Skip to content

Thermodynamic Variability in Magma Mush Reservoirs: Implications for Volcano Deformation

Rami Alshembari1, James Hickey1, Lorenzo Mantiloni1 and Brendan McCormick Kilbride2

  • Affiliations: 1Department of Earth and Environmental Sciences, University of Exeter, UK 2Department of Earth and Environmental Sciences, University of Manchester, UK

  • Presentation type: Poster

  • Presentation time: Friday 16:30 - 18:00, Room Poster Hall

  • Poster Board Number: 40

  • Programme No: 2.3.26

  • Theme 2 > Session 3

Abstract

Magma is likely stored in heterogeneous, vertically extensive, porous "mush" zones. A magma mush can be modelled as a poroelastic material in response to melt injection or withdrawal. An increasing number of studies consider the role of magma mush poroelasticity in analyses of volcano surface deformation and the evolution of stress around a magma reservoir. Most of these studies, however, consider constant and uniform magma mush properties in time and space. Here, we incorporate thermodynamically variable magma properties and consider their role in modulating volcano deformation, thereby also beginning to address the role of volatiles in poroelastic volcano deformation models. We utilize thermodynamic models, specifically MagmaSat and MELTS, to simulate decompression-driven H₂O-CO₂ exsolution, melt-crystal phase development, and crystallization processes in magmatic systems. These models calculate phase assemblage, crystal fraction, gas volume fraction, density, viscosity, and compressibility as functions of temperature, pressure, and composition, which are subsequently input into new deformation models. By comparing our results with previous studies that assumed uniform bulk magma properties, we will determine how thermodynamically induced dynamic changes in magma properties affect surface deformation patterns and resolve evolving internal heterogeneities.