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Scaling in natural and laboratory earthquakes
Author(s) -
Nielsen S.,
Spagnuolo E.,
Smith S. A. F.,
Violay M.,
Di Toro G.,
Bistacchi A.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl067490
Subject(s) - slip (aerodynamics) , seismology , scaling , power law , geology , shear (geology) , scaling law , lubrication , physics , geometry , thermodynamics , mathematics , petrology , statistics
Abstract Laboratory experiments reproducing seismic slip conditions show extreme frictional weakening due to the activation of lubrication processes. Due to a substantial variability in the details of the weakening transient, generalization of experimental results and comparison to seismic observations have not been possible so far. Here we show that during the weakening, shear stress τ is generally well matched by a power law of slip u in the form τ ∝ u − α(with 0.35 < α < 0.6). The resulting fracture energy G f can be approximated by a power law in some aspects in agreement with the seismological estimatesG ′ . It appears that G f andG ′are comparable in the range 0.01 < u < 0.3 m. However,G ′surpasses G f at larger slips: at u ≈10 m,G ′ ≈ 1 0 8and G f ≈10 6 . Possible interpretations of this misfit involve the complexity of damage and weakening mechanisms within mature fault zone structures.