Effect of radioactive heating (H^R), tidal heating(H^T), and induction heating (H^I) on mantle depletion (and hence volcanic outgassing) for the example case from Fig. 6 after 2 Gyr. Blue colours show volatile-rich material and yellow to pink colours indicate depleted, volatile-deprived material. The half-sphere extends from the pole over the equator to the other pole. From top to bottom: only radioactive heating and secular cooling of the core (corresponding to 10.8 bar volcanic outgassed pressure), effect of adding tidal heating (17.7 bar), effect of adding induction heating (19.1 bar), and effect of adding both tidal and induction heating (27.3 bar).