Anomalies of Schumann resonances as observed near Nagoya associated with two huge (M∼7) Tohoku offshore earthquakes in 2021

Hayakawa, Masashi; Izutsu, Jun; Schekotov, A.; Nickolaenko, A. P.; Galuk, YuP.; Kudintseva, I. G.

doi:10.1016/j.jastp.2021.105761

Cited by 9 publications

(9 citation statements)

References 27 publications

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“…Additional evidence on the conductivity changes in the lower ionosphere and stratosphere was recently presented with the use of anomalous Schumann resonances for the same two EQs in this paper [102]. The anomalies of Schumann resonances near Nagoya were detected before and after each EQ (10-15 February for the first EQ and 19-24 March for the second EQ), which are characterized by enhancements in amplitudes of Schumann resonance harmonic frequencies.…”

Section: Lower Ionospheric Perturbationssupporting

confidence: 52%

Lithosphere–Atmosphere–Ionosphere Coupling Effects Based on Multiparameter Precursor Observations for February–March 2021 Earthquakes (M~7) in the Offshore of Tohoku Area of Japan

et al. 2021

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The purpose of this paper is to discuss the lithosphere–atmosphere–ionosphere coupling (LAIC) effects with the use of multiparameter precursor observations for two successive Japanese earthquakes (EQs) (with a magnitude of around 7) in February and March 2021, respectively, considering a seemingly significant difference in seismological and geological hypocenter conditions for those EQs. The second March EQ is very similar to the famous 2011 Tohoku EQ in the sense that those EQs took place at the seabed of the subducting plate, while the first February EQ happened within the subducting plate, not at the seabed. Multiparameter observation is a powerful tool for the study of the LAIC process, and we studied the following observables over a 3-month period (January to March): (i) ULF data (lithospheric radiation and ULF depression phenomenon); (ii) ULF/ELF atmospheric electromagnetic radiation; (iii) atmospheric gravity wave (AGW) activity in the stratosphere, extracted from satellite temperature data; (iv) subionospheric VLF/LF propagation data; and (v) GPS TECs (total electron contents). In contrast to our initial expectation of different responses of anomalies to the two EQs, we found no such conspicuous differences of electromagnetic anomalies between the two EQs, but showed quite similar anomaly responses for the two EQs. It is definite that atmospheric ULF/ELF radiation and ULF depression as lower ionospheric perturbation are most likely signatures of precursors to both EQs, and most importantly, all electromagnetic anomalies are concentrated in the period of about 1 week–9 days before the EQ to the EQ day. There seems to exist a chain of LAIC process (cause-and-effect relationship) for the first EQ, while all of the observed anomalies seem to occur nearly synchronously in time for the send EQ. Even though we tried to discuss possible LAIC channels, we cannot come to any definite conclusion about which coupling channel is plausible for each EQ.

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Section: Lower Ionospheric Perturbationssupporting

confidence: 52%

Lithosphere–Atmosphere–Ionosphere Coupling Effects Based on Multiparameter Precursor Observations for February–March 2021 Earthquakes (M~7) in the Offshore of Tohoku Area of Japan

et al. 2021

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“…This would have been a promising mechanism with which the relatively high frequency anomalies could have been observed from ground vibrations in the lithosphere, atmospheric pressure in the atmosphere and TEC in the ionosphere during the Luxian earthquake. Note that the upward and downward resonance motion can also modulate the level of the Schumann resonances prior to earthquakes [47]. In short, high-mode natural frequency ground vibrations would be the causal mechanism dominating ground vibrations at a relatively high frequency.…”

Section: Discussionmentioning

confidence: 99%

The LAI Coupling Associated with the M6 Luxian Earthquake in China on 16 September 2021

