Statistics of inter-time of Strombolian explosion-quakes

We consider long-time recorded seismic signals of Stromboli volcano to determine the inter-time distribution function of the Strombolian explosion-quakes. We show that it is Poissonian. Hence, the apparently observed periodic recurrence of the explosions is actually described by the constant rate of a Poisson process. Moreover, combining a diffusive model with the experimental inter-time distribution, we can determine the size distributions of the bubbles and infer the observed slug sizes.