Earth-prints repository, logo   DSpace

About DSpace Software
|earth-prints home page | roma library | bologna library | catania library | milano library | napoli library | palermo library
Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/4249

Authors: De Lauro, E.*
De Martino, S.*
Del Pezzo, E.*
Falanga, M. R.*
Paolo, M.*
Scarpa, R.*
Title: Model for high-frequency Strombolian tremor inferred by wavefield decomposition andreconstruction of asymptotic dynamics
Title of journal: Journal of Geophysical Research
Series/Report no.: /113 (2008)
Publisher: Amerrican Geophysical Union
Issue Date: 2008
DOI: 10.1029/2006JB004838
Keywords: Volcanic tremor
Stromboli
Abstract: We study the volcanic tremor time series recorded by a broadband three-component seismic network installed at Stromboli volcano during 1997. By using decomposition methods in both frequency and time domains, we prove that Strombolian tremor can be described as a linear combination of nonlinear signals in time domain. These ‘‘components’’ are similar to those obtained for explosion quakes, with the only difference being the amplitude enhancement. We characterize each of these nonlinear signals both in terms of their wavefield properties as well as dynamic systems. Moreover, we take into account the complex processes of magma flow and turbulent degassing, looking at time and amplitude modulation of tremor on a suitable scale. The distribution of tremor amplitudes is Gaussian while the intertimes between the maxima in a suitable scale are described by a Poisson clustered process. Starting from these analyses, a first approximate model for volcanic tremor field can be deduced. The recorded signals, i.e., the elastic vibrations at a point, can be described by a nonlinear equation which gives limit cycles (different observed ‘‘nonlinear modes’’). This equation is governed by a time-dependent threshold which represents the variability of bubble flux. We take into account some inelasticity in the medium perturbing the elastic potential with a Gaussian function on a suitable scale. It acts as a radiance function modulating the frequency of the limit cycle. This proposed model is able to reproduce waveform, Fourier spectrum, and phase space dimension of one of the extracted nonlinear wave packets.
Appears in Collections:04.06.08. Volcano seismology
Papers Published / Papers in press

Files in This Item:

File Description SizeFormatVisibility
n. 7 J. Geophys. Res. 2008 De Lauro113.pdfMain Article1.06 MBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


Share this record
Del.icio.us

Citeulike

Connotea

Facebook

Stumble it!

reddit


 

Valid XHTML 1.0! ICT Support, development & maintenance are provided by CINECA. Powered on DSpace Software. CINECA