When water is trapped in a narrow channel such as a wave tank, it’s much easier for large waves to form and to be observed. These experiments can even account for currents and winds, although the controlled settings have their own limitations. “Recreations in a laboratory mimic almost one-to-one what happens on the ocean surface,” Chabchoub says. To compensate for limited observations of rogue waves, scientists rely on wave tanks. A 2019 study led by Chabchoub evaluated several rogue wave observations and models, and the team concluded that the inciting rogue wave mechanism can change depending on the varying factors in the sea at a given time, known as the sea state. “Generally ocean rogue waves are measured from platform measurements or buoys, which record time-measurements at a specific location without any knowledge of what happened before or will happen further,” says Amin Chabchoub, a wave physicist at the University of Sydney in Australia. Even now, there’s a dearth of quality tracking data. One reason for the uncertainty is that rogue waves are rare. Nonlinear focusing assumes waves travel in groups and can lend energy to one another, which sometimes spawns a rogue wave. Linear addition assumes that waves travel through the ocean at different speeds, and when they overlap, they can strengthen into a rogue wave. Two main mathematical theories have emerged to explain the wave movements that spawn rogue waves: Linear addition and nonlinear focusing. Scientists have since figured out that unlike tsunamis, which are large waves produced by a sudden displacement of water from an event such as an earthquake or landslide, rogue waves form due to a chance combination of wave movements through the ocean. The wave’s peak, measured by a laser detector on the rig’s scaffolding, rose 85 feet above the surface. Scientific doubts about these mysterious, giant waves were not completely dispelled until 1995, when a rogue wave hit the Draupner oil rig, a natural gas platform in the North Sea off the coast of Norway. A lifeboat that had been attached to the ship about 65 feet above the water was recovered, but it appeared to have been ripped from its post, likely by a towering wave at least that high. After reporting bad weather and sending out distress signals in the early morning hours of December 13, the ship and everyone on it disappeared. In December 1978 the ship left the German port city of Bremerhaven for Savannah, Georgia, packed with steel cargo and a crew of 28. The crew aboard the MS Mü nchen, a German container ship, weren’t so lucky. The ship sustained significant damage and three people were drowned, but most who were on board made it safely back to shore. In April 1966 an Italian cruise ship called the Michelangelo met with an 80-foot wave that rose high above the storm-driven waves around it. ![]() How waves can growĪs shipbuilding technologies advanced in the 20th century, the number of surviving witnesses to rogue waves grew. ![]() Their work offers hope that we may even be able to predict rogue waves before they strike. More recently, mathematicians have been combining real-world data collected from monitoring buoys with statistical models to understand what causes these gargantuan waves to form. In the vastness of the ocean, the interaction of the many forces leading to rogue waves can be difficult to untangle. Though they are relatively rare, rogue waves can cause severe damage and loss of life if they hit a ship in the open sea. Scientists have recognized rogue waves as real phenomena since the mid-1990s-but keeping sea travelers safe from them is still a major challenge. They can occur during storms with choppy seas but have also been reported in calm waters, which is one reason they’re so difficult to predict. With steep sides and a deep trough below, they resemble a wall of water rising out of the sea. These giant swells can appear suddenly and seemingly out of nowhere. Today a rogue wave is defined as one that is more than twice as tall as the waves around it.
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