Preliminary analyses of seismo-acoustic wave propagation in outdoor field-scale analog volcanic explosions

Shallow and subaerial volcanic processes radiate infrasound directly into the atmosphere; sampling these infrasound complement seismic data and aids with physical quantification of explosive eruption mechanisms. More advanced quantitative models of the infrasonic source and associated seismo-acoustic wave conversion and coupling have the potential to improve volcano monitoring capability. Field-scale outdoor experiments under relatively controlled conditions provide the opportunity to test, refine seismo-acoustic wave propagation and source inversion strategies, and provide a critical bridge between laboratory-scale experiments, numerical simulations, and full-scale volcano field data. We present preliminary investigations of data collected during an NSF-sponsored workshop at the University at Buffalo in July 2018. Sets of buried explosives were detonated sequentially. The explosions were recorded at 30–330 m on colocated broadband seismometers buried at 1 m, infrasound sensors, and microphones. Analyses of waveform signatures, including cross-correlation and coherence analyses, provide insights into coupling between seismic and acoustic signals over different frequency bands as a function of distance. Comparisons of the seismo-acoustic coupling for a variety of blast strengths and detonation sequences provide insights into how seismo-acoustic coupling scales with amplitude and source depth. The use of both microphones and infrasound sensors highlights the potential benefit of wideband volcano-acoustic recordings.