Aretusini, S;
Meneghini, F;
Spagnuolo, E;
Harbord, CW;
Di Toro, G;
(2021)
Fluid pressurisation and earthquake propagation in the Hikurangi subduction zone.
Nature Communications
, 12
(1)
, Article 2481. 10.1038/s41467-021-22805-w.
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Abstract
In subduction zones, seismic slip at shallow crustal depths can lead to the generation of tsunamis. Large slip displacements during tsunamogenic earthquakes are attributed to the low coseismic shear strength of the fluid-saturated and non-lithified clay-rich fault rocks. However, because of experimental challenges in confining these materials, the physical processes responsible for the coseismic reduction in fault shear strength are poorly understood. Using a novel experimental setup, we measured pore fluid pressure during simulated seismic slip in clay-rich materials sampled from the deep oceanic drilling of the Pāpaku thrust (Hikurangi subduction zone, New Zealand). Here, we show that at seismic velocity, shear-induced dilatancy is followed by pressurisation of fluids. The thermal and mechanical pressurisation of fluids, enhanced by the low permeability of the fault, reduces the energy required to propagate earthquake rupture. We suggest that fluid-saturated clay-rich sediments, occurring at shallow depth in subduction zones, can promote earthquake rupture propagation and slip because of their low permeability and tendency to pressurise when sheared at seismic slip velocities.
Type: | Article |
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Title: | Fluid pressurisation and earthquake propagation in the Hikurangi subduction zone |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1038/s41467-021-22805-w |
Publisher version: | https://doi.org/10.1038/s41467-021-22805-w |
Language: | English |
Additional information: | This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences |
URI: | https://discovery.ucl.ac.uk/id/eprint/10128659 |
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