*2.2. Seismic Network (Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Vesuviano - INGV-OV)*

During the 2014 eruption the seismic broadband network of Stromboli [29] was operating with 10 broadband seismic stations. In this work, we used data from 3 seismic stations (Figure 1b). STR1 is located on the flank of the volcano at an elevation of about 560 m and has the longest and most complete record of seismological parameters. STRA is located at about 840 m, it is the closest to the summit craters, therefore is particularly suitable to study the dynamics of explosive activity. Lastly, STR8, located at about 570 m, is the closest to the SdF, hence it is the best suited to study seismic signals related to landslides in this area.

The seismological parameters considered here are: the amplitude of volcanic tremor, the amplitude of explosion quakes and the inclination of the seismic polarization in the Very-Long-Period (VLP) band (0.05–0.5 Hz). We also performed the analysis of seismic signals, using neural networks, which allows detecting signals related to landslides occurring along the SdF [30]. Landslides signals have shown to be a reliable precursor of effusive activity at Stromboli. Their occurrence rate increased markedly during the onset of the previous effusive eruption in 2007 [12]. To quantify the intensity of landslide

activity, Esposito, et al. [31] defined a landslide index following a fuzzy logic scheme. This parameter varies smoothly between 0 and 1, with 0 indicating a low probability of ongoing landslide activity and, conversely, 1 indicating a high probability of occurrence.
