EAGER: Test of Concept for Induced Fuel-Coolant Interaction Experiments with Bubbly Melt

This Early-Concept Grant for Exploratory Research (EaGER) addresses a newly observed phenomenon that occurred during the January 15, 2022 eruption of the Hunga Tonga volcano. Although phreatomagmatic eruptions tend to be unpredictable, the very high eruption column of Hunga Tonga created a pressure pulse in the atmosphere that was measured around the globe, leading scientists to estimate that the energy released was equivalent to several 10 megatons of TNT. Initial findings show that some properties of the magma may have played a critical role in making this volcano so explosive. The investigators will attempt to conduct laboratory experiments in larger scales than before to test the hypothesis that the presence of vesicle networks, bubbles, enhanced the rate of heat transfer from magma to water during induced fuel coolant interaction, caused the highly explosive system expansion observed. In terms of broader impacts, successful results would help our understanding of how interactions between magma and water can lead to explosive events and constrain the effects of scaling on our models for this phenomenon. Support will also help enhance infrastructure for research and education, while providing training for a student. The investigators propose to study the possible influence of bubble networks on the explosivity of magma-water interaction, by conducting induced fuel coolant interaction experiments on a meter-scale, which involves about 30 Liters of melt. This will be the first realization of this mechanism type on a larger than lab scale, which allows for more material complexities and helps to scale laboratory findings to field scale. It is suggested that that in the Hunga Tonga volcanic eruption of January 2022, the presence of vesicle networks, bubbles, enhanced the rate of heat transfer from magma to water during induced fuel coolant interaction that caused the highly explosive system expansion. The investigators will adapt their current experimental setup that have proven to work in previous magma-water interaction tests to provide means to scale lab- and meter-scale observations to natural scale scenarios. If successful, they hope to answer whether bubbles can serve as a booster to interaction intensity. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.