Phenomena preceding major earthquakes interconnected through a physical model

Abstract

Abstract. The analysis of earthquake time series in a new time domain termed natural time enables the uncovering of hidden properties in time series of complex systems and has been recently employed as basis of a method to estimate seismic risk. Applying this analysis, as an example, to the Japanese seismic data from 1 January 1984 until the super-giant M9 Tohoku earthquake on 11 March 2011, we find that almost three months before its occurrence the entropy change of seismicity under time reversal is minimized on 22 December 2010, which signals an impending major earthquake. On this date the order parameter fluctuations of seismicity exhibit abrupt increase. This increase is accompanied by various phenomena, e.g., from this date the horizontal GPS azimuths start to become gradually oriented toward the southern direction, while they had random orientation during the preceding period. Two weeks later, a minimum of the order parameter fluctuations of seismicity appears accompanied by anomalous Earth's magnetic field variations and by full alignment of the orientations of GPS azimuths southwards leading to the most intense crust uplift. These phenomena are discussed and found to be in accordance with a physical model which seems to explain on a unified basis anomalous precursory changes observed either in ground-based measurements or in satellite data.

Unveiling Informational Properties of the Chen-Ouillon-Sornette Seismo-Electrical Model

“…On the other hand, the mechanisms of the stress-activated charge carriers and the pressure-stimulated currents can well justify the generation and transportation of electrical charges in seismogenic processes. As for pressure-stimulated currents, Varotsos et al [ 58 ] also provided a useful review of a pressure-stimulated currents model proposed in the 1980s and explained that this model is compatible with experimental results deduced recently by independent research groups. After the combination, the seismo-electrical model, named Chen–Ouillon–Sornette (COS), can thus mimic fracture-induced electrical signals at a laboratory scale [ 40 , 59 , 60 ] and earthquake-related geoelectrical signals at a geological scale [ 18 , 32 ].…”

“…The electrical characteristics of the crust are affected by rock composition, porosity, fluid permeability, permittivity, and so forth [ 17 , 33 , 44 ]. For instance, during an earthquake preparation, dielectric crystals may be polarized towards a preferred orientation under tectonic stresses [ 17 , 58 ]; hence, the permittivity increases. In electromagnetism, the capacitance is proportional to the permittivity.…”

Nowcasting Avalanches as Earthquakes and the Predictability of Strong Avalanches in the Olami-Feder-Christensen Model

“…For the analysis of time series coming from complex systems, a procedure termed natural time analysis [ 24 ] was proposed [ 21 , 25 , 26 , 27 ] in the beginning of 2000s which enables us to determine when the system approaches the critical point. Natural time analysis also uncovers unique dynamic features hidden behind the time series of complex systems and has found applications in diverse fields, including the Olami-Feder-Christensen (OFC) EQ model [ 28 ] (see also Section 2.2 ), such as the study of EQs [ 29 , 30 ] and the identification of the sudden cardiac death risk [ 31 ], compiled in Reference [ 24 ], see also References [ 32 , 33 , 34 , 35 ] for more recent applications. Natural time, which is unique in its characteristics [ 36 ], is currently considered to be the basis for a new methodology to estimate the seismic risk by Turcotte and coworkers [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ] termed “nowcasting earthquakes”.…”