Seismo Electromagnetics and Earthquake Prediction: History and New directions

Abstract

This review will focus on earthquake (EQ) precursor studies for EQ prediction. Among the long-, medium-, and short-term EQ predictions, the most meaningful are short-term predictions because of their immediate effect on human lives. Investigations of EQ precursors were very scarce before the 1995 Kobe EQ, but various kinds of precursors were reported for this disastrous Kobe EQ. Then intensive observations and studies were initiated after the Kobe EQ in different countries, especially in Japan in collaboration with two Japanese frontier projects engaged in seismo-electromagnetic studies during the years of 1996-2001 which contributed very much to the progress of precursor studies. Electromagnetic phenomena in possible association with EQs have been reviewed with special reference to those achievements made during and after the frontier projects. Being stimulated by the success of these Japanese frontier projects, national precursors studies devoted to EQ prediction have been developed in different countries. The most important findings during the past two decades are that many of short-term EQ precursors are non-seismic (electromagnetic, geochemical) rather than seismological, and that the ionosphere (both the lower and upper layers) and atmosphere are perturbed prior to an EQ, being coupled to the lithosphere (the presence of lithosphere-atmosphere-ionosphere coupling). As recent research activities, we will present the precursors for the recent 2011 Tohoku mega-EQ, not only electromagnetic but also of ground movements. Finally, future directions of EQ precursor studies and short-term EQ prediction will be extensively discussed with paying particular attention to the importance of multidisciplinary and multi-parameters observations and critical analyses. IntroductionDue to enormous advance in seismology, geodesy, and so on, we find significant developments both in the long-(with the time scale of hundred years) and medium-term (with the time scale of a few decades to

Observation of the Preparation Phase Associated with Mw = 7.2 Haiti Earthquake on 14 August 2021 from a Geophysical Data Point of View

“…Electromagnetic precursors have been searched historically from ground geomagnetic observatories in different areas of the world [22][23][24][25][26][27] and, more recently, from space satellites [28][29][30][31][32]. Comprehensive recent reviews of seismo-electromagnetic phenomena have been provided by Chen et al [33] and Hayakawa et al [34,35]. A comparison between surface and land temperature values and Swarm magnetic anomalies has been supplied by Ghamry et al [36].…”

Lower-ionosphere anomalies prior to strong earthquakes that occurred in north-central mainland Greece on March 2021 as revealed by multi-method analysis of VLF sub-ionospheric propagation data

“…Various seismo-electromagnetic (seismo-EM) phenomena have been observed before earthquakes (EQs) from the ground up to space, while an enormous effort for short-term EQ prediction has already been carried out by many scientists in the last three decades [Molchanov and Hayakawa, 1995;Pulinets and Boyarchuk, 2004;Molchanov and Hayakawa, 2008;Varotsos, 2005;Hayakawa, 2019]. For example, the subionospheric monitoring of the lower ionosphere through very low to low frequency (VLF/LF) propagation has been established as a wide-spread radiotechnique for searching electromagnetic (EM) signatures in the signal (amplitude and phase) characteristics which are associated with many different extreme events such as EQs, volcanoes, geomagnetic storms, solar flares and typhoons, [e.g., Malkotsis et al, 2022;Rozhnoi et al, 2014aRozhnoi et al, , 2014bHayakawa, 2011;Nina et al, 2021].…”

“…The involved parameters have extensively been used together or separately to investigate the possible correlation between the time of the occurrence of the EQ and the time of appearance of the anomaly. These parameters are grouped into five supposed characteristic channels (electromagnetic, electrostatic, thermal, acoustic and chemical) of the LAIC, where some of them can be found to be interconnected in a way that the one can possibly trigger the other [Hayakawa, 2019;Pulinets & Ouzounov, 2011;Pulinets et al, 2022]. In this perspective, several scientific works have recently been published in the literature including a vast variety of EQ-related anomalies, [e.g., Ghosh et al, 2021Ghosh et al, , 2023Chakraborty et al, 2018;Conti et al, 2021;Picozza et al, 2021].…”

The Theoretical and Practical Foundations of Strong Earthquake Predictability

“…One of the best known is a family of M8 algorithms from Keilis-Borok's school that uses various kinds of seismic anomalies or deviations from "normal" seismic behavior [7] [8] [9]. Among other traditional approaches are electromagnetic methods [10] [11] [12], hydrological methods based on changes in the composition and levels of water [13] [14] [15], changes in the level of radon [16] [17], the observation of unusual clouds [18] [19], changes in meteorological data and animal behavior [20] etcetera. Over the past decade we have seen a dramatic growth in the new, primarily satellite remote sensing methods that study earthquakes [21] [22].…”