On the modulation of intensity of Alfvén resonances before earthquakes: Observations and model

Grimalsky, V.; Kotsarenko, A.; Пулинец, С. А.; Koshevaya, S.; Pérez-Enríquez, R.

doi:10.1016/j.jastp.2009.09.017

Cited by 5 publications

(4 citation statements)

References 14 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ULF waves of different frequencies and polarizations observed on the ground may originate from different regions of the magnetosphere, the distant space or the Sun's environment. Ultra-low frequency waves are detected on the ground as geomagnetic pulsations, ranging in frequency from some Hz to less than 1 mHz and numerous theories have been proposed to explain their origin (Pilipenko, 1990;McPherron, 2005;Pulinets and Boyarchuk, 2004;Grimalsky et al, 2010) On the other hand, there have been many reports of ULF waves observed before an earthquake, which have been considered as originating from tectonic processes. Many other electromagnetic EM field changes have also been reported before earthquakes on the ground, in the atmosphere and in a wide range of frequency of the EM spectrum as sub-ULF, ULF/ELF, VLF, IR (Hayakawa and Fujinawa, 1994;Molchanov and Hayakawa, 1998;Ouzounov and Freund, 2004;Hattori, 2004;Liu et al, 2004;Balasis and Mandea, 2007;Hayakawa et al, 2010;Uyeda et al, 2009, Pulinets andOuzounov, 2011;Athanasiou et al, 2011Athanasiou et al, , 2014Freund et al, 2012;ZhangShen et al, 2012;Tramutoli et al, 2015, De Santis et al, 2015, 2017Han, 2020).…”

Section: Theoretical and Observational Framework Ultra Low Frequency Electromagneticmentioning

confidence: 99%

“…The Origin of Terrestrial Ultra Low Frequency Electromagnetic Waves and the Taiwan Chi-Chi 7.7M w 1999 Earthquake Ultra low frequency (ULF) waves observed by terrestrial observatories is a matter of scientific research of great interest. ULF waves provide significant information about geomagnetic processes and earthquake (EQ) preparation processes and they have significant influence on biological organisms (Reichmanis et al, 1979;Pilipenko, 1990;Poole, 1993;Kivelson and Russell, 1995;Poole et al, 1993;McPherron, 2005;Pulinets and Boyarchuk, 2004;Grimalsky et al, 2010;Anagnostopoulos. 2015.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the Origin of ULF Magnetic Waves Before the Taiwan Chi-Chi 1999 Earthquake

Anagnostopoulos

2021

Front. Earth Sci.

View full text Add to dashboard Cite

The ultra low frequency (ULF) electromagnetic (EM) wave activity usually recorded on Earth’s ground has been found to depend on various types of space weather. In addition ULF waves observed before an earthquake have been hypothesized to be a result of geotectonic processes. In this study we elaborate for the first time the origin of sub-ULF (<1 msec) magnetic field waves before an earthquake (Chi-Chi/Taiwan, 20.9.1999) by comparing simultaneously obtained measurements in the interplanetary space (ACE satellite) and on the Earth’s ground (Taiwan). The most striking result of our data analysis, during a period of 7 weeks, is that the detection of four groups of sub-ULF waves in Taiwan coincide in time with the quasi-periodic detection of two solar wind streams by the satellite ACE with approximately the solar rotation period (∼28 days). The high speed solar wind streams (HSSs) in the interplanetary space were accompanied by sub-ULF Alfvén wave activity, quasi-periodic southward IMF and solar wind density perturbations, which are known as triggering agents of magnetic storm activity. The four HSSs were followed by long lasting decreases in the magnetic field in Taiwan. The whole data set examined in this study strongly suggest that the subULF magnetic field waves observed in Taiwan before the Chi-Chi 1999 earthquake is a normal consequence of the incident of HSSs to the magnetosphere. We provide some observational evidence that the sub-ULF electromagnetic radiation on the Earth was most probably a partner to (not a result of) geotectonic processes preparing the Taiwan 1999 earthquake.

show abstract

Section: Theoretical and Observational Framework Ultra Low Frequency Electromagneticmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

On the Origin of ULF Magnetic Waves Before the Taiwan Chi-Chi 1999 Earthquake

Anagnostopoulos

2021

Front. Earth Sci.

