scholarly journals Time-scale invariant changes in atmospheric radon concentration and crustal strain prior to a large earthquake

2007 ◽  
Vol 14 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Y. Kawada ◽  
H. Nagahama ◽  
Y. Omori ◽  
Y. Yasuoka ◽  
T. Ishikawa ◽  
...  
Keyword(s):  
Power Law ◽  
Time Scale ◽  
Radon Concentration ◽  
Large Earthquake ◽  
Irreversible Thermodynamic ◽  
Time To Failure ◽  
Scale Invariant ◽  
Crustal Strain ◽  
Kobe Earthquake ◽  
Atmospheric Radon

Abstract. Prior to large earthquakes (e.g. 1995 Kobe earthquake, Japan), an increase in the atmospheric radon concentration is observed, and this increase in the rate follows a power-law of the time-to-earthquake (time-to-failure). This phenomenon corresponds to the increase in the radon migration in crust and the exhalation into atmosphere. An irreversible thermodynamic model including time-scale invariance clarifies that the increases in the pressure of the advecting radon and permeability (hydraulic conductivity) in the crustal rocks are caused by the temporal changes in the power-law of the crustal strain (or cumulative Benioff strain), which is associated with damage evolution such as microcracking or changing porosity. As the result, the radon flux and the atmospheric radon concentration can show a temporal power-law increase. The concentration of atmospheric radon can be used as a proxy for the seismic precursory processes associated with crustal dynamics.

scholarly journals Time-scale invariances in preseismic electromagnetic radiation, magnetization and damage evolution of rocks

2007 ◽  
Vol 7 (5) ◽  
pp. 599-606 ◽  
Author(s):  
Y. Kawada ◽  
H. Nagahama ◽  
N. Nakamura
Keyword(s):  
Electromagnetic Radiation ◽  
Energy Release ◽  
Time Scale ◽  
Damage Evolution ◽  
Damage Mechanics ◽  
Mechanical Energy ◽  
Large Earthquake ◽  
Irreversible Thermodynamic ◽  
Rock Failure ◽  
Scale Invariant

Abstract. We investigate the time-scale invariant changes in electromagnetic and mechanical energy releases prior to a rock failure or a large earthquake. The energy release processes are caused by damage evolutions such as crack propagation, motion of charged dislocation, area-enlargement of sheared asperities and repetitive creep-rate changes. Damage mechanics can be used to represent the time-scale invariant evolutions of both brittle and plastic damages. Irreversible thermodynamics applied to the damage mechanics reveals that the damage evolution produces the variations in charge, dipole and electromagnetic signals in addition to mechanical energy release, and yields the time-scale invariant patterns of Benioff electromagnetic radiation and cumulative Benioff strain-release. The irreversible thermodynamic framework of damage mechanics is also applicable to the seismo-magnetic effect, and the time-scale invariance is recognized in the remanent magnetization change associated with damage evolution prior to a rock failure.

Evidence of precursor phenomena in the Kobe earthquake obtained from atmospheric radon concentration

2006 ◽  
Vol 21 (6) ◽  
pp. 1064-1072 ◽  
Author(s):  
Yumi Yasuoka ◽  
George Igarashi ◽  
Testuo Ishikawa ◽  
Shinji Tokonami ◽  
Masaki Shinogi
Keyword(s):  
Radon Concentration ◽  
Kobe Earthquake ◽  
Atmospheric Radon

scholarly journals Anomalous radon emanation linked to preseismic electromagnetic phenomena

2007 ◽  
Vol 7 (5) ◽  
pp. 629-635 ◽  
Author(s):  
Y. Omori ◽  
Y. Yasuoka ◽  
H. Nagahama ◽  
Y. Kawada ◽  
T. Ishikawa ◽  
...  
Keyword(s):  
Electric Field ◽  
Power Law ◽  
Radon Concentration ◽  
Damage Evolution ◽  
Atmospheric Electric Field ◽  
Ionospheric Disturbances ◽  
Radon Emanation ◽  
Radon Anomaly ◽  
Large Earthquakes ◽  
Atmospheric Radon

Abstract. Anomalous emanation of radon (222Rn) was observed preceding large earthquakes and is considered to be linked to preseismic electromagnetic phenomena (e.g. great changes of atmospheric electric field and ionospheric disturbances). Here we analyze atmospheric radon concentration and estimate changes of electrical conditions in atmosphere due to preseismic radon anomaly. The increase of radon emanation obeys crustal damage evolution, following a power-law of time-to-earthquake. Moreover, the radon emanation decreases the atmospheric electric field by 40%, besides influencing the maximum strength of atmospheric electric field by 104–105 V/m enough to trigger ionospheric disturbances. These changes are within the ranges observed or explaining electromagnetic phenomena associated with large earthquakes.

