Rogue waves, unusually large and sudden ocean waves, have been recorded in various parts of the world. In 2020, a wave approximately four stories high was recorded off the coast of Vancouver Island in Canada. This wave, which occurred in Ucluelet, was about three times the height of the waves around it, making it the most extreme rogue wave ever officially recorded. No injuries or damage were reported from this event.
For centuries, sailors reported encountering giant waves that appeared without warning, though these accounts were often dismissed by the scientific community. In 1826, a French naval officer described seeing waves over 98 feet tall during a storm in the Indian Ocean. His report was not taken seriously, as scientists at the time believed waves could not exceed 30 feet.
The scientific consensus changed in 1995 when a wave hit the Draupner gas platform in the North Sea. The wave, which was 84 feet tall and twice the size of surrounding waves, was recorded by sensors on the platform. This event led to the official definition of a rogue wave: a wave more than twice as tall as the waves around it.
Rogue waves can occur in both stormy and calm seas. They have been linked to several maritime disasters, including the disappearance of the MS München in 1978 and the sinking of the SS Edmund Fitzgerald in Lake Superior in 1975. The U.S. National Oceanic and Atmospheric Administration has identified 50 historical maritime tragedies that were likely caused by rogue waves.
Scientists have proposed two main theories to explain how rogue waves form. The linear addition theory suggests that waves can combine forces when they cross paths. The nonlinear focusing theory proposes that waves in a group can exchange energy, with some waves growing larger at the expense of others. Research conducted in Antarctica by scientists from the University of Melbourne found that strong winds over young waves can cause some waves to steal energy from nearby waves, leading to the formation of rogue waves. These events occurred about once every six hours in the conditions studied.
A 2018 laboratory study recreated the Draupner wave and found that rogue waves can form when waves meet from different directions. This creates a crosswave that can continue growing even after a normal wave would break. The study suggested that these waves can become four times steeper than previously thought possible, information that could be relevant for designing offshore structures like wind turbines and oil platforms.
Rogue waves are distinct from tsunamis. Tsunamis are caused by large-scale events like earthquakes, volcanic eruptions, or landslides that displace the entire water column. Rogue waves form at the surface level, although similar phenomena called rogue internal waves can occur deep below the surface.
The Cascadia Subduction Zone, a fault line running from Northern California to Vancouver Island, is a focus of ongoing research. This zone has produced major earthquakes and tsunamis in the past, most recently in 1700. That event sent a tsunami across the Pacific that was recorded in Japan, though it took centuries for scientists to connect the two. Studies of the seafloor have found evidence of at least ten major earthquake events, suggesting the region experiences very large earthquakes periodically rather than releasing pressure gradually.
The fault is currently locked, meaning pressure has been building for over 300 years. Scientists estimate a 10 to 15 percent chance of a major earthquake in the next 50 years. A magnitude 9 earthquake in the region could cause severe shaking for several minutes and generate a tsunami that could reach coastal areas within 15 to 30 minutes. Computer models project that such an event could damage around 620,000 buildings, and the economic toll could exceed $70 billion.
Researchers have been studying the Cascadia zone using underwater scans and sediment analysis. They have identified marine terraces along the coast that were pushed upward by past earthquakes, providing a timeline of major events. The most recent large quake in the zone, other than the 1700 event, occurred around 923 C.E. and lifted the land by about 26 feet.
The Seattle Fault Zone, a separate system that runs beneath the city of Seattle, has also been studied. Research suggests that very large earthquakes in this zone are rare, possibly occurring every 5,000 years or more. However, smaller faults in the zone have produced earthquakes about every 350 years over the last 2,500 years. These smaller events, which have included a magnitude 6.7 quake, are strong enough to damage buildings and infrastructure in a modern city.
Scientists have found evidence that the San Andreas Fault in California and the Cascadia Subduction Zone may be linked. Analysis of marine sediment cores suggests that paired earthquakes, where one fault ruptures shortly after the other, have occurred at least ten times in the last 3,100 years. The two faults meet at the Mendocino Triple Junction, where stress changes from one rupture could destabilize the other. If both faults were to rupture in sequence, it would affect a densely populated region with significant economic impact.
The 1995 Kobe earthquake in Japan, which occurred on a different fault system, provides an example of the potential consequences of a major quake in an industrial area. The magnitude 6.9 earthquake caused extensive damage, including the collapse of approximately 400,000 buildings and widespread infrastructure failure. The economic losses were estimated at around $200 billion, and it took years for the region to fully recover. Japan subsequently overhauled its building codes and disaster management systems.
Japan’s approach to earthquake preparedness is considered a model. The country experiences about 1,500 noticeable earthquakes each year. Building codes require structures to be able to withstand magnitude 7 earthquakes without collapsing. Modern buildings use techniques such as base isolation pads, thick walls, and dampers to absorb seismic energy. Japan also operates an earthquake early warning system that can detect initial seismic waves and send alerts to slow trains, stop elevators, and shut down gas lines before the strongest shaking arrives.
The Nankai Trough, a fault line off the coast of southern Japan, is another area of concern. The last major earthquakes on this fault occurred in 1944 and 1946, both with magnitudes around 8.1. Scientists estimate an 80 percent probability of a major earthquake in the region in the coming decades, though the exact timing cannot be predicted. In August 2024, a magnitude 7.1 earthquake in the region prompted the Japanese Meteorological Agency to issue its first-ever megaquake advisory. The warning was lifted a week later after no further significant activity occurred.
Undersea observatories are helping scientists monitor geological activity in real time. The Axial Seamount, an underwater volcano about 300 miles off the coast of Oregon, is connected to a network of sensors via 550 miles of fiber optic cable. The volcano erupted in 2015, and scientists expected another eruption around 2025 based on patterns of ground swelling and earthquake activity. The eruption has not occurred as predicted, though the volcano remains active and continues to build pressure.
Scientists have also been studying slow-slip events, where tectonic plates move gradually over weeks or months without causing earthquakes. A laboratory study using plexiglass sheets found that earthquakes may begin with a slow, quiet crack that spreads invisibly before suddenly accelerating into a fast-moving rupture. Understanding this process could potentially help scientists detect early warning signs of major earthquakes, though reliable prediction remains a long-term goal.
The recent seismic swarm near Santorini, Greece, which began in January 2025, provided additional data on how fault systems behave. More than 20,000 small earthquakes were recorded in less than a month. The activity was concentrated near the underwater Kolumbo volcano and was likely caused by fluids moving through fault lines. No significant damage was reported, though authorities closed schools and evacuated some areas as a precaution.
In the United States, scientists have documented that the New Madrid Seismic Zone, which produced major earthquakes in 1811 and 1812, may still be experiencing aftershocks from those events. Some researchers estimate that between 10 and 65 percent of recent quakes in the region could be aftershocks. The debate continues, as other scientists attribute the activity to ancient rift zones left behind when the supercontinent Rodinia broke up.
The Earth’s crust is in constant motion, and earthquakes occur somewhere on the planet about 500,000 times each year. Most are too small to be felt, and only about 100 cause noticeable damage each year. While scientists cannot predict exactly when or where the next major earthquake will strike, ongoing research on fault systems and improved monitoring technology are helping communities prepare for the possibility of significant seismic events.
