Seismic anisotropy due to textures above and below the 410 km discontinuity

Autor: Saki, Morvarid, Ledoux, Estelle, Pisconti, Angelo, Thomas, Christine, Merkel, Sébastien
Jazyk: angličtina
Rok vydání: 2023
Zdroj: XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG)
Popis: We investigate the effect of various geodynamic contexts on the reflection coefficients of P and S waves underside reflections off the 410 km discontinuity, to detect seismic anisotropy at this boundary layer due to textures above and below the 410 discontinuity. We calculate the reflection coefficient for P and SH underside reflections using velocity perturbations resulting from aligned minerals above and below the 410 km discontinuity for different deformation scenarios. Our results indicate some differences in amplitude and polarity patterns of reflection coefficients of different deformation geometries in the case of an anisotropic olivine layer above an anisotropic wadsleyite layer, compared to the case of anisotropic olivine above an isotropic wadsleyite layer. The amplitudes of P and SH waves are influenced by the effect of angle of incidence and polarity reversal of the P and S waves are observed for some deformation styles. Furthermore, water content of wadsleyite plays an important role in creating the polarity reversal of the waves compared to the case of dry wadsleyite.
The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)
Databáze: OpenAIRE