The world's largest waterfall isn't on land. It is hidden beneath the ocean, where billions of litres of water plunge every second

For most people, the world's largest waterfall brings to mind towering cliffs, crashing water and famous landmarks such as Niagara or Angel Falls. Yet Earth's biggest waterfall is nowhere to be seen. It lies hidden deep beneath the ocean between Greenland and Iceland, where an extraordinary natural process has been taking place for thousands of years. Every second, billions of litres of icy, dense seawater sink beneath warmer Atlantic waters, creating a vast underwater cascade that dwarfs any waterfall on land. Although invisible from the surface, this remarkable phenomenon plays a crucial role in the movement of ocean currents and the global climate system. Here's how this hidden giant forms, why it exists and why scientists continue to study it so closely.The unusual science behind a waterfall beneath the ocean The Denmark Strait sits between Greenland and Iceland, connecting the Nordic Seas with the North Atlantic. At first glance, nothing at the surface hints at what is happening below. Ships cross the area without seeing any visible sign of the enormous movement taking place hundreds of metres beneath them.Unlike waterfalls on land, this one exists entirely within the ocean. C...