We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Wavefield decomposition and phase space dynamics of the seismic noise at Volcàn de Colima, Mexico: evidence of a two-state sourcee process.
- Authors
Palo, M.; Cusano, P.
- Abstract
We analyse the seismic noise recorded at the Colima Volcano (Mexico) in the period December 2005=May 2006 by four broadband three-component seismic stations. Specifically, we characterize the spectral content of the signal and follow its time evolution along all the data set. Moreover, we infer the properties of the attractor in the phase space by false nearest neighbours analysis and Grassberger=Procaccia algorithm, and adopt a time-domain decomposition method (independent component analysis) to find the basic constituents (independent components) of the system. Constraints on the seismic wavefield are inferred by the polarization analysis.We find two states of the background seismicity visible in different time-intervals that are Phase A and Phase B. Phase A has a spectrum with two peaks at 0.15Hz and 0.3Hz, with the latter dominating, an attractor of correlation dimension close to 3, three quasi-monochromatic independent components, and a relevant fraction of crater-pointing polarization solutions in the near-field. In Phase the spectrum is preserved but with the highest peak at 0.15Hz, the attractor has a correlation dimension close to 2, two independent components are extracted, and the polarization solutions are dominated by Rayleigh waves incoming from the southwest direction. We depict two sources acting on the background seismicity that are the microseismic noise loading on the Pacific coastline and a low-energy volcanic tremor. A change in the amplitude of the microseismic noise can induce the switching from a state of the system to the other.
- Subjects
COLIMA (Mexico : Volcano); MEXICO; SEISMIC waves; PHASE space; MICROSEISMS; SEISMOLOGY; ALGORITHMS; TIME-domain analysis; DECOMPOSITION method
- Publication
Nonlinear Processes in Geophysics, 2013, Vol 20, Issue 1, p71
- ISSN
1023-5809
- Publication type
Article
- DOI
10.5194/npg-20-71-2013