Most of us are familiar with tsunamis, even if we’ve never experienced one ourselves, but far fewer have heard of “rogue waves”.
And yet, the rare phenomenon has the potential to wreak havoc across the world, particularly as the devastating effects of climate change continue to ramp up.
Unlike tsunamis, which are massive waves caused by earthquakes or eruptions under the sea, rogue waves are giants which don’t have easily traceable origins.
And yet, they can – and have – formed walls of water some nine stories tall.
In November 2020, one such freak wave emerged, literally, from out of the blue off the coast of Ucluelet, British Columbia, towering over the surrounding ocean at some 17.6 metres (58 feet) high.
It took another year and a half for scientists to confirm that the monster which, fortunately, did little more than toss around a buoy, was the most extreme rogue ever recorded.
Scientists define rogue waves – also known as “freak”, “killer” or “extreme storm” waves – as being more than twice the size of those surrounding them.
They are very unpredictable, according to the US National Ocean Service, and often appear unexpectedly from different directions to that of the prevailing wind and waves.
For centuries, they were simply considered part of marine folklore, with the scientific community only accepting them as real over the past few decades.
Most reports describe them as “walls of water” owing to their steep sides and unusually deep troughs.
And whilst the rogue wave that surfaced near Ucluelet wasn’t the tallest on record, its relative size compared to its surrounding waves was unprecedented, as Science Alert notes.
On January 1, 1995, a huge wave struck an oil drilling platform some 160 kilometres (100 miles) off the coast of Norway.
This beast, dubbed the Draupner, was almost 26 metres (85 feet)-tall, while its neighbours were only 12 metres tall.
Compare this to our Ucluelet example, which was nearly three times the size of its peers, and you’ll see the latter was in a league of its own.
“Proportionally, the Ucluelet wave is likely the most extreme rogue wave ever recorded,” physicist Johannes Gemmrich, of the University of Victoria, said in a statement last year.
“Only a few rogue waves in high sea states have been observed directly, and nothing of this magnitude.
Now, researchers are trying to pinpoint what exactly causes rogue waves so that they can spot them sooner.
Having previously been considered the stuff of myth, experts believe as many as ten rogue waves could be forming in the world’s oceans at any given moment, according to the American Physical Society (APS).
This would explain the mysterious sudden destruction of several ships over the years, such as the cargo ship MS München in 1978.
Like the Titanic, the München was considered to be unsinkable, yet the ship and her crew were lost at sea, with a single lifeboat recovered from the floating wreckage.
The damage to the lifeboat led experts to conclude that the wave that hit the ship must have been around 65 feet high.
Furthermore, in 2007, America’s National Oceanic and Atmospheric Administration compiled a list of 50 historical maritime incidents that were most likely caused by rogue waves.
These included events recorded in lakes, where rogue waves are believed to form via a phenomenon known as the “Three Sisters”.
This occurs when three large waves form at the same time and strike a ship in quick succession, creating a large backwash and flooding the vessel’s deck with water.
There is also evidence of “super rogue waves” that appear suddenly in seemingly calm seas and engulf unsuspecting ships, according to the APS.
Back in 2012, an international team of scientists based in Australia, Germany and Italy, published the results of an experiment they conducted using a LEGO pirate on a ship in a fish tank.
Their findings endorsed the idea that nonlinear interactions between waves can allow one wave to sap energy from those surrounding it, thereby condensing this into a single larger, short-lived wave – a rogue.
Ultimately, the main concern is that even when “killer waves” occur far offshore, they can still destroy oil rigs, wind farms or other marine operations and, if they’re big enough, their impact could still be felt on land.
In addition, a 2020 study predicted that climate change will cause wave heights in the North Pacific to increase, suggesting that the Ucluelet wave may not hold its record for long.
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