Quick, name the biggest waterfall in the world. Niagara Falls? Angel Falls? Nope! The real champion is hiding under the ocean, between Greenland and Iceland. Scientists call it the Denmark Strait cataract. Cataract is just a fancy old word for a big waterfall.
But wait, how can water fall through water? Here's the trick. Very cold water is heavier than warmer water. Up near the Arctic, the sea gets super chilly. That cold, heavy water sinks and slides along the ocean floor. Then it reaches a giant underwater cliff and pours down the slope, sliding underneath the lighter, warmer water.
And this waterfall is huge. The water drops about 11,500 feet from top to bottom. That's more than 2 miles! It's over three times as tall as Angel Falls, the tallest waterfall on land. It also moves about 175 million cubic feet of water every second. That's way, way more than Niagara Falls.
Here's the goofiest part. There's no roar, no splash, and no mist. A ship could sail right over it, and the people on board would have no idea. This hidden waterfall also does an important job. It's part of a giant loop of ocean currents that carries warm and cold water around the whole planet.
So next time you pour cold milk into hot cocoa, watch closely. You might see your own tiny underwater waterfall!
Ask your kid: If you could ride a submarine down the world's biggest waterfall, what would you name your sub?