Shark Week: Here Is the Wild Physics of a Great White Leap
You don't want to be a seal when it's chow time.
If a shark stops swimming, they sink. Luckily for great whites, they are are so remarkably good at moving. When a great white attacks a seal, it’s a Lebron James drunk of the natural world: In the moment where predator-meets-prey, the masterful water-slicing that is a shark’s movement is capped off by an emphatic finish — the sharks’s launch from the sea and into the air.
On Wednesday, the efforts of filmmaker Jeff Kurr and shark photographer Chris Fallows, who’ve documented launching sharks for the past 17 years, materialized into the Shark Week hypebeast episode “Air Jaws: Back From the Dead.”
The show chronicles the launching sharks they’ve filmed before off the coast of South Africa, and the new great white breaches they were able to witness in New Zealand. It was the Sportscenter of Shark Week, with highlights showing the remarkable feats individual athleticism.
“It’s absolutely incredible to see what they can do,” marvels James Sulikowski, Ph.D. to Inverse. “It is just insane.”
“It’s absolutely incredible what they can do. It’s insane.”
Sulikowski is a marine biologist and professor at the University of New England. He’s seen sharks get 20 to 30 feet of air, and says each time he witness a leap, it seems remarkable. Sharks, says Sulikowski, can be thought of as a contender for the ultimate predator. It’s the morphology that underlies that title which allows them to fly.
The ancestry of sharks dates back more than 400 millions years and in that time, they’ve evolved to have highly refined senses of smell, hearing, touch, taste, and sight. They also have bodies shaped like torpedoes and crescent-moon shaped tales that swing side-to-side, spinning off two rings of water with each tail flick. These rings help sharks generate a lot of force and move with a double-bolstered thrust through the sea.
Great whites, like other sharks, also have scales that share the same structure as their teeth. Called placoid scales, these backward-facing entities contain a central pulp cavity rich with blood vessels, a layer of dentine, and a hard enamel-like outer layer of vitrodentine. Because of placoid scales, if you pet a shark from tail to head, the skin would feel like sandpaper. Sulikowski explains that these help the sharks cut through water with little resistance.
“They have really powerful, sleek bodies so they are meant to go fast and through the water,” says Sulikowski. “They’re also 80 to 90 percent muscle.”
It’s all of those qualities combined that allows for a shark-seal attack to turn into a “I Believe I Can Fly” moment. In a 2012 study published in Marine Biology Research scientists explain that 48 percent of surface attacks on seals result in successful kills. From 1997 to 2010, these researchers videotaped white sharks off the coast of Seal Island, South Africa in pursuit of seels. In their words they found: “Sharks attack seals on the surface via a sudden vertical rush, which propels predator and prey out of the water in an awesome display of power and acrobatic prowess.”
A seal escapes.
On average, the sharks observed in this study emerged out of the water with a burst speed of around 11 meters per second. Most shark attacks on the dummy seals they set out in the water began from watery depths of about 26 to 30 meters. If a shark attacks a seal vertically from the depth of 28 meters, they write, then it could grab the seal in about 2.15 seconds. Meanwhile, if a great white comes at it from a 45-degree angle at the same depth, trigonometry indicates that it would likely travel 39.6 meters in just 2.57 seconds before encountering the seal with a munch.
These attacks, despite the misconception that sharks are just lumbering, nonsensical killers, are planned. In the same study the scientists found that sharks place themselves at specific points around the bay — choices optimized for capture rates and lack of competition with other sharks. Key to the attack is stealth and ambush, and while seals regularly check for sharks below, the grey-dorsal fins of the great whites allows them to sneakily lay in wait.
Meanwhile, the speed and angles that the great whites employ means they are going to achieve velocity at the moment of impact.
“Think of all the force — the water is thick, the shark is moving up quickly to make the hit, and all of a sudden they encounter this water-air boundary,” says Sulikowski. “It’s a lot less resistant and they just continue and shoot straight up and out of the water.”
Because we’re not seals, and it’s not the only method of attack great whites use, humans are very unlikely to see one of these sick jumps up-close. That is, unless you’re watching Shark Week which you can indulge in until July 29 this year.
Just remember that sharks aren’t some crazed ocean-monster — they’re just down to snack when they’re hungry like the rest of us.
