Global

Underwater Range

Photo credit: J M Watson

The vast majority of the Earth’s longest mountain range is underwater. The Mid-Ocean Ridge spans more than 40,000 miles around the planet and was formed by movement of tectonic plates. According to the National Oceanic and Atmospheric Administration, as these huge plates push apart, “mountains and valleys form along the seafloor as magma rises up to fill the gaps. As the Earth’s crust spreads, new ocean floor is created. This process literally renews the surface of our planet.”