Order parameter fluctuations of seismicity and Tsallis entropic index q variation before large earthquakes in Japan

P.A. Varotsos, N. V. Sarlis, E.S. Skordas, Stavros Christopoulos

Research output: Contribution to conferenceAbstractpeer-review


Τhe seismicity of Japan from January 1, 1984 to March 11, 2011 (the occurrence time of the M9 Tohoku earthquake) is analyzed in a new time domain[1] called natural time χ. In this domain, an order parameter of seismicity can be defined[2]. We find that the fluctuations of this order parameter exhibit 15 characteristic minima that are followed[3] by the occurrence of large earthquakes 1 to 3 months later. Six (out of 15) of these earthquakes have magnitude 7.6 or larger. By employing event coincidence analysis[4], we show that the probability to achieve such a result is far beyond chance. In addition, we investigate the change of the Tsallis entropic index q [5,6] before these six earthquakes which are all shallow earthquakes of magnitude 7.6 or larger that occurred during the study period.
[1] Varotsos, P.A.; Sarlis, N.V.; Skordas, E.S. Natural Time Analysis: The new view of time. Precursory Seismic Electric Signals, Earthquakes and other Complex Time-Series; Springer-Verlag: Berlin Heidelberg, 2011. doi:10.1007/978-3-642-16449-1.

[2] Varotsos, P.A.; Sarlis, N.V.; Tanaka, H.K.; Skordas, E.S. Similarity of fluctuations in correlated systems: The case of seismicity. Physical Review E 2005, 72, 041103. doi:10.1103/physreve.72.041103.

[3] Sarlis, N.V.; Skordas, E.S.; Varotsos, P.A.; Nagao, T.; Kamogawa, M.; Tanaka, H.; Uyeda, S. Minimum of the order parameter fluctuations of seismicity before major earthquakes in Japan. Proc. Natl. Acad. Sci. USA 2013, 110, 13734–13738. doi: 10.1073/pnas.1312740110

[4] Donges, J.; Schleussner, C.F.; Siegmund, J.; Donner, R. Event coincidence analysis for quantifying statistical interrelationships between event time series. Eur. Phys. J. Spec. Top. 2016, 225, 471–487. doi: 10.1140/epjst/e2015-50233-y

[5] Tsallis, C. Possible generalization of Boltzmann-Gibbs statistics. J. Stat. Phys. 1988, 52, 479–487. doi: 10.1007/BF01016429

[6] Tsallis, C. Introduction to Nonextensive Statistical Mechanics; Springer: Berlin/Heidelberg, Germany, 2009. doi: 10.1007/978-0-387-85359-8
Original languageEnglish
Publication statusPublished - 11 Dec 2018
Event2018 American Geophysical Union (AGU) fall meeting - Washington, D.C., United States
Duration: 10 Dec 201814 Dec 2018


Conference2018 American Geophysical Union (AGU) fall meeting
Country/TerritoryUnited States
CityWashington, D.C.
Internet address


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