Strombolian-like volcano activity: a common macroscopic behaviour

We report the results of the analysis of the occurrence times of the strombolian-like explosions at Stromboli (Italy) and Erebus volcano (Antarctica). The distribution of the inter-times between successive explosion-quakes is exponential for both volcanoes, the only difference being the occurrence rate. It suggests that the signature of the standard Strombolian activity can be identified in a Poissonian process that rules the mechanism of generation of the explosions. Finally, we adopt coalescence Chandrasekar-Landau mean-field model for the formation of the exploding gas bubbles. The model provides a size distribution that is in a good agreement with the observed bubble dimensions.