Preseismic changes in atmospheric radon concentration and crustal strain

2009 ◽  
Vol 34 (6-7) ◽  
pp. 431-434 ◽  
Author(s):  
Yumi Yasuoka ◽  
Yusuke Kawada ◽  
Hiroyuki Nagahama ◽  
Yasutaka Omori ◽  
Tetsuo Ishikawa ◽  
...  
Keyword(s):  
Radon Concentration ◽  
Crustal Strain ◽  
Atmospheric Radon

scholarly journals Distributed power-law seismicity changes and crustal deformation in the SW Hellenic ARC

2003 ◽  
Vol 3 (3/4) ◽  
pp. 179-195 ◽  
Author(s):  
A. Tzanis ◽  
F. Vallianatos
Keyword(s):  
Critical Exponent ◽  
Power Law ◽  
Critical Time ◽  
Stress Transfer ◽  
Large Earthquake ◽  
Time To Failure ◽  
Release Rates ◽  
Distributed Power ◽  
Hellenic Arc ◽  
Bright Spots

Abstract. A region of definite accelerating seismic release rates has been identified at the SW Hellenic Arc and Trench system, of Peloponnesus, and to the south-west of the island of Kythera (Greece). The identification was made after detailed, parametric time-to-failure modelling on a 0.1° square grid over the area 20° E – 27° E and 34° N–38° N. The observations are strongly suggestive of terminal-stage critical point behaviour (critical exponent of the order of 0.25), leading to a large earthquake with magnitude 7.1 ± 0.4, to occur at time 2003.6 ± 0.6. In addition to the region of accelerating seismic release rates, an adjacent region of decelerating seismicity was also observed. The acceleration/deceleration pattern appears in such a well structured and organised manner, which is strongly suggestive of a causal relationship. An explanation may be that the observed characteristics of distributed power-law seismicity changes may be produced by stress transfer from a fault, to a region already subjected to stress inhomogeneities, i.e. a region defined by the stress field required to rupture a fault with a specified size, orientation and rake. Around a fault that is going to rupture, there are bright spots (regions of increasing stress) and stress shadows (regions relaxing stress); whereas acceleration may be observed in bright spots, deceleration may be expected in the shadows. We concluded that the observed seismic release patterns can possibly be explained with a family of NE-SW oriented, left-lateral, strike-slip to oblique-slip faults, located to the SW of Kythera and Antikythera and capable of producing earthquakes with magnitudes MS ~ 7. Time-to-failure modelling and empirical analysis of earthquakes in the stress bright spots yield a critical exponent of the order 0.25 as expected from theory, and a predicted magnitude and critical time perfectly consistent with the figures given above. Although we have determined an approximate location, time and magnitude, it is as yet difficult to assert a prediction for reasons discussed in the text. However, our results, as well as similar independent observations by another research team, indicate that a strong earthquake may occur at the SW Hellenic Arc, in the next few years.

scholarly journals Radon degassing triggered by tidal loading before an earthquake

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yasutaka Omori ◽  
Hiroyuki Nagahama ◽  
Yumi Yasuoka ◽  
Jun Muto
Keyword(s):  
Earthquake Prediction ◽  
Radon Concentration ◽  
Quantitative Relationship ◽  
Stress Regime ◽  
Crustal Stress ◽  
Crustal Fluid ◽  
Kobe Earthquake ◽  
Long Time ◽  
Tidal Loading ◽  
Atmospheric Radon

