Extended Data Fig. 6: Influence of the surface pressure and internal heat flux.

a) Profiles for Venus gravity and insolation 4.5 Gyrs ago. b) Profiles for an Earth gravity with an ISR of 378 Wm−2 and T-1 spectrum. At ϕint = 0 both cases have an OTR of 378 Wm−2. Dashed lines indicate convective layers. Dots indicate the surface of each individual profile.