HR: 1340h
AN: NG33A-0165    [Abstracts]
TI: Numerical Study of Burridge-Knopoff Model with Self-Affine Fault Surfaces
AU: Kamogawa, M
EM: kamogawa@u-gakugei.ac.jp
AF: Department of Physics, Tokyo Gakugei University, 4-1-1 Nukui-kitamachi, Koganei-shi, Tokyo, 184-8501 Japan
AU: * Hasumi, T
EM: t-hasumi.1981@toki.waseda.jp
AF: Department of Physics, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo, 169-8555 Japan
AB: Earthquakes (EQs) are natural phenomena involving frictional slip and fracture processes on the fault surfaces. One of the established statistical properties is magnitude-frequency distribution, Gutenberg-Richter (GR) law. This law is power law and the slope of this distribution, b-value, ranges from about 0.8 to 1.1 in the recent publication. Another property of EQs is self-affine fractal structure on the fault surfaces and the Hurst (Roughness) exponent H representative of self-affine fractals is around 0.8. Burridge and Knopoff proposed a primitive spring-block EQ model called BK model. Carlson et al. and many later works showed that the BK model, behaving like self-organized criticality (SOC) proposed by Bak et al., produced GR law. However, b-values are still far from the observation value because these works might not sufficiently take into account the fault surface structure. In the present paper, we numerically investigate a one-dimensional BK model with inhomogeneous fault surfaces consisting of self-affine fractals. We use two parameters, stiffness and friction parameter, for fault surfaces. It is demonstrated that b-value is closer to the observation result, satisfying the observation H, when we took into account self-affine fault surfaces. We also found that the stiffness parameter is more effective to b-value.
DE: 4440 Fractals and multifractals
DE: 4480 Self-organized criticality
DE: 7290 Computational seismology
SC: Nonlinear Geophysics [NG]
MN: Fall Meeting 2005