LABORATORY STUDIES OF VOLCANIC JETS.

The study of the fluid dynamics of violent volcanic eruptions by laboratory experiment is described, and the important fluid-dynamic processes that can be examined in laboratory models are discussed in detail. The topics covered include: the response of the atmosphere in the vicinity of an eruption to the eruption of fluids of differing thermodynamic properties; the flow characteristics of the first fluid out of the vent, that is, of the unsteady flow before steady flow is established; the evolution of the steady flow regime from the unsteady flow; the effect of entrainment of ambient atmospheric air at the edges of the jet on the flow of the fluid within the jet; and the relation between the observable properties of the external flow and the internal history of the reservoir as the discharge develops.