title: Natural and experimental evidence of melt lubrication of faults during earthquakes.
abstract: Melt produced by friction during earthquakes may act either as a coseismic fault lubricant or as a viscous brake. Here we estimate the dynamic shear resistance (tau(f)) in the presence of friction-induced melts from both exhumed faults and high-velocity (1.28 meters per second) frictional experiments. Exhumed faults within granitoids (tonalites) indicate low tau(f) at 10 kilometers in depth. Friction experiments on tonalite samples show that tau(f) depends weakly on normal stress. Extrapolation of experimental data yields tau(f) values consistent with the field estimates and well below the Byerlee strength. We conclude that friction-induced melts can lubricate faults at intermediate crustal depths.
authors.affiliation: Dipartimento di Geologia, Paleontologia e Geofisica, Università di Padova, 35137, Padova, Italy. giulio.ditoro@unipd.it
authors.forename: Giulio
authors.initials: G
authors.lastname: Di Toro
authors.forename: Takehiro
authors.initials: T
authors.lastname: Hirose
authors.forename: Stefan
authors.initials: S
authors.lastname: Nielsen
authors.forename: Giorgio
authors.initials: G
authors.lastname: Pennacchioni
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Shimamoto