Ground-coupled airwaves template match detection using broadband seismic records of explosive eruptions at Popocatépetl volcano, Mexico

The utility of infrasound technology for detecting explosive eruptions is well established. However, many active volcanoes are currently monitored exclusively with seismic networks and lack infrasonic sensor networks. Here, we demonstrate the ability of template matching to automatically detect ground-coupled airwave signatures (infrasound signals recorded on seismometers), associated with mild to large explosive eruptions in continuous broadband displacement waveforms from Popocatépetl volcano, Mexico. As templates, we use five verified high-amplitude ground-coupled airwave signals that were recorded in November 2017 by both a temporary broadband infrasound array co-located with a broadband seismometer at station ATLI (15.8 km range) and a permanent broadband seismic monitoring station PPIG (4.9 km range). We systematically apply the template matching procedure to two years of continuous seismic records from PPIG station (2017–2018), to identify ground-coupled airwaves in a time span exceeding the operation time of the temporary infrasound array at ATLI. We identify 43 ground-coupled airwaves that occurred during the period of study and with absolute correlation coefficients of 0.5 ≤|R| < 0.8 (using templates of 100 s length). These events are in the catalog of Popocatépetl seismic activity reported by the Centro Nacional de Prevención de Desastres (CENAPRED). The results obtained with template matching using a small number of starting templates points to a ground-coupled airwave signature dominated by a repetitive and fairly stable seismo-acoustic explosion signature during the two-year time frame considered. Future work with an expanded number of templates should improve the results.