Analyzing earthquake clustering features by using stochastic reconstruction
Analyzing earthquake clustering features by using stochastic reconstruction
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DOI：
10.1029/2003jb002879
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发表时间：
2004-05-04
影响因子：
3.9
通讯作者：
Vere-Jones, D
中科院分区：
文献类型：
--
作者：
Zhuang, JC;Ogata, Y;Vere-Jones, D
[1]本文在地震类型余震序列（ETAS）模型和细化过程的基础上，给出了如何将给定目录中的地震随机地划分为不同的余震群的方法。该方法的关键点是一个事件被另一个先前事件触发并成为背景事件的概率。利用这些概率，我们可以重建与地震丛特征相关的函数，以检验有关地震丛现象的一些重要假设。我们将这种重建方法应用于日本的浅层地震数据和模拟目录。结果表明：（1）时空ETAS模型中各分量的函数作为描述地震群的一阶近似是足够好的;（2）背景事件比同震级触发事件预期触发的后代更少;（3）触发事件的震级分布依赖于其直接祖先的震级;（4）余震序列的扩散主要是由单个触发过程的级联引起的，但没有证据表明每个触发过程都是扩散性的;（5）触发区的规模仍然是模型中所表述的指数规律，但对于预期的后代数量来说并不相同。
[1] On the basis of the epidemic-type aftershock sequence ( ETAS) model and the thinning procedure, this paper gives the method about how to classify the earthquakes in a given catalogue into different clusters stochastically. The key points of this method are the probabilities of one event being triggered by another previous event and being a background event. Making use of these probabilities, we can reconstruct the functions associated with the characteristics of earthquake clusters to test a number of important hypotheses about the earthquake clustering phenomena. We applied this reconstruction method to the shallow seismic data in Japan and also to a simulated catalogue. The results show the following assertions: ( 1) The functions for each component in the formulation of the space-time ETAS model are good enough as a first-order approximation for describing earthquake clusters; ( 2) a background event triggers less offspring in expectation than a triggered event of the same magnitude; ( 3) the magnitude distribution of the triggered event depends on the magnitude of its direct ancestor; ( 4) the diffusion of the aftershock sequence is mainly caused by cascades of individual triggering processes, while no evidence shows that each individual triggering process is diffusive; and ( 5) the scale of the triggering region is still an exponential law, as formulated in the model but not the same one for the expected number of offspring.