Y. Luo, L. F. Chernogor, K. P. Garmash, Q. Guo, Yu. Zheng


Purpose: The object of the radio study is to investigate dynamic processes, which occurred over the People’s Republic of China following three moderate (magnitudes 5.9-6.6) earthquakes in Japan in 2018–2019. The distances between the earthquake epicenters and the radio paths midpoints varied from approximately 1300 to 2000 km The aim of the study is to present observations of the dynamic processes in the ionosphere, which accompanied the earthquakes in Japan, and the analysis of intercomparison between the events.

Design/methodology/approach: To continuously observe the ionosphere state over the ~ 100-300 -km altitude range, the multi-frequency multiple path radio system for oblique incidence soundings of the ionosphere has been designed by the specialists at the V. N. Karazin  National University (Ukraine) and the Harbin Engineering University, PRC (45.78 N, 126.68 E). The basic premise upon which the system operation is based are the measurements of the Doppler shift of frequency, fD, and of the amplitude of radio waves reflected from the ionosphere. The Doppler spectra are calculated over the 20-s intervals, with the Doppler resolution of 0.02 Hz and the time resolution of 7.5 s.

Findings: The seismic activity in Japan on July 7, 2018 was accompanied by an increase in a number of rays, by a significant broadening of the Doppler spectra, and by aperiodic processes in the ionosphere at distances no less than 1000–2000 km from the earthquake epicenters. Also, wave disturbances, generated by the seismic waves (speeds of 3 km/s), have been revealed in the 4–5-min infrasonic period range; the amplitude, δN, of the quasi-periodic variations in the electron density, N, was observed to be 4.5–9 %, and the duration of the oscillation trains to vary in the 24–55-min range. The relative amplitude δNa, of the electron concentration variations with the period 15-30 min caused by the propagation of atmospheric gravity wave (AGW) was estimated to be 30–55 %, the oscillation train duration was observed to be approximately 100 min, and the speed 0.3 km/s. The character of the Doppler spectrum variations, the Doppler shift of frequency over the main ray, and of the signal amplitude were found to be notably different during the September 5, 2018 earthquake and on the reference days. Two characteristic apparent speeds of 3.3 km/s and of 500 m/s were revealed. The former is close to that of seismic waves, and the latter to the speed of AGWs in the terrestrial ionosphere. The relative amplitudes in the infrasonic and AGW wave fields were estimated to be δN1.5-3 % and δNa6-7.5 %, respectively. The April 11, 2019 earthquake was accompanied by the Doppler spectrum broadening by 1-1.5 Hz in the 5–9.8 MHz frequency range, the generation of AGWs with 0.5-1 -km/s speeds and 8-20 -min periods, and by the generation of infrasonic waves with 2-5 -min periods and 0.3-0.4 -km/s speeds.

Conclusions: Moderate earthquakes of Richter magnitudes 6 have been determined to give rise to dynamic processes in the ionosphere at distances no less than 1000-2000 km. The disturbances are transported by seismic waves with 3 km/s speeds and by acoustic and atmospheric gravity waves with 0.3–1 km/s speeds and periods varying from units to tens of minutes.

Key words: earthquake, oblique incidence ionospheric sounding, Doppler spectrum, aperiodic and quasi-periodic disturbances, seismic wave, acoustic and atmospheric gravity waves

Manuscript submitted 10.06.2020

Radio phys. radio astron. 2020, 25(3): 218-230


1. CHERNOGOR, L. F., 2003. Physics of Earth, Atmosphere, and Geospace from the Standpoint of System Paradigm. Radio Phys. Radio Astron. vol. 8, is. 1, pp. 59–106. (in Russian).

2. CHERNOGOR, L. F. and ROZUMENKO, V. Т., 2008. Earth – Atmosphere – Geospace as an Open Nonlinear Dynamical System. Radio Phys. Radio Astron. vol. 13, is. 2, pp. 120–138.

