Spatial and Temporal Patterns of Aftershocks: Log-Periodicity and its Physical Origins

[9804870]本研究包括对地震余震时空格局的观测和理论研究。这将是对临界点模型的检验，在该模型中，在板块边界尺度上，地壳不是处于连续的自组织临界状态，而是反复接近和退出临界状态。这方面的证据包括在许多大事件之前观察到的区域活动的幂律增加和随后的区域平静。幂律的增长有时由对数周期波动调制。如果临界点模型是地震活动性的有效表示，那么在大事件后的余震序列中也应观察到幂律标度。这体现在大森定律中。这些结果将有助于了解对数周期波动的物理起源，以及临界点模型与其他最近的余震理论模型之间的关系，这些模型也产生了Omori定律。这项研究是国家减少地震危害计划的一个组成部分。

9804870SaleurThis research consists of a joint observational and theoretical investigation of the spatio-temporal pattern of earthquake aftershocks. This will be a test of the critical point model in which, on a plate boundary scale, the crust is not in a continuous state of self-organized criticality but repeatedly approaches and retreats from the critical state. Evidence for this includes the power law increase in regional activity observed to precede many large events and the regional quiescence, which follows. The power law increase is sometimes modulated by a log-periodic fluctuation. If the critical point model is a valid representation for seismicity, then power law scaling should also be observed in the aftershock sequence following large events. This is seen in the form of Omori's Law. The results should improve understanding of the physical origin of log periodic fluctuations and the relationship between the critical point model and other recent theoretical models of aftershocks, which also yield Omori's Law. This research is a component of the National Earthquake Hazard Reduction Program.