How long does it take to supersize an eruption?

A long-recognized correlation between the volume of major eruptions and the time interval between them suggests that magma may accumulate for about a million years before a supereruption. However, radiometric ages and time-dependent phenomena like crystal growth and compositional homogenization show that the duration of supervolcano magma accumulation could be significantly shorter than this. Crystals in supervolcano magmas may have protracted growth histories and may grow from chemically different hosts as crystallization progresses. Semisolid crystal mushes rather than liquid-rich magma chambers may be the prevalent state of supervolcano feeder systems and should be the focus of geophysical studies aimed at predicting future supereruptions.