“From the ocean surface to depths of about 500 meters CO2 would exist as a gas and would tend to rise in the water column, since it is less dense than seawater.

“From the ocean surface to depths of about 500 meters CO2 would exist as a gas and would tend to rise in the water column, since it is less dense than seawater. Between 500 meters and 2,700 meters CO2 would exist as a liquid, but one that is still lighter than seawater and would thus also rise in the water column. At depths up to 2,700 meters CO2 will create a rising plume and dissolve into the surrounding seawater relatively quickly. At depths deeper than 3,000 meters the weight of the water column compresses the liquid CO2 and it becomes denser than seawater and sinks slowly to the seafloor.” [0] So yes, even at normal temperatures for that depth C02 would be a gas; definitely so at volcanic temperatures! [0] https://maritime-executive.com/features/ocean-storage-of-co2 https://maritime-executive.com/features/ocean-storage-of-co2