Earthquakes occur when tectonic stresses build up deep in the Earth before catastrophic rupture. During the build-up of stress, processes that occur in the crustal rocks lead to the activation of highly mobile electronic charge carriers. These charge carriers are able to flow out of the stressed rock volume into surrounding rocks. Such outflow constitutes an electric current, which generates electromagnetic (EM) signals. If the outflow occurs in bursts, it will lead to short EM pulses. If the outflow is continuous, the currents may fluctuate, generating EM emissions over a wide frequency range. Only ultralow and extremely low frequency (ULF/ELF) waves travel through rock and can reach the Earth surface. The outflowing charge carriers are (i) positively charged and (ii) highly oxidizing. When they arrive at the Earth surface from below, they build up microscopic electric fields, strong enough to field-ionize air molecules. As a result, the air above the epicentral region of an impending major earthquake often becomes laden with positive airborne ions. Medical research has long shown that positive airborne ions cause changes in stress hormone levels in animals and humans. In addition to the ULF/ELF emissions, positive airborne ions can cause unusual reactions among animals. When the charge carriers flow into water, they oxidize water to hydrogen peroxide. This, plus oxidation of organic compounds, can cause behavioral changes among aquatic animals.
Hough, S.E. Earthshaking Science: What We Know (and Don’t Know) about Earthquakes; Princeton University Press: Princeton, NJ, USA, 2002.
[3]
Rundle, J.B.; Turcotte, D.L.; Shcherbakov, R.; Klein, W.; Sammis, C. Statistical physics approach to understanding the multiscale dynamics of earthquake fault systems. Rev. Geophys. 2003, 41, 1019–1049, doi:10.1029/2003RG000135.
[4]
Keilis-Borok, V. Fundamentals of Earthquake Prediction: Four Paradigms. In Nonlinear Dynamics of the Lithosphere and Earthquake Prediction; Keilis-Borok, V., Soloviev, A.A., Eds.; Springer: Heidelberg, Germany, 2003; pp. 1–36.
Brace, W.F.; Paulding, B.W., Jr.; Scholz, C. Dilatancy in the fracture of crystalline rocks. J. Geophys. Res. 1966, 71, 3939–3953, doi:10.1029/JZ071i016p03939.
[10]
Cristescu, N. Rock dilatancy in uniaxial tests. Rock Mech. 1982, 15, 133–144, doi:10.1007/BF01238260.
[11]
Reches, Z.E.; Lockner, D.A. Nucleation and growth of faults in brittle rocks. J. Geophys. Res. 1994, 99, 18159–18173, doi:10.1029/94JB00115.
[12]
Yamashita, T. Generation of microcracks by dynamic shear rupture and its effects on rupture growth and elastic wave radiation. Geophys. J. Int. 2000, 143, 395–406, doi:10.1046/j.1365-246X.2000.01238.x.
[13]
Dobrovolsky, I.P.; Gershenzon, N.I.; Gokhberg, M.B. Theory of electrokinetic effects occurring at the final stage in the preparation of a tectonic earthquake. Phys. Earth Planet. Int. 1989, 57, 144–156, doi:10.1016/0031-9201(89)90224-0.
[14]
Merzer, M.; Klemperer, S.L. Modeling low-frequency magnetic-field precursors to the Loma Prieta earthquake with a precursory increase in fault-zone conductivity. Pure Appl. Geophys. 1997, 150, 217–248, doi:10.1007/s000240050074.
[15]
Gershenzon, N.; Bambakidis, G. Modeling of seismo-electromagnetic phenomena. Russian J. Earth Sci. 2001, 3, 247–275, doi:10.2205/2001ES000058.
[16]
Simpson, J.J.; Taflove, A. Electrokinetic effect of the Loma Prieta earthquake calculated by an entire-Earth FDTD solution of Maxwell’s equations. Geophys. Res. Lett. 2005, 32, doi:10.1029/2005.
[17]
Hauksson, E. Radon content of groundwater as an earthquake precursor: Evaluation of worldwide data and physical basis. J. Geophys. Res. 1981, 86, 9397–9410, doi:10.1029/JB086iB10p09397.
[18]
Igarashi, G.; Saeki, S.; Takahata, N.; Sumikawa, K.; Tasaka, S.; Sasaki, Y.; Takahashi, M.; Sano, Y. Ground-Water Radon Anomaly Before the Kobe Earthquake in Japan. Science 1995, 269, 60–61.
