Freak waves able to sink a ship may occur ten times more often than previously thought.

Freak waves able to sink a ship may occur ten times more often than previously thought. Oceanographers in the USA have identified ‘hot spots’ where strong currents and sandbanks cause waves to change direction and speed, concentrating the energy into a single point.

Dr Tim Janssen of San Francisco State University and Thomas H C Herbers of the Naval Postgraduate School say that their research shows that such ‘hot spots’ or wave focal zones are much more likely to generate monster waves up to 18m in height and are particularly common in coastal areas. “In a normal wave field, on average, roughly three waves in every 10,000 are extreme”, said Dr Janssen, “but in a focal zone this could increase to about three in every thousand”.

The study was carried out by feeding real wave data into a computer model, so the results are, at present, theoretical. Dr Janssen says it is easy to validate the research, however, and plans to visit known freak wave ‘hot spots’ to test the accuracy of the simulations.