Wavelet Spectrum of Freak Waves in the Ocean

This paper presents a wavelet transform analysis of continuous wave recordings in the Sea of Japan during 1986 – 1990. The analysis is carried out to study the incidents of freak waves. The results show that a well-defined freak wave can be readily identified from the wavelet spectrum where strong energy density in the spectrum is instantly surged and seemingly carried over to the high frequency components at the instant the freak wave occurs. Thus for a given freak wave, there appears a clear corresponding signature shown in the time-frequency wavelet spectrum. Since freak waves are primarily transient events occurring unexpectedly, wavelet transform analysis on continuous, long duration wave measurements clearly represents the most ideal approach to discern the localized characteristics of freak waves for further exploration.