Stickiness in the order parameter time-series as a signature of criticality

2020 ◽  
Vol 544 ◽  
pp. 123508
Author(s):  
Y.F. Contoyiannis ◽  
S.M. Potirakis ◽  
F.K. Diakonos
Keyword(s):  
Time Series ◽  
Order Parameter

scholarly journals Phenomena preceding major earthquakes interconnected through a physical model

2019 ◽  
Vol 37 (3) ◽  
pp. 315-324 ◽  
Author(s):  
Panayiotis A. Varotsos ◽  
Nicholas V. Sarlis ◽  
Efthimios S. Skordas
Keyword(s):  
Time Series ◽  
Physical Model ◽  
Order Parameter ◽  
Tohoku Earthquake ◽  
Entropy Change ◽  
Natural Time ◽  
Earth Magnetic Field ◽  
Preceding Period ◽  
Magnetic Field Variations

Abstract. The analysis of earthquake time series in a new time domain termed natural time enables the uncovering of hidden properties in time series of complex systems and has been recently employed as the basis of a method to estimate seismic risk. Natural time also enables the determination of the order parameter of seismicity, which is a quantity by means of which one can identify when the system approaches the critical point (the mainshock occurrence is considered the new phase). Applying this analysis, as an example, to the Japanese seismic data from 1 January 1984 until the super-giant M 9 Tōhoku earthquake on 11 March 2011, we find that almost 3 months before its occurrence the entropy change of seismicity under time reversal is minimized on 22 December 2010, which signals an impending major earthquake. On this date the order parameter fluctuations of seismicity exhibit an abrupt increase. This increase is accompanied by various phenomena; e.g., from this date the horizontal GPS azimuths start to become gradually oriented toward the southern direction, while they had random orientation during the preceding period. Two weeks later, a minimum of the order parameter fluctuations of seismicity appears accompanied by anomalous Earth magnetic field variations and by full alignment of the orientations of GPS azimuths southwards leading to the most intense crust uplift. These phenomena are discussed and found to be in accordance with a physical model which seems to explain on a unified basis anomalous precursory changes observed either in ground-based measurements or in satellite data.

Statistical significance of the precursory minima of the order parameter fluctuations of seismicity by modern methods of Statistical Physics

2020 ◽  
Author(s):  
Panayiotis A. Varotsos ◽  
Nicholas V. Sarlis ◽  
Efthimios S. Skordas ◽  
Stavros-Richard G. Christopoulos
Keyword(s):  
Time Series ◽  
Order Parameter ◽  
Statistical Physics ◽  
Statistical Significance ◽  
Time Analysis ◽  
Seismic Electric Signals ◽  
Natural Time ◽  
Natural Time Analysis ◽  
Global Seismicity ◽  
Electric Signals

