Self-Organized Criticality and earthquakes (original) (raw)
Related papers
Scaling in a nonconservative earthquake model of self-organized criticality
Physical Review E, 2001
We numerically investigate the Olami-Feder-Christensen model for earthquakes in order to characterise its scaling behaviour. We show that ordinary finite size scaling in the model is violated due to global, system wide events. Nevertheless we find that subsystems of linear dimension small compared to the overall system size obey finite (subsystem) size scaling, with universal critical coefficients, for the earthquake events localised within the subsystem. We provide evidence, moreover, that large earthquakes responsible for breaking finite size scaling are initiated predominantly near the boundary.
Self organized criticality in a modified Olami-Feder-Christensen model
The European Physical Journal B, 2011
An improved version of the Olami-Feder-Christensen model has been introduced to consider avalanche size differences. Our model well demonstrates the power-law behavior and finite size scaling of avalanche size distribution in any range of the adding parameter p add of the model. The probability density functions (PDFs) for the avalanche size differences at consecutive time steps (defined as returns) appear to be well approached, in the thermodynamic limit, by q-Gaussian shape with appropriate q values which can be obtained a priori from the avalanche size exponent τ . For the small system sizes, however, return distributions are found to be consistent with the crossover formulas proposed recently in Tsallis and Tirnakli, J. Phys.: Conf. Ser. 201, 012001 (2010). Our results strengthen recent findings of Caruso et al. [Phys. Rev. E 75, 055101(R) ] on the real earthquake data which support the hypothesis that knowing the magnitude of previous earthquakes does not make the magnitude of the next earthquake predictable. Moreover, the scaling relation of the waiting time distribution of the model has also been found. *
Earthquakes as a self-organized critical phenomenon
Journal of Geophysical Research, 1989
The Gutenberg-Richter power law distribution for energy released at earthquakes can be understood as a consequence of the earth crust being in a self-organized critical state. A simple cellular automaton stick-slip type model yields D(E) • E-• with r = 1.0 and r = 1.35 in two and three dimensions, respectively. The size of earthquakes is unpredictable since the evolution of an earthquake depends crucially on minor details of the crust.
Self-organized criticality and universality in a nonconservative earthquake model
Physical Review E, 2001
We make an extensive numerical study of a two dimensional nonconservative model proposed by Olami-Feder-Christensen to describe earthquake behavior. By analyzing the distribution of earthquake sizes using a multiscaling method, we find evidence that the model is critical, with no characteristic length scale other than the system size, in agreement with previous results. However, in contrast to previous claims, we find convergence to universal behaviour as the system size increases, over a range of values of the dissipation parameter, α. We also find that both "free" and "open" boundary conditions tend to the same result. Our analysis indicates that, as L increases, the behaviour slowly converges toward a power law distribution of earthquake sizes P (s) ∼ s −τ with exponent τ ≃ 1.8. The universal value of τ we find numerically agrees quantitatively with the empirical value (τ = B + 1) associated with the Gutenberg-Richter law.
2008
I have proposed a non-Abelian and stochastic self-organized criticality model in which each avalanche contains one stochastic site and all remaining sites in the avalanche are deterministic with a constant threshold E I c. Studies of avalanche structures, waves and autocorrelations, size moments and probability distribution functions of avalanche size, for the thresholds 4 ≤ E I c ≤ 256, were performed. The shell-like avalanche structures, correlated waves within avalanches, complex size moments and probability distribution functions show multifractal scaling like the Abelian and deterministic BTW model despite the fact that the model is non-Abelian and stochastic with unbalanced relaxation rules at each stochastic site.
Self-organized criticality and earthquake predictability
Physics of the Earth and Planetary Interiors, 1993
We analyse a seismic catalogue of South California to investigate the possibility of earthquake prediction using the hypothesis that the seismic events are self-organized critical phenomena. The relation found previously is valid only in a mean field approximation, but cannot be used for earthquake prediction because the time clustering of seismic events makes the definition of a standard deviation of waiting times of earthquakes impossible.
Self-organized critical earthquake model with moving boundary
The European Physical Journal B, 2006
A globally driven self-organized critical model of earthquakes with conservative dynamics has been studied. An open but moving boundary condition has been used so that the origin (epicenter) of every avalanche (earthquake) is at the center of the boundary. As a result, all avalanches grow in equivalent conditions and the avalanche size distribution obeys finite size scaling excellent. Though the recurrence time distribution of the time series of avalanche sizes obeys well both the scaling forms recently observed in analysis of the real data of earthquakes, it is found that the scaling function decays only exponentially in contrast to a generalized gamma distribution observed in the real data analysis. The non-conservative version of the model shows periodicity even with open boundary.