Evolution of volatile reservoirs (mantle – dashed line, atmosphere – solid line, lid – dotted line) of a planet in the plate tectonics (left) and stagnant lid (right) regime, with Earth-like bulk mantle iron (8 wt% FeO), as a function of model time (Gyr). Total water mass is equal to three Earth ocean masses. Note that the lid reservoir occurs only in the SL regime, being fed by intrusions. In the PT regime, the lid reservoir is counted towards the atmosphere reservoir, and eventually becomes part of the ingassing term (see Sect. 2).