Models of volcanic processes: a review and some new ideas

Different models of pre-eruptive magmas behavior are examined to determine the factors relevant in triggering eruptions. Statistical models of the activity pattern of volcanoes show that an eruption may be treated as a casual event, and that the probability of an eruption is controlled by the size of stochastic perturbations. Qualitative and energetic models suggest that an energy threshold is necessary to start an eruption when magmas approach the Earth’s surface. The peculiarities of such state are connected with the mechanism of rise of magmas. Factors such as rise velocity of magmas, regional stress field, viscosity and interaction with pore fluid are believed to be the most important causes of the different behavior of magmas.