High-Broadband Seismoacoustic Signature of Vulcanian Explosions at Popocatépetl Volcano, Mexico

Abstract

We present high-broadband infrasound (0.01–100 Hz; 200-Hz sample rate) observations of Vulcanian explosions at Popocatépetl volcano, Mexico. Popocatépetl is a highly active andesitic stratovolcano with regular violent explosions, making it a promising target for seismoacoustic observations. We deployed a four-element broadband infrasound array (aperture 50 m) colocated with a compact broadband (120 s) seismometer at a site (ATLI) 15.8 km to the east-southeast of Popocatépetl's summit. We highlight waveform examples from five powerful explosions during October to December 2017 that produced infrasound zero-to-peak pressure amplitudes ranging from 30 to 100 Pa at ATLI. The infrasound waveforms are highly asymmetric and are associated with clear air-ground-coupled arrivals on seismometers, with inverted vertical displacement waveforms tracking infrasonic pressure waveforms. Popocatépetl is close to major population centers, and array processing reveals persistent background infrasound from multiple directions, presumably of anthropogenic origin; our results have implications for infrasound monitoring at populated volcanoes.