Thursday, April 28, 2011 2:54:49 PM
The Draupner wave - a single giant wave measured on New Year's Day 1995
Monster waves are also known as Rogue waves, freak waves, killer waves, extreme waves, or abnormal waves. I have to stress that they have nothing to do with tsunamis or tidal waves.
Monster waves are waves whose height are more than twice the significant wave, the significant wave being the mean of the largest third of waves in a wave record. This means that monster waves are not necessarily the biggest waves found at sea. They are, rather, surprisingly large waves for a given condition at sea (sea state).
Mid-ocean storm waves commonly reach 7 m in height, and in extreme conditions such waves can reach heights of 15 m. Before the Draupner event wave heights were supposed to follow the so-called normal distribution, also known as the Gaussian function or “bell curve”.
If this was strictly true such extreme wave heights would only occur with maybe 1000 or 10000 years intervals, and they are therefor sometimes referred to as "hundred-year waves," due to the supposed likelihood of their occurrence, although they have now turned out to occur much more frequently (today they can be detected by satellite).