I watched a documentary on Rogue Waves this evening on the History Channel. Truly scary stuff. The reason there are so few images of what happens as the wave hits is because they strike so fast, with so much force. Hell under water.
For centuries sailors have been telling stories of encountering monstrous ocean waves which tower over one hundred feet in the air and toss ships about like corks. Historically oceanographers have discounted these reports as tall tales– the embellished stories of mariners with too much time at sea. But in the last eleven years scientists have discovered strong evidence indicating that such massive rogue waves do exist.
This rare photo of a rogue wave was taken by first mate Philippe Lijour aboard the supertanker Esso Languedoc, during a storm off Durban in South Africa in 1980.
Check out this article for a good history of these waves. Until recently, mathematical models concluded that these waves could only strike every ten thousand years or so (obviously not the case). This began to change on New Year’s Day in 1995, when 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 laser designed to measure wave height.
During a furious storm, it registered an 84-foot giant.
It’s just like the Poseidon Adventure, only very real. Apparently, the Bermuda Triangle is a breeding ground for Rouge Waves, offering a potential explanation for some of the ‘mysterious and supernatural’ ship disappearances over the years.
By one definition, the titans of the sea rise to heights of at least 25 meters, or 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 or the Capitol rotunda in Washington. Large rogues seem to average around 100 feet.
According to NOAA (the National Oceanic and Atmospheric Administration), over the past twenty or thirty years, rouge waves have come to be recognized as a unique phenomena with several possible causes:
1) Constructive interference. Several different wave trains of differing speeds and directions meet at the same time. The heights of the crests are additive so that an extreme wave may result when very high waves are included in the wave trains. The effect is normally short lived since the wave trains continue to separate and move on.
2) Focusing of wave energy. When storm forced waves are developed in a water current counter to the wave direction an interaction can take place which results in a shortening of the wave frequency. The result is the superimposing of the wave trains and the generation of extreme waves. Examples of currents where these are sometimes seen are the Gulf Stream and Agulhas current. Extreme wave developed in this regime tend to be longer lived.
3) Normal part of the wave spectrum. The generation of waves on water results not in a single wave height but in a spectrum of waves distributed from the smallest capillary waves to large waves indeed. Within this spectrum there is a finite possibility of each of the wave heights to occur with the largest waves being the least likely. The wave height most commonly observed and forecast is the significant wave height. This is defined as the average of the one third highest waves. The random nature of waves implies that individual waves can be substantially higher than the significant wave height. In fact, observations and theory show that the highest individual waves in a typical storm with typical duration to be approximately two times the significant wave height. Some reported rogue waves are well within this factor of two envelope. Waves higher than roughly twice the significant wave height fall into the category of extreme or rogue waves.
While not the usual subject matter of PSM, I found this to be very interesting and worth sharing.
Do you watch Deadliest Catch?