“These large spikes are the rogues jumping out of a deepwater wave field,” Osborne says. “Water, the stuff we drink, is nonlinear! So in the end the exotic case is the more natural. Isn’t that pretty?”
As he talks, the water undulates down the tank in a lustrous black ribbon, then washes up on the concrete beach at the end of the pool. Osborne clambers down from the bridge and continues his commentary, almost coaching the water now. “The first wave starts to live its own life. Then it eats from the other waves.” A wave lifts. “There. That’s got to be the leading-edge effect.” Then, two-thirds of the way down the tank, a wave rises higher than the ones before or the ones behind. It has a steep face and a narrow crest. “There!”
As he speaks, the wave jumps the pool wall.
“Bravo!” Osborne, Onorato, and Brandini all shout. But before they can enjoy the moment, Osborne sees yet another rogue rearing up.
“Here it comes!” It, too, rears up, creating a trough before and after, then clears the edge of the pool, spilling water over the side.
“Bella! I bet Carl’s about to drop his drawers! They told us we couldn’t do it, and we did. If we had a really big tank, we could take out a 10-story building!”
“Now what?” Onorato asks, a huge grin on his face.
Osborne doesn’t take his eyes off the tank.
“Turn it up.”
Oil companies, shipbuilders, fishermen, and the U.S. Navy are beginning to take rogue waves seriously. Despite Osborne’s efforts, however, there is a serious lack of data. The main means of measuring seas and waves is around 50 years old: Buoys at sea record the heights to which they’re raised. Although many buoys are now supplied with electronic transmitters and high-tech electronics, the likelihood of one being in the path of a rogue wave is small. Even if it is, its anchor will most likely pull it down off the face of the wave before the wave’s true height has been measured. Satellites and aircraft can measure only large-scale effects, and they’re limited by cloud cover.
The secrecy that surrounds offshore drilling rigs is another limiting factor. None of the reports on the wave that struck on New Year’s Day in 1995 mentions the exact nature of the damage it did. Drilling platforms are built to withstand even waves that occur once in 100 years, and none has ever been reported toppled. But that doesn’t mean it hasn’t happened, Osborne says.
Ten years ago, several European science organizations began to pool everything known about rogue waves. Between the scientists who didn’t believe the waves existed and the principals of oil, shipping, and insurance companies, who preferred not to discuss them if they did, MaxWave, as the project was known, had a great deal to find out. The project’s final report, released only months ago, summarizes the main findings of dozens of studies. It concludes that rogue waves not only exist but are also more common than previously thought. They can be described with nonlinear physics and reproduced in a wave tank. But while wave tanks can approximate the instabilities that cause rogues, they can’t replicate the constantly shifting winds and currents that make rogue waves impossible to anticipate in real oceans.
Over the next few years, Osborne and others hope to offer ship captains reports on the likelihood of rogue waves appearing in certain regions. The British Meteorological Office created a crude version of such a report in 2001, but it requires much more data to be useful. Meanwhile, the U.S. Office of Naval Research has considered Osborne’s work in designing its mobile offshore base—a floating platform as large as 10 aircraft carriers.
Osborne’s restless energy has led him back to the blackboard. He believes there’s more to be found in the nonlinear equations that describe solitons and rogues. What if the equations can describe even larger waves? What if rogue waves appear in plasma as well as in the ocean? And what if these nonlinearities can be controlled in nuclear fusion reactions? Who knows? We may one day use such plasma jets to ride rogue waves to distant planets. “Understanding the physics is paramount,” he says. “It’s lovely. Every time we turn a leaf we find another marvelous world.”