AbstractThe presence of anomalous geochemical changes related to earthquakes has been controversial despite widespread, long time challenges for earthquake prediction. Establishing a quantitative relationship among geochemical changes and geodetical and seismological changes can clarify their hidden connection. Here we determined the response of atmospheric radon (222Rn) to diurnal tidal (K1 constituent) loading in the reported 11-year-long variation in the atmospheric radon concentration, including its anomalous evolution for 2 months before the devastating 1995 Kobe earthquake in Japan. The response to the tidal loading had been identified for 5 years before the occurrence of the earthquake. Comparison between these radon responses relative to crustal strain revealed that the response efficiency for the diurnal K1 tide was larger than that for the earthquake by a factor of 21–33, implying the involvement of crustal fluid movement. The radon responses occurred when compressional crustal stress decreased or changed to extension. These findings suggest that changes in radon exhaled from the ground were induced by ascent flow of soil gas acting as a radon carrier and degassed from mantle-derived crustal fluid upwelling due to modulation of the crustal stress regime.

Anomalous change in atmospheric radon concentration sourced from broad crustal deformation: A case study of the 1995 Kobe earthquake

2012 ◽  
Vol 27 (4) ◽  
pp. 825-830 ◽  
Author(s):  
Yumi Yasuoka ◽  
Yusuke Kawada ◽  
Yasutaka Omori ◽  
Hiroyuki Nagahama ◽  
Tetsuo Ishikawa ◽  
...  
Keyword(s):  
Crustal Deformation ◽  
Radon Concentration ◽  
Anomalous Change ◽  
Kobe Earthquake ◽  
Atmospheric Radon

Fractal Properties of Sympathetic Nerve Discharge

2003 ◽  
Vol 89 (2) ◽  
pp. 833-840 ◽  
Author(s):  
Mahasweta Das ◽  
Gerard L. Gebber ◽  
Susan M. Barman ◽  
Craig D. Lewis
Keyword(s):  
Power Law ◽  
Time Scale ◽  
Sympathetic Nerve ◽  
Window Size ◽  
Fano Factor ◽  
Slow Waves ◽  
Long Term Memory ◽  
Scale Invariant ◽  
Random Fluctuations ◽  
Nerve Discharge

Fano factor analysis and dispersional analysis were used to characterize time series of single and multifiber spikes recorded from the preganglionic cervical sympathetic nerve and cardiac-related slow-wave activity of the whole postganglionic sympathetic vertebral nerve (VN) in anesthetized cats. Fluctuations in spike counts and interspike intervals for single preganglionic fibers proved to be fractal (i.e., time-scale invariant), as reflected by a power law relationship between indices of the variance of these properties and the window size used to make the measurements. Importantly, random shuffling of the data eliminated the power law relationships. Fluctuations in spike counts in preganglionic multifiber activity also were fractal, as were fluctuations in the height and of the area of cardiac-related slow waves recorded from the whole postganglionic VN. These fractal fluctuations were persistent (i.e., positively correlated), as reflected by a Hurst exponent significantly >0.5. Although fluctuations in the interval between cardiac-related VN slow waves were random, those in the interval between heart beats were fractal and persistent. These results demonstrate for the first time that apparently random fluctuations in sympathetic nerve discharge are, in fact, dictated by a complex deterministic process that imparts “long-term” memory to the system. Whether such time-scale invariant behavior plays a role in generating the fractal component of heart rate variability remains to be determined.

scholarly journals Linearity and time-scale invariance of the creep function in living cells

2004 ◽  
Vol 1 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Guillaume Lenormand ◽  
Emil Millet ◽  
Ben Fabry ◽  
James P. Butler ◽  
Jeffrey J. Fredberg
Keyword(s):  
Power Law ◽  
Time Scale ◽  
Relaxation Times ◽  
Cell Types ◽  
Creep Function ◽  
Scale Invariant ◽  
Time Constants ◽  
Frequency Domains ◽  
Power Law Exponent ◽  
The Matrix

We report here the creep function measured in three cell types, after a variety of interventions, and over three time decades (from 3ms to 3.2 s). In each case the response conformed to a power law, implying that no distinct molecular relaxation times or time constants could characterize the response. These results add to a growing body of evidence that stands in contrast to widely used viscoelastic models featuring at most a few time constants. We show instead that the ability of the matrix to deform is time-scale invariant and characterized by only one parameter: the power law exponent that controls the transition between solid-like and liquid-like behaviour. Moreover, we validate linearity by comparison of measurements in the time and frequency domains.

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