Rogue waves, also known as freak waves or monster waves, have long captured the attention of sailors and sea enthusiasts—and in recent decades, marine scientists. These massive, towering waves seemingly appear out of nowhere, posing a significant threat to ships, offshore structures, and people in their path. Read on to learn more about these fascinating natural occurrences.
1. Rogue waves are often described as “walls of water.”
Rogue waves are extremely large and powerful waves that appear suddenly in open water, surpassing the average height of the tallest surrounding waves by at least double. While there is no universally accepted height threshold to qualify as a rogue wave, they have been observed ranging from 26 feet to as tall as 100 feet. These bodies of water are characterized by their steepness, sharp crests, and immense destructive power, making them objects of both fear and fascination.
2. Rogue waves don’t have a single distinct cause.
Several factors contribute to the formation of rogue waves. The convergence of multiple wave systems is one key element: When waves with different wavelengths (space between their crests) and amplitudes (the height from trough to crest) meet, they can combine and reinforce each other, resulting in a sudden increase in wave height and power. Other factors include strong ocean currents, changing wind patterns, and the presence of underwater topographical features such as reefs or deep channels, which can concentrate waves in a specific area. Even considering these known causes, rogue waves are still rare and unpredictable.
3. Rogue waves are different from tidal waves and tsunamis.
Although rogue waves can cause devastating effects similar to tidal waves and tsunamis, each type of wave has distinct characteristics and causes. Tidal waves result from the gravitational interactions between Earth, the moon, and the sun, which cause sudden rushes of water up rivers or narrow bays during certain tidal conditions. Tsunamis, on the other hand, are caused by undersea earthquakes, volcanic eruptions, or landslides, generating incredibly powerful and far-reaching waves.
4. Rogue waves can disable and even sink container ships and oil rigs.
Modern ships and offshore structures like oil rigs are constructed to withstand expected conditions at sea, which include maximum wave heights of 15 meters (about 50 feet). Yet rogue waves typically surpass these heights and cause major damage. One colossal wave crashed over a cruise ship called the Viking Polaris on a trip to Antarctica in December 2022, killing one passenger and injuring four, in addition to breaking windows and other parts of the vessel. Rogue waves have also caused other freak accidents worldwide.
5. There are more rogue waves than you might think.
Once considered rare and mythical in maritime lore, rogue waves have emerged as more frequent phenomena than previously believed, with estimates suggesting that one in every 10,000 waves is rogue. A 2019 study analyzing 22 years of measurements gathered by wave buoys also found an increase in the waves’ height between 1994 and 2016. But efforts to understand and forecast these waves are hindered by the limited data and the waves’ unpredictable nature.
6. Rogue waves are more likely to occur in some parts of the world.
Rogue waves have the potential to appear in oceans and large bodies of water worldwide, but certain locations have a higher likelihood of encountering them. Off the southeast coast of South Africa where the Agulhas current flows is one; the North Atlantic Ocean, where the powerful Gulf Stream and other major ocean currents converge, is also notorious for birthing these colossal waves. Parts of the South Atlantic, Indian, and Pacific oceans have witnessed their fair share of rogue wave incidents as well.
7. Rogue waves can form in freshwater lakes.
Rogue waves are mainly connected with oceans and seas, but they can surprise us by appearing inland. In one famous example, a rogue wave may have caused the tragic shipwreck of the S.S. Edmund Fitzgerald on Lake Superior in 1975. The massive cargo ship disappeared from radar during a gale and sank off Whitefish Point, Michigan. All 29 crew members were lost.
8. Several shipwrecks in recent history are attributed to rogue waves.
Though scientists lack hard data about rogue waves prior to the mid-1990s, some researchers have attributed historical shipwrecks to them in hindsight. One theory for the mysterious disappearance of the U.S.S. Cyclops in 1918 is that a rogue wave or an unexpected, severe storm fractured the vessel and its heavy cargo of manganese ore dragged the ship to the ocean’s depths. In 1974, the Norwegian tanker Wilstar sustained structural damage (but didn’t sink) likely caused by a rogue wave, while in 1978, German freighter M.S. München transmitted a distress signal reporting that a colossal wave had struck the ship. No one survived. A rogue wave is also thought to have smashed the swordfish boat Andrea Gail in the North Atlantic in 1991, chronicled in Sebastian Junger’s bestseller The Perfect Storm.
Modern cruise ships have not been immune to damage, either. The Bremen and Caledonian Star had their bridge windows shattered by waves in the South Atlantic estimated to be 98 feet (30 meters) tall. The incidents occurred just days apart in 2001. The Holland America cruise ship M.S. Prinsendam also faced two 39-foot (12-meter) rogue waves near Cape Horn in 2007 [PDF], resulting in numerous injuries and medical evacuations.
9. The Draupner wave marked the first recorded measurement of a rogue wave.
On January 1, 1995, an extraordinary event took place on the Draupner oil-drilling platform situated about 100 miles off the Norwegian coast. The platform had a device called a sea surface elevation probe that recorded a massive wave of 85 feet (26 meters) crashing into the structure. Thanks to this instrument, the Draupner wave holds the distinction of being the first rogue wave ever recorded and confirming the existence of the long-rumored freak occurrences.
10. Rogue waves have become pop culture icons.
Under the Wave off Kanagawa, the famous woodblock print by the Japanese artist Katsushika Hokusai, portrays a towering wave with boats in the foreground and a tiny Mount Fuji in the distance. Though viewers often mistake the wave for a tsunami, historians and scientists have suggested that the print depicts a rogue wave because it appears to be driven by wind rather than an earthquake.
A rogue wave also starred in 1972 disaster flick The Poseidon Adventure, though the captain and crew on the S.S. Poseidon’s bridge incorrectly cites the wave’s cause as an underwater earthquake. In the 2005 remake Poseidon, the oversight is corrected and a crew member just feels like “something’s off” before the wave slams the ship.
This article was originally published on www.mentalfloss.com as 10 Surprising Facts About Rogue Waves.