In 1909 in Italy, a Franciscan Monk Was the First to Discover Electromagnetic Seismic Precursors

We present to the international scientific community three important works by Father Maccioni adapted into English with several parts literally translated. The investigation into the existence of an electromagnetic (EM) seismic precursor was carried on in Italy in the beginning of the twentieth century and exploited the capabilities of a specifically designed coherer. For several reasons, both the work and the author are widely unknown even in Italy. We think this is likely to be the very first historical case of a study of a seismic precursor of the EM type.

RADIO DIRECTION FINDING, A NEW METHOD FOR THE INVESTIGATION OF PRESISMIC PHENOMENA. THE CASE OF JAPAN

This study the LTPA Emission Project Team presents a new method of detecting electromagnetic signals that is a candidate for the analysis of seismic precursors and for a crustal diagnosis in real time. Earthquakes are an expression of the Earth System and is therefore clear that the anlysis of data must be evaluated in a holistic context, supported by advanced technologies and by the constant and rapid synergy with the scientific community thanks to the web. The RDF experimentation proposed in this paper is based on some precursor candidates, such as a magnetic anomalies and particular frequency bands, activated by the minerals of the rocks under tectonic stress. The monitoring station, localted in Rome and Pisa (Italy), used two types of radio receivers to continuosly monitor the electromagnetic spectrum located between the lower limit of the SELF band (Super Extremely Low Frequency) and upper limit of the VLF band (Very Low Frequency). In this study, as a demonstrative example, the seismicity in Japan is analyzed, as detected by the Italian monitoring stations

Global Earthquake Forecasting System (GEFS): The challenges ahead

We conclude this special issue on the Global Earthquake Forecasting System (GEFS) by briefly reviewing and analyzing the claims of non-seismic precursors made in the present volume, and by reflecting on the current limitations and future directions to take. We find that most studies presented in this special volume, taken individually, do not provide strong enough evidence of non-seismic precursors to large earthquakes. The majority of the presented results are hampered by the fact that the task at hand is susceptible to potential biases in data selection and possible overfitting. The most encouraging results are obtained for ground-based geoelectric signals, although the probability gain is likely small compared to an earthquake clustering baseline. The only systematic search on satellite data available so far, those of the DEMETER mission, did not find a robust precursory pattern. The conclusion that we can draw is that the overall absence of convincing evidence is likely due to a deficit in systematically applying robust statistical methods and in integrating scientific knowledge of different fields. Most authors are specialists of their field while the study of earthquake precursors requires a system approach combined with the knowledge of many specific characteristics of seismicity. Relating non-seismic precursors to earthquakes remains a challenging multidisciplinary field of investigation. The plausibility of these precursors predicted by models of lithosphere-atmosphere-ionosphere coupling, together with the suggestive evidence collected here, call for further investigations. The primary goal of the GEFS is thus to build a global database of candidate signals, which could potentially improve earthquake predictability (if the weak signals observed are real and false positives sufficiently uncorrelated between different data sources). Such a stacking of disparate and voluminous data will require big data storage and machine learning pipelines, which has become feasible only recently. This special issue compiled an eclectic list of non-seismic precursor candidates, which is in itself a valuable source of information for seismologists, geophysicists and other scientists who may not be familiar with such types of investigations. It also forms the foundation for a coherent, multi-disciplinary collaboration on earthquake prediction.

The challenges and possibilities of earthquake predictions using non-seismic precursors

The catastrophic magnitude of life and monetary losses associated with earthquakes deserve serious attention and mitigation measures. However, in addition to the pre-earthquake and post-earthquake alleviation actions, the scientific community indeed needs to reconsider the possibilities of earthquake predictions using non-seismic precursors. A significant number of studies in the recent decades have reported several possible earthquake precursors such as anomalies in electric field, magnetic field, gas/aerosol emissions, ionospheric signals, ground water level, land surface temperature, surface deformations, animal behaviour, thermal infrared signals, atmospheric gravity waves, and lightning. Such substantial number of scientific articles and reported anomalous signals cannot be overlooked without a thoughtful appraisal. Here, we provide an opinion on the way forward for earthquake prediction in terms of challenges and possibilities while using non-seismic precursors. A general point of concern is the widely varying arrival times and the amplitudes of the anomalies, putting a question mark on their universal applicability as earthquake markers. However, a unifying concept which does not only define the physical basis of either all or most of these anomalies but which also streamlines their characterisation procedure must be the focus of future earthquake precursory research. Advancements in developing the adaptable instrumentation for in-situ observations of the claimed non-seismic precursors must be the next step and the satellite observations should not be taken as a replacement for field-based research. We support the need to standardise the precursor detection techniques and to employ a global-scale monitoring system for making any possible earthquake predictions reliable.

Possible Seismo Ionospheric Anomalies before the 2016 Mw 7.6 Chile Earthquake from GPS TEC, GIM TEC and Swarm Satellites

The recent advances in space based ionospheric measurements can help to investigate seismic precursors before earthquake with multi-parameter observations and more dedicated instrumentations. In this paper, seismo ionospheric anomalies before the December 25, 2016, Mw 7.6, Chile earthquake are investigated in Total Electron Content (TEC) and Global Ionosphere Map (GIM). The temporal TEC from GPS stations and GIM show enhancement during 5- 10 days (local daytime) before main shock. Similarly, spatial TEC confirms abnormal dense cloud at LT=12h-14h on December 21, 2016, that lingers over the epicenter of Chile earthquake. On the other hand, the geomagnetic indices show Dst < -50nT of low intensity variation. Similarly, Kp > 3 on December 21, 2016 within 5-10 days before the Mw 7.6. This study emphasizes that the ionosphere anomalies may not be the possible association of earthquakes induced variation but it is due to the active storm conditions (Kp>3).