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Breakdown in power‐law scaling in an analogue model of earthquake rupture and stick‐slip
Author(s) -
Hamilton T.,
McCloskey J.
Publication year - 1997
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 - 10.1029/97gl00203
Subject(s) - extrapolation , scaling , induced seismicity , seismology , geology , slip (aerodynamics) , power law , magnitude (astronomy) , earthquake rupture , seismic moment , fault (geology) , physics , geometry , mathematics , mathematical analysis , statistics , astronomy , thermodynamics
The Gutenberg‐Richter relationship for earthquakes in both global and fault‐specific seismicity has been interpreted as an indication of self‐similarity for events of all magnitudes. It is observed, however, that the linear extrapolation of this relationship to high‐magnitude often fails to predict the frequency of occurrence of large events; earthquake hazard cannot, generally, be predicted solely by examination of microseismicity. It has been postulated that this break in power‐law scaling is due to a change in the rupture mechanism as the size of the rupture becomes larger than the thickness of the seismogenic layer. Here we examine the scaling of earthquake‐like failures in an analogue model consisting of an elastic solid confined and driven by a steel stressing apparatus. Sensors embedded in the solid close to the interface with a rough substrate measure local strain, and allow the examination of rupture scaling and moment release. The frequency‐magnitude distribution for events is a power‐law at low magnitude but exhibits enhancement for high‐energy events which is consistent with a characteristic earthquake model. We show, unambiguously, that this break in scaling corresponds to ruptures whose diameter is equal to the smaller dimension of the model fault.