3. CHERNOGOR, L. F., 2011. The Earth – atmosphere – geospace system: main properties and processes. Int. J. Remote Sens. vol. 32, is. 11, pp. 3199–3218. DOI:

4. PULINETS, S. A., OUZOUNOV, D. P., KARELIN, A. V., and DAVIDENKO, D. V., 2015. Physical bases of the generation of short-term earthquake precursors: A complex model of ionization-induced geophysical processes in the lithosphere-atmosphere-ionosphere-magnetosphere system. Geomagn. Aeron. vol. 55, is. 4, pp. 521–538. DOI:

5. BOLT, B. A., 1964. Seismic Air Waves from the Great 1964 Alaskan Earthquake. Nature. vol. 202, is. 4937, pp. 1095–1096. DOI:

6. DONN, W. L. and POSMENTIER, E. S., 1964. Ground-Coupled Air Waves from the Great Alaskan Earthquake. J. Geophys. Res. vol. 69, is. 24, pp. 5357–5361. DOI:

7. DAVIES, K. and BAKER, D. M., 1965. Ionospheric Effects Observed around the Time of the Alaskan Earthquake of March 28. J. Geophys. Res. vol. 70, is. 9, pp. 2251–2253. DOI:

8. ROW, R. V., 1966. Evidence of Long-Period Acoustic Gravity Waves Launched into the F Region by the Alaskan Earthquake of March 28. J. Geophys. Res. vol. 71, is. 1, pp. 343–345. DOI:

9. PAVLOV, V. A., 1979. Effects of earthquakes and volcanic eruptions on the ionospheric plasma. Radiophys. Quantum. Electron. vol. 22, is. 1, pp. 10–23. DOI:

10. AL’PEROVICH, L. S., GOKHBERG, M. B., SOROKIN, V. M. and FEDOROVICH, G. V., 1979. On generation of geomagnetic variations by acoustic oscillations during earthquakes. Izv. AN SSSR. Fizika Zemli. no. 3, pp. 58–68. (in Russian).

11. DOIL’NITSYNA, É. G., DROBYAZKO, I. N. and PAVLOV, V. A., 1981. Influence of an earthquake on the electron concentration in the F layer of the ionosphere. Radiophys. Quantum. Electron. vol. 24, is. 7, pp 535–542. DOI:

12. PAVLOV, V. A., 1986. Acoustic pulse above the earthquake epicenter. Geomagn. Aeron. vol. 26, no. 5, pp. 807–815. (in Russian).

13. SURKOV, V. V., 2000. Electromagnetic effects caused by earthquakes and explosions. Moscow: MEPhI Press. (in Russian).

14. SHINAGAWA, H., IYEMORI, T., SAITO, S. and MARUYAMA, T., 2007. A numerical simulation of ionospheric and atmospheric variations associated with the Sumatra earthquake on December 26, 2004. Earth Planets Space. vol. 59, pp. 1015–1026. DOI:

15. LIPEROVSKY, V. A., POKHOTELOV, O. A., MEISTER, C.-V. and LIPEROVSKAYA, E. V., 2008. Physical models of coupling in the lithosphere-atmosphere-ionosphere system before earthquakes. Geomagn. Aeron. vol. 48, is. 6, pp. 795–806. DOI:

16. GOKHBERG, M. B. and SHALIMOV, S. L., 2008. The Impact of Earthquakes and Explosions on the Ionosphere. Moscow: Nauka Publ. (in Russian).

17. SURKOV, V. and HAYAKAWA, M., 2014. Ultra and Extremely Low Frequency Electromagnetic Fields. Tokyo, Heidelberg, New York, Dordrecht, London: Springer Japan. DOI:

18. SHARADZE, Z. S., DZHAPARIDZE, G. A., MATIASHVILI, T. G. and MOSASHVILI, N. V., 1989. Strong earthquakes and theirs connection with perturbations in the ionosphere and geomagnetic field. Izv. AN SSSR. Fizika Zemli. no. 1, pp. 20–32. (in Russian).

19. GARMASH, K. P., GRITCHIN, A. I., LEUS, S. G., PAKHOMOVA, O. V., POHIL’KO, S. N. and CHERNOGOR, L. F., 1994. Ionospheric plasma effect investigation on underground, ground and air explosions and earthquakes. In: Space Plasma Physics. Proceedings of International Workshop. Kyv: State Space Agency of Ukraine, Main Astronomic Observatory of National Academy of Sciences of Ukraine, T. G. Shevchenko Kyiv National University Publ., pp. 151–160. (in Russian).

