Rogue Waves

So-called "rogue waves" (also known as "freak waves" or "monster waves") are extraordinarily large, rare surface ocean waves whose existence has only recently been confirmed. Unlike tsunamis, rogue waves are not believed to be caused by seismic events and are generally believed to be generated by a mechanism other than the normal surface ocean waves. This is both because of their unusual size and because they have been observed to propagate in a direction other than that of the background of normal surface waves, winds and ocean currents.

What makes rogue waves distinct from "normal" waves can be subjective, since the physical mechanisms behind these waves is not yet understood. There is a commonly accepted classification by size, however, which holds that any wave which is more than twice the "significant wave height", which is defined by NOAA as the average height, from trough to crest, of the one-third highest waves for a indicated 12-hour period.

NOAA photo library image of a large wave on the bay of Biscay in 1993