Fig. 3: Waiting times to observe inner core nucleation for Fe–C alloys.
From: Constraining Earth’s core composition from inner core nucleation
Upper: Waiting time for a critical nucleation event to occur for four Fe1−xCx compositions at a range of supercooling. Uncertainties are shown as shaded colours. Estimates from Wilson et al.33 for xC = 0.01 and xC = 0.03 are also shown (without uncertainty for clarity). The dashed black line shows the maximum waiting time for an inner core half its present radius supercooled for 1 Gyr, and the grey shaded region represents supercooling values compatible with the present-day size of the inner core33. The pink area highlights areas of the Fe0.9C0.1 uncertainty envelop which represent a supercooling that is compatible with geophysically observations33 Lower: Interpolation (solid blue line) and extrapolation (dashed blue line) of Fe1−xCx results (solid lines, without exploring uncertainty) at τw = 3.1 × 1034 s m3 to estimate the δT needed to nucleate the inner core for values of xC up to the maximum proposed C content of the core, xC = 0.156 (red line)37.
