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Constraints on an intrusive system beneath the Soufriére Hills Volcano, Montserrat, from finite difference modeling of a controlled source seismic experiment
Author(s) -
Paulatto M.,
Minshull T. A.,
Henstock T. J.
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl041805
Subject(s) - geology , sill , volcano , seismology , dike , amplitude , scattering , attenuation , seismic wave , seismic vibrator , seismometer , geophysics , petrology , physics , quantum mechanics , optics
The SEA‐CALIPSO wide‐angle seismic experiment revealed a high velocity region beneath the island of Montserrat. Field recordings show a decrease in the amplitude of seismic signals crossing this high velocity region. We constrain the geometry and nature of this attenuating body, by forward modeling of the seismic wave field with a viscoelastic finite‐difference method. We interpret the attenuation observed as caused by a scattering region, which we model as a stochastic perturbation of the velocity field with characteristic length scale of 0.4 km. The scattering region approximately coincides with the top part of the high velocity region and is estimated to have a volume of about 800 km 3 . We argue that the scattering is caused by geological heterogeneities corresponding to a system of dikes and sills and to the complex structure of the volcanic edifice.