et al. 2021

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Periodic signals replaced noise that was found in continuous seismic data, particularly in the nighttime, from the broadband seismometer at the MVP-LAI (monitoring vibrations and perturbations in the lithosphere, atmosphere and ionosphere) system before the occurrence of the Luxian earthquake on 16 September 2021. A short distance of ~150 km between the MVP-LAI system and the epicenter of the Luxian earthquake suggests the periodic singles as promising seismo-phenomena, due to that the radius of the earthquake preparation zone is ~380 km for an M6 event. Integration of geophysical parameters, including atmospheric pressure, vertical electric field, radon concentration, groundwater level and precipitation, at the MVP-LAI system provides an excellent opportunity for studying the seismo-LAI coupling associated with the Luxian earthquake. Analytical results show that ground vibrations, atmospheric pressure and total electron content varied from ~10−3 to ~10−2 Hz before the Luxian earthquake. The seismo-LAI coupling in the relatively low frequency band (~10−3 Hz) can be referred to as the acoustic-gravity waves triggered by the amplified ground vibrations. In contrast, the seismo-LAI coupling in a relatively high frequency band (~10−2 Hz) would be caused by micro-cracks and/or the high-mode natural frequency that further drives changes of TEC due to the atmospheric resonance.

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“…The enhancement of the near-surface electric field can be attributed to dust from atmospheric resonance [Dolezalek et al, 1974]. The relationship between earthquakes and the Schumann resonance in the upper atmosphere has been reported by numerous studies [Ohta et al, 2006[Ohta et al, , 2009Ouyang et al, 2013;Hayakawa et al, 2021b]. The Schumann resonance may originate from high frequencies of atmospheric resonance.…”

Section: Chieh-hung Chen Et Almentioning

confidence: 94%

“…Future inclusion of a magnetotelluric system will allow the MVP-LAI system to routinely monitor electromagnetic signals across a wide frequency band, as well as detect changes in the underlying electric current. These instruments would be helpful in studying seismo-electromagnetic anomalies in a relatively high frequency band, and exploring further the seismo-Schumann resonance in the upper atmosphere [Hayakawa et al, 2021b].…”

Section: Mvp-lai In the Near Futurementioning

confidence: 99%

Double resonance in seismo-lithosphere-atmosphere-ionosphere coupling

Chen,

Sun,

Zhang

et al. 2023

Annals of Geophysics

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nvestigations into causal mechanisms behind anomalous pre-earthquake phenomena are considered a promising way of earthquake prediction. Numerous promising channels for seismo-lithosphere-atmosphere-ionosphere coupling have been proposed; however, predicting earthquakes remains a great challenge in the scientific society. Short-period ground vibrations exhibiting frequency characteristics similar to natural frequencies caused by strata failure resonance have recently been detected using tiltmeters embedded in magnetometers prior to earthquakes. These vibrations originate from regions near the epicentres of forthcoming earthquakes and can be simultaneously detected by broadband seismometers and ground-based global navigation satellite system (GNSS) receivers. Unlike the total electron contents (TECs) obtained from orbiting satellites, the vibrations and the identifiable TEC perturbations in data from geostationary satellites of the BeiDou Navigation System share frequencies prior to earthquakes. However, the causal relationship between the vibrations and TEC perturbations remains unclear due to a gap in data observations between the lithosphere and ionosphere. To address this issue, an instrumental array was established to monitor vibrations and perturbations in the lithosphere, atmosphere, and ionosphere. Observational data from the array partially fill the gap, and analytical results show that ground vibrations, air pressure, magnetic fields, and TEC data shared a common frequency of approximately 5 × 10–3 Hz (5 mHz) before major earthquakes. This suggests that the resonant ground vibrations trigger atmospheric resonance before earthquakes. Therefore, the double resonance (crustal and atmospheric resonance) model is a new explanation for the observed anomalies in multiple geophysical parameters in the lithosphere, atmosphere, and ionosphere. Retrieving resonant signals from multiple sources of observational data is a significant challenge, but once this issue is overcome, double resonance may contribute to practical earthquake prediction.

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Anomalies of Schumann resonances as observed near Nagoya associated with two huge (M∼7) Tohoku offshore earthquakes in 2021

Cited by 9 publications

References 27 publications

Lithosphere–Atmosphere–Ionosphere Coupling Effects Based on Multiparameter Precursor Observations for February–March 2021 Earthquakes (M~7) in the Offshore of Tohoku Area of Japan

Lithosphere–Atmosphere–Ionosphere Coupling Effects Based on Multiparameter Precursor Observations for February–March 2021 Earthquakes (M~7) in the Offshore of Tohoku Area of Japan

The LAI Coupling Associated with the M6 Luxian Earthquake in China on 16 September 2021

Double resonance in seismo-lithosphere-atmosphere-ionosphere coupling

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