View full text Add to dashboard Cite

show abstract

“…Furthermore, anomalous emissions related to the Guam EQ, were observed two weeks prior and then again a few days before the main event on 8 August 1993 (M s = 8.0) (Hayakawa et al, 1996). Recent studies in the ULF range reveal a possible connection between the impact of the earthquake preparation process and ionospheric resonance phenomena prior to crustal rupture (Grimalsky et al, 2010).…”

Section: Introductionmentioning

confidence: 95%

Detection of ULF geomagnetic signals associated with seismic events in Central Mexico using Discrete Wavelet Transform

Chavez¹,

Millán-Almaraz²,

Pérez-Enríquez³

et al. 2010

Nat. Hazards Earth Syst. Sci.

Self Cite

View full text Add to dashboard Cite

Abstract.The geomagnetic observatory of Juriquilla Mexico, located at longitude -100.45 • and latitude 20.70 • , and 1946 m a.s.l., has been operational since June 2004 compiling geomagnetic field measurements with a three component fluxgate magnetometer. In this paper, the results of the analysis of these measurements in relation to important seismic activity in the period of 2007 to 2009 are presented. For this purpose, we used superposed epochs of Discrete Wavelet Transform of filtered signals for the three components of the geomagnetic field during relative seismic calm, and it was compared with seismic events of magnitudes greater than M s > 5.5, which have occurred in Mexico. The analysed epochs consisted of 18 h of observations for a dataset corresponding to 18 different earthquakes (EQs). The time series were processed for a period of 9 h prior to and 9 h after each seismic event. This data processing was compared with the same number of observations during a seismic calm. The proposed methodology proved to be an efficient tool to detect signals associated with seismic activity, especially when the seismic events occur in a distance (D) from the observatory to the EQ, such that the ratio D/ρ < 1.8 where ρ is the earthquake radius preparation zone. The methodology presented herein shows important anomalies in the Ultra Low Frequency Range (ULF; 0.005-1 Hz), primarily for 0.25 to 0.5 Hz. Furthermore, the time variance (σ 2 ) increases prior to, during and after the seismic event in relation to the coefficient D1 obtained, principally in the Bx (N-S) and By (E-W) geomagnetic components. Therefore, this paper proposes and develops a new methodology to extract the abnormal signals of the geomagnetic anomalies related to different stages of the EQs.

show abstract

“…For example, thunderstorms, volcanic eruptions, tsunami, typhoons, zonal winds, and earthquakes can be a strong sources of such waves (see e.g. Kazimirovsky et al, 2003;Occhipinti and Lognonné, 2008;Varney et al, 2009;Grimalsky et al, 2010;Rozhnoi et al, 2012, for details). It was shown (see e.g.…”

Section: Introductionmentioning

confidence: 99%

Convective cells of internal gravity waves in the earth's atmosphere with finite temperature gradient

2013

View full text Add to dashboard Cite

Abstract. In this paper, we have investigated vortex structures (e.g. convective cells) of internal gravity waves (IGWs) in the earth's atmosphere with a finite vertical temperature gradient. A closed system of nonlinear equations for these waves and the condition for existence of solitary convective cells are obtained. In the atmosphere layers where the temperature decreases with height, the presence of IGW convective cells is shown. The typical parameters of such structures in the earth's atmosphere are discussed.

show abstract

On the modulation of intensity of Alfvén resonances before earthquakes: Observations and model

Cited by 5 publications

References 14 publications

On the Origin of ULF Magnetic Waves Before the Taiwan Chi-Chi 1999 Earthquake

On the Origin of ULF Magnetic Waves Before the Taiwan Chi-Chi 1999 Earthquake

Detection of ULF geomagnetic signals associated with seismic events in Central Mexico using Discrete Wavelet Transform

Convective cells of internal gravity waves in the earth's atmosphere with finite temperature gradient

Contact Info

Product

Resources

About