20. GARMASH, K. P., GOKOV, A. M., KOSTROV, L. S., ROZUMENKO, V. T., TYRNOV, O. F., FEDORENKO, Y. P., TSYMBAL, A. M. and CHERNOGOR, L. F., 1999. Radiophysical Investigations and Modeling of Ionospheric Processes Generated by Sources of Various Nature. 1. Processes in a Naturally Disturbed Ionosphere. Technical Facilities. Telecomm. Radio Eng. vol. 53, is. 4-5, pp. 6–20. DOI:

21. GARMASH, K. P., GOKOV, A. M., KOSTROV, L. S., ROZUMENKO, V. T., TYRNOV, O. F., FEDORENKO, Y. P., TSYMBAL, A. M. and CHERNOGOR, L. F., 1999. Radiophysical Investigations and Modeling of Ionospheric Processes Generated by Sources of Various Nature. 2. Processes in a Modified Ionosphere. Signal Parameter Variations. Disturbance Simulation. Telecomm. Radio Eng. vol. 53, is. 6, pp. 1–22. DOI:

22. GARMASH, K. P., ROZUMENKO, V. T., TYRNOV, O. F., TSYMBAL, A. M. and CHERNOGOR, L. F., 1999. Radio-propagation studies of the processes acting in the near-Earth plasma disturbed by high-energy sources. Part 1. Zarubezhnaya radioelektronika. Uspekhi sovremennoi radioelektroniki. no. 7, pp. 3–15. (in Russian).

23. GARMASH, K. P., ROZUMENKO, V. T., TYRNOV, O. F., TSYMBAL, A. M. and CHERNOGOR, L. F., 1999. Radio-propagation studies of the processes acting in the near-Earth plasma disturbed by high-energy sources. Part 2. Zarubezhnaya radioelektronika. Uspekhi sovremennoi radioelektroniki. no. 8, pp. 3–19. (in Russian).

24. BABA, K. and HAYAKAWA, M., 1994. The Effect of Localized Ionospheric Perturbations on Subionospheric VLF Propagation on the Basis of the Finite Element Method. In: M. HAYAKAWA and Y. FUJINAWA, eds. Electromagnetic Phenomena Related to Earthquake Prediction. Tokyo: Terra Sci. Publ. Comp., pp. 399–407.

25. CALAIS, E. and MINSTER, J. B., 1995. GPS detection of ionospheric perturbations following the January 17, 1994, Northridge earthquake. Geophys. Res. Lett. vol. 22, is.9, pp. 1045–1048. DOI:

26. CALAIS, E. and BERNARD, J., 1998. GPS, Earthquake, the ionosphere, and Space Shuttle. Phys. Earth Planet Inter. vol. 105, is. 3-4, pp. 167–181. DOI:

27. GARCIA, R., CRESPON, F., DUCIC, V. and LOGNONNÉ, P., 2005. Three-dimensional ionospheric tomography of post-seismic perturbations produced by the Denali earthquake from GPS data. Geophys. J. Int. vol. 163, is. 3, pp. 1049–1064. DOI:

28. HEKI, K. and PING, J., 2005. Directivity and apparent velocity of the coseismic ionospheric disturbances observed with a dense GPS array. Earth Planet. Sci. Lett. vol. 236, is. 3-4, pp. 845–855. DOI:

29. FEDORENKO, A. K., LIZUNOV, G. V. and ROTHKAEHL, H., 2005. Satellite observations of quasi-wave atmospheric disturbances at heights of the F region caused by powerful earthquakes. Geomagn. Aeron. vol. 45, is. 3, pp. 380–387.

