Measurements of the dielectric properties of limestone under pressure and their importance for seismic electric signals

Autor:	Anthony N. Papathanassiou, I. Sakellis, J. Grammatikakis
Rok vydání:	2014
Předmět:	Condensed matter physics Relaxation (NMR) Mineralogy Absolute value Dielectric Conductivity Physics::Geophysics Gibbs free energy symbols.namesake Geophysics Volume (thermodynamics) symbols Compression (geology) Geology Energy (signal processing)
Zdroj:	Journal of Applied Geophysics. 102:77-80
ISSN:	0926-9851
DOI:	10.1016/j.jappgeo.2013.12.013
Popis:	The pressure and temperature evolution of an intense dielectric relaxation mechanism in as-received and wetted limestone (from Ioannina region (Greece)) are studied experimentally through complex impedance spectroscopy. The relaxation time decreases on compression, yielding a negative value for the corresponding activation volume. Furthermore, the role of water incorporated in the mineral was examined, revealing the remarkable fact that water not only enhances the absolute value of negative derivative of Gibbs energy with respect to pressure but also lowers significantly the energy barrier of the corresponding physical processes. Both findings are crucial for the explanation of the sensitivity of an electrotelluric station at Ioannina region in detecting Seismic Electric Signals emitted prior to earthquakes.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::581e63678f4b2bf27b9fce01501c7735 https://doi.org/10.1016/j.jappgeo.2013.12.013 Zobrazit plný text záznamu Full Text from ScienceDirect