ESA highlights rogue waves

European satellites confirm the stories of mariners who describe seeing freak waves as tall as 10-storey buildings, according to the European Space Agency (ESA). ?Rogue waves? have been the anecdotal cause behind a number of sinkings over the past two decades.

Until now, evidence to support this has been sketchy and many marine scientists have clung to statistical models that say significant deviations from the normal sea state only occur once every thousand years. Testing this premise, ESA used two of its earth-scanning satellites, ERS-1 and ERS-2, to monitor the oceans. They sent back pictures of the sea surface in a rectangle measuring 10 by five kilometres taken every 200km. The two satellites in a three-week project codenamed MaxWave took around 30,000 separate images.

Even though the research period was brief, the satellites identified more than 10 individual giant waves around the globe that measured more than 25 metres in height, ESA said. The waves exist “in higher numbers than anyone expected,” said Wolfgang Rosenthal, senior scientist with the GKSS Research Centre in Geesthacht, Germany, who analysed the data. “The next step is to see if they can be predicted,” he said.

The research coincided with two ?rogue wave? incidents in which two small cruise ships, the Bremen and the Caledonian Star, had their bridge windows smashed by 30 metre monsters in the South Atlantic. The Bremen was left drifting without navigation or propulsion for two hours after the hit.

In 1995, the Queen Elizabeth II encountered a 29m wall of water during a hurricane in the North Atlantic which its captain, Ronald Warwick, likened to ?the White Cliffs of Dover?. Finding the cause of these giant waves would help ship architects to design wave-proof vessels.