ESTIMATION AND MODELING OF THE TOTAL ENERGY BUDGET OF A VOLCANO

Volcanic eruptions are one of the major natural hazards beside earthquakes, floods and storms. They can be very destructive locally, but unlike the others, major volcanic eruptions can also have global impacts by e.g. modulating atmospheric chemistry and thus climate. Here we investigate the physics of volcanic eruption dynamics in general and the burst of gas slugs (large conduit filling gas bubbles) in particular in depth. At Mt.Yasur, Tanna Island, Vanuatu, one of the few accessible and highly active, open-vent volcanic systems besides Erta Ale (Ethiopia) and Mt. Erebus (Antarctica), processes at the magma/air interface could be observed from the crater rim during a field campaign in 2008. Data collection was done using Doppler radar systems to measure eruption velocities as well as infrasound arrays to record overpressure of gas slugs when bursting at the magma/air interface. Seismic events during slug generation and rise were monitored using seismic arrays. Sampled eruptive products were analyzed for crystallinity, porosity, viscosity and composition and deliver valuable physical boundary conditions for the (computational) modeling of the eruption processes. The combination of this multi-disciplinary field approach with a thorough petrophysical description of eruptive products allows for constraining and understanding the physical processes during this type of eruption. To the best of our knowledge a comparable data set does not exist. Here we show preliminary results from the analysis of seismic, infrasound and Doppler Radar data and link them to our petrophysical characterization of Mt.Yasur's eruptive products.