Figure 2
From: Infrasonic gliding reflects a rising magma column at Mount Etna (Italy)
36 h of seismo-acoustic records from 19 February at 12:00 to 21 February at 00:00 recorded by ECPN. (a) Infrasonic signal and (b) vertical component of the seismic signal. (c, d) Corresponding spectrograms and (e, f) normalized spectrograms computed for hour-long intervals. The symbols (i), (ii) and (iii) in (a, b) show the time intervals when the signals shown in Fig. 3 were recorded. The black dotted lines show the different phases of the eruption, described in the text, as well as the time intervals characterised by different kinds of eruptive activity.
