Rogue...

Freak Wave

From Sailing Anarchy

A team of researchers based at the Universities of Oxford and Edinburgh have recreated the famous Draupner rogue (freak) wave for the first time.

The wave was measured in the North Sea on January 1, 1995 and was one of the first confirmed observations of a rogue wave in the ocean. Rogue waves are unexpectedly large in comparison to surrounding waves. They are difficult to predict, often appearing suddenly without warning.

The wave was measured from the Draupner Oil Platform during a sea state with significant wave height of approximately 12 meters (39 feet), a freak wave with a maximum wave height of 25.6 meters (84 feet) occurred. Prior to the measurement, made by a downwards-pointing laser sensor, no instrument-recorded evidence for rogue waves existed.

The team of researchers recreated the wave using two smaller wave groups and varying the crossing angle – the angle at which the two groups travel. It was only possible to reproduce the freak wave when the crossing angle between the two groups was approximately 120 degrees.

When waves are not crossing, wave breaking limits the height that a wave can achieve. However, when waves cross at large angles, wave breaking behavior changes and no longer limits the height a wave can achieve in the same manner.

The research was led by Dr. Mark McAllister and Professor Ton van den Bremer at the University of Oxford, in collaboration with Dr. Sam Draycott at the University of Edinburgh. The project builds upon work previously carried out at the University of Oxford by Professors Thomas Adcock and Paul Taylor. Props to Marex.