Numerical simulations were performed to examine the effects of heterogeneity of frictional properties on earthquake cycles. In the model, rate- and state-dependent friction was assumed at a planar fault in an infinite uniform elastic medium. Simulated earthquake cycles were compared at model faults with one to four circular patches with velocity-weakening frictional properties. The characteristic slip distances for the patches were varied so that the effects of interactions between patches with different frictional properties could be assessed. Simple periodic, multiperiodic, and aperiodic earthquake cycles were observed in the simulation results. The frequencies of the multiperiodic and aperiodic cycles increased with the number of velocity-weakening patches, suggesting that more complex cycles may occur in a fault as the frictional properties become more heterogeneous. The simulated earthquake cycles were divided into several classes according to the combinations of ruptured patches in the earthquakes. Complex aperiodic earthquake cycles tended to occur when the values of the parameters lay between the parameter ranges for the different patterns. The frequency distribution of simulated earthquake recurrence intervals became more continuous and smooth as the number of patches increased. The simulation results suggest that interactions between many patches with different frictional properties form part of the explanation of realistic complex earthquake cycles.

中文翻译：

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地震周期的复杂性随着相互作用块的数量而增加

进行了数值模拟以检查摩擦特性的异质性对地震循环的影响。在该模型中，假设在无限均匀弹性介质中的平面断层处发生速率和状态相关的摩擦。模拟的地震循环在模型断层处进行了比较，该断层具有一到四个具有减弱速度的摩擦特性的圆形补丁。贴片的特征滑移距离是变化的，因此可以评估具有不同摩擦特性的贴片之间相互作用的影响。模拟结果中观察到简单周期、多周期和非周期地震循环。多周期和非周期周期的频率随着速度减弱补丁的数量而增加，表明随着摩擦特性变得更加不均匀，断层中可能会发生更复杂的循环。根据地震中破裂斑块的组合，将模拟的地震循环分为几类。当参数值介于不同模式的参数范围之间时，往往会发生复杂的非周期性地震循环。随着斑块数量的增加，模拟地震复发间隔的频率分布变得更加连续和平滑。模拟结果表明，许多具有不同摩擦特性的斑块之间的相互作用构成了对现实复杂地震循环的解释的一部分。根据地震中破裂斑块的组合，将模拟的地震循环分为几类。当参数值介于不同模式的参数范围之间时，往往会发生复杂的非周期性地震循环。随着斑块数量的增加，模拟地震复发间隔的频率分布变得更加连续和平滑。模拟结果表明，许多具有不同摩擦特性的斑块之间的相互作用构成了对现实复杂地震循环的解释的一部分。根据地震中破裂斑块的组合，将模拟的地震循环分为几类。当参数值介于不同模式的参数范围之间时，往往会发生复杂的非周期性地震循环。随着斑块数量的增加，模拟地震复发间隔的频率分布变得更加连续和平滑。模拟结果表明，许多具有不同摩擦特性的斑块之间的相互作用构成了对现实复杂地震循环的解释的一部分。随着斑块数量的增加，模拟地震复发间隔的频率分布变得更加连续和平滑。模拟结果表明，许多具有不同摩擦特性的斑块之间的相互作用构成了对现实复杂地震循环的解释的一部分。随着斑块数量的增加，模拟地震复发间隔的频率分布变得更加连续和平滑。模拟结果表明，许多具有不同摩擦特性的斑块之间的相互作用构成了对现实复杂地震循环的解释的一部分。