Quirks & Quarks

Can large underwater volcanoes increase ocean temperatures? Quirks Question

Volcanic eruptions on the ocean floor have a minimal effect on water temperature and are unlikely to contribute to global warming.
An underwater eruption in the southern ring of fire, south of Japan (NOAA)

Volcanic eruptions that occur underwater have a minimal effect on the temperature of the oceans.  Dr. May Ver, a lecturer in the Department of Earth, Ocean and Atmospheric Sciences at the University of British Columbia says that the volume of ocean water above the volcano has a cooling effect.   It would take an extremely  large eruption to make a difference, but those are very rare.  Sub-marine eruptions are also unlikely to release CO2 to the atmosphere and contribute to global warming.