Linking monitoring data and timescales of mafic recharge during the 2013–17 eruption at Volcán de Colima, Mexico

Timescales of mafic magma recharge beneath Volcán de Colima have been calculated from diffusion modelling of reversely zoned pyroxene crystals erupted in the 2013–17 interplinian eruptive period. The results suggest that injections of low volume mafic magma are periodic and ephemeral, residing in the plumbing system for only weeks to months before eruption. At least three separate periods of magma recharge and mixing occurred within c. 3 years in October 2013–April 2014, September 2014–June 2015 and November 2015–September 2016. These timescales have been compared with the continuous seismic monitoring of the volcano and quasi-continuous gas monitoring data. Each eruptive phase shows different patterns between petrological and monitoring data, suggesting a complex mixing-eruption relationship, which may be related to the frequency and volume of recharge events, as well as the thermal state of the magma reservoir. Low frequency or low volumes of magma injection may result in a lack of correlation with any change in the monitoring data. High frequency of magma injections priming the magma reservoir results in a strong correlation between recharge events and monitoring record, which may be useful for interpreting future monitoring data.