Fig. 8. Timelines relating diffusion timescales to eruption ages.
(A) Timeline showing the three longest maximum quartz residence times (above 750°C) of each pumice population, using C07. Timescales project from the 14C eruption ages, which are plotted in dark blue (±2σ). The range of maximum plagioclase Sr diffusion times (1200 to 2500 years) determined by this study are comparable to quartz residence times and are shown above the AT timescales for comparison. (B) Timeline with the maximum quartz diffusion timescale from each pumice population, calculated using A21, J20, and A23 at 750° and 800°C. Note the change in timescale axis; the scale of (A) is shown by the red box at the bottom of (B). The curves in the figure at the top of (B) show the cumulative frequency of literature zircon residence times, determined by U-Pb dating (oldest zircon age minus the eruption age), U-Pb range (oldest age minus youngest age), and U-Th disequilibria dating (minus eruption age) (97). To compare zircon residence times from other systems to Aira quartz residence, cumulative density function (CDF) curves are set to have the same 30-ka eruption age as the AT eruption. The 90th percentile of each zircon residence time is projected down onto the timeline for comparison. “SE” indicates that no U-Th residence times larger than 350 kyr are resolvable due to secular equilibrium. Data compilation and sources are given in data S6.