Integrating isotope geochemistry with geodynamical modelling to investigate the evolution of the terrestrial mantle and crust
Many attributes of arc volcanism, whether physical, geochemical/petrological, or geophysical, can change on timescales from minutes to millions of years. Understanding these variations is important both for hazard assessment and in understanding volcanic and magmatic processes. I will present three diverse case studies that exemplify how detailed characterisation of records of activity can provide insights on the nature of and controls on changes in arc volcanism on various time scales:
(1) Analysis of time-series of seismicity during lava dome-forming eruptions of Soufrière Hills Volcano (Montserrat) and Volcán de Colima (Mexico) using two statistical techniques,
which reveals temporal variation in the extent of long-range correlations and randomness in these data, which could potentially inform to real-time monitoring and constrain eruptive processes.
(2) Reconstruction of the history and geochemical analysis of explosive eruptions of Mocho-Choshuenco and Hudson volcanoes (Chile) from tephra deposits, which show previously unrecognised shifts in eruptive flux and magma composition through the Holocene that are proposed to be in response to regional deglaciation.
(3) Analysis of sequences of lithofacies from effusive eruptions of Volcán Sollipulli (Chile), from which changes in eruption style through time are inferred and attributed to changes in the extent of interaction with ice.