Air Date: Week of January 23, 1998

This week, facts about...rogue waves.

Transcript

CURWOOD: Fifty-six years ago the Queen Mary, pressed into wartime transport service, was nearly capsized off Scotland by what her captain called "one freak mountainous wave." Scientists call them "rogue waves." Sailors call them "non-negotiable waves." And they are thought to be responsible for the more than 40 big ships that are lost at sea each year. A rogue wave happens when many small waves get in step with each other and pile up to form one giant wave, often more than 70 feet tall. By comparison most ocean waves are under 12 feet. The other big difference with rogue waves is their unpredictability. Unlike tidal waves or tsunamis, which need a trigger, say an earthquake or a volcanic eruption, rogue waves can occur with little or no warning. While scientists don't know for sure what causes the waves, some areas of the globe see them more often. For example, the Cape of Good Hope off South Africa is notorious for titanic waves. But obtaining reliable data is difficult. After all, the biggest rogue waves tend to silence their only observers. And for this week, that's the Living on Earth Almanac.