Fig. 5
From: Volcanic crystals as time capsules of eruption history
Intrusion to eruption timescales calculated using the thickness of Cr-rich rims and Cr-poor outermost rims. The ‘clinopyroxene clock’ provides magma intrusion to eruption timescales of ~2 weeks. Timescales of crystallisation were calculated using an average clinopyroxene growth rate of 10−8 cm/s calculated for Mt. Etna26,54,55. Chomium-poor outermost rims potentially grew faster upon final magma ascent and degassing56, so extracted timescales are considered maxima. The example Cr map is from the 2002–2003 eccentric eruption. The Cr-rich and Cr-poor timescale values on either side of the map are average figures for eccentric eruptions, where most antecrysts show rims crystallised from intruding magma (Fig. 3). The upper histograms include data from all studied eruptions (1974–2014) and the other histograms summarise data from individual eccentric eruptions. The white circles mark the average time value (days) per data set. Note the consistency of timescale results across 40 years of eruptive activity (Supplementary Table 4; Supplementary Data 1)
