Here’s the third essay I wrote for this week’s New York Times Magazine issue on the year’s biggest ideas. It’s about the freaky phenomenon of “rogue waves”:

Giga-Waves

by Clive Thompson

In March 2001, the first officer of the cruise ship Caledonian Star saw a wave that chilled his soul. It stood almost 100 feet tall, towering over the surrounding waves, and it didn’t slope — it was a sheer wall of water. It smashed into the ship with such force that it broke windows and flooded the command deck.

This watery beast was what scientists are now calling a rogue wave. According to a study released this year, there are more of them roaming the oceans than anyone ever imagined. In July, the European Space Agency announced that it had conducted the first satellite study of the oceans, looking specifically for rogues. In a three-week period, the satellites discovered 10 rogues, some taller than 85 feet. The scientists involved said they were stunned by the results, because for centuries skeptics dismissed reports of gigantic waves as myths. Wave equations normally describe an average wave height; they don’t describe rogues.

Now scientists are rushing to produce models that illustrate the behavior of rogues — which rear up and tower twice as high as nearby waves. ”They come out of nowhere, and they’re short-lived,” says Martin Holt, a scientist with Britain’s meteorological office. ”You could be in the same area of sea, and you wouldn’t even know they were there.” Holt is a member of the MaxWave project, a three-year effort to understand what causes rogues. In Norway, one researcher has successfully created his own minirogues in a tank of water.

If rogues are truly common, the implications for sea safety are significant. Every year, big ships are lost at sea; are some being done in by rogues? Critics say today’s ships aren’t strong enough to withstand rogue waves, because they weren’t designed to face down massive walls of water. A rogue can hit with a force of more than 100 tons per square meter. Certifying agencies and oil companies — which operate offshore rigs — are now paying close attention to the MaxWave research. Because if the scientists are right, the biggest sea monsters aren’t beneath the surface — they’re right on top.