Evolution of the temporal multifractal scaling properties of the Chiayi earthquake (M_L = 6.4), Taiwan

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• 作者：Yi-Jiun Tang^a ; Young-Fo Chang^a ; ^{seichyo@ccu.edu.tw} ; Tai-Sheng Liou^a ; Chien-Chih Chen^b ; Yih-Min Wu^c
• 关键词：Multifractal ; Seismicity ; Seismogenic regimes ; Precursor of a large earthquake
• 刊名：Tectonophysics
• 出版年：2012
• 出版时间：11 June, 2012
• 年：2012
• 卷：546-547
• 期：Complete
• 页码：1-9
• 全文大小：1723 K

文摘

Variations in the fractal dimension of earthquakes have been suggested to be a precursor of a large earthquake. However, the physical characteristics and seismicity are always different along a large fault system, and it is difficult to segment a large fault for further investigating. Therefore, the fractal dimension of earthquakes on a given fault only reflects the average seismic characteristics of the area and may be unrelated to precursory activity. In this paper, the evolution of the temporal generalized fractal dimension (D_q) of a seismic cluster within a small fault system associated with the Chiayi earthquake (M_L = 6.4), Taiwan, is investigated. The earthquakes of this sequence are confined in small source volume and reflect the behavior of the local fault system.

Our results show that the D_q curve of the background stage is smooth with a low multifractal degree (0.36) and the seismicity is nearly monofractal in the Chiayi region. During the foreshock stage, the seismicity becomes active such that not only the D_q curve exhibits greater variability especially for the steep slope of D_q curve at q = 0 but also the temporal fractal dimension changes from nearly monofractal to multifractal. In the aftershock stage, the fluctuation of D_q is large and the multifractal degree is up to 1.0. The temporal multifractal property becomes more pronounced as well. Finally, when the seismicity returns to the background stage, the D_q curve becomes smooth and nearly monofractal again. Therefore, the fluctuations in the D_q spectrum of an earthquake cluster associated with a large earthquake not only give a clear picture of the temporal alterations in the seismogenic regimes but also illustrate their variability through time for a large earthquake. In addition, the variation of the slope of D_q curve at q = 0 in the foreshocks may be used as a precursor of a large earthquake.