Titre :

On the Influence of Pressure, Phase Transitions, and Water on Large‐Scale Seismic Anisotropy Underneath a Subduction Zone

Auteur(s) :

Magali, John-Keith [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Thomas, Christine [Auteur]
Westfälische Wilhelms-Universität Münster = University of Münster [WWU]
Ledoux, Estelle Elisa [Auteur]
University of Utah
Capdeville, Yann [Auteur]
Nantes Université [Nantes Univ]
Merkel, Sébastien [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207

Titre de la revue :

Geochemistry, Geophysics, Geosystems

Nom court de la revue :

Geochem Geophys Geosyst

Numéro :

26

Pagination :

e2024GC011827

Éditeur :

American Geophysical Union (AGU)

Date de publication :

2025-03

Discipline(s) HAL :

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

Résumé en anglais : [en]

Seismic anisotropy mainly originates from the crystallographic preferred orientation (CPO) of minerals deformed in the convective mantle flow. While fabric transitions have been previously observed in experiments, their ...
Lire la suite >Seismic anisotropy mainly originates from the crystallographic preferred orientation (CPO) of minerals deformed in the convective mantle flow. While fabric transitions have been previously observed in experiments, their influence on large‐scale anisotropy is not well‐documented. Here, we implement 2D geodynamic models of intra‐oceanic subduction coupled with mantle fabric modeling to investigate the combined effect of pressure ‐and water‐dependent microscopic flow properties of upper mantle and upper transition zone (UTZ) minerals, respectively, on large‐scale anisotropy. We then compare our anisotropy models with anisotropic tomography observations across the Honshu subduction zone. Our results for the upper mantle correlate well with observations, implying that the ‐dependence of olivine fabrics is sufficient to explain the variability of anisotropy. Meanwhile, a dry UTZ tends to be near‐isotropic whereas a relatively wet UTZ could produce up to azimuthal and radial anisotropy. Because water facilitates CPO development, it is therefore likely a requirement to explain the presence of anisotropy in the transition zone close to subducting slabs.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Projet ANR :

Transformations de phase, microstructures, et leur signatures sismiques dans le manteau terrestre

Établissement(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Matériaux Terrestres et Planétaires

Date de dépôt :

2025-03-12T16:29:19Z
2025-03-12T16:37:02Z
2025-03-14T09:31:55Z