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Numerical modelling of magma ascent dynamics of the 2021 Cumbre Vieja eruption: Insights into conduit processes and eruptive style transitions in mafic systems

Elisa Biagioli 1, Giuseppe La Spina2, Margherita Polacci1, Barbara Bonechi1, Jorge E. Moyano3, Mike Burton1

  • Affiliations: 1 Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK 2 Istituto Nazionale di Geofisica e Vulcanologia (INGV), Catania, Italy 3 Instituto de Ciencias de la Ingenieria, Universidad de O'Higgins. Lib. Gral. Bernardo O'Higgins 611, Rancagua, Chile

  • Presentation type: Poster

  • Presentation time: Tuesday 16:30 - 18:30, Room Poster Hall

  • Poster Board Number: 217

  • Programme No: 3.2.40

  • Theme 3 > Session 2

Abstract

Abrupt transitions in eruptive style are common at low-viscosity mafic volcanoes, presenting significant challenges for volcanic hazard assessment. During the 19th September - 13th December 2021 Cumbre Vieja eruption on La Palma, Canary Islands, exhibited numerous shifts in eruptive styles, making it an ideal case for investigating the physical and chemical processes underlying such transitions. We used a numerical 1D steady-state magma ascent model to study the interplay between conduit processes and eruptive style. The model captures the complex non-linear interdependence amongst key processes: temperature and viscosity evolution, non-ideal gas behaviour, disequilibria in outgassing and crystallization, and volatile exsolution. Input parameters (inlet pressure, magma temperature, volatile and crystal content) are constrained by empirical and analytical data. We investigated several scenarios by varying the input conditions in plausible ranges for this eruption. Simulations show that the system favoured effusive and fountaining behaviour, consistent with the observed dominant styles. However, a change in the degree of coupling between gas and melt may have triggered transitions to explosive style.