The World's Largest Waterfall Is Under the Ocean

The largest waterfall on Earth cannot be seen. NOAA’s National Ocean Service states that the world’s largest waterfall lies beneath the Denmark Strait, which separates Iceland and Greenland. At the bottom of the strait is a series of cataracts that begin 2,000 feet under the surface and plunge to a depth of 10,000 feet at the southern tip of Greenland, nearly a two-mile drop. A waterfall inside the sea is possible because cold water is denser than warm water. In the Denmark Strait, southward-flowing frigid water from the Nordic Seas meets warmer water from the Irminger Sea. The cold water sinks below the warmer water and flows over the drop in the ocean floor, a downward flow NOAA estimates at well over 123 million cubic feet per second.