Skip to Main content Skip to Navigation
Journal articles

Dehydration-driven stress transfer triggers intermediate-depth earthquakes

Abstract : 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.
Document type :
Journal articles
Complete list of metadatas

Cited literature [47 references]  Display  Hide  Download

https://hal.sorbonne-universite.fr/hal-01534482
Contributor : Gestionnaire Hal-Upmc <>
Submitted on : Wednesday, June 7, 2017 - 4:15:00 PM
Last modification on : Monday, September 28, 2020 - 2:46:02 PM
Long-term archiving on: : Friday, September 8, 2017 - 1:00:15 PM

File

ncomms15247.pdf
Publication funded by an institution

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Citation

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

Share

Metrics

Record views

1967

Files downloads

973