A methodology for filtering and inversion of surface waves: an example of application to the lithospheric structure deternination of the south Iberia
Most important features of the earth structure can be studied through the analysis of Rayleigh wave dispersion. This consists on its filtering and inversion to obtain shear wave velocity distribution with depth. I have applied this analysis to show lithospheric structure of South Iberia, by means of...
Autor Principal: | Corchete, Victor |
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Formato: | Artículo |
Idioma: | Español |
Publicado: |
2006
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Materias: | |
Acceso en línea: |
http://up-rid.up.ac.pa/778/ http://up-rid.up.ac.pa/778/1/Tecnociencia%20Articulo%207%208%281%29%2006.pdf |
Sumario: |
Most important features of the earth structure can be studied through the analysis of
Rayleigh wave dispersion. This consists on its filtering and inversion to obtain shear
wave velocity distribution with depth. I have applied this analysis to show lithospheric
structure of South Iberia, by means of a set of 2D images of shear velocity for depths
ranging from 1.5 to 46 km. The data used to obtain Rayleigh wave dispersion are the
traces of 44 earthquakes, occurred on the neighbouring of Iberia. These earthquakes
have been registered at 3 WWSSN stations located on Iberia. These stations have been
considered because period range of best registration for WWSSN seismograph is the
more suitable to explore the elastic structure of the Earth, for the depth range which is
the objective of this study. I have proceeded to group all seismic events in source
zones to obtain a dispersion curve for each path source-station. Dispersion curves are
obtained by digital filtering with a combination of MFT and TVF filtering techniques.
Thus, a set of source-station averaged dispersion curves was obtained. This set of
dispersion curves is inverted according to generalized inversion theory, to obtain shear
wave velocity models for each source-station path. These models can be interpolated
to obtain a 2D mapping of the elastic structure of South Iberia, by kriging method. This
mapping reveals the principal structural features of South Iberia and surroundings
zones. Such features, as the existence of lateral and vertical heterogeneity in the study
area, also can be seen in Moho depth mapping presented in this paper. Finally, I want
to remark that no shear velocity models have been obtained for intermediate depths
(5 to 30 km), up to date, for the Iberian area. For this reason, this is the goal of the
study presented in this paper |
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