Spectral precursors of paroxysmal phases of Stromboli

R. Carniel, F. Iacop


In this work we investigate the characteristics of the seismicity at Stromboli volcano during more than two years, i.e. from 11 May 1992 to 21 August 1994. The three paroxysmal phases of 1993 mark significant changes in the Strombolian activity; nevertheless, these are not the only ones observed. In fact, the energy content, both in terms of volcanic tremor and of number of events drops to very low values after the periods of intense activity, accompanied by a change in the spectral content of the tremor. However, equally abrupt changes in the frequency content, not accompanied by evident intensity variations, can be observed some weeks after the end of the crises. The volcano seems therefore to behave like a dynamical system with many «quite stable » states with abrupt transitions between them. An interesting observation is the appearance of an energy concentration in the spectral sectors below 3 Hz before more violent eruptive episodes; although the duration of such a phenomenon is variable, it has to be investigated as a possible precursor of potentially dangerous activity of the volcano. A continuous monitoring of the spectral content of volcanic tremor on Stromboli is confirmed to be an essential tool in order to understand the behaviour of Stromboli volcano and to try to forecast its paroxysmal phases.


Spectral analysis;volcanic tremor;precursors

Full Text:



DOI: https://doi.org/10.4401/ag-3978
We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it (Read more).

Published by INGV, Istituto Nazionale di Geofisica e Vulcanologia - ISSN: 2037-416X