![]() ![]() Their existence has also since been confirmed by video and photographs, satellite imagery, radar of the ocean surface, stereo wave imaging systems, pressure transducers on the sea-floor, and oceanographic research vessels. During that event, minor damage was inflicted on the platform far above sea level, confirming the validity of the reading made by a down-pointing laser sensor. ![]() However, what caught the attention of the scientific community was the digital measurement of a rogue wave at the Draupner platform in the North Sea on Janucalled the "Draupner wave", it had a recorded maximum wave height of 25.6 metres (84 ft) and peak elevation of 18.5 metres (61 ft). A stand-out wave was detected with a wave height of 11 metres (36 ft) in a relatively low sea state. Eyewitness accounts from mariners and damage inflicted on ships have long suggested that they occur, however the first scientific evidence of their existence came with the recording of a rogue wave by the Gorm platform in the central North Sea in 1984. Once considered mythical and lacking hard evidence for their existence, rogue waves are now proven to exist and known to be a natural ocean phenomenon. (In deep ocean the speed of a gravity wave is proportional to the square root of its wavelength, the peak-to-peak distance between adjacent waves.) However, other situations can also give rise to rogue waves, particularly situations where non-linear effects or instability effects can cause energy to move between waves and be concentrated in one or very few extremely large waves before returning to "normal" conditions. The basic underlying physics that makes phenomena such as rogue waves possible is that different waves can travel at different speeds, and so they can "pile up" in certain circumstances, known as " constructive interference". Rogue waves are an open-water phenomenon, in which winds, currents, non-linear phenomena such as solitons, and other circumstances cause a wave to briefly form that is far larger than the "average" large wave (the significant wave height or "SWH") of that time and place. Īlthough commonly described as a tsunami, the titular wave in The Great Wave off Kanagawa by Hokusai is more likely an example of a large rogue wave. Rogue holes have been replicated in experiments using water wave tanks, but have not been confirmed in the real world. Ī 2012 study supported the existence of oceanic rogue holes, the inverse of rogue waves, where the depth of the hole can reach more than twice the significant wave height. ![]() They appear to be ubiquitous in nature and have also been reported in liquid helium, in quantum mechanics, in nonlinear optics, in microwave cavities, in Bose–Einstein condensation, in heat and diffusion, and in finance. Rogue waves can occur in media other than water. Rogue waves seem not to have a single distinct cause, but occur where physical factors such as high winds and strong currents cause waves to merge to create a single exceptionally large wave. ![]() Therefore, rogue waves are not necessarily the biggest waves found on the water they are, rather, unusually large waves for a given sea state. In oceanography, rogue waves are more precisely defined as waves whose height is more than twice the significant wave height ( H s or SWH), which is itself defined as the mean of the largest third of waves in a wave record. A rogue wave appearing at the shore is sometimes referred to as a sneaker wave. They are distinct from tsunamis, which are often almost unnoticeable in deep waters and are caused by the displacement of water due to other phenomena (such as earthquakes). Rogue waves (also known as freak waves, monster waves, episodic waves, killer waves, extreme waves, and abnormal waves) are unusually large, unpredictable and suddenly appearing surface waves that can be extremely dangerous to ships, even to large ones. A merchant ship labouring in heavy seas as a large wave looms ahead, Bay of Biscay, ca. ![]()
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