ENDGAME · laboratory Experiments, Numerical moDellinG and field observAtions of basaltic Magma fragmEntation

For low viscosity magmas such as basalts, rapid and unpredictable transitions between effusive and explosive activity may occur. These transitions dramatically alter the impact of an eruption and pose a real challenge to policymakers tasked with mitigating the risks associated with basaltic eruptions. Mechanisms controlling these transitions, however, are not well understood, mainly due to the lack of a clear understanding of basaltic magma fragmentation. The ENDGAME project proposes to investigate transitions in eruptive styles at basaltic volcanoes by studying fragmentation of basaltic magmas through a combination of targeted cutting-edge fluid dynamics experiments, new holistic numerical modelling of magma ascent and brand new field observations collected during a basaltic eruption. ENDGAME will aim to:1) define new constitutive equations for basaltic magma fragmentation by implementing and performing jet flow and shock-tube experiments with a bubble- and particle-bearing analogue material in combination with high-speed Schlieren shadow photography;2) extend a state-of-the-art 3D transient model of magma ascent to model the evolution of the particle-size distribution resulting from fragmentation through time by using a numerical technique which has been recently applied in volcanology, the “Method of Moments”;3) use the new 3D magma ascent model to investigate the transitions in eruptive style by comparing numerical results with laboratory experiments and field observations that will be collected during an eruption at Piton de la Fournaise.The interdisciplinary approach that characterizes ENDGAME, e.g. linking cutting-edge fluid-dynamics experiments with state-of-the-art 3D magma ascent modelling and field observations of an active eruption, will allow us to shed light on one of the biggest challenges in volcanic hazard assessment: what parameters and how they control the transition in eruptive style at basaltic volcanoes?