Non-equilibrium structures in lava flows.
Lava flows are dissipative systems evolving far from the thermodynamic equilibrium. Within the framework of the thermodynamics of irreversible processes, lava flows can evolve according to very different dynamical regimes related to the strength of the active constraint. The higher the constraint, the faster the energy dissipation. A faster dissipation promotes the onset of fast-relaxing non-equilibrium structures, which undermine the efficiency of the flow as mass transport system and decrease the expected runout from the vent. The model presented recombines previously unrelated concepts regarding the dynamics and the thermal regimes observed in terrestrial lava flows, providing a global consistent picture.