This Small Grant for Exploratory research seeks to characterize and quantify the effects of particle size and source momentum and buoyancy fluxes on the overall behavior of jets, plumes and pyroclastic density currents (PDC) generated by highly-unsteady, short duration sources (order < 10 s). As part of this study, the PI will be undergoing feasibility experiments that use particle image velocimetry (PIV) that record jet, plume and PDC front velocities as functions of time and space. The long-term goals of this project are to document and understand how spatial variations of particle concentration and settling rate, in conjunction with source unsteadiness, relate to overall jet, plume and PDC development. As part of this exploratory period, they will first test and demonstrate efficient and appropriate means of measuring these parameters. If successful, this approach will be central to making a full assessment of Vulcanian eruption dynamics.
This research will support an international collaborative effort between the PI and J. C. Phillips from the University of Bristol, in the UK, and will allow a transfer of technology in the field of experimental volcanological fluid dynamics. The proposed work will implement experimental and data-acquisition methods intended for study of particle-laden flows with potential application to many other settings and environments beyond this volcanological application. Techniques such as high-speed video analysis for velocity and concentration measurements as well as Particle Image Velocimetry (PIV) will make the lab useful to the broader Arizona State University Earth and Space Sciences community, including planetary scientists interested in sediment transport on Mars.