A lithosphere-atmosphere-ionosphere coupling model for ELF electromagnetic waves radiated from seismic sources and its possibility observed by the CSES

Zhao, Shufan; Shen, Xuhui; Liao, Li; Zhima, Zeren

doi:10.1007/s11431-021-1934-5

Cited by 15 publications

(11 citation statements)

References 46 publications

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“…It can be well understood from Figures 2, 3 by Zhao et al (2021) that the wave power of the EM waves radiated by the EQs with a magnitude greater than 6.0 can propagate to high altitudes. At CSES's orbit space, the wave power can sustain a higher level (-0-20 dB) at the frequency band from 20 Hz to 1000 Hz; and at a frequency higher than 1000 Hz, the wave power dramatically declines to below 0 dB.…”

Section: Figure 10mentioning

confidence: 91%

“…Additionally, the lower the depth, the lower frequency of waves that can be observed by satellite. The simulation from Zhao et al (2021) suggests that the EM waves radiated from an EQ with a magnitude more than 6.0 can be recorded by CSES, but there exists a dominant frequency band for waves radiated from the epicenters with depths from 20 km to 10 km in the lithosphere. The dominant frequency is about 300 Hz for a source with a 10 km depth and the dominant frequency might be 100 Hz for a depth of 20 km.…”

Section: Figure 10mentioning

confidence: 98%

“…Frontiers in Astronomy and Space Sciences frontiersin.org upward ionospheric hiss under quiet conditions is far less than that in the seismic time. Zhao et al (2021) built an ELF wave propagation model to simulate the propagating process of waves from the lithosphere to the ionosphere, and results show that the wave power decreases with increasing frequency due to skin effect through an isotropic conductive medium. In other words, the higher frequency waves are more easily attenuated by the medium, leading to their propagation path being relatively short.…”

Section: Figure 10mentioning

confidence: 99%

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The upward propagating ionospheric hiss waves during the seismic time observed by the China seismo-electromagnetic satellite

Lv¹,

Zhima³

et al. 2023

Front. Astron. Space Sci.

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The ionospheric hiss wave is a broadband incoherent and structureless electromagnetic emission. They appear in a relatively narrower frequency range between −0.1 and 1.5 kHz. However, according to previous observations, abnormal electromagnetic emissions during seismic activities also preferentially appear in the same frequency range of ionospheric hiss. This work studies the propagation features of the ionospheric hiss during seismic time based on the observations from the CSES (China Seismo-Electromagnetic Satellite). The wave vector analysis shows that during seismic activities, except for the downward propagating ionospheric hiss which is a common phenomenon in the ionosphere, there are upward propagating emissions mixed with the downward propagating ionospheric hiss. We made a statistical analysis of the shallow strong earthquakes (M ≥ 6.0, depth below 30 km) that occurred in mainland China from 2019 to 2022. We selected the ionospheric hiss events recorded by orbits passing over the epicenters within a time window (the 1-month prior to and 1-week after the main shock). We found that although most of the events are the typical downward propagating ionospheric hiss waves, however, there are certain events mixed with the upward propagating emissions. The statistical distribution analysis of wave propagation parameters shows that the major part of wave normal angles vary from 40 to 60, the azimuthal angles predominately attain below 40, and the ellipticity shows a more complicated feature varying around ± 0.5, and the planarity values predominate at values between 0.6 and 1. The frequency band of the upward propagating ionospheric hiss mostly varies between 300 Hz and 800 Hz. To further study the behavior of such upward propagating ionospheric hiss wave during the seismic time, we compared the wave activities under non-seismic activity and quiet space weather conditions, and the results confirm that the occurrence rate of the upward propagating emissions under quiet conditions is far less than that in the seismic time. We suggest that there is a link between the upward propagating ionospheric hiss and the seismic activity, but the physical reason behind it still remains a puzzle to us.

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Section: Figure 10mentioning

confidence: 91%

Section: Figure 10mentioning

confidence: 98%

Section: Figure 10mentioning

confidence: 99%

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The upward propagating ionospheric hiss waves during the seismic time observed by the China seismo-electromagnetic satellite

Lv¹,

Zhima³

et al. 2023

Front. Astron. Space Sci.

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“…In recent years, with the improvement of electromagnetic observation technology, the anomalous disturbances of the ionospheric electric field before strong earthquakes have been observed by various means (Ouzounov et al, 2007;Liu et al, 2010;Pulinets et al, 2018). The ground-based electromagnetic observation and simulation experimental study revealed anomalous pre-earthquake ionospheric electric field disturbances in a wide frequency band, especially in the very-low-frequency/ ultra-low-frequency (ELF/VLF) band, which is easily observed (Zhao et al, 2021). Gokhberg et al (1982) first discovered anomalous disturbances in electromagnetic signals before earthquakes by satellite.…”

Section: Introductionmentioning

confidence: 99%

Statistical analysis of electric field perturbations in ELF based on the CSES observation data before the earthquake

Zhang

Huang²,

Li³

et al. 2023

Front. Earth Sci.

