Hi, this is Kate from MinuteEarth.
The biggest waves on Earth - those that are the height of entire office buildings - become
truly gigantic because of what happens out of sight.
That’s because waves don’t just sit on the surface; the waves’ energy can extend
more than 1500 meters below it.
Once a wave reaches shallow enough water, it makes contact with the seafloor.
In most places around the world, the seafloor gently slopes upward, slowly pushing the wave’s
energy above the surface, while friction against the seafloor slows it down.
This creates an unstable column of water and energy that eventually comes crashing down;
that’s a “break.”
But the seafloor doesn't always slope gently, and its shape is what makes or breaks a break.
Big underwater geological features like reefs can get in a wave's way and compress its energy.
All that energy gets abruptly funneled up into a shallow channel - something like a
four-lane highway’s worth of traffic being forced to suddenly merge into one lane.
But while cars can use their brakes to slow down and dissipate their excess energy, waves
can’t, and the resulting pile-up bursts over the barrier in huge, dramatic wave breaks.
But the biggest waves on earth occur in places where undersea canyons not only funnel massive
amounts of wave energy into a narrow channel, but also launch that energy over a shelf just
before the shoreline.
For example, during the most recent ice age, a combination of rivers and tectonic activity
carved the V-shaped Nazaré Canyon into the continental shelf off Portugal's coast.
And then oceans rose and filled it back in.
As a wave moves through the 230-kilometer-long, ever-narrowing canyon, its energy gets funneled
into a more focused - and therefore stronger - wave.
But since the canyon remains several thousand meters deep, the wave energy inside it doesn’t
touch the seafloor, and it doesn’t get slowed down...yet.
Meanwhile, wave energy moving alongside the canyon’s edges gets bent inside it too - like
multiple onramps adding cars to a highway - further boosting the wave’s energy.
At the canyon’s narrowest point, right before the shore, the seafloor shoots up at a nearly
vertical angle, creating a natural seawall that compresses all that energy - essentially
blocking 7 lanes of an 8-lane highway.
That energy then gets launched up; the resulting ten-story-tall breaks are truly the biggest
waves you will ever "sea."
At MinuteEarth, we are all about stuff that looks simple but amazing AND helps you appreciate
the world around you.
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Okay, so this a MOVA globe.
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MOVA globes come in 3 sizes and more than 40 designs - you can even build your own tiny
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Okay, I’ll be honest - they aren’t cheap, but they are an absolute joy to have, and
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Even if you’re not in the market for an awesome globe, just go check out the innovative
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Thanks to MOVA for sponsoring this video and putting something truly inspiring on my shelf.