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| Titel |
On the physical interconnection of Seismic Electric Signals with seismicity: Recent advances |
| VerfasserIn |
Nicholas Sarlis, Efthimios Skordas, Mary Lazaridou, Panayiotis Varotsos |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250075610
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| Zusammenfassung |
| We review the recent advances on Seismic Electric Signals (SES) which are low frequency
(-¤ 1Hz) signals that precede earthquakes [1-3]. Since the 1980’s Varotsos and Alexopoulos
proposed [4] that SES are generated in the future focal area when the stress reaches a
critical value, thus causing a cooperative orientation of the electric dipoles that
anyhow exist in the focal area due to lattice imperfections in the ionic constituents of
the rocks. A series of such signals within a short time are termed SES activity [5]
and usually appear before major earthquakes. The combination of their physical
properties enable the determination of the epicentral region and the magnitude well in
advance.
Natural time analysis introduced a decade ago [6, 7] may uncover novel dynamic features
hidden behind time series in complex systems [8]. By employing this analysis, several
advances have been made towards a better understanding of the SES properties. For example,
it has been found [6, 8] that the natural time analysis of the seismicity subsequent to the
initiation of a SES activity enables the determination of the occurrence time of an impending
major mainshock within a time window of around one week. On this basis, predictions
-including the magnitude, epicenter and time window of the expected event- have been
documented well in advance for all five mainshocks with M_w-¥6.4 in Greece since 2001 [8,
9].
In addition, by applying natural time analysis to the time series of earthquakes, we
recently found [10] that the order parameter of seismicity exhibits a unique change
approximately at the date at which SES activities have been reported to initiate.
This is the first time that before the occurrence of major earthquakes, anomalous
changes are found to appear almost simultaneously in two different geophysical
observables.
1. P. Varotsos and K. Alexopoulos, Tectonophysics 110, 73-98, 1984a.
2. P. Varotsos and K. Alexopoulos, Tectonophysics 110, 99-125, 1984b.
3. P.A. Varotsos, N.V. Sarlis, and E.S. Skordas, Phys. Rev. Lett., 91, 148501 (4),
2003.
4. P. Varotsos and K. Alexopoulos, Thermodynamics of Point Defects and their relation
with the bulk properties, North Holland, Amsterdam(1986) 474 pages.
5. P. Varotsos and M. Lazaridou, Tectonophysics 188, 321-347, 1991.
6. P. Varotsos, N. Sarlis, and E. Skordas, Practica of Athens Academy, 76, 294-321,
2001.
7. P.A. Varotsos, N.V. Sarlis, and E.S. Skordas, Phys. Rev. E, 66, 011902 (7),
2002.
8. P.A.Varotsos, N.V.Sarlis and E.S.Skordas, NATURAL TIME ANALYSIS:
THE NEW VIEW OF TIME. Precursory Seismic Electric Signals, Earthquakes
and other Complex Time-Series, Springer-Verlag, Berlin, Heidelberg (2011) 484
pages.
9. M. S Lazaridou-Varotsos, EARTHQUAKE PREDICTION BY SEISMIC ELECTRIC
SIGNALS. The success of the VAN method over thirty years, Springer-Verlag, Berlin,
Heidelberg (2012) 271 pages.
10. P. Varotsos, N. Sarlis, E. Skordas and M. Lazaridou, Tectonophysics (DOI:
10.1016/j.tecto.2012.12.020). |
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