Minimum of the order parameter fluctuations of seismicity before major earthquakes in Japan
Minimum of the order parameter fluctuations of seismicity before major earthquakes in Japan
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DOI：
10.1073/pnas.1312740110
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发表时间：
2013-08-20
影响因子：
11.1
通讯作者：
Uyeda, Seiya
中科院分区：
文献类型：
--
作者：
Sarlis, Nicholas V.;Skordas, Efthimios S.;Uyeda, Seiya
研究表明，如果我们在一个称为自然时间的时域中分析复杂系统的时间序列，就可以发现隐藏在时间序列中的一些动态特征。在这个时间域中引入的地震活动序参量是各次地震归一化能量的chi加权方差。在这里，我们分析了从1984年1月1日到2011年3月11日，M9东北地震的日本地震目录的自然时间，通过考虑一个固定长度的滑动自然时间窗口，包括在几个月内发生的事件的数量。我们发现，地震活动的序参量的波动表现出明显的最小值前几个月的所有浅源地震的震级7.6或更大的发生在这27年期间在日本地区。在最小值中，东北9级地震前的最小值最深。大地震的最小值似乎有两种，即超震性和非超震性。
It has been shown that some dynamic features hidden in the time series of complex systems can be uncovered if we analyze them in a time domain called natural time chi. The order parameter of seismicity introduced in this time domain is the variance of chi weighted for normalized energy of each earthquake. Here, we analyze the Japan seismic catalog in natural time from January 1, 1984 to March 11, 2011, the day of the M9 Tohoku earthquake, by considering a sliding natural time window of fixed length comprised of the number of events that would occur in a few months. We find that the fluctuations of the order parameter of seismicity exhibit distinct minima a few months before all of the shallow earthquakes of magnitude 7.6 or larger that occurred during this 27-y period in the Japanese area. Among the minima, the minimum before the M9 Tohoku earthquake was the deepest. It appears that there are two kinds of minima, namely precursory and non-precursory, to large earthquakes.