Pre-earthquake Magnetic Pulses

Abstract. A semiconductor model of rocks is shown to describe unipolar magnetic pulses, a phenomenon that has been observed prior to earthquakes. These pulses are suspected to be generated deep in the Earth's crust, in and around the hypocentral volume, days or even weeks before earthquakes. Their extremely long wavelength allows them to pass through kilometers of rock. Interestingly, when the sources of these pulses are triangulated, the locations coincide with the epicenters of future earthquakes. We couple a drift-diffusion semiconductor model to a magnetic field in order to describe the electromagnetic effects associated with electrical currents flowing within rocks. The resulting system of equations is solved numerically and it is seen that a volume of rock may act as a diode that produces transient currents when it switches bias. These unidirectional currents are expected to produce transient unipolar magnetic pulses similar in form, amplitude, and duration to those observed before earthquakes, and this suggests that the pulses could be the result of geophysical semiconductor processes.

[1]  F. Freund,et al.  Estimating the seismotelluric current required for observable electromagnetic ground signals , 2010 .

[2]  C. Dunson,et al.  Investigation of ULF magnetic pulsations, air conductivity changes, and infra red signatures associated with the 30 October Alum Rock M5.4 earthquake , 2009 .

[3]  M. Johnston,et al.  On the reported magnetic precursor of the 1989 Loma Prieta earthquake , 2009 .

[4]  F. Freund,et al.  Surface charges and subsurface space-charge distribution in magnesium oxides containing dissolved traces of water , 1984 .

[5]  F. Freund,et al.  Prevalence of Earthquake Lights Associated with Rift Environments , 2014 .

[6]  On the reported magnetic precursor of the 1993 Guam earthquake , 2009 .

[7]  M. Freund,et al.  Highly mobile oxygen hole-type charge carriers in fused silica , 1991, Journal of materials research.

[8]  Robert H. Halstead,et al.  Matrix Computations , 2011, Encyclopedia of Parallel Computing.

[9]  G. Moore,et al.  Magnetic Disturbances preceding the 1964 Alaska Earthquake , 1964, Nature.

[10]  Wallace H. Campbell,et al.  Natural magnetic disturbance fields, not precursors, preceding the Loma Prieta earthquake , 2009 .

[11]  André Revil,et al.  Principles of electrography applied to self‐potential electrokinetic sources and hydrogeological applications , 2003 .

[12]  R. Fox,et al.  Classical Electrodynamics, 3rd ed. , 1999 .

[13]  F. Freund.  Charge Generation and Propagation in Igneous Rocks , 2002 .

[14]  A. Duba,et al.  Free carbon & electrical conductivity in the Earth's mantle , 1982 .

[15]  Kiyohumi Yumoto,et al.  Results of ultra-low-frequency magnetic field measurements during the Guam Earthquake of 8 August 1993 , 1996 .

[16]  F. Freund.  Toward a unified solid state theory for pre-earthquake signals , 2010 .

[17]  M. Freund,et al.  Positive holes in magnesium oxide. Correlation between magnetic, electric, and dielectric anomalies. , 1991, Journal of applied physics.

[18]  Davide Ricci,et al.  Modeling disorder in amorphous silica with embedded clusters: The peroxy bridge defect center , 2001 .

[19]  Gene H. Golub,et al.  Matrix computations (3rd ed.) , 1996 .

[20]  D. A. Dunnett.  Classical Electrodynamics , 2020, Nature.

[21]  J. Gale,et al.  THEORETICAL SIMULATION OF LOCALIZED HOLES IN MGO , 1992 .

[22]  C. Holbrow,et al.  Nonclassical Physics: Beyond Newton's View , 1998 .

[23]  D. Vasileska,et al.  Semiconductor Device Modeling , 2008 .

[24]  A. Fraser-Smith,et al.  Comment on “Natural magnetic disturbance fields, not precursors, preceding the Loma Prieta earthquake” by Wallace H. Campbell , 2011 .

[25]  William Shockley,et al.  Hole injection in germanium - Quantitative studies and filamentary transistors , 1949, Bell Syst. Tech. J..

[26]  K. Selway.  On the Causes of Electrical Conductivity Anomalies in Tectonically Stable Lithosphere , 2013, Surveys in Geophysics.

[27]  Masashi Hayakawa,et al.  The ultra-low-frequency magnetic disturbances associated with earthquakes , 2011 .

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

[29]  Vern C. Vanderbilt,et al.  Comparison of the stress-stimulated current of dry and fluid-saturated gabbro samples , 2014 .

[30]  I. Stavrakas,et al.  Electric earthquake precursors: from laboratory results to field observations , 2004 .

[31]  Yu. A. Kopytenko,et al.  Detection of ultra-low-frequency emissions connected with the Spitak earthquake and its aftershock activity, based on geomagnetic pulsations data at Dusheti and Vardzia observatories , 1993 .

[32]  F. Freund,et al.  On the electrical conductivity structure of the stable continental crust , 2003 .

[33]  Gary D. Egbert,et al.  High‐resolution electromagnetic imaging of the San Andreas Fault in central California , 1999 .

[34]  Panayiotis A. Varotsos,et al.  The physics of seismic electric signals , 2005 .

[35]  David L. Griscom,et al.  Trapped-electron centers in pure and doped glassy silica: A review and synthesis , 2011 .

[36]  Akihiro Takeuchi,et al.  Electric currents streaming out of stressed igneous rocks - A step towards understanding pre-earthquake low frequency EM emissions , 2006 .