Dynamical tools for the analysis of long term evolution of volcanic tremor at Stromboli

Abstract

Stromboli is characterized by persistent seismic activity, both in terms of tremor and of discrete events associated with moderate explosions defining the so-called "Strombolian activity". This kind of permanent activity suggests the probable existence of a dynamical system governing the volcano. The purpose of this paper is to extract information on the "Stromboli dynamical system" from the seismic recordings. The analysis is carried out using the theory of non-linear dynamical systems and the delayed coordinates phase-space reconstruction. Several methods are presented and discussed in order to analyze volcanic tremor data in this framework; finally the time evolution of the computed parameters, both in the long term and close in time to paroxysmal phases, is presented and discussed. Evidence for a strong deterministic component in the dynamics of the volcano is shown.