Integrating field, textural, and geochemical monitoring to track eruption triggers and dynamics: a case study from Piton de la Fournaise

A 2014 eruption at Piton de la Fournaise (PdF), La Réunion, revealed that shallow magma pockets can be rapidly reactivated by deep processes without significant mass or energy transfer, producing hazardous eruptions with minimal short-term precursors. The study integrated field observations, textural analyses of pyroclastic material, and geochemical monitoring to track eruption triggers and dynamics. It found that the eruption's small volume and brief duration were linked to a stratified magma storage system, where golden basaltic pumice and fluidal clasts represented hotter, less crystalline magma, while spiny scoria reflected cooler, more crystalline portions. Exponential decay in magma ascent rates indicated progressive reservoir depressurization, with syn-eruptive degassing leading to a shift from fountaining to Strombolian activity. Geochemical data confirmed the absence of new hot magma input, suggesting the 2014 eruption sourced residual magma from a previous 2009 event.

Gurioli, L., Di Muro, A., Vlastélic, I., Moune, S., Thivet, S., Valer, M., Villeneuve, N., Boudoire, G., Peltier, A., Bachèlery, P., Ferrazzini, V., Métrich, N., Benbakkar, M., Cluzel, N., Constantin, C., Devidal, J.-L., Fonquernie, C., & Hénot, J.-M. (2018). Integrating field, textural, and geochemical monitoring to track eruption triggers and dynamics: a case study from Piton de la Fournaise. Solid Earth, 9(2), 431–455. https://doi.org/10.5194/se-9-431-2018