<p>An order parameter for seismicity was introduced in the frame of natural time analysis [1].  Recent studies of the fluctuations of this order parameter revealed the existence of minima preceding major earthquakes [2-7]. Here, we review the statistical significance of these minima by using recent methods of Statistical Physics, such as receiver operating characteristics [8] and event coincidence analysis [9,10]. These methods are also applied to the investigation [11] of the statistical significance of Seismic Electric Signals [12].</p><p>References</p><ol><li>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.</li> <li>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 110 (2013) 13734–13738, dx.doi.org/10.1073/pnas.1312740110.</li> <li>Varotsos, P.A.; Sarlis, N.V.; Skordas, E.S. Study of the temporal correlations in the magnitude time series before major earthquakes in Japan. J. Geophys. Res.: Space Physics 119 (2014) 9192–9206, dx.doi.org/10.1002/2014JA020580.</li> <li>Sarlis, N.V.; Christopoulos, S.R.G.; Skordas, E.S. Minima of the fluctuations of the order parameter of global seismicity. Chaos 25 (2015) 063110, dx.doi.org/10.1063/1.4922300.</li> <li>Sarlis, N.V.; Skordas, E.S.; Christopoulos, S.-R.G.; Varotsos, P.A. Statistical significance of minimum of the order parameter fluctuations of seismicity before major earthquakes in Japan, Pure Appl. Geophys. 173 (2016) 165–172, dx.doi.org/10.1007/s00024-014-0930-8.</li> <li>Sarlis, N.V.; Skordas, E.S.; Mintzelas, A.; Papadopoulou, K.A. Micro-scale, mid-scale, and macro-scale in global seismicity identified by empirical mode decomposition and their multifractal characteristics. Scientific Reports 8 (2018) 9206, dx.doi.org/10.1038/s41598-018-27567-y.</li> <li>Mintzelas, A.; Sarlis, N. Minima of the fluctuations of the order parameter of seismicity and earthquake networks based on similar activity patterns. Physica A 527 (2019) 121293, dx.doi.org/10.1016/j.physa.2019.121293.</li> <li>Fawcett, T., An introduction to ROC analysis, Pattern Recognit. Lett. 27 (2006) 861–874, dx.doi.org/10.1016/j.patrec.2005.10.010.</li> <li>Donges, J.; Schleussner, C.F.; Siegmund, J.; Donner, R. Event coincidence analysis for quantifying statistical interrelationships between event time series. The European Physical Journal Special Topics 225 (2016) 471–487, dx.doi.org/10.1140/epjst/e2015-50233-y.</li> <li>Siegmund, J.F.; Siegmund, N.; Donner, R.V. CoinCalc - A new R package for quantifying simultaneities of event series. Computers & Geosciences 98 (2017) 64-72, dx.doi.org/10.1016/j.cageo.2016.10.004.</li> <li>Sarlis, N.V. Statistical Significance of Earth’s Electric and Magnetic Field Variations Preceding Earthquakes in Greece and Japan Revisited. Entropy 20 (2018) 561, dx.doi.org/10.3390/e20080561.</li> <li>Varotsos, P.; Lazaridou, M. Latest aspects of earthquake prediction in Greece based on seismic electric signals, Tectonophysics 188 (1991) 321–347, dx.doi.org/10.1016/0040-1951(91)90462-2.</li> </ol>

scholarly journals Analysis of the determinism of time-series extracted from social and biological systems

2010 ◽  
Vol 6 (2) ◽  
pp. 180-185
Author(s):  
Luigi Fortuna ◽  
Frasca Mattia ◽  
Gambuzza Valentina ◽  
Angelo Sarra ◽  
Ramzy Ali ◽  
...  
Keyword(s):  
Time Series ◽  
Order Parameter ◽  
Biological Systems ◽  
Biological Data ◽  
Central Question ◽  
Analyze Data ◽  
Self Organizing

Self-organizing systems arise in many different fields. In this work we analyze data from social and biological systems. A central question is to demonstrate the presence of the determinism in time-series extracted from such systems that appear apparently not correlated but that are two good benchmarks for the study of complexity in real systems. We will apply the Kaplan test and we will define an order parameter for the biological data to characterize the complexity of the system.

scholarly journals Phenomena preceding major earthquakes interconnected through a physical model

2019 ◽  
Author(s):  
Panayiotis A. Varotsos ◽  
Nicholas V. Sarlis ◽  
Efthimios S. Skordas
Keyword(s):  
Time Series ◽  
Physical Model ◽  
Seismic Data ◽  
Order Parameter ◽  
Tohoku Earthquake ◽  
Entropy Change ◽  
Abrupt Increase ◽  
Natural Time ◽  
Preceding Period ◽  
Magnetic Field Variations

Abstract. The analysis of earthquake time series in a new time domain termed natural time enables the uncovering of hidden properties in time series of complex systems and has been recently employed as basis of a method to estimate seismic risk. Applying this analysis, as an example, to the Japanese seismic data from 1 January 1984 until the super-giant M9 Tohoku earthquake on 11 March 2011, we find that almost three months before its occurrence the entropy change of seismicity under time reversal is minimized on 22 December 2010, which signals an impending major earthquake. On this date the order parameter fluctuations of seismicity exhibit abrupt increase. This increase is accompanied by various phenomena, e.g., from this date the horizontal GPS azimuths start to become gradually oriented toward the southern direction, while they had random orientation during the preceding period. Two weeks later, a minimum of the order parameter fluctuations of seismicity appears accompanied by anomalous Earth's magnetic field variations and by full alignment of the orientations of GPS azimuths southwards leading to the most intense crust uplift. These phenomena are discussed and found to be in accordance with a physical model which seems to explain on a unified basis anomalous precursory changes observed either in ground-based measurements or in satellite data.

scholarly journals Interlimb Coordination: A New Order Parameter and a Marker of Fatigue During Quasi-Isometric Exercise?