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To explore the correlation between earthquakes and the pre-earthquake ionospheric shallow frequency (ELF) electric field perturbations phenomenon, the paper investigated the pre-earthquake ionospheric perturbations phenomenon, and then the Spatio-temporal evolution characteristics of the electromagnetic field before and after the global Ms ≥6.0 strong earthquakes from 2019 to 2021 were statistically analyzed. In this paper, the power spectrum data of the ELF (19.5–250 Hz) band of ionospheric electric field observed by the China Seismo-Electromagnetic Satellite (CSES) electric field detector are preclinically processed by the C-value method. A stable background field observation model was constructed using the data from 75 to 45 days before the earthquake observed by the CSES in the range of 15° above the epicenter. Then, the amplitude of the spatial electric field disturbance over the epicenter relative to the background field is extracted. Finally, the superposition analysis method statistically analyzes the spatial and temporal evolution of the spatial electric field before and after the earthquake with different characteristics. The statistical results show that the anomalies first appear in the fourth period (15–19 days before the earthquake) and the third period (10–14 days before the earthquake) and then reach the most vital and most evident during the pro-earthquake period (4 days before the earthquake and the day of the earthquake); In terms of the intensity of the anomalies caused, the magnitude seven earthquakes are stronger than the magnitude 6.0–7.0 earthquakes, and marine earthquakes are stronger than land earthquakes; in terms of the ease of observing the anomalies, the magnitude 7.0 and above are more accessible to observe than the magnitude 6.0–7.0 earthquakes, and marine earthquakes are more accessible to observe than land earthquakes.

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“…Following the launch of the China Seismo-Electromagnetic Satellite (CSES) on February 2, 2018, a series of studies have been conducted in various areas. These include data availability (Yan et al, 2020;Liu et al, 2021), global geomagnetic models , ionospheric events such as magnetic storms (Spogli et al, 2021), statistical characteristics of seismic ionospheric disturbances (Li et al, 2020; De Santis et al, 2021), and multi-layer coupling (Marchetti et al, 2019;Zhao et al, 2021;Liu et al, 2023;.…”

Section: Introductionmentioning

confidence: 99%

An Improved Pattern Informatics Method for Extracting Ionospheric Disturbances Related to Seismicity Based on CSES Data: A Case Study of the Mw 7.3 Maduo Earthquake

Tian,

Zhang,

et al. 2023

Preprint

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The exploration of multi-layer coupling mechanisms between earthquakes and the ionosphere is crucial for utilizing ionospheric precursors in earthquake prediction. A significant research task involves continuously tracking the spatio-temporal changes in ionospheric parameters, acquiring comprehensive seismic anomaly information, and capturing “deterministic” precursor anomalies. Building upon previous research on seismic ionospheric signal characteristics and data from the China Seismo-Electromagnetic Satellite (CSES), we have enhanced the Pattern Informatics(PI) Method and proposed an Improved Pattern Informatics(IPI) Method. The IPI method enables the calculation of the spatio-temporal dynamics of electronic density anomalies detected by the CSES satellite. Taking the 2021 Maduo Mw7.3 earthquake as a case study, we analyzed the seismic signals potentially contained in the electronic density anomaly disturbances. The results show that: 1) Compared to original electronic density images, the IPI method-derived models extracted distinct electronic density anomaly signals, regardless of the data collected whether during descending (daytime) or ascending (nighttime) orbits, or across different time scales of change window. 2) The electronic density anomalies appeared about 40 days prior to the Maduo Mw7.3 earthquake. The evolution of these anomalies followed a pattern of appearance, persistence, disappearance, re-emergence, and final disappearance. Moreover, the evolution trends of the IPI hotspot images calculated from descending and ascending orbit data were similar. These results suggest that the IPI method can capture the spatio-temporal trends of ionospheric parameters and effectively extract electronic precursors related to strong earthquakes.

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A lithosphere-atmosphere-ionosphere coupling model for ELF electromagnetic waves radiated from seismic sources and its possibility observed by the CSES

Cited by 15 publications

References 46 publications

The upward propagating ionospheric hiss waves during the seismic time observed by the China seismo-electromagnetic satellite

The upward propagating ionospheric hiss waves during the seismic time observed by the China seismo-electromagnetic satellite

Statistical analysis of electric field perturbations in ELF based on the CSES observation data before the earthquake

An Improved Pattern Informatics Method for Extracting Ionospheric Disturbances Related to Seismicity Based on CSES Data: A Case Study of the Mw 7.3 Maduo Earthquake

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