At 8:29:56 UTC on November 1, 2017, Stromboli experienced an explosive sequence of about 3 minutes, with characteristics similar to those of October 23 at 14:04 UTC. Analysis of the surveillance camera image showed that the sequence began with a more intense event in the south-central crater area, followed by fewer explosions in the following minutes.
This event was accompanied by a strong signal of soil deformation (0.8 μrad in the Rina Grande inclinometer on OHO) preceded by about 2 minutes of inflation. The exponential expansion of the soil is identical to that recorded during all major explosions.
Stromboli - 01.11.2017 / 8.30am - Initial phases of the explosive sequence taken by thermal (SQT) and visible (SQV) cameras at altitude 400. - Doc INGV Catania
The sequence generated falls of abundant coarse pyroclastic material on the Sciara del Fuoco and Pizzo sopra la Fossa, and a plume of dense ash quickly dispersed by the wind on the southern slope of the volcano.
An analysis of the seismic trace indicates that it is a typical explosive sequence, characterized by a series of transient phenomena, followed by a persistent signal (tremor) lasting a few minutes. This phenomenon is not necessarily related to the rise of the new magma.
No other significant phenomena occurred in the following sequence. The seismic parameters also returned to the situation before the event.
Over the next few days, an inspection will be conducted to characterize the event in more detail. At present, it can not be ruled out that such events can be repeated in the short term.
Source: INGV Catania & Laboratoria Geofisica Sperimentale