Order Parameter and Entropy of Seismicity in Natural Time before Major Earthquakes: Recent Results

A lot of work in geosciences has been completed during the last decade on the analysis in the new concept of time, termed natural time, introduced in 2001. The main advances are presented, including, among others, the following: First, the direct experimental verification of the interconnection betw...

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Main Authors: Panayiotis A. Varotsos, Nicholas V. Sarlis, Efthimios S. Skordas
Format: Article
Language:English
Published: MDPI AG 2022-05-01
Series:Geosciences
Subjects:
Online Access:https://www.mdpi.com/2076-3263/12/6/225
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author Panayiotis A. Varotsos
Nicholas V. Sarlis
Efthimios S. Skordas
author_facet Panayiotis A. Varotsos
Nicholas V. Sarlis
Efthimios S. Skordas
author_sort Panayiotis A. Varotsos
collection DOAJ
description A lot of work in geosciences has been completed during the last decade on the analysis in the new concept of time, termed natural time, introduced in 2001. The main advances are presented, including, among others, the following: First, the direct experimental verification of the interconnection between a Seismic Electric Signals (SES) activity and seismicity, i.e., the order parameter fluctuations of seismicity exhibit a clearly detectable minimum when an SES activity starts. These two phenomena are also linked closely in space. Second, the identification of the epicentral area and the occurrence time of an impending major earthquake (EQ) by means of the order parameter of seismicity and the entropy change of seismicity under time reversal as well as the extrema of their fluctuations. An indicative example is the <i>M</i>9 Tohoku EQ in Japan on 11 March 2011. Third, to answer the crucial question—when a magnitude 7 class EQ occurs—whether it is a foreshock or a mainshock. This can be answered by means of the key quantities already mentioned, i.e., the order parameter of seismicity and the entropy change of seismicity under time reversal along with their fluctuations. The explanation of the experimental findings identified before major EQs is given in a unified way on the basis of a physical model already proposed in the 1980s.
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spelling doaj.art-097bbcefe30f4493a99b428e34b98c9a2023-11-23T16:49:42ZengMDPI AGGeosciences2076-32632022-05-0112622510.3390/geosciences12060225Order Parameter and Entropy of Seismicity in Natural Time before Major Earthquakes: Recent ResultsPanayiotis A. Varotsos0Nicholas V. Sarlis1Efthimios S. Skordas2Section of Condensed Matter Physics and Solid Earth Physics Institute, Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis Zografos, 157 84 Athens, GreeceSection of Condensed Matter Physics and Solid Earth Physics Institute, Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis Zografos, 157 84 Athens, GreeceSection of Condensed Matter Physics and Solid Earth Physics Institute, Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis Zografos, 157 84 Athens, GreeceA lot of work in geosciences has been completed during the last decade on the analysis in the new concept of time, termed natural time, introduced in 2001. The main advances are presented, including, among others, the following: First, the direct experimental verification of the interconnection between a Seismic Electric Signals (SES) activity and seismicity, i.e., the order parameter fluctuations of seismicity exhibit a clearly detectable minimum when an SES activity starts. These two phenomena are also linked closely in space. Second, the identification of the epicentral area and the occurrence time of an impending major earthquake (EQ) by means of the order parameter of seismicity and the entropy change of seismicity under time reversal as well as the extrema of their fluctuations. An indicative example is the <i>M</i>9 Tohoku EQ in Japan on 11 March 2011. Third, to answer the crucial question—when a magnitude 7 class EQ occurs—whether it is a foreshock or a mainshock. This can be answered by means of the key quantities already mentioned, i.e., the order parameter of seismicity and the entropy change of seismicity under time reversal along with their fluctuations. The explanation of the experimental findings identified before major EQs is given in a unified way on the basis of a physical model already proposed in the 1980s.https://www.mdpi.com/2076-3263/12/6/225natural timeearthquakesorder parameterentropycriticalityseismic electric signals
spellingShingle Panayiotis A. Varotsos
Nicholas V. Sarlis
Efthimios S. Skordas
Order Parameter and Entropy of Seismicity in Natural Time before Major Earthquakes: Recent Results
Geosciences
natural time
earthquakes
order parameter
entropy
criticality
seismic electric signals
title Order Parameter and Entropy of Seismicity in Natural Time before Major Earthquakes: Recent Results
title_full Order Parameter and Entropy of Seismicity in Natural Time before Major Earthquakes: Recent Results
title_fullStr Order Parameter and Entropy of Seismicity in Natural Time before Major Earthquakes: Recent Results
title_full_unstemmed Order Parameter and Entropy of Seismicity in Natural Time before Major Earthquakes: Recent Results
title_short Order Parameter and Entropy of Seismicity in Natural Time before Major Earthquakes: Recent Results
title_sort order parameter and entropy of seismicity in natural time before major earthquakes recent results
topic natural time
earthquakes
order parameter
entropy
criticality
seismic electric signals
url https://www.mdpi.com/2076-3263/12/6/225
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AT nicholasvsarlis orderparameterandentropyofseismicityinnaturaltimebeforemajorearthquakesrecentresults
AT efthimiossskordas orderparameterandentropyofseismicityinnaturaltimebeforemajorearthquakesrecentresults