Dehydration-driven stress transfer triggers intermediate-depth earthquakes - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Accéder directement au contenu
Article Dans Une Revue Nature Communications Année : 2017

Dehydration-driven stress transfer triggers intermediate-depth earthquakes

Résumé

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.
Fichier principal
Vignette du fichier
ncomms15247.pdf (3.54 Mo) Télécharger le fichier
Origine : Publication financée par une institution
Loading...

Dates et versions

hal-01534482 , version 1 (07-06-2017)

Licence

Paternité

Identifiants

Citer

Thomas P. Ferrand, Nadège Hilairet, Sarah Incel, Damien Deldicque, Loic Labrousse, et al.. Dehydration-driven stress transfer triggers intermediate-depth earthquakes. Nature Communications, 2017, 8, pp.15247. ⟨10.1038/ncomms15247⟩. ⟨hal-01534482⟩
1125 Consultations
217 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More