[19]
Virk, H.S.; Walia, V.; Kumar, N. Helium/radon precursory anomalies of Chamoli earthquake, Garhwal Himalaya, India. J. Geodynam. 2001, 31, 201–210, doi:10.1016/S0264-3707(00)00022-3.
[20]
King, C.-Y. Episodic radon changes in subsurface soil gas along active faults and possible relation to earthquakes. J. Geophys. Res. 1980, 85, 3065–3078, doi:10.1029/JB085iB06p03065.
[21]
Dobrovolsky, I.P.; Zubkov, S.I.; Miachkin, V.I. Estimation of the size of earthquake preparation zones. Pure Appl. Geophys. 1979, 117, 1025–1044, doi:10.1007/BF00876083.
[22]
Bowman, D.D.; Ouillon, G.; Sammis, C.G.; Sornette, A.; Sornette, D. An observational test of the critical earthquake concept. J.Geophys. Res. 1998, 103, 24359–24372.
[23]
Johnston, M.J.S.; Linde, A.T. Implications of crustal strain during conventional, slow and silent earthquakes. In International Handbook of Earthquake and Engineering Seismology; Academic Press: San Diego, CA, USA, 2002; pp. 589–605.
[24]
McGarr, A.; Fletcher, J.B. Maximum slip in earthquake fault zones, apparent stress, and stick-slip friction. Bull. Seism. Soc. Am. 2003, 93, 2355–2362, doi:10.1785/0120030037.
[25]
Tzanis, A.; Vallianatos, F.; Gruszow, S. Identification and discrimination of transient electrical earthquake precursors: Fact, fiction and some possibilities. Phys. Earth Planet. Inter. 2000, 121, 223–248, doi:10.1016/S0031-9201(00)00170-9.
[26]
Zadro, M.; Braitenberg, C. Measurements and interpretations of tilt-strain gauges in seismically active areas. Earth-Sci. Rev. 1999, 47, 51–187.
[27]
Freund, F.T.; Takeuchi, A.; Lau, B.W.S. Electric currents streaming out of stressed igneous rocks—A step towards understanding pre-earthquake low frequency EM emissions. Phys. Chem. Earth 2006, 31, 389–396, doi:10.1016/j.pce.2006.02.027.
[28]
Freund, F.T. Pre-earthquake signals: Underlying physical processes. J. Asian Earth Sci. 2011, 41, 383–400, doi:10.1016/j.jseaes.2010.03.009.
[29]
Bortnik, J.; Bleier, T.E.; Dunson, C.; Freund, F. Estimating the seismotelluric current required for observable electromagnetic ground signals. Ann. Geophys. 2010, 28, 1615–1624, doi:10.5194/angeo-28-1615-2010.
[30]
Zhadin, M.N. Review of Russian literature on biological action of DC and low-frequency AC magnetic fields. Bioelectromagnetics 2001, 22, 27–45, doi:10.1002/1521-186X(200101)22:1<27::AID-BEM4>3.0.CO;2-2.
[31]
Ritz, T. Quantum effects in biology: Bird navigation. Proc. Chem. 2011, 3, 262–275, doi:10.1016/j.proche.2011.08.034.
[32]
Ritz, T.; Yoshii, T.; Helfrich-Foerster, C.; Ahmad, M. Cryptochrome: A photoreceptor with the properties of a magnetoreceptor? Commun. Integr. Biol. 2010, 3, 24–27, doi:10.4161/cib.3.1.9865.
[33]
Cherry, N. Schumann Resonances, a plausible biophysical mechanism for the human health effects of Solar/Geomagnetic Activity. Nat. Hazards 2002, 26, 279–331, doi:10.1023/A:1015637127504.
[34]
Adair, R.K. Biophysical limits on athermal effects of RF and microwave radiation. Bioelectromagnetics 2003, 24, 39–48, doi:10.1002/bem.10061.
[35]
International Commission on Non-Ionizing Radiation Protection. Guidelines for limiting exposure to time-varying electric and magnetic fields. Health Phys. 2010, 99, 818–836.
[36]
Wiltschko, W.; Wiltschko, R. Magnetic orientation and magnetoreception in birds and other animals. J. Comp. Physiol. A Neuroethol. Sens. Neural Behav. Physiol. 2005, 191, 675–693, doi:10.1007/s00359-005-0627-7.
[37]
Dyson, P.J. Biology: Electric Cows. Nature 2009, 458, doi:10.1038/458389a.
[38]
Burda, H.; Begall, S.; ？erveny, J.; Neef, J.; Němec, P. Extremely low-frequency electromagnetic fields disrupt magnetic alignment of ruminants. Proc. Nat. Acad. Sci. USA 2009, 106, 5708–5713.
