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.
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.