|
Titel |
Self-sustained vibrations in volcanic areas extracted by Independent Component Analysis: a review and new results |
VerfasserIn |
E. Lauro, S. Martino, M. Falanga, M. Palo |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1023-5809
|
Digitales Dokument |
URL |
Erschienen |
In: Nonlinear Processes in Geophysics ; 18, no. 6 ; Nr. 18, no. 6 (2011-12-08), S.925-940 |
Datensatznummer |
250014006
|
Publikation (Nr.) |
copernicus.org/npg-18-925-2011.pdf |
|
|
|
Zusammenfassung |
We investigate the physical processes associated with volcanic tremor and explosions. A volcano is a complex
system where a fluid source interacts with the solid edifice so generating seismic waves in a regime of low turbulence.
Although the complex behavior escapes a simple universal description, the phases of activity generate stable
(self-sustained) oscillations that can be described as a non-linear dynamical system of low dimensionality. So, the system requires to
be investigated with non-linear methods able to individuate, decompose, and extract the main characteristics of the phenomenon.
Independent Component Analysis (ICA), an entropy-based technique is a good candidate for this purpose. Here, we review the
results of ICA applied to seismic signals acquired in some volcanic areas. We emphasize analogies and differences among the
self-oscillations individuated in three cases: Stromboli (Italy), Erebus (Antarctica) and Volcán de Colima (Mexico). The
waveforms of the extracted independent components are specific for each volcano, whereas the similarity can be ascribed to a very
general common source mechanism involving the interaction between gas/magma flow and solid structures (the volcanic edifice).
Indeed, chocking phenomena or inhomogeneities in the volcanic cavity can play the same role in generating self-oscillations as
the languid and the reed do in musical instruments. The understanding of these background oscillations is relevant not
only for explaining the volcanic source process and to make a forecast into the future, but sheds light on the physics of
complex systems developing low turbulence. |
|
|
Teil von |
|
|
|
|
|
|