Figure 3
SOM best matching units for the classified patterns (RGB colors converted to integer values; see Method section), gravity and fountain height (meters above the vent) during four 34-hour intervals encompassing lava fountaining episodes (numbers correspond to the sequential numbering in Fig. 2).
The dashed red lines and color bars in the top graphs of each panel represent, respectively, (i) the threshold above which the SOM patterns are indicative of critical “ground shaking conditions” and gravity data are disregarded (lacking filtered data in the gravity graphs) and (ii) the RGB colors of the SOM best matching units for the patterns classified during the four time intervals (see Method section). Intervals when Strombolian and fountaining activity took place are reported in the lower graphs of each panel. The height of the 29 August fountaining episode could not be calculated through our automated procedure since it occurred from an extended fissure along the flank of the NSEC, rather than from a single vent (see text for details).
