DV3M: Deforming Volcanoes with Dynamic Magma-Mush Models

Lead Research Organisation: UNIVERSITY OF EXETER
Department Name: Camborne School of Mines


Over 800 million people live near volcanoes, while many more depend on them for their livelihoods. Protecting lives and livelihoods during volcanic eruptions is the key challenge in volcanology, complicated by uncertainties in hazard assessment and eruption forecasting.

Measurable ground deformation is one of the main tools used to monitor volcanoes and often results from the injection of magma beneath the surface. By combining measurements of deformation with models we can estimate locations and rates of magma supply that drive the displacements; these parameters feed into hazard assessments and eruption forecasts. However, the majority of models are based on outdated concepts and may be contributing to the noted uncertainties. They assume static fluid filled magma chambers despite a recent and exciting paradigm shift in our understanding of sub-volcanic magmatic systems which indicates magma is rather most likely stored in vertically extensive porous "mush" zones. The static magma chambers are also assumed to rupture (possibly leading to eruption) at a fluid-solid boundary according to a finite stationary failure threshold, but the distinct fluid-solid boundary is now thought to be unlikely in real scenarios, and the system inherently evolves dynamically in response to moving magma rather than statically. Therefore, the simple process of artificially inflating and rupturing a static chamber in the majority of volcano deformation models is a major simplification of reality, and introducing additional uncertainty into crucial model outputs. We do not know the influence of the new mush-paradigm on volcano deformation.

Aims and objectives
DV3M is needed to advance a new generation of dynamic magma mush (DMM) volcano deformation models. DV3M aims to resolve the impact of porous magma-mush reservoirs on volcano deformation and reservoir stability. Project objectives are:
1. Incorporate magma properties in DMM models that evolve in response to temperature and pressure.
Evolution of magma properties cannot be accounted for in commonly employed static models of volcano deformation. DV3M will deliver a suite of DMM volcano deformation models that are coupled with temperature and pressure dependent changes in magma, exploiting new computationally efficient open-source tools. We will determine how dynamic changes in magma properties influence surface deformation patterns.
2. Examine how time-dependent strain evolves in DMM models to understand magma-mush reservoir stability.
New DMM models only now enable exploration of more realistic dynamic failure/stability criteria. DV3M will illuminate the range of expected strain-rates produced in magma-mush reservoirs undergoing magma recharge. DV3M model outputs with strain rates in excess of a newly determined threshold will promote brittle behaviour of the mush reservoir and could lead to failure; we will therefore provide a step-change in understanding of processes leading to potential eruptions.
3. Apply DMM models to past and present periods of volcanic deformation at targeted high-risk volcanic centres.
The new DMM models will be applied at Soufriere Hills volcano, Montserrat, and Sakurajima volcano, Japan. Accurate analysis of ongoing deformation and reservoir stability is needed using DMM models to fundamentally improve hazard assessments; continued use of static model approaches may be providing incorrect assessments influencing eruption potential analyses.

Applications and benefits
DV3M will push beyond the state-of-the-art and fundamentally advance volcano deformation interpretations by more robustly and realistically estimating magma system parameters from observations. These improvements will reduce uncertainties in hazard assessment and eruption forecasting for benefit globally at deforming volcanoes, and in particular at our target volcanoes. The approaches developed will be globally applicable and of use in short- and long-term risk mitigation.


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