Statistics for the Draupner January 1995 Freak Wave Event

Abstract

The wave time series recorded at “Draupner”, January 1, 1995 at 15:20 exhibits an unsymmetrical, freak wave event. The statistics of the peak event is studied within the framework of traditional non-Gaussian process models. Assuming that the sea surface is adequately described by (one of) commonly applied non-Gaussian wave models, the paper shows that the probability of occurrence of a freak event like the one observed at Draupner January 1995 is very low.

Modeling extreme wave heights from laboratory experiments with the nonlinear Schrödinger equation

“…Now it is confirmed again that the behavior of some statistical quantities such as λ 40 could work as an indicator on the presence of extreme events in the time series (Guedes Soares et al, 2004). In this sense, the coefficient of kurtosis is thought to be the representative statistical measure with respect to the probability of occurrence of abnormal waves (Hagen, 2002). Meanwhile, it is observed again that the simulated results are larger than those in the experiments, particularly in the case with larger initial BFI.…”

“…Some previous investigations (Hagen, 2002;Onorato et al, 2006;Cherneva et al, 2009;Toffoli et al, 2008aToffoli et al, , b, 2010aToffoli et al, , b, 2011 suggest that the noticeably increasing frequency of occurrence of unusually large waves is accompanied by an increment on the coefficient of kurtosis λ 40 , which has been related with the Benjamin-Feir index for narrowband long-crested waves at long times (Janssen, 2003).…”

“…The deviation from Gaussian structure is mainly attributed to modulation instability in the wave train, which can be considered as a quasiresonant four-wave interaction in unidirectional narrowband waves. The third-order nonlinear interactions between free wave modes, described quantitatively by means of the coefficient of kurtosis λ 40 , are responsible for the large amplitude events and the increased probability of occurrence of abnormal waves, as shown in a series of studies (e.g., Hagen, 2002; Onorato et al, 2006;Mori et al, 2007;Cherneva et al, 2009Cherneva et al, , 2011Shemer et al, 2009Shemer et al, , 2010.…”

Characteristics of abnormal waves in North Sea storm sea states

“…If one considers that the probability of these sea states to occur can be of the order of magnitude of 10 23 , this would imply that the probability of these waves to occur would be of The number of time records available from Draupner is not representative enough to allow similar type of estimates to be made but reference is made to Refs. [2,12] where a discussion can be found of this subject.…”

The predictability of the "Voyager" accident

“…Note that this wave had an 18.5 m crest height within an 11.5 m significant wave height field. Good descriptions of the event can be found in Sunde (1995) and Hagen (2002).…”