Title :

Detecting seismic anisotropy above the 410 km discontinuity using reflection coefficients of underside reflections

Author(s) :

Saki, Morvarid [Auteur]
Institut für Geophysik [Münster]
Thomas, Christine [Auteur]
Institut für Geophysik [Münster]
Merkel, Sébastien [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Wookey, James [Auteur]
University of Bristol [Bristol]

Journal title :

Physics of the Earth and Planetary Interiors

Volume number :

274

Pages :

170-183

Publication date :

2018-01

HAL domain(s) :

Planète et Univers [physics]/Astrophysique [astro-ph]
Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Physique [physics]/Astrophysique [astro-ph]
Planète et Univers [physics]/Sciences de la Terre
Chimie/Matériaux
Physique [physics]/Physique [physics]/Géophysique [physics.geo-ph]

English abstract : [en]

We investigate the effect of various types of deformation mechanisms on the reflection coefficients of P and S waves underside reflections off the 410 km discontinuity, to develop a diagnostic tool to detect the style of ...
Show more >We investigate the effect of various types of deformation mechanisms on the reflection coefficients of P and S waves underside reflections off the 410 km discontinuity, to develop a diagnostic tool to detect the style of deformation at boundary layers. We calculate the reflection coefficient for P and SH underside reflections using velocity perturbations resulting from aligned minerals above the 410 km discontinuity for different deformation scenarios. The results show that in the case of an anisotropic olivine layer above an isotropic wadsleyite layer, the P wave reflection coefficient amplitudes are only slightly influenced by the joint effect of angle of incidence and the strength of imposed deformation, without any polarity reversal and for all deformation styles. For the SH wave underside reflections the incidence angle for which a polarity reversal occurs, changes with distance for all scenarios and in addition changes with azimuth for shear deformation scenarios. These differences in amplitude and polarity patterns of reflection coefficients of different deformation geometries, especially for S wave at shorter distances potentially provide a possibility to distinguish between different styles of deformation at a boundary layer. We also show a first test using currently available elastic constants of anisotropic wadsleyite beneath anisotropic olivine.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
ENSCL
CNRS
INRA

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Matériaux Terrestres et Planétaires

Submission date :

2019-05-16T17:21:29Z
2023-11-15T12:55:33Z