Behaviors of Electromagnetic Waves Directly Excited by Earthquakes

We detected electromagnetic (EM) waves directly excited by earthquakes in a deep borehole and confirmed them by simultaneous capturing of their waveforms and of seismic waves measured at the same observation site. Furthermore, the excitation mechanism of the EM pulse was confirmed as the piezoelectric effect by a laboratory experiment, in which a seismic P-wave was readily generated by a small stress impact, and the EM wave was simultaneously excited basically by the P-wave. Here, we show behaviors of seismic waves and of their excited EM waves when small and large earthquakes occurred. We also found that EM waves excited by seismic waves have leaked out of the ground surface.

[1]  M. Tsutsui.  Detection of earth‐origin electric pulses , 2002 .

[2]  M. Matsushima,et al.  Seismoelectromagnetic Effect Associated with the İzmit Earthquake and Its Aftershocks , 2002 .

[3]  Y. Fujinawa,et al.  Emission of electromagnetic radiation preceding the Ito seismic swarm of 1989 , 1990, Nature.

[4]  Efthimios S. Skordas,et al.  Seismic Electric Signals: An additional fact showing their physical interconnection with seismicity☆ , 2013 .

[5]  Qinghua Huang,et al.  One possible generation mechanism of co-seismic electric signals , 2002 .

[6]  Masashi Kamogawa,et al.  Preseismic anomalous telluric current signals observed in Kozu-shima Island, Japan , 2012, Proceedings of the National Academy of Sciences.

[7]  H. Tanaka,et al.  Electric and magnetic phenomena observed before the volcano-seismic activity in 2000 in the Izu Island Region, Japan , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[8]  M. S. Lazaridou,et al.  Latest aspects of earthquake prediction in Greece based on seismic electric signals, II☆ , 1993 .

[9]  Qinghua Huang,et al.  Retrospective investigation of geophysical data possibly associated with the Ms8.0 Wenchuan earthquake in Sichuan, China , 2011 .

[10]  Minoru Tsutsui,et al.  Polarization and propagation property of electromagnetic pulses in the earth , 2011, 2011 IEEE International Geoscience and Remote Sensing Symposium.

[11]  Minoru Tsutsui,et al.  Identification of earthquake epicenter from measurements of electromagnetic pulses in the Earth , 2005 .

[12]  Wang Li.  Electromagnetic coseismic effect associated with aftershock of Wenchuan M_s8.0 earthquake , 2010 .

[13]  Panayiotis A. Varotsos,et al.  Physical properties of the variations of the electric field of the earth preceding earthquakes. II. determination of epicenter and magnitude , 1984 .

[14]  M. Ladd,et al.  Low‐frequency magnetic field measurements near the epicenter of the Ms 7.1 Loma Prieta Earthquake , 1990 .

[15]  P. Varotsos,et al.  Physical properties of the variations of the electric field of the earth preceding earthquakes, I , 1984 .

[16]  Masashi Kamogawa,et al.  Analysis of electrical activity and seismicity in the natural time domain for the volcanic-seismic swarm activity in 2000 in the Izu Island region, Japan , 2009 .