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 a seamount?

A seamount is an underwater mountain formed by volcanic activity.

Seamount is an underwater mountain formed by volcanic activity

TThis image shows the topography of the Kaunana Seamount. The seamount was named in honor of OER’s remotely operated vehicle Deep Discoverer for its role in the discoveries made during an expedition to the Northwestern Hawaiian Islands. Colors represent water depth in meters as defined in the color key. Credit: NOAA Office of Ocean Exploration and Research, 2016 Hohonu Moana.

Seamounts — undersea mountains formed by volcanic activity — were once thought to be little more than hazards to submarine navigation. Today, scientists recognize these structures as biological hotspots that support a dazzling array of marine life.

The biological richness of seamount habitats results from the shape of these undersea mountains. Thanks to the steep slopes of seamounts, nutrients are carried upwards from the depths of the oceans toward the sunlit surface, providing food for creatures ranging from corals to fish to crustaceans.

New estimates suggest that, taken together, seamounts encompass about 28.8 million square kilometers of the Earth's surface. That's larger than deserts, tundra, or any other single land-based global habitat on the planet.