Generation and propagation of stick-slip waves over a fault with rate-independent friction
Stick-slip sliding is observed at various scales in fault sliding and the accompanied seismic events. It is conventionally assumed that the mechanism of stick-slip over geo-materials lies in the rate dependence of friction. However, the movement resembling the stick-slip could be associated with...
Main Authors: | , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2017-07-01
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Series: | Nonlinear Processes in Geophysics |
Online Access: | https://www.nonlin-processes-geophys.net/24/343/2017/npg-24-343-2017.pdf |
Summary: | Stick-slip sliding is observed at various scales in fault
sliding and the accompanied seismic events. It is conventionally
assumed that the mechanism of stick-slip over geo-materials lies in the rate
dependence of friction. However, the movement resembling the
stick-slip could be associated with elastic oscillations of the rock around
the fault, which occurs irrespective of the rate properties of the
friction. In order to investigate this mechanism, two simple models
are considered in this paper: a mass-spring model of self-maintaining
oscillations and a one-dimensional (1-D) model of wave propagation through an
infinite elastic rod. The rod slides with friction over a stiff base. The
sliding is resisted by elastic shear springs. The results show that the
frictional sliding in the mass-spring model generates oscillations that
resemble the stick-slip motion. Furthermore, it was observed that the
stick-slip-like motion occurs even when the frictional coefficient is
constant. The 1-D wave propagation model predicts that despite the presence
of shear springs the frictional sliding waves move with the P wave velocity,
denoting the wave as intersonic. It was also observed that the amplitude of
sliding is decreased with time. This effect might provide an explanation to
the observed intersonic rupture propagation over faults. |
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ISSN: | 1023-5809 1607-7946 |