METADATA IN ENGLISH
About the journal
SEISMICHESKIE PRIBORY, ISSN: 0131-6230, eISSN: 2312-6965, DOI:
10.21455/si,
http://elibrary.ru/title_about.asp?id=25597)
English Translation: Seismic Instruments, ISSN: 0747-9239 (Print)
1934-7871 (Online),
https://link.springer.com/journal/11990
The
apparatus for physical modeling
of electroseismic effect of the first kind
V.A. Zeigarnik, V.N. Klyuchkin
Joint
Institute for High Temperatures, Russian Academy of Sciences, Moscow, Russia
Corresponding
author: V.A. Zeigarnik, e-mail: zeigarnik@ihed.ras.ru
Abstract. Modified facility
for physical modeling of electroseismic effect of the first kind in mountain
rocks is described. The apparatus provides an opportunity to model
electric-seismic effect upon exposure of a mountain rock sample to the electric
field either with or without electric current in a sample. The apparatus
enables the use two methods of measurement of acoustic field velocity change. First one is the excitation of pulsed
acoustic field and measurement of this field propagation time from acoustic
source to receiver. Second one is based on the measurement of phase modulation
of sinusoidal acoustic field when a sample is exposed to electric field. The
first method was implemented in two versions: first version – only electric
field without active electric current component is generated within a sample,
second version – both ones are generated.
The apparatus includes
a signal generator that induces coherent electric and acoustic fields within
the sample. Coherence enables the use of noise-resistant technique for
measuring the sinusoidal acoustic field velocity and decreasing the sensitivity
threshold for velocity change from 0.2 % to 0.02 %. The results of modeling of
the effect for four limestone samples and four sandstone samples saturated by
salt water with mineralization 1% are described. For all of them a decrease in
the acoustic field velocity about 0.2 % was obtained under electric field.
The acoustic field velocity decrease within the interval 2–200 kHz is
independent on frequency for all samples of limestone and sandstone. It is
shown that modified apparatus makes it possible to confidently detect
electric-seismic effect without current through the sample despite the fact
that its value is above the sensitivity threshold by only 20–25 dB.
The field coherence
permits us to measure the relaxation velocity after electric field switching on
or off if there is no current through the sample. It has been shown that, after
electric field is switched on, the velocity relaxation time does not exceed 2
ms, and after its switching off, is 10–20 ms. Such a
difference between velocity relaxation times forms the ground for estimating
nonlinearity in the electroseismic effect of the first kind.
Keywords: geophysics,
apparatus, electric-seismic effect, physical modeling, electrical field.
About the authors
Zeigarnik Vladimir Al’bertovich – professor, senior
researcher, Joint Institute for High Temperatures. 125412, Moscow,
Izhorskaya Str. 13, Bd. 2. Phone: +7(495) 485-93-18. E-mail: zeigarnik@ihed.ras.ru
KLYUCHKIN Vadim Nikolaevich – doctor, leading
researcher, Joint Institute for High Temperatures. 125412, Moscow, Izhorskaya Str. 13, Bd. 2. Phone:
+7(495) 484-19-44. E-mail: klvn38@mail.ru
Cite this article as: Zeigarnik V.A., Klyuchkin V.N. The apparatus for
physical modeling of electroseismic effect of the first kind. Seismicheskie Pribory, 2018, Vol. 54, no 1, pp. 5-18. DOI: 10.21455/si2018.1-1 (in Russ.).
English translation of the article will be published in Seismic
Instruments, ISSN: 0747-9239 (Print) 1934-7871 (Online),
https://link.springer.com/journal/11990), 2019, Volume 55, Issue 1.