Are there active volcanoes under the ocean?

The answer

Submarine volcanoes are far more common than those on land, with an estimated 75% of all volcanic activity occurring on the ocean floor. Most are found along mid-ocean ridges where tectonic plates diverge, continuously creating new seafloor. The largest known submarine volcanic eruption in modern history occurred at Hunga Tonga-Hunga Ha'apai in 2022, sending an ash plume into the mesosphere and generating a global atmospheric shock wave. Some submarine volcanoes, called seamounts, rise thousands of meters from the ocean floor and serve as biodiversity hotspots.