Natural Time Analysis: Recent results.

Phenomena preceding the M9 Tohoku earthquake in Japan on 11 March 2011 and the M8.2 Mexico earthquake on 7 September 2017 have been explored by analyzing the seismic data in natural time. Interesting results have been obtained for the following quantities that have been studied very recently [1-4]: First, the entropy change under time reversal [1,2]. Second, the complexity measure quantifying the fluctuations of the entropy change under time reversal [3,4]. Third, the fluctuations of the order parameter of seismicity.References:1. N. V. Sarlis, E. S. Skordas P. A. Varotsos, A. Ramírez-Rojas, E. L. Flores-Márquez, "Natural time analysis: On the deadly Mexico M8.2 earthquake on 7 September 2017", Physica A 506 (2018), 625-634.2. N. V. Sarlis, E. S. Skordas, and P. A. Varotsos, "A remarkable change of the entropy of seismicity in natural time under time reversal before the super-giant M9 Tohoku earthquake on 11 March 2011", Europhysics Letters (EPL), 124 (2018), 29001.3. A. Ramírez-Rojas, E. L. Flores-Márquez, N. V. Sarlis and P. A. Varotsos, "The Complexity Measures Associated with the Fluctuations of the Entropy in Natural Time before the Deadly México M8.2 Earthquake on 7 September 2017", Entropy 20 (2018), 477.4. P. A. Varotsos, N. V. Sarlis and E. S. Skordas, "Tsallis Entropy Index q and the Complexity Measure of Seismicity in Natural Time under Time Reversal before the M9 Tohoku Earthquake in 2011", Entropy 20 (2018), 757. [ABSTRACT FROM AUTHOR]