[39]
Nakamoto, R.K.; Baylis Scanlon, J.A.; Al-Shawi, M.K. The Rotary Mechanism of the ATP in Synthase. Arch. Biochem. Biophys. 2008, 476, 43–50, doi:10.1016/j.abb.2008.05.004.
[40]
Bohren, C.F. How can a particle absorb more than the light incident on it? Am. J. Phys. 1983, 51, 323–327, doi:10.1119/1.13262.
[41]
Paul, H.; Fischer, R. Light absorption by a dipole. Sov. Phys. Usp. 1983, 26, 923–926, doi:10.1070/PU1983v026n10ABEH004523.
[42]
Lloyd, D.; Murray, D.B. The Temporal Architecture of Eukaryotic Growth. FEBS Lett. 2006, 580, 2830–2865, doi:10.1016/j.febslet.2006.02.066.
[43]
Freund, F.T.; Kulahci, I.G.; Cyr, G.; Ling, J.; Winnick, M.; Tregloan-Reed, J.; Freund, M.M. Air ionization at rock surface and pre-earthquake signals. J. Atmos. Sol.-Terr. Phys. 2009, 71, 1824–1834, doi:10.1016/j.jastp.2009.07.013.
[44]
Rycroft, M.J.; Harrison, R.G.; Nicoll, K.A.; Mareev, E.A. An Overview of Earth’s Global Electric Circuit and Atmospheric Conductivity. Space Science Rev. 2008, 137, 83–105, doi:10.1007/s11214-008-9368-6.
[45]
Bleier, T.; Dunson, C.; Alvarez, C.; Freund, F.; Dahlgren, R. Correlation of pre-earthquake electromagnetic signals with laboratory and field rock experiments. Nat. Hazards Earth Syst. Sci. 2010, 10, 1965–1975, doi:10.5194/nhess-10-1965-2010.
[46]
Bryant, N. Ground-based and space-based electromagnetic monitoring for pre-earthquake signals. In The Frontier of Earthquake Prediction Studies; Hayakawa, M., Ed.; Nihon-senmontosho-shuppan: Tokyo, Japan, 2011.
[47]
Krueger, A.P.; Reed, E.J. Effect of the air ion environment on influenza in the mouse. Int. J. Biometeor. 1972, 16, 209–232, doi:10.1007/BF01553734.
[48]
Krueger, A.P.; Reed, E.J. Biological impact of small air ions. Science 1976, 193, 1209–1213.
[49]
Ganguly, N.D. Variation in atmospheric ozone concentration following strong earthquakes. Int. J. Remote Sens. 2009, 30, 349–356, doi:10.1080/01431160802282862.
[50]
Balk, M.; Bose, M.; G？zen, E.; Rogoff, D.A.; Rothschild, L.J.; Freund, F.T. Oxidation of water to hydrogen peroxide at the rock-water interface due to stress-activated electric currents in rocks. Earth Planet. Sci. Lett. 2009, 283, 87–92, doi:10.1016/j.epsl.2009.03.044.
[51]
Grant, R.A.; Halliday, T.; Balderer, W.P.; Leuenberger, F.; Newcomer, M.; Cyr, G.; Freund, F.T. Ground Water Chemistry Changes before Major Earthquakes and Possible Effects on Animals. Int. J. Environ. Res. Public Health 2011, 8, 1936–1956, doi:10.3390/ijerph8061936.
[52]
Kirschvink, J.L. Earthquake prediction by animals: Evolution and sensory perception. Bull. Seism. Soc. Am. 2000, 90, 312–323, doi:10.1785/0119980114.
[53]
LiveScience. Mystery of Mass Squid ‘Suicides’ Possibly Solved. Available online: http://www.livescience.com/25550-mass-squid-suicide.html (accessed on 27 May 2013).
Lefebvre, K.A.; Robertson, A. Domoic acid and human exposure risks: A review. Toxicon 2010, 56, 218–230, doi:10.1016/j.toxicon.2009.05.034.
[56]
Than, K. Dozens of Jumbo Squid Beached after Quake—Coincidence? National Geographic News 2009.
[57]
Martens, D.A.; Frankenberger, W.T. Enhanced degradation of polycyclic aromatic hydrocarbons in soil treated with an advanced oxidative process—Fenton’s reagent. J. Soil Contam. 1995, 4, 175–190, doi:10.1080/15320389509383491.
