanographers doubted their existence and tended to lump them together with mermaids and sea monsters as myths. There were many accounts of sightings of giant waves over the years, but the scientists were skeptical. The human imagination embellishes, they said. They even had mathematical models of the oceans that showed that giant waves were statistical improbabilities that arise no more than once every 10,000 years or so.

But research has since found that these giants of the sea are far more common and destructive than once imagined, prompting a rush of studies and research projects.

Now one scientist estimated that at any given moment 10 of the giants are churning through the world's oceans. In size and reach these waves are quite different from earthquake- induced tsunamis, which form low, almost invisible mounds at sea and just gain height when crashing ashore. Rogue waves seldom, if ever, go close to land.

The large waves rise to heights of at least 25 meters (82 feet) about the size of an eight-story building. Scientists have calculated their theoretical maximum at 198 feet — higher than the Statue of Liberty. So far, the large rogues that have been measured come in at around 100 feet.

Waves of about 6 feet are common everywhere in the ocean, though waves up to 30 or even 50 feet are considered unexceptional. As waves gain energy from the wind, they become steeper and the crests can break into whitecaps.

Over the centuries, many accounts have told of monster waves. In 1933 in the North Pacific, the US Navy ship Ramapo encountered a huge wave. The crew estimated its height at 112 feet. In 1966, the Italian cruise ship Michelangelo was steaming toward New York when a giant wave tore a hole in its superstructure, smashed heavy glass 80 feet above the waterline, and killed a crewman and two passengers. Philippe Lijour, first mate of the oil tanker Esso Languedoc, described a huge wave that slammed into his ship off the east coast of South Africa in 1980.

On New Year's Day in 1995, a rock-steady oil platform in the North Sea produced what was considered the first hard evidence of a rogue wave. The platform had a special laser tool designed to measure wave height. During a subsequent storm, it registered an 84-foot giant.

In February 1995 the cruiser liner Queen Elizabeth II met a 29-meter high rogue wave during a hurricane in the North Atlantic that Captain Ronald Warwick described as "a great wall of water . . . it looked as if we were going into the White Cliffs of Dover."

In February 2000, a British oceanographic research vessel fighting its way through a gale west of Scotland measured titans of up to 95 feet, "the largest waves ever recorded by scientific instruments," seven researchers wrote in the journal Geophysical Research Letters soon after that.

Once-skeptical scientists were soon holding conferences about the newly-discovered waves. A large meeting in France in November 2000 attracted researchers from around the world.

It quickly became apparent that the big waves formed with some regularity in regions swept by powerful currents: the Agulhas off South Africa, the Kuroshio off Japan, and the Gulf Stream off the eastern United States. The Gulf Stream also flows through the Bermuda Triangle, famous for allegedly sinking large numbers of ships.

Results from the European Space Agency's (ESA) ERS satellites helped establish the widespread existence of these rogue waves. Studying just three weeks of data, scientists identified more than ten individual giant waves around the globe above 25 meters (82 feet) in height.

During Hurricane Ivan in September 2004 in the Gulf of Mexico, six wave-tide gauges of the Naval Research Laboratory showed waves measuring more than 90 feet from trough to crest.

But scientists were skeptical and ship designers followed their recommendations. Ships are designed to withstand a 15 meter wave — much more than was expected. The same specifications were used to design ocean drilling platforms and bridges. Now they are obsolete.

Once that they were convinced that they existed, the scientists quickly came up with explanations for why they form. Dr. Bengt Fornberg, a mathematician at the University of Colorado, said the strong ocean currents appeared to focus waves "like a magnifying glass concentrates sunlight."

"It's the same idea," he told the New York Times. "There are a few places in the world where there is a regular current, like a steady magnifying glass. In other places, the eddies come and go, and that makes the waves less predictable."

One way that rogue waves apparently form is when the strong currents meet winds and waves moving in the opposite direction, he said. The currents focus and concentrate sets of waves, shortening the distance between them and sending individual peaks higher. "That," Dr. Fornberg said in an interview, "makes for hot spots in a fairly predictable area."

Engineers cannot practically build ships that can withstand such massive forces as are unleashed by the rogue waves, so scientists are trying to predict their ocurrence so that they can be avoided.

Now rogue waves are an accepted scientific fact. But until 1995, even though thousands of ships sailed the seas, they were considered a myth.

 

All material on this site is copyrighted and its use is restricted.
Click here for conditions of use.