Brantut, N;
Passelegue, FX;
Deldicque, D;
Rouzaud, J-N;
Schubnel, A;
(2016)
Dynamic weakening and amorphization in serpentinite during laboratory earthquakes.
GEOLOGY
, 44
(8)
pp. 607-610.
10.1130/G37932.1.
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Abstract
The mechanical properties of serpentinites are key factors in our understanding of the dynamics of earthquake ruptures in subduction zones, especially intermediate-depth earthquakes. Here, we performed shear rupture experiments on natural antigorite serpentinite, which showed that friction reaches near-zero values during spontaneous dynamic rupture propagation. Rapid coseismic slip (>1 m/s), although it occurs over short distances (<1 mm), induces significant overheating of microscale asperities along the sliding surface, sufficient to produce surface amorphization and likely some melting. Antigorite dehydration occurs in the fault walls, which leaves a partially amorphized material. The water generated potentially contributes to the production of a low-viscosity pressurized melt, explaining the near-zero dynamic friction levels observed in some events. The rapid and dramatic dynamic weakening in serpentinite might be a key process facilitating the propagation of earthquakes at intermediate depths in subduction zones.
Type: | Article |
---|---|
Title: | Dynamic weakening and amorphization in serpentinite during laboratory earthquakes |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1130/G37932.1 |
Publisher version: | http://dx.doi.org/10.1130/G37932.1 |
Language: | English |
Additional information: | © The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license. |
Keywords: | Science & Technology, Physical Sciences, Geology, STICK-SLIP, TEMPERATURE, FAULTS |
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/1521308 |
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