Tuesday, March 12, 2013 |
Recently, five Nova Scotia fishermen lost their lives when their boat, the Miss Ally, was overcome by 10-metre waves in high winds off the southern coast of Nova Scotia. In the wake of the tragedy, Mainstreet Halifax spoke to Susan Casey, editor-in-chief of Oprah's O magazine, and the author of The Wave: In Pursuit of the Rogues, Freaks and Giants of the Ocean, about the phenomenon of colossal waves.
"My heart sunk when I heard about [the tragedy], but it's a story that I heard over and over again while I was researching The Wave," Casey said. "It's amazing how, even today, there are so many boats that go down, with all hands lost, in these conditions that become very extreme very quickly and often don't obey the weather models or any of the weather forecasts and get much worse than anyone was able to foresee."
Mainstreet host Stephanie Domet quoted a fact cited in The Wave, that a wall built to withstand winds of 200 km an hour can be toppled by a wave just a half-metre high. Casey said that when she submitted that chapter of the book, her editor queried that statistic -- but it's accurate. "The reason I wrote the book is that I believe this is the most powerful force of nature on Earth," she said.
A 30-metre wave generates a force of a hundred tons per square metre -- and these waves are "becoming more common. Our most extreme storms are becoming stronger," Casey said. "When a storm arises quickly, the waves become very unstable, they're steeper, and when waves are steeper they can quickly become non-linear. So in other words, you can get a 30-metre-high wave in 10-metre seas. You can get a wave that's three, four and even more times higher than the seas around it."
Scientists are using quantum physics to try to understand waves, including the soliton, a type of wave that doesn't behave according to typical wave theory. "A soliton is a wave that behaves both like a wave and a particle. So it's actually a motion and a thing," Casey said, adding that "a tsunami is a type of soliton. It's a lump of energy that's moving." The waves that swamped the Miss Ally, however, were not solitons, but rather "waves created by a storm, and driven by wind."
Even large vessels are at risk from rogue waves. As part of her research, Casey went to the insurer Lloyd's of London to talk to them about missing ships, after reading in a New Yorker Times article that "two large ships a week go missing on average, in the global seas. And these are freighters and tankers, large, large objects."
Casey mentioned the case of a British ship, the MV Derbyshire. "They found the stern and the bow about a mile apart. It went down in a typhoon off of Japan, they didn't even have time to send a mayday." At Lloyd's, she was told that "ships were getting snapped in half like pencils."
Part of Casey's book is about the surfers who also go in pursuit of these giant waves -- but she made it clear that they're not doing it for sport. "When it comes to surfing giant waves, fun is really not the operative word. The men who do this are a rare breed. They are to surfing what astronauts are to pilots," Casey said. "Nobody who sees a 70-foot wave thinks they're in charge or that they're going to have their way with it."
Casey draws a link between climate change and the prevalence of rogue waves. "Every scientist that I spoke to is very aware that climate change is a real factor in the natural world right now, particularly in the ocean. We are seeing the waves all over the world grow. Between the '60s and '90s, we've seen in some cases, in the North Atlantic, for instance, a 30 per cent uptick in the average size of waves. And that seems to be happening also on the west coast of North America," she said.
Casey went on to compare our current situation to the last Ice Age. It was "quite a volatile time of volcanic and earthquake activity," she pointed out. "And a couple of the scientists I spoke to believe that we are in for a time of more volatility in a lot of different ways as a result of climate change."