Contrary to what most people think, the highest waterfall in the world is not Niagara, Iguazu, or even the Victoria Falls, but rather a fall most of you probably never heard about – The Denmark Strait Cataract.
The Denmark Strait Cataract waters fall almost 11,500 feet (3,505 meters) – that’s 68 times the Niagara Fall.
Its flow rate exceeds 175 million cubic feet (5million cubic meters) per second, making it 350 times as voluminous as the Guaíra Falls, which was previously thought to be the most voluminous waterfall on Earth; And 4200 times more voluminous than – the Victoria Falls, which is next in line.
So, how can a waterfall exist under the Ocean? – the Denmark Strait is located between two huge masses of water, the western side and the eastern side. The latter is colder and cold water is denser and therefore heavier. Hence, when the two water masses meet along the top ridge of the strait, the colder, denser water flows downwards and underneath the warmer, less dense water.
Bonus Fact: The Guaíra Falls, which, as said was once considered the most voluminous waterfall on Earth is now extinct. It is completely submerged under an artificial lake created by the Itaipu Dam.