FN Archimer Export Format
PT J
TI Seismic precursors linked to super-critical fluids at oceanic transform faults
BT 
AF GELI, Louis
   PIAU, Jean-Michel
   DZIAK, Robert
   MAURY, Vincent
   FITZENZ, Delphine
   COUTELLIER, Quentin
   HENRY, Pierre
AS 1:1;2:2;3:3;4:4,5;5:6;6:1,7;7:8;
FF 1:PDG-REM-GM;2:;3:;4:;5:;6:PDG-REM-GM-LGG;7:;
C1 IFREMER, Inst Carnot Ifremer, EDROME, Marine Geosci Dept, F-29280 Plouzane, France.
   IFSTTAR, Dept Mat & Struct MAST, Bouguenais, France.
   Oregon State Univ, Pacific Marine Environm Lab, Cooperat Inst Marine Resource Studies, Natl Ocean & Atmospher Adm Hatfield Marine Sci Ct, Newport, OR 97365 USA.
   Univ Montpellier 2, F-34000 Montpellier, France.
   IFP Sch, F-92852 Rueil Malmaison, France.
   RMS, Newark, CA 94546 USA.
   Parvis Blaise Pascal, ENIB, F-29280 Plouzane, France.
   Aix Marseille Univ, CEREGE, F-13545 Aix En Provence 04, France.
C2 IFREMER, FRANCE
   IFSTTAR, FRANCE
   UNIV OREGON STATE, USA
   UNIV MONTPELLIER, FRANCE
   IFP, FRANCE
   RMS, USA
   ENIB, FRANCE
   UNIV AIX MARSEILLE, FRANCE
SI BREST
SE PDG-REM-GM
   PDG-REM-GM-LGG
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
IF 11.74
TC 15
UR https://archimer.ifremer.fr/doc/00229/34049/85997.pdf
LA English
DT Article
AB Large earthquakes on mid-ocean ridge transform faults are commonly preceded by foreshocks(1-3) and changes in the seismic properties of the fault zone(3). These seismic precursors could be linked to fluid-related processes(2,3). Hydrothermal fluids within young, hot crust near the intersection of oceanic transform faults are probably in a supercritical condition(4). At constant temperature, supercritical fluids become significantly more compressible with decreasing pressure, with potential impacts on fault behaviour. Here we use a theoretical model to show that oceanic transform faults can switch from dilatant and progressive deformation to rupture in response to fluid-related processes. We assume that the fault core material behaves according to a Cam-clay-type(5) constitutive law, which is commonly used to account for the behaviour of clays. According to our model, we find that the fault is initially stable, with stresses gradually increasing over a timescale of years in response to tectonic loading. The fault evolves into a metastable phase, lasting a few days, during which the fault rocks dilate and pore pressures decrease, causing the compressibility of the supercritical fluids to increase. This in turn triggers fault-slip instability that creates foreshock swarms. In the final phase, the fault fails in the mainshock rupture. Our results imply that seismic precursors are caused by changes in fluid pressure which result in variations in fluid compressibility, in response to rock deformation just before rupture.
PY 2014
PD OCT
SO Nature Geoscience
SN 1752-0894
PU Nature Publishing Group
VL 7
IS 10
UT 000343112600022
BP 757
EP 761
DI 10.1038/NGEO2244
ID 34049
ER

EF