Formation, maturation, and failure of viscosity-stabilized foams: application to volcanic eruptions

This project will investigate the stability and dynamics of viscosity-stabilized foams. A particular focus will be the mechanisms through which large, decoupled bubbles can form, and then ascend through a magma foam to burst explosively at the surface. Experiments on surface-tension dominated foams with high gas fraction suggest that this decoupling may occur through a sub-critical bifurcation as the bubble size increases. Our aim is to develop a continuum model of film rupture that explains how these bubbles grow, and then to incorporate this into discrete numerical simulations of the rheology of suspensions of deformable particles. This will allow us to identify the critical conditions at which the yield stress is exceeded to cause magmatic explosions.