In the Denmark Strait, southward-flowing frigid water from the Nordic Seas meets warmer water from the Irminger Sea. The cold, dense water quickly sinks below the warmer water and flows over the huge drop in the ocean floor, creating a downward flow estimated over 123 million cubic feet per second. Download Infographic | Infographic Text

Rivers flowing over Earth’s gorges create waterfalls that are natural wonders, drawing millions of visitors to their breathtaking beauty, grandeur, and power. But no waterfall is larger or more powerful than those that lie beneath the ocean, cascading over immense cataracts hidden from our view.

Indeed, the world’s largest waterfall lies beneath the Denmark Strait, which separates Iceland and Greenland. At the bottom of the strait are a series of cataracts that begin 2,000 feet under the strait’s surface and plunge to a depth of 10,000 feet at the southern tip of Greenland—nearly a two-mile drop.

But how can there be waterfalls in the ocean? It’s because cold water is denser than warm water, and in the Denmark Strait, southward-flowing frigid water from the Nordic Seas meets warmer water from the Irminger Sea. The cold, dense water quickly sinks below the warmer water and flows over the huge drop in the ocean floor, creating a downward flow estimated at well over 123 million cubic feet per second. Because it flows beneath the ocean surface, however, the massive turbulence of the Denmark Strait goes completely undetected without the aid of scientific instruments.

Infographic Text

The world's largest waterfall is in the ocean

This infographic illustrates how a large underwater cataract (waterfall) naturally forms underneath the waves within the Denmark Strait. A map in the upper right of the graphic shows the location of Denmark Strait, between Greenland and Iceland.