Molecular-Dynamics Simulation of Vulcanian Eruption

Vulcanian explosive eruption, which is a nonlinear and nonequilibrium abrupt dynamics of magma-gas mixture, is modeled by a two-component Lennard-Jones particle system. Molecular-dynamics simulation of a shock-tube experiment gives consistent results with a explosive eruption picture of volcanology; Shock wave and expansion wave are reproduced. In addition bubble nucleation of a gas component in the magma melt and spinodal-like decomposition are observed in the simulation. The result is also compared with a continuum hydrodynamic model; Qualitative features of continuum dynamics are reproduced by the present model. We find that the particle description of dynamics is an effective method in such kind of abrupt dynamics.