I think the average pressure should stay about the same because the mass stays the same, but if it compresses maybe the pressure goes up in low-lying areas and goes down at higher altitudes.
According to Wikipedia, CO2 can liquify at around 5 atmospheres, though it has to be pretty cold at that pressure. The phase diagram shows it as a liquid around room temperature (300K or so) at about a hundred atmospheres. Which makes a liquid ocean of CO2 is at least sort of plausible if the temperature drops far enough.
According to Wikipedia, CO2 can liquify at around 5 atmospheres, though it has to be pretty cold at that pressure. The phase diagram shows it as a liquid around room temperature (300K or so) at about a hundred atmospheres. Which makes a liquid ocean of CO2 is at least sort of plausible if the temperature drops far enough.
https://en.wikipedia.org/wiki/Carbon_dioxide#/media/File:Car...