Stability of volcanic conduits during explosive eruptions and the influence of conduit geometry.
Aravena Á., de' Michieli Vitturi M. Cioni R., Neri A.
Stability of volcanic conduits is a key factor that can affect the dynamics of explosive eruptions. Based on numerical simulations carried out by a two-phase steady-state model, it emerges that conduit stability is mainly controlled by magma rheology and conduit radius. We estimated a minimum magma flux for developing stable conduits, which is consistent with the unsteady character usually observed in low-mass flux events, opposite to mainly stationary eruptions, commonly characterized by high magma fluxes. As instability conditions are not uniform along the conduit, two non-cylindrical geometries have been tested, evidencing major modifications in some eruptive parameters.