U.S. flag An official website of the United States government.

dot gov icon Official websites use .gov

A .gov website belongs to an official government organization in the United States.

https icon Secure websites use HTTPS

A small lock or https:// means you’ve safely connected to a .gov website. Share sensitive information only on official, secure websites.

What is the longest mountain range on Earth?

The mid-ocean ridge is the longest mountain range on Earth.

satellite capture of the mid-ocean ridge

The mid-ocean ridge is visible in this satellite captured, bathymetric data of the western Atlantic Ocean Basin. The mid-ocean range stretches around the globe like the seam of a baseball.

The longest mountain range on Earth is called the mid-ocean ridge. Spanning 40,389 miles around the globe, it's truly a global landmark.

About 90 percent of the mid-ocean ridge system is under the ocean. This system of mountains and valleys criss-crosses the globe, resembling the stitches in a baseball. It's formed by the movement of the Earth's tectonic plates.

As the great 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.

If you look at a map of the world's volcanoes, you'll find that most of them form along the boundaries of this great system. In fact, the global mid-ocean ridge system forms the largest single volcanic feature on the Earth. The mid-ocean ridge consists of thousands of individual volcanoes or volcanic ridge segments which periodically erupt.

Search Our Facts
Get Social

More Information

Last updated: 01/20/23
Author: NOAA
How to cite this article

Contact Us