NMSU - Department of Physics - Colloquium Abstract



	Gary Glatzmaier Earth & Planetary Sciences UC Santa Cruz
Computer simulations of explosive volcanic eruptions.
The destructive nature of explosive volcanic eruptions obviously poses real hazards for nearby population centers. The gases and aerosols injected into the atmosphere are also hazardous to air traffic and could have global effects on climate. However, the internal dynamics of these eruptions and of the resulting buoyant plumes or pyroclastic flows are difficult to observe. We have been studying these events with 2D and 3D computer simulations to improve our understanding of how various factors control the evolution of such eruptions. In particular, we find that the vent over-pressure, which simpler models used for hazard prediction have ignored, significantly affects the flow profile and time dependence. The erosion of the solid host rock during an eruption and the crater formation also significantly influence the eruption dynamics. Computer graphical movies of our simulations will illustrate these effects.