30. AFRAIMOVICH, E. L., ASTAFIEVA, E. I. and KIRUSHKIN, V. V., 2006. Localization of the source of ionospheric disturbance generated during an earthquake. Int. J. Geomagn. Aeron. vol. 6, is. 2, id. GI2002. DOI:

31. HEKI, K., OTSUKA, Y., CHOOSAKUL, N., HEMMAKORN, N., KOMOLMIS, T. and MARUYAMA, T., 2006. Detection of ruptures of Andaman fault segments in the 2004 great Sumatra earthquake with coseismic ionospheric disturbances. J. Geophys. Res. vol. 111, is. B9, id. B09313. DOI:

32. LIU, J. Y., TSAI, Y. B., CHEN, S. W., LEE, C. P., CHEN, Y. C., YEN, H. Y., CHANG, W. Y. and LIU, C., 2006. Giant ionospheric disturbances excited by the M9.3 Sumatra earthquake of 26 December 2004. Geophys. Res. Lett. vol. 33, is. 2, id.  L02103. DOI:

33. ASTAFYEVA, E. I. and AFRAIMOVICH, E. L., 2006. Long-distance traveling ionospheric disturbances caused by the great Sumatra-Andaman earthquake on 26 December 2004. Earth Planets Space. vol. 58, is. 8, pp. 1025–1031. DOI:

34. AFRAIMOVICH, E. L., DING F., KIRYUSHKIN, V. V., ASTAFYEVA, E. I., JIN S. and SANKOV, V. A., 2010. TEC Response to the 2008 Wenchuan Earthquake in comparison with other strong earthquakes. Int. J. Remote Sens. vol. 31, is. 13, pp. 3601–3613. DOI:

35. KIRYUSHKIN, V. V., AFRAIMOVICH, E. L. and ASTAFYEVA, E. I., 2011. Evolution of seismo-ionospheric disturbances according to the data of dense network of GPS stations. Cosm. Res. vol. 49, is. 3, id. 227. DOI:

36. ROLLAND, L. M, LOGNONNÉ, P., ASTAFYEVA, E., KHERANI, E. A., KOBAYASHI, N., MANN, M. and MUNEKANE, H., 2011. The resonant response of the ionosphere imaged after the 2011 off the Pacific coast of Tohoku earthquake. Earth Planets Space. vol. 63, is. 7, pp. 853–857. DOI:

37. LIU, J. Y., CHEN, C. H., SUN, Y. Y., CHEN, C. H., TSAI, H. F., YEN, H. Y., CHUM, J., LAŠTOVIČKA, J., YANG, Q. S., CHEN, W. S. and WEN, S., 2016. The vertical propagation of disturbances triggered by seismic waves of the 11 March 2011 M9.0 Tohoku earthquake over Taiwan. Geophys. Res. Lett. vol. 43, is. 4, pp. 1759–1765. DOI:

38. HEKI, K., 2020. Ionospheric disturbances related to Earthquakes. In: C. HUANG, G. LU, Y. ZHANG, and L. J. PAXTON, eds. Space Physics and Aeronomy. Volume 3: Advances in Ionospheric Research: Current Understanding and Challenges. Wiley. 2020.

39. GUO, Q., CHERNOGOR, L. F., GARMASH, K. P., ROZUMENKO, V. T. and ZHENG, Y., 2019. Dynamical processes in the ionosphere following the moderate earthquake in Japan on 7 July 2018. J. Atmos. Sol.-Terr. Phys. vol. 186, pp. 88–103. DOI:

40. GUO, Q., CHERNOGOR, L. F., GARMASH, K. P., ROZUMENKO, V. T. and ZHENG, Y., 2020. Radio Monitoring of Dynamic Processes in the Ionosphere over China during the Partial Solar Eclipse of 11 August 2018. Radio Sci. vol. 55, is. 2, id. e2019RS006866. DOI:

41. Chernogor, L. F., GARMASH, K. P., GUO, Q., LUO, Y., ROZUMENKO, V. T. and ZHENG, YU., 2020. Ionospheric storm effects over the People’s Republic of China on 14 May 2019: Results from multipath multi-frequency oblique radio sounding. Adv. Space Res. vol. 66, is. 2, pp. 226–242. DOI:

42. MARPLE JR., S. L., 1987. Digital spectral analysis: with applications. Englewood Cliffs, N.J.: Prentice-Hall, Inc., 1987. 492 p.

43. DAVIES, K., 1990. Ionospheric radio. London: Peter Peregrinus Ltd. 1990. 580 p. DOI:



earthquake; oblique incidence ionospheric sounding; Doppler spectrum; aperiodic and quasi-periodic disturbances; seismic wave; acoustic and atmospheric gravity waves

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