Rogue waves
Stories from Physics
for 11-14
14-16
For centuries, sailors have spoken of rogue waves, which are freakishly large waves that appear without warning. Rogue ocean waves are defined as waves twice the significant wave height, the mean height of the largest third of recorded waves. Between 1969 and 1994 more than 22 super carriers have been lost to rogue waves. Waves as high as 26 m have been reported and rogue waves are expected to occur every 10,000 waves. A number of effects have been proposed to explain rogue waves including spatial focusing of waves by changing seabed topography and the co-occurrence of meteorological phenomena.
The first rogue wave to be recorded by an instrument was named the Draupner wave, after the gas platform where it was observed. On 1 January 1995, whilst the significant wave height was 12 m, a 25.6 m wave was recorded at the gas platform in the North Sea. The wave caused only minor damage to the platform.
Researchers from the universities of Oxford and Edinburgh have recently been successful in recreating rogue waves in the laboratory. They found that the phenomenon occurred when wave groups crossed at an angle of 120°.
References
K. Dysthe, H. E. Krogstad, P. & Müller, P. Oceanic rogue waves. Annual Review of Fluid Mechanics, vol. 40, 2008, pp. 287-310. p. 289.
M. L. McAllister, S. Draycott, T. A. A. Adcock, P. H. Taylor, Laboratory recreation of the Draupner wave and the role of breaking in crossing seas. Journal of Fluid Mechanics, vol. 860, 2019, pp. 767-786.
