Earthquake lights and rupture processes

Losseva, T. V.; Nemchinov, I. V.

doi:10.5194/nhess-5-649-2005

Cited by 15 publications

(6 citation statements)

References 26 publications

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“…They have been witnessed at numerous occasions (Galli, 1910;Losseva and Nemchinov, 2005;Mack, 1912;St-Laurent, 2000;Terada, 1931;Tsukuda, 1997), even photographed (Derr, 1986). Many different explanations have been given (Hedervari and Noszticzius, 1985;King, 1983;Ouellet, 1990), often considering piezoelectricity as the physical cause (Finkelstein et al, 1973) or effects of fluids (Lockner et al, 1983;Nur, 1974).…”

Section: Light Emission and Rf Noisementioning

confidence: 93%

Pre-earthquake signals: Underlying physical processes

Freund

2011

Journal of Asian Earth Sciences

235

148

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Section: Light Emission and Rf Noisementioning

confidence: 93%

Pre-earthquake signals: Underlying physical processes

Freund

2011

Journal of Asian Earth Sciences

235

148

View full text Add to dashboard Cite

“…However, the underlying formation mechanism is still controversial. A flurry of mechanisms have been put forward to explain the charge generation in the subsurface during earthquake motion: piezomagnetism, piezoelectricity, electrokinetic flow processes, opening of the tips of cracks, stress‐activation of positive holes, and hydromechanical rupture (Enomoto et al, 2017; Freund et al, 2007; Losseva & Nemchinov, 2005; St‐Laurent et al, 2006). Regardless of its formation mechanism, the coseismic electric current is expected to travel along the fault plane, which often acts as a good electrical conductor with a conductivity of up to 4 orders higher than the surrounding insulating host rocks (Ferré et al, 2005).…”

Section: Drivers For Changes In Magnetic Properties Of Fault Rocksmentioning

confidence: 99%

“…According to the Biot-Savart law, a transient strong azimuthal magnetic field will be produced perpendicular to the fault plane (Ferré et al, 2005(Ferré et al, , 2012Losseva & Nemchinov, 2005). In this arrangement-lamellar conductive rocks enveloped by insulating margins-fault gouge, pseudotachylite generation veins, parallel or near parallel to the fault plane, will readily acquire an IRM.…”

Section: Eql-induced Irm Acquisitionmentioning

confidence: 99%

“…This IRM is a secondary NRM termed "earthquake lightning-induced remanent magnetization (EQLIRM)" (Enomoto et al, 2001;Enomoto & Zheng, 1998;Ferré et al, 2005Ferré et al, , 2012. EQLIRM is distinct from lightning NRM in rocks struck by surface lighting; in the latter the lightning IRM remagnetization pattern is circular (either clockwise or counterclockwise) centered on the lightning-bolt impact location, coupled with a decrease in magnetization intensity away from the electric bolt (e.g., Losseva & Nemchinov, 2005;Verrier & Rochette, 2002). In the context of EQLIRM fault rocks, several paleointensity tests (e.g., Ferré, Geissman, et al, 2014;Gattacceca & Rochette, 2004) and normalization of the NRM intensity by M s are helpful to discriminate high NRM caused by a strong ambient magnetic field from that caused by high concentrations of magnetic minerals.…”

Section: Eql-induced Irm Acquisitionmentioning

confidence: 99%

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Faulting Processes Unveiled by Magnetic Properties of Fault Rocks

Yang

Chou

Ferré

et al. 2020

Reviews of Geophysics

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As iron-bearing minerals-ferrimagnetic minerals in particular-are sensitive to stress, temperature, and presence of fluids in fault zones, their magnetic properties provide valuable insights into physical and chemical processes affecting fault rocks. Here, we review the advances made in magnetic studies of fault rocks in the past three decades. We provide a synthesis of the mechanisms that account for the magnetic changes in fault rocks and insights gained from magnetic research. We also integrate nonmagnetic approaches in the evaluation of the magnetic properties of fault rocks. Magnetic analysis unveils microscopic processes operating in the fault zones such as frictional heating, energy dissipation, and fluid percolation that are otherwise difficult to constrain. This makes magnetic properties suited as a "strain indicator," a "geothermometer," and a "fluid tracer" in fault zones. However, a full understanding of faulting-induced magnetic changes has not been accomplished yet. Future research should focus on detailed magnetic property analysis of fault zones including magnetic microscanning and magnetic fabric analysis. To calibrate the observations on natural fault zones, laboratory experiments should be carried out that enable to extract the exact physicochemical conditions that led to a certain magnetic signature. Potential avenues could include (1) magnetic investigations on natural and synthetic fault rocks after friction experiments, (2) laboratory simulation of fault fluid percolation, (3) paleomagnetic analysis of postkinematic remanence components associated with faulting processes, and (4) synergy of interdisciplinary approaches in mineral-magnetic studies. This would help to place our understanding of the microphysics of faulting on a much stronger footing. Plain Language Summary The Earth's surface is riddled with faults that largely contribute to landscape evolution and human activities. Some of these faults produce earthquakes of different magnitudes including some with catastrophic consequences. Understanding faulting mechanisms benefits society when predictions about rupture are made. Fault zones preserve an excellent record of chemical and physical processes involved in failure. Among other analytical methods, magnetic studies prove to be an emergent and untapped source of information on these processes. These methods, focused on prefaulting, synfaulting, and postfaulting mineral changes, have resulted in significant advances in our understanding of the conditions of faulting. In this review, we present an extensive account of the state of knowledge and highlight current challenges and future avenues of fault magnetism research.