[58]
Salazar, J.M.L.; Pérez, N.M.; Hernández, P.A.; Soriano, T.; Barahona, F.; Olmos, R.; Cartagena, R.; López, D.L.; Lima, R.N.; Melián, G.; Galindo, I.; Padrón, E.; Sumino, H.; Notsu, K. Precursory diffuse carbon dioxide degassing signature related to a 5.1 magnitude earthquake in El Salvador, Central America. Earth Planet. Sci. Lett. 2003, 205, 81–89.
[59]
Tyrtyshinikov, A.V. The variations of ozone content in the atmosphere above strong earthquake epicenter. Phys. Solid Earth 1996, 31, 789–794.
[60]
Heraud, J.A.; Lira, J.A. Co-seismic luminescence in Lima, 150 km from the epicenter of the Pisco, Peru earthquake of 15 August 2007. Nat. Haz. Earth Syst. Sci. 2011, 11, 1025–1036, doi:10.5194/nhess-11-1025-2011.
[61]
Health Effects of Ozone in the General Population; EPA: Research Triangle Park, NC, USA, 2013.
[62]
Nagarajaa, K.; Prasad, B.S.N.; Madhava, M.S.; Chandrashekara, M.S.; Paramesh, L.; Sannappa, J.; Pawar, S.D.; Murugavel, P.; Kamra, A.K. Radon and its short-lived progeny: Variations near the ground. Radiat. Meas. 2003, 36, 413–417, doi:10.1016/S1350-4487(03)00162-8.
[63]
Tsivion, E.; Zilberg, S.; Gerber, R.B. Predicted stability of the organo-xenon compound HXeCCH above the cryogenic range. Chem. Phys. Lett. 2008, 460, 23–26, doi:10.1016/j.cplett.2008.05.032.
[64]
Freund, F.T. Toward a unified solid state theory for pre-earthquake signals. Acta Geophys. 2010, 58, 719–766, doi:10.2478/s11600-009-0066-x.
[65]
Kamsali, N.; Pawar, S.D.; Murugavel, P.; Gopalakrishnan, V. Estimation of Small ion concentration near the Earth’s surface. J. Atmos. Sol.-Terr. Phys. 2011, 73, 2345–2351, doi:10.1016/j.jastp.2011.07.011.
[66]
Singh, R.P.; Kumar, J.S.; Zlotnicki, J.; Kafatos, M. Satellite Detection of Carbon Monoxide Emission Prior to the Gujarat Earthquake of 26 January 2001. Appl. Geochem. 2010, 25, 580–585, doi:10.1016/j.apgeochem.2010.01.014.
[67]
Stolc, V.; Shmygelska, A.; Griko, Y. Adaptation of organisms by resonance of RNA transcription with the cellular redox cycle. PLoS ONE 2011, 6, doi:10.1371/journal.pone.0025270.
[68]
Lu, D. Impending Earthquake Prediction; Jinangsu Science and Publishing House: Nanjing, China, 1988. (In Chinese).
[69]
Varon, J.; Marik, P.E. Carbon Monoxide Poisoning. Int. J. Emerg. Intens. Care Med. 1997, 1, doi:10.5580/1943.
[70]
Italy – Hundreds of Dead Mice Found in Earthquake Area (in Italian, translated into English). Available online: http://iceagenow.info/2012/06/italy-hundreds-dead-mice-earthquake-area/ (accessed on 27 May 2013).
[71]
Jordan, T.H.; Chen, Y.; Gasparini, P.; Madariaga, R.; Main, I.; Marzocchi, W.; Papadopoulos, G.; Sobolev, G.; Yamaoka, K.; Zschau, J. Operational earthquake forecasting: State of knowledge and guidelines for utilization. Ann. Geophys. 2011, 54, 315–391.
[72]
Grant, R.A.; Halliday, T. Predicting the unpredictable: Evidence of pre-seismic anticipatory behaviour in the common toad. J. Zool. 2010, 281, 263–271.
[73]
Schall, R.B. An evaluation of the animal-behavior theory for earthquake prediction. Calif. Geol. 1988, 41, 41–45.
[74]
Evernden, J.F. Abnormal Animal Behavior Prior to Earthquakes; U.S. Department of Interior Geological Survey: Menlo Park, CA, USA, 1976.
[75]
Tributsch, H. When the Snakes Awake; The MIT Press: Cambridge, MA, USA, 1982.
[76]
Murphy, M.P. How mitochondria produce reactive oxygen species. Biochem. J. 2009, 417, 1–13, doi:10.1042/BJ20081386.
