Titre :

Dehydration-driven stress transfer triggers intermediate-depth earthquakes

Auteur(s) :

Ferrand, Thomas [Auteur]
Laboratoire de géologie de l'ENS [LGENS]
Hilairet, Nadege [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Incel, Sarah [Auteur]
Institut des Sciences de la Terre de Paris [iSTeP]
Deldicque, Damien [Auteur]
Laboratoire de géologie de l'ENS [LGENS]
Labrousse, Loïc [Auteur]
Lithosphère, structure et dynamique [LSD]
Gasc, Julien [Auteur]
Laboratoire de géologie de l'ENS [LGENS]
Renner, Jörg [Auteur]
Institut für Geologie, Mineralogie und Geophysik
Wang, Yanbin [Auteur]
Center for Advanced Radiation Sources [University of Chicago] [CARS]
Green Ii, Harry W. [Auteur]
University of California [Riverside] [UC Riverside]
Schubnel, Alexandre [Auteur]
Laboratoire de géologie de l'ENS [LGENS]

Titre de la revue :

Nature communications

Numéro :

8

Pagination :

15247

Date de publication :

2017-05-15

Discipline(s) HAL :

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]

Résumé en anglais : [en]

Intermediate-depth earthquakes (30–300 km) have been extensively documented within subducting oceanic slabs, but their mechanics remains enigmatic. Here we decipher the mechanism of these earthquakes by performing deformation ...
Lire la suite >Intermediate-depth earthquakes (30–300 km) have been extensively documented within subducting oceanic slabs, but their mechanics remains enigmatic. Here we decipher the mechanism of these earthquakes by performing deformation experiments on dehydrating serpentinized peridotites (synthetic antigorite-olivine aggregates, minerals representative of subduction zones lithologies) at upper mantle conditions. At a pressure of 1.1 gigapascals, dehydration of deforming samples containing only 5 vol% of antigorite suffices to trigger acoustic emissions, a laboratory-scale analogue of earthquakes. At 3.5 gigapascals, acoustic emissions are recorded from samples with up to 50 vol% of antigorite. Experimentally produced faults, observed post-mortem, are sealed by fluid-bearing micro-pseudotachylytes. Microstructural observations demonstrate that antigorite dehydration triggered dynamic shear failure of the olivine load-bearing network. These laboratory analogues of intermediate-depth earthquakes demonstrate that little dehydration is required to trigger embrittlement. We propose an alternative model to dehydration-embrittlement in which dehydration-driven stress transfer, rather than fluid overpressure, causes embrittlement.Lire moins >

Langue :

Anglais

Audience :

Internationale

Vulgarisation :

Non

Établissement(s) :

Université de Lille
ENSCL
CNRS
INRA

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Matériaux Terrestres et Planétaires

Date de dépôt :

2019-05-16T17:20:47Z
2024-04-23T14:27:34Z