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“…Increasing the electric field at the ground surface up to the possible triggering of corona discharges suggests that transient phenomena usually reported as earthquake lights may also occur (Galli, 1910;Losseva and Nemchinov, 2005;Mack, 1912;St Laurent, 2000;Terada, 1931;Tsukuda, 1997;Derr, 1986). Such corona discharge are also speculated to generate a significant amount of RF (Radio Frequency) noise (Freund, 2010) which should be recorded.…”

Section: First-order Predictions Of the Modelmentioning

confidence: 99%

Earthquake precursors in the light of peroxy defects theory: Critical review of systematic observations

Freund

Ouillon²,

Scoville

et al. 2021

Eur. Phys. J. Spec. Top.

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Forecasting earthquakes implies that there are time-varying processes, which depend on the changing conditions deep in the Earth's crust prior to major seismic activity. These processes may be linearly or non-linearly correlated. In seismology, the research has traditionally been centered on mechanical variables, including precursory ground deformation (revealing the build-up of stress deep below) and on prior seismic events (past earthquakes may be related to or even trigger future earthquakes). Since the results have been less than convincing, there is a general consensus in the geoscience community that earthquake forecasting on time scales comparable to meteorological forecasts are still quite far in the future, if ever attainable.The starting point of the present review is to acknowledge that there are innumerable reports of other types of precursory phenomena ranging from emission of electromagnetic waves from ultralow frequency (ULF) to visible (VIS) and near-infrared (NIR) light, electric field and magnetic field anomalies of various kinds (see below), all the way to unusual animal behavior, which has been reported again and again. These precursory signals are intermittent and seem not to occur systematically before every major earthquake and reports on pre-earthquake signals are not widely accepted by the geoscience community at large because no one could explain their origins. In addition, the diversity of the signals makes them look disparate and unrelated, hampering any progress.We review a credible, unifying theory for a solid-state mechanism, which is based on decades of research bridging semi-conductor physics, chemistry and rock physics. This theory, which we refer to as the "peroxy defect theory", is capable of providing explanations for the multitude of reported pre-earthquake phenomena. A synthesis has emerged that all pre-earthquake phenomena could trace back to one fundamental physical process: the activation of electronic charges (electrons and positive holes) in rocks subjected to ever-increasing tectonic stresses prior to any major seismic activity, via the rupture of peroxy bonds. The holes are unusual I-Introduction 1.1 The cost of earthquakesLarge earthquakes are, by far, the deadliest of all natural disasters, claiming an average of 60,000 lives a year, featuring gigantic fluctuations (e.g. 80,000 victims from 1994 to 2004, and 780,000 from 2001 to 2010; see e.g. Knopoff and Sornette, 1995, for the size distribution of death tolls related to seismic events), which partly mirrors the highly intermittent distribution of seismicity in space, time, and magnitude. On more economic grounds, such disasters are also causing colossal property and industrial damage, with that of the 1989 Loma Prieta earthquake in California alone estimated at $6 billions (over €4 billions), the 1995 Kobe event in Japan estimated at $200 billions (€150 billions), while the 2011 Tohoku earthquake followed by its great tsunami already stands with much higher losses, with costs continuing to rise with the on-going m...

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Earthquake lights and rupture processes

Cited by 15 publications

References 26 publications

Pre-earthquake signals: Underlying physical processes

Pre-earthquake signals: Underlying physical processes

Faulting Processes Unveiled by Magnetic Properties of Fault Rocks

Earthquake precursors in the light of peroxy defects theory: Critical review of systematic observations

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