Monster waves that come out of nowhere and devour or severely damage ships are a horror for every seafarer. Now scientists at the University of Copenhagen and the University of Victoria in Canada have developed a formula to predict these dangerous waves using 700 years of wave data and artificial intelligence. The focus is, of course, on making shipping safer. Whether the model can also recognise "surfable" waves remains to be seen.
Until 1995, when a 26 metre high wave hit the Norwegian oil platform "Draupner", stories about monster waves or cavemen, as they are also known, were considered to be ridiculed sailors' fiction. At that time, a monster wave was measured for the first time using digital instruments, proving that abnormal ocean waves really do exist.
Large waves are caused by a combination of many factors
Since then, the waves have been the subject of numerous studies. But only now have researchers at the Niels Bohr Institute at the University of Copenhagen succeeded in developing a mathematical model that provides the recipe for how - and above all when - extreme ocean waves can occur.
"Basically, it's bad luck when one of these very large waves occurs. It is a combination of many factors that could not previously be summarised in a single risk assessment. In the study, we mapped the causes of a monster wave and combined them in a model that uses artificial intelligence to calculate the probability of it actually occurring," says Dion Häfner, former doctoral student at the Niels Bohr Institute and lead author of the scientific study.
Abnormal waves occur daily
The research results show that monster waves occur regularly. In the calculations, the researchers combined available data on sea movements and the shape of the seabed. Most important, however, is the wave data from a total of 150 buoys that continuously collect wave data off the US coast. The huge dataset recorded 100,000 waves that can be defined as monster waves, meaning that between 0.1 and 1 abnormal waves occur daily at any given location in the ocean. "However, not all of these waves are monster waves of extreme strength," explains Johannes Gemmrich from the University of Victoria and second author of the study.
When two wave systems cross each other, monster waves can be created
The researchers also concluded that the predominant factor in the formation of giant waves is what is known as "linear superposition". This phenomenon has been known for 400 years and occurs when two wave systems intersect and then reinforce each other for a short time.
Safe shipping traffic
With the help of the formula, it will be possible to predict when the "perfect" combination of factors is present to create a monster wave. No doubt wave hunters like Jason Polakow, who are on the lookout for big waves around the world, will also take a look at the predictions - whether surfable waves can then also be recognised at the world's big wave spots remains to be seen. However, the researchers' algorithm is first and foremost good news for the shipping industry, where around 50,000 cargo ships are travelling the seas at any time of day or night. Monster waves pose a serious danger to people at sea.
"When shipping companies plan their shipping routes days in advance, our algorithm gives them a risk assessment of whether the route they have planned is at risk of encountering monster waves. On this basis, they can then choose alternative routes," says Dion Häfner.
The algorithm and the research results are publicly accessible, as are the weather and wave data used by the researchers. Therefore, according to Dion Häfner, interested authorities and weather services can simply start calculating the probability of monster waves.