2021 ◽  
Vol 11 ◽  
Author(s):  
Pablo Vázquez ◽  
Monika Petelczyc ◽  
Robert Hristovski ◽  
Natàlia Balagué
Keyword(s):  
Time Series ◽  
Order Parameter ◽  
Isometric Exercise ◽  
Elbow Flexion ◽  
Interlimb Coordination ◽  
New Order ◽  
Self Organized ◽  
Isometric Actions ◽  
Driven System ◽  
Exercise Induced

Although exercise-induced fatigue has been mostly studied from a reductionist and component-dominant approach, some authors have started to test the general predictions of theories of self-organized change during exercises performed until exhaustion. However, little is known about the effects of fatigue on interlimb coordination in quasi-isometric actions. The aim of this study was to investigate the effect of exercise-induced fatigue on upper interlimb coordination during a quasi-isometric exercise performed until exhaustion. In order to do this, we hypothesized an order parameter that governs the interlimb coordination as an interlimb correlation measure. In line with general predictions of theory of phase transitions, we expected that the locally averaged values of the order parameter will increase as the fatigue driven system approaches the point of spontaneous task disengagement. Seven participants performed a quasi-isometric task holding an Olympic bar maintaining an initial elbow flexion of 90 degrees until fatigue induced spontaneous task disengagement. The variability of the elbow angle was recorded through electrogoniometry and the obtained time series were divided into three segments for further analysis. Running correlation function (RCF) and adopted bivariate phase rectified signal averaging (BPRSA) were applied to the corresponding initial (30%) and last (30%) segments of the time series. The results of both analyses showed that the interlimb correlation increased between the initial and the final segments of the performed task. Hence, the hypothesis of the research was supported by evidence. The enhancement of the correlation in the last part means a less flexible coordination among limbs. Our results also show that the high magnitude correlation (%RCF > 0.8) and the %Range (END-BEG) may prove to be useful markers to detect the effects of effort accumulation on interlimb coordination. These results may provide information about the loss of adaptability during exercises performed until exhaustion. Finally, we briefly discuss the hypothesis of the inhibitory percolation process being the general explanation of the spontaneous task disengagement phenomenon.

The LDE-Type Flare Occurrence (1969-1993)

1994 ◽  
Vol 144 ◽  
pp. 279-282
Author(s):  
A. Antalová
Keyword(s):  
Time Series ◽  
Fourier Analysis ◽  
Sunspot Cycle ◽  
List Type ◽  
Type Number ◽  
Solar Cycles ◽  
Type Iv ◽  
Long Duration ◽  
Cycle Maximum ◽  
Flare Index

AbstractThe occurrence of LDE-type flares in the last three cycles has been investigated. The Fourier analysis spectrum was calculated for the time series of the LDE-type flare occurrence during the 20-th, the 21-st and the rising part of the 22-nd cycle. LDE-type flares (Long Duration Events in SXR) are associated with the interplanetary protons (SEP and STIP as well), energized coronal archs and radio type IV emission. Generally, in all the cycles considered, LDE-type flares mainly originated during a 6-year interval of the respective cycle (2 years before and 4 years after the sunspot cycle maximum). The following significant periodicities were found:• in the 20-th cycle: 1.4, 2.1, 2.9, 4.0, 10.7 and 54.2 of month,• in the 21-st cycle: 1.2, 1.6, 2.8, 4.9, 7.8 and 44.5 of month,• in the 22-nd cycle, till March 1992: 1.4, 1.8, 2.4, 7.2, 8.7, 11.8 and 29.1 of month,• in all interval (1969-1992):a)the longer periodicities: 232.1, 121.1 (the dominant at 10.1 of year), 80.7, 61.9 and 25.6 of month,b)the shorter periodicities: 4.7, 5.0, 6.8, 7.9, 9.1, 15.8 and 20.4 of month.Fourier analysis of the LDE-type flare index (FI) yields significant peaks at 2.3 - 2.9 months and 4.2 - 4.9 months. These short periodicities correspond remarkably in the all three last solar cycles. The larger periodicities are different in respective cycles.

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