Transient electric signals prior to rock failure under uniaxial compression

Hadjicontis, V.; Mavromatou, C.

doi:10.1029/94gl00694

Cited by 79 publications

(24 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It would even be consistent with the view that the amount of electric current density at the source would have to be unrealistically huge for SES to travel hundreds of km in a homogeneous medium. Simple calculation indicated that 10 -9 A/cm 2 , which is compatible with laboratory data (Hadjicontis and Mavromatou 1994), would suffice if the observation site and focal area are connected by a narrow conductive channel. One interesting feature of the selectivity map discovered by us ) is that it changes with time: the EQ source mechanism in Kefallinia region changed from a strike-slip type to thrust type in late 1987 and this coincided with a shift in the sensitive site from PIR station to IOA station.…”

Section: Selectivity: (How To Predict An Epicenter)mentioning

confidence: 74%

A Report from the RIKEN International Frontier Research Project on Earthquakes (IFREQ)

Uyeda¹,

Nagao²,

Tanaka³

2004

Terr. Atmos. Ocean. Sci.

View full text Add to dashboard Cite

ABSTRACT1 Earthquake Prediction Research Center, Tokai University, Shizuoka, Japan * Corresponding author address: Prof. S. Uyeda, Earthquake Prediction Research Center, Tokai University, Shimizu Orido, Shizuoka, Japan; Mitigation of seismic hazards requires integration of science and human action, namely the science of earthquakes, anti-seismic engineering and socio-political measures. In this paper, we will be primarily examining the problem of saving human life from earthquakes. Loss of human life from earthquakes is caused overwhelmingly by the collapse of houses and buildings within less than a few minutes of the main shocks. When structural damage is reduced, most other seismic hazards will also be reduced. On top of that, if short-term prediction could be made, casualties would be further reduced dramatically. We review the state of the art in short-term prediction, in particular recent progress in approaches using electromagnetic phenomena.The RIKEN International Frontier Research Project on Earthquakes (IFREQ) has demonstrated the existence of pre-seismic ultra-low frequency (ULF) geo-electric potential changes, a claim that has long been made by the Greek VAN group. In addition, IFREQ has been able to verify the precursory signatures of ULF geomagnetic variations. A review is also made for another promising method using pre-seismic over-the-horizon transmission of VHF (~100MHz) FM radio waves. Thus, the reinforcement of existing structures and enhancement of short-term prediction research are the two keys for seismic hazard mitigation.

show abstract

Section: Selectivity: (How To Predict An Epicenter)mentioning

confidence: 74%

A Report from the RIKEN International Frontier Research Project on Earthquakes (IFREQ)

Uyeda¹,

Nagao²,

Tanaka³

2004

Terr. Atmos. Ocean. Sci.

View full text Add to dashboard Cite

show abstract

“…In bibliography it has been observed that when mechanical stress is applied upon a rock sample it reacts by emitting electric current (Brady and Rowell, 1986;Enomoto and Hashimoto, 1990;Hadjicontis and Mavromatou, 1994;Takeuchi and Nagahama, 2001;Freund, 2002;Stavrakas et al, 2003). Numerous laboratory experiments including many fracture tests have been conducted on various minerals and rocks both dry and saturated in order to understand and interpret the nature of the mechanisms responsible for the production of such electrical signals (Yoshida et al, 1998;Vallianatos et al, 2004;St-Laurent et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Electric signal emissions during repeated abrupt uniaxial compressional stress steps in amphibolite from KTB drilling

Triantis

Anastasiadis

Vallianatos

et al. 2007

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract.Laboratory experiments have confirmed that the application of uniaxial stress on rock samples is accompanied by the production of weak electric currents, to which the term Pressure Stimulated Currents -PSC has been attributed. In this work the PSC emissions in amphibolite samples from KTB drilling are presented and commented upon. After having applied sequential loading and unloading cycles on the amphibolite samples, it was ascertained that in every new loading cycle after unloading, the emitted PSC exhibits lower peaks. This attitude of the current peaks is consistent with the acoustic emissions phenomena, and in this work is verified for PSC emissions during loading -unloading procedures. Consequently, the evaluation of such signals can help to correlate the state and the remaining strength of the sample with respect to the history of its mechanical stress.

show abstract

“…It should be mentioned that the recombination rate of the sample's separated charges is clearly larger than the stress variations rate. As far as the origin of the sample's electric polarization (due to the stress variations) is concerned, it could be attributed either to the well known piezoelectric effect, if the sample has piezoelectric properties (granite, quartzite), or to the movements of segments of charged dislocations with respect to their compensating Debye-Hückel cloud of point defects, if the sample is not piezoelectric, (pure LiF) (Hadjicontis and Mavromatou, 1994). We must take under consideration that the stress field within the sample is inhomogeneous.…”

Section: Stress Induced Polarization Currentsmentioning

confidence: 99%

“…Enough cases of laboratory experiments are reported in the literature (Enomoto and Hasimoto, 1990;Hadjicontis and Mavromatou, 1994;Freund, 2002;Khatiashvili and Perelman, 1989;Mogi, 1962;Nitsan, 1977;Ogawa et al, 1985;Yamada et al, 1982;Warwick, 1982). Although various aspects, that satisfactorily explain the generation mechanisms of an earthquake, have been suggested so far, it cannot be maintained that the special conditions and processes…”

Section: Introductionmentioning

confidence: 99%

Stress induced polarization currents and electromagnetic emission from rocks and ionic crystals, accompanying their deformation

Hadjicontis

Mavromatou

Νίνος

2004

Nat. Hazards Earth Syst. Sci.

Self Cite

View full text Add to dashboard Cite

Part of Special Issue "Precursory phenomena, seismic hazard evaluation and seismo-tectonic electromagnetic effects" Abstract. A crucial question of the scientific community nowadays, concerns the existence of electric signals preceding earthquakes. In order to give a plausible answer to this question, we carried out two kinds of laboratory experiments of uniaxial deformation of ionic crystals and rock samples: a) In the first kind, stress induced polarization currents are detected and recorded. Our experimental results showed not only the existence of stress induced polarization currents before the fracture of the samples, but the possibility of the propagation of these signals, as well, through conductive channels, for distances much longer than the source dimensions. b) In the second, acoustic and electromagnetic signals are detected and recorded in the frequency range from 1 KHz to some MHz. The mechanism of generation of these signals is shown to be different for those emitted from piezoelectric and from non-piezoelectric materials.A plausible model is also suggested, on the compatibility of our laboratory results with the processes occurring in the earth during the earthquake preparatory stage.

show abstract

Transient electric signals prior to rock failure under uniaxial compression

Cited by 79 publications

References 11 publications

A Report from the RIKEN International Frontier Research Project on Earthquakes (IFREQ)

A Report from the RIKEN International Frontier Research Project on Earthquakes (IFREQ)

Electric signal emissions during repeated abrupt uniaxial compressional stress steps in amphibolite from KTB drilling

Stress induced polarization currents and electromagnetic emission from rocks and ionic crystals, accompanying their deformation

Contact Info

Product

Resources

About