Electromagnetic Changes Detected at Explosion Seismic Experiment.

Sakai, Hideo; Oda, Hiroyuki; Nakayama, Tsuneyoshi; Doi, Hikaru

doi:10.4294/jpe1952.40.447

Cited by 6 publications

(9 citation statements)

References 7 publications

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“…Also, referring to the study by Sakai and colleagues [12], where the similar change of magnetic field is measured by artificial explosion, it was considered that the change of magnetization properties in underground is affected by the magnetization (residual magnetization, induced magnetization) change of underground materials including casing. The change was generated after approximately 0.2 s of the explosion (i.e., after 0.1 s after seismic wave arrives), and this change is not generated by the movement of the magnetometer's sensor.…”

Section: Resultsmentioning

confidence: 99%

“…The change of magnetic field by several nT is measured as reported in the paper by Sakai and colleagues [12]. The magnetic field in this study is not changed when seismic wave arrives at the sensor and is changed after 0.1 s to 0.2 s of the arrival of seismic wave, the area to place sensor is selected where the gradient of magnetic field is under 1 nT in the region of some 10 cm from each sensor.…”

Section: Change Of Magnetic Fieldmentioning

confidence: 86%

“…In Japan, a study on electromagnetic observation using explosion seismic experiment has been also reported, but there is still problem that many observed phenomena has not been explained yet, and so more experiments are required to solve them [10][11][12]. In Japan, a study on electromagnetic observation using explosion seismic experiment has been also reported, but there is still problem that many observed phenomena has not been explained yet, and so more experiments are required to solve them [10][11][12].…”

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confidence: 99%

“…With artificial explosion, more detailed investigation can be performed because its explosion location and time are known. In Japan, a study on electromagnetic observation using explosion seismic experiment has been also reported, but there is still problem that many observed phenomena has not been explained yet, and so more experiments are required to solve them [10][11][12].…”

mentioning

confidence: 99%

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Induced Change of Electric Self‐Potential and Magnetic Field at the Artificial Explosion

Sakai

Kobayashi

Izumi³

et al. 2017

Elect Comm in Japan

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Study of the electric self-potential (SP) and the magnetic field was conducted at the explosion seismic experiment in Ooyama, Toyama Prefecture. The explosion was induced by 450-kg gun powder placed at a depth of 32.2 m to 75 m. The SP was measured by four electrodes arranged in a line crossing the explosion point, where the distance of each electrode from the explosion ranged from 10 m to 100 m. Induced SP changes consisted of two portions, namely, fluctuations with shorter period (∼10 ms) and fluctuations with longer periods (∼50 ms). Regarding the latter, the amplitude was in proportion to the span length of electrode couples and the fluctuations arrived faster at the electrode couples nearer to the explosion. Furthermore, the increment of ground level in SP was observed in each electrode couple after the explosion, which was concordant with the distribution of apparent resistivity underground studied by the survey. The magnetic field measured by the fluxgate magnetometer at the site 35 m north from the explosion also showed change of a few nT after the explosion. This may have been caused by change of magnetic properties underground. C⃝ 2017 Wiley Periodicals, Inc. Electron Comm Jpn, 100(3): 68-75, 2017; Published online in Wiley Online Library (wileyonlinelibrary.com).

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Section: Resultsmentioning

confidence: 99%

Section: Change Of Magnetic Fieldmentioning

confidence: 86%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Induced Change of Electric Self‐Potential and Magnetic Field at the Artificial Explosion

Sakai

Kobayashi

Izumi³

et al. 2017

Elect Comm in Japan

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“…A few examples of the EPD signals observed during an earthquake include the surface wave (not the P-or S-wave) of the Alaskan earthquake measured in the horizontal method [2] and that observed in the explosion seismic experiment [3]. There is also an observation of earth resistivity during seismic wave propagation [4].…”

Section: Introductionmentioning

confidence: 99%

Analysis of earth potential difference signals by using seismic wave signals

Takeuchi

Chubachi

Hotta³

et al. 1999

Elect. Eng. Jpn.

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A modified measurement method has been used to continuously observe earth potential difference (EPD) signals induced by seismic waves. This method reduces the level of extraneous signals induced by artificial and natural earth current sources. The observed signals were compared with the corresponding seismic waveforms from the Earthquake Observatory of Tohoku University, which is located 700 m from us. Comparison with each waveform component (acceleration, velocity, and displacement) showed that the proposed streaming potential model reflecting the earth acceleration adequately explains the EPD signal. The estimated ratio between the earth electrical field (potential difference) and the pressure difference in the ground, i.e., the coupling coefficient, was found to be reasonable based on the streaming potential model. © 1998 Scripta Technica, Electr Eng Jpn, 125(4): 52–59, 1998

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Fracture induced electromagnetic radiation

Frid

Rabinovitch

Bahat

2003

J. Phys. D: Appl. Phys.

153

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In our laboratory, we combine accurate electromagnetic radiation (EMR) measurements during fracture of rocks (carbonate and igneous) and transparent materials (glass, PMMA and glass ceramics) with careful fractographic methods. A critical analysis of experimental observations, accumulated here during the last decade together with supporting material from the works of other authors are used in this study to demonstrate the failure of all current models to explain the properties of EMR arising from fracture. The basic elements of a new model are proposed. These are (a) the EMR amplitude increases as long as the crack continues to grow, since new atomic bonds are severed and their contribution is added to the EMR. As a result, the atoms on both sides of the bonds are moved to 'non-equilibrium' positions relative to their steady state ones and begin to oscillate collectively in a manner similar to Debye model bulk oscillations-'surface vibrational optical waves'; (b) when the crack halts, the waves and the EMR pulse amplitude decay by relaxation. These basic elements are already enough to describe the characteristics of the experimentally obtained isolated individual EMR pulses. These characteristics include the shape of the EMR pulse envelope, and the frequency, time duration and rise-fall time of the pulse.

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Electromagnetic Changes Detected at Explosion Seismic Experiment.

Cited by 6 publications

References 7 publications

Induced Change of Electric Self‐Potential and Magnetic Field at the Artificial Explosion

Induced Change of Electric Self‐Potential and Magnetic Field at the Artificial Explosion

Analysis of earth potential difference signals by using seismic wave signals

Fracture induced electromagnetic radiation

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