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| Titel |
Piezo stimulated currents in marble samples: precursory and concurrent-with-failure signals |
| VerfasserIn |
I. Stavrakas, C. Anastasiadis, D. Triantis, F. Vallianatos |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 3, no. 3/4 ; Nr. 3, no. 3/4, S.243-247 |
| Datensatznummer |
250000683
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| Publikation (Nr.) |
 copernicus.org/nhess-3-243-2003.pdf |
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| Zusammenfassung |
| The Earth’s
electric field transient variations are promising candidates of earthquake
precursors. In order to study the physical mechanisms of such precursory
signals, laboratory experiments of uniaxial compression were carried out.
More specifically the behaviour of stressed marble samples from Penteli
Mountain was investigated. The samples were subjected to a time-varying
uniaxial compression at both variable and constant stress rates. During
the first set of experiments weak electric currents were detected during
pressure variations. Such Piezo Stimulated Currents (PSC) were detected
while stress steps, both positive and negative were applied, the maximum
stress never being greater than the elasticity limit. During the second
set of experiments stress was applied at a constant rate starting from
zero-stress and ending in fracture. In the region beyond the elastic limit
a PSC was detected which after reaching a peak suffered a reversal in its
polarity just before fracture. In a third set of experiments the same
procedure was applied to previously structurally damaged samples taking
care not to fracture them. In all cases the PSC followed the variation of
stress and moreover it was observed that a linear relationship existed
between the PSC maxima and the corresponding stress-rate maxima. The
mechanism responsible for the described phenomena can be ascribed to the
Moving Charged Dislocations model. |
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