Determining Eruption Source Processes at Explosive Basaltic Stratovolcanoes

Volcanic eruptions can threaten nearby communities, critical infrastructure, and aircraft that fly near ash clouds. It is important to improve our understanding of how and why volcanoes erupt explosively for both public safety and scientific discovery. Scientists often monitor volcanoes using measurements of ground shaking (seismic waves) and low-frequency sound waves (infrasound). These provide information about the movement of magma and volcanic gases. Volcanoes like Shishaldin in Alaska and Mount Etna in Italy produce distinctive seismic and acoustic signals during explosive eruptions. Scientists have developed models to explain these signals. However, observations suggest that the processes driving explosive eruptions may be more complex than people thought. It is important to resolve this uncertainty to improve our ability to interpret monitoring data and assess volcanic hazards in real time. This project will address three key scientific questions: 1) How do seismoacoustic signals vary between explosive eruptions at Shishaldin and Etna? 2) What processes generate seismic and acoustic signals during explosive eruptions at basaltic stratovolcanoes? 3) Can seismoacoustic observations be used to quantitatively determine eruption source processes? The research team hypothesizes that gas discharge regimes primarily control seismoacoustic signal characteristics and eruption style at basaltic stratovolcanoes. To test this hypothesis, they will use newly developed techniques to 1) create systematic seismoacoustic catalogs of recent eruptions, 2) determine seismic and infrasound source locations, and 3) relate seismoacoustic observations to documented eruptive phenomena. These results will be used to develop conceptual and quantitative models that estimate eruption source parameters, such as volcanic gas flow rate, from seismoacoustic observations. A targeted field experiment at Mount Etna will supplement the existing monitoring network and provide critical data for comparison with Shishaldin Volcano. The project will improve volcano hazard monitoring in Alaska and at similar volcanoes worldwide. In addition, researchers will produce a social media video series designed to engage middle and high school students and promote public understanding of Earth science and volcanic hazards. 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.