Skip to content

Transient numerical conduit model of magma ascent for explosive basaltic eruptions

Giuseppe La Spina 1, Fabio Arzilli2, Emily C. Bamber3, Margherita Polacci4, Mike R. Burton4

  • Affiliations: 1Osservatorio Etneo, Istituto Nazionale di Geofisica e Vulcanologia, Catania, Italy; 2School of Science and Technology Geology Division, University of Camerino, Camerino, Italy; 3Institute of Science, Technology and Sustainability for Ceramics (ISSMC), National Research Council (CNR), Faenza, Italy; 4Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK 

  • Presentation type: Poster

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

  • Poster Board Number: 203

  • Programme No: 3.2.26

  • Theme 3 > Session 2

Abstract

Basaltic volcanism is the most common form of volcanism on Earth. Basaltic volcanoes are capable of promoting different eruptive styles, from relatively gentle effusive eruptions generating lava flows, to highly hazardous explosive eruptions, in which large volumes of fragmented magma and volcanic gases are ejected high into the atmosphere. The hazards associated with effusive and explosive eruptions differ, particularly in relation to the timescales, volumes of magma ejected and energy associated with these activities. During basaltic eruptions, rapid and unpredictable transitions between the two regimes may occur, posing a real challenge to policymakers tasked with mitigating the risks associated with basaltic eruptions. In order to investigate the evolution of magma ascent dynamics through time at basaltic volcanoes and possible transitions in eruptive style, we developed a 1D transient numerical model of magma ascent in volcanic conduits. This model is able to solve for the main volcanic processes occurring during magma ascent, such as non-equilibrium crystallisation, non-equilibrium exsolution, temperature and rheological variations, permeability development and outgassing, and magma fragmentation. As test case scenarios, we considered two well-known, highly explosive basaltic eruptions: the Etna 122 BC Plinian eruption and the Masaya Triple Layer Plinian eruption. We used this model to investigate the evolution of magma ascent dynamics and eruptive style resulting from a sudden decompression at the conduit vent (for example due to a partial collapse of the volcanic edifice), or due to a perturbation of thermodynamic conditions within the magma storage region.