Volume Flow Rate Estimation for Small Explosions at Mt. Etna, Italy, From Acoustic Wave form Inversion

Rapid and realistic assessment of the volume of erupted material, and the rate at which gas and pyroclasts are injected into the atmosphere during volcanic explosions, is crucial for effective monitoring and hazard mitigation. These parameters, for instance, are key inputs into models of atmospheric rise and transport of volcanic plumes. Volcanic explosions, among many other phenomena, generate atmospheric pressure waves known as infrasound. These sound waves that propagate at frequencies below 20 Hz, represent a powerful tool to investigate the dynamics and source mechanisms of volcanic explosions. Here, we demonstrate how recordings of acoustic infrasound generated by explosions at Mt. Etna can be used to assess the volume flow history of these events. We introduce and apply a data modeling workflow that could be implemented in near real time at Mt. Etna and other volcanoes worldwide.This study was supported by NERC Grant NE/P00105X/1 and by European Unions Horizon 2020 Research and Innovation Programme Under the Marie Sklodowska-Curie Grant Agreement 798480.We thank Jeffrey B. Johnson for his input on the application of the FWZPZF method, Giuseppe Salerno for providing SO2 data, Massimo Cantarero and Emanuela de Beni for providing initial digital elevation models of Mt. Etna, Andrea Cannata for input on the semblance method, and Ornella Cocina for fieldwork support. The infrasound data, and related metadata, used in this study are available from the IRIS Data Management Center. IRIS Data Services are funded through the Seismological Facilities for the Advancement of Geoscience and EarthScope (SAGE) Proposal of the National Science Foundation under Cooperative Agreement EAR-1261681