Rapid Decompression of Pressurized Magma and Laterally-Directed Blasts: Determining Required Initial Conditions and Predicting Hazards Using 3D Multi-Phase Numerical Simulations

Arizona State University, Scottsdale AZ

Investigators

Abstract

Intellectual Merit: Laterally-directed blasts are some of the most dangerous volcanic events ever documented, with large areas of complete devastation possible. Blasts are currently included in modern hazard assessments and maps at composite volcanoes, including Mt. Hood, Mt. Rainier and other US Cascades Range volcanoes, with potential impacts on large populations. However, few such events have been studied and observed in detail. The directed blast is a significant enigma in volcanology, with key questions remaining, including 1) What causes them to be laterally directed? 2) What controls their size? 3) How does local topography affect hazards to surrounding populations? The proposed work will answer specific questions about the two best-documented events to date (Soufriere Hills volcano, Montserrat, 1997 - SHV; Mount St. Helens, 1980 - MSH) and use comparisons between real volcanic events and numerical models to gain a generalized understanding of blast behavior. In the future, 3D numerical models of explosive eruptions will be important tools for predicting volcanic behavior and making more accurate hazards assessments. Broader Inpacts: This project promises to educate a young graduate student in quantitative, computational volcanology, preparing him or her for the increasingly numerical future of Earth science. The work will foster a productive, continuing US/European scientific collaboration, and will enable the US team to collaborate with a world-leader in numerical modeling technology.