%0 Journal Article
%T Filtering of a Ricker wavelet induced by anelastic seismic wave propagation and reflection
%+ Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)
%+ Géosciences Rennes (GR)
%A Ker, Stephan
%A Le Gonidec, Yves
%< avec comité de lecture
%@ 1742-2132
%J Journal of Geophysics and Engineering
%I IOP Publishing
%V 17
%N 5
%P 838-851
%8 2020-10-25
%D 2020
%R 10.1093/jge/gxaa033
%K seismic attenuation
%K Q factor
%K anelasticity
%K seismic data analysis
%Z Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]Journal articles
%X A varying Q factor with depth induces modifications of seismic wave features due to anelastic propagation but also reflections at the discontinuities. Standard signal analysis methods often neglect the reflection contribution when assessing Q values from seismic data. We have developed an analytical quantification of the cumulative effects of both the propagation and reflection contributions by considering Kjartansson's model and a seismic plane wave at normal incidence on a step-like discontinuity. We show that the cumulative effects are equivalent to a frequency filter characterised by a bandform and phase that both depend on the ratio between the elastic and anelastic contrasts. When considering this filter applied to a Ricker wavelet, we establish an analytical expression of the peak-frequency attribute as a function of propagation and reflection properties. We demonstrate that this seismic attribute depends on the anelastic contrast, which cannot be neglected when assessing Q factors: the error in Q estimate is not linearly dependent on the anelastic contrast and we establish an analytical expression for the case where this contrast is weak. An unexpected phenomenon for a step-like interface is an increase in the peak frequency that is observed when the anelastic and elastic contrasts have opposite signs, with a constraint on the anelastic propagation properties. This behaviour allows for assessment of the elastic and anelastic parameters.
%G English
%2 https://univ-rennes.hal.science/hal-02989177/document
%2 https://univ-rennes.hal.science/hal-02989177/file/gxaa033.pdf
%L hal-02989177
%U https://univ-rennes.hal.science/hal-02989177
%~ INSU
%~ UNIV-RENNES1
%~ UR2-HB
%~ CNRS
%~ IFREMER
%~ GR
%~ OSUR
%~ UR1-HAL
%~ UR1-SDLM
%~ GR-DIMENV
%~ UNIV-RENNES2
%~ TEST-UR-CSS
%~ UNIV-RENNES
%~ INRAE
%~ UR1-ENV
%~ GR-DEMO
%~ RESEAU-EAU