In:
Nonlinear Processes in Geophysics, Copernicus GmbH, Vol. 13, No. 4 ( 2006-08-10), p. 393-400
Abstract:
Abstract. We analyze time series of Strombolian volcanic tremor, focusing our attention on the frequency band [0.1–0.5] Hz (very long period (VLP) tremor). Although this frequency band is largely affected by noise, we evidence two significant components by using Independent Component Analysis with the frequencies, respectively, of ~0.2 and ~0.4 Hz. We show that these components display wavefield features similar to those of the high frequency Strombolian signals (〉0.5 Hz). In fact, they are radially polarised and located within the crater area. This characterization is lost when an enhancement of energy appears. In this case, the presence of microseismic noise becomes relevant. Investigating the entire large data set available, we determine how microseismic noise influences the signals. We ascribe the microseismic noise source to Scirocco wind. Moreover, our analysis allows one to evidence that the Strombolian conduit vibrates like the asymmetric cavity associated with musical instruments generating self-sustained tones.
Type of Medium:
Online Resource
ISSN:
1607-7946
DOI:
10.5194/npg-13-393-2006
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2006
detail.hit.zdb_id:
2078085-0
