Rethinking earthquake-related DC-ULF electromagnetic phenomena: towards a physics-based approach

Abstract

Numerous electromagnetic changes possibly related with earthquakes have been independently reported and have even been attempted to apply to short-term prediction of earthquakes. However, there are active debates on the above issue because the seismogenic process is rather complicated and the studies have been mainly empirical (i.e. a kind of experience-based approach). Thus, a physics-based study would be helpful for understanding earthquake-related electromagnetic phenomena and strengthening their applications. As a potential physics-based approach, I present an integrated research scheme, taking into account the interaction among observation, methodology, and physical model. For simplicity, this work focuses only on the earthquake-related DC-ULF electromagnetic phenomena. The main approach includes the following key problems: (1) how to perform a reliable and appropriate observation with some clear physical quantities; (2) how to develop a robust methodology to reveal weak earthquake-related electromagnetic signals from noisy background; and (3) how to develop plausible physical models based on theoretical analyses and/or laboratory experiments for the explanation of the earthquake-related electromagnetic signals observed in the field conditions

Features of criticality in precursory seismic electric signals and earthquakes in Greece

“…In particular we mention a recent work considering the electrokinetic effect as a mechanism causing the coupling between seismic and electromagnetic energies (Ren et al, 2012) the stress drop due to dislocation theory of a fault (Huang, 2002(Huang, , 2011. Here, we rely on an alternative model for the generation of earthquake-related very low frequency EM signals, which is based on the stress-stimulated currents (Varotsos, 2005), and it is briefly discussed below.…”

“…Various possible physical mechanisms of generating earthquake-related EM signals, such as the electrokinetic effect (Mizutani et al, 1976;Johnston, 1997) and the piezoelectric effect (Nitsan, 1977;Ikeya et al, 1997;Huang, 2002Huang, , 2011, have been proposed. In particular we mention a recent work considering the electrokinetic effect as a mechanism causing the coupling between seismic and electromagnetic energies (Ren et al, 2012) the stress drop due to dislocation theory of a fault (Huang, 2002(Huang, , 2011.…”

Critical dynamic processes prior to destructive earthquakes

“…When the increasing tectonic stress in the preseismic region reaches a critical value, these dipoles cooperatively change orientation giving rise to a transient current which is the SES signal. Other possible generation mechanisms are the piezoelectric (Huang 2002(Huang , 2011b and elecrtokinetic effects (Ren, Chen, and Huang 2012).…”

Shifting Correlation Between Earthquakes and Electromagnetic Signals: A Case Study of the 2013 Minxian–Zhangxian M L 6.5 (M W 6.1) Earthquake in Gansu, China

“…SEMS have been reported in a large amount of literature (EFTAXIAS et al 2001(EFTAXIAS et al , 2009FUJINAWA et al 1998;HAN et al 2014;HATTORI et al 2012;Huang et al 2011b;KING 1983;PARK et al 1993;ZHANG et al 2011;ZHAO et al 2009). Abundant indoor and/ or outdoor experiments and numerical simulations have been conducted to verify the existence of SEMS phenomena (HUANG et al 1998;KUO et al 2014;ZHAO et al 2009;ENOMOTO et al 2012;REN et al 2012;POTIRAKIS et al 2012;HUANG 2011a). For example, radiation of ultra-low-frequency (ULF) electromagnetic signals was observed in the early, middle, and late stages of a rock-fracture experiment (HAO et al 2003).…”