Vestnik КRAUNC. Fiz.-Mat. nauki. 2023. vol. 45. no. 4. P. 67-80. ISSN 2079-6641

Research Article
Full text in Russian
MSC 86A10, 86A15

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Disturbances in the F2 Layer of the Ionosphere Preceding the Onset of Earthquakes with M\geq6.0 in the Kamchatka Region

V. V. Bogdanov, A. V. Pavlov^\ast

Institute of Cosmophysical Research and Radio Wave Propagation FEB RAS, 684034, Kamchatka region, Elizovskiy district, Paratunka, Mirnaya str., 7, Russia

Abstract. The paper presents an analysis of data from hourly measurements of the critical frequency of the ionospheric F2 layer (foF2), carried out over the time interval 01.07.1968-30.07.1997 at the vertical radio sounding station of the ionosphere PK553 (Paratunka, Kamchatka region) in order to identify seismoionospheric anomalies preceding earthquakes with magnitudes M\geq6.0. During the analysis, 45 earthquakes of corresponding magnitudes were considered, in the preparation zone of which, determined by the Dobrovolsky formula, the PK553 ionospheric station was located. The vertical radio sounding station of the ionosphere MG560 (Stekolny, Magadan region) was chosen as a control station. The procedure for detecting seismic-ionospheric disturbances consisted of a joint analysis of the foF2 critical frequency data measured at the reference and control ionospheric stations for vertical radio sounding of the ionosphere. An ionospheric disturbance recorded at a reference station was considered as a possible ionospheric precursor of earthquakes if the deviation of the reference station’s foF2 values from the boundaries of the background range of values was observed under conditions of low geomagnetic activity, while the foF2 values of the control station were within its range of background values. Anomalies in foF2 values of the reference station preceded 20% of the considered seismic events. The quantitative characteristics of ionospheric disturbances were made: the maximum relative deviations of the anomalous foF2 values from the median values and from the boundaries of the background range, the lead time of the ionospheric disturbance at the moment of the earthquake. Empirical dependencies were obtained that connect the epicentral distances of earthquakes and the lead time of ionospheric disturbances at the moment of the onset of earthquakes with their magnitude. The identified disturbances of the critical frequency foF2 may be associated with the processes of preparation of the corresponding earthquakes, i.e. may be possible ionospheric precursors of earthquakes.

Key words: ionosphere, vertical radio sounding, lithosphere, earthquake, earthquake precursor.

Received: 02.11.2023; Revised: 11.12.2023; Accepted: 13.12.2023; First online: 14.12.2023

For citation. Bogdanov V. V., Pavlov A. V. Disturbances in the F2 layer of the ionosphere preceding the onset of earthquakes with M\geq6.0 in the Kamchatka region. Vestnik KRAUNC. Fiz.-mat. nauki. 2023, 45: 4, 67-80. EDN: TQCCNS.

Funding. The research was carried out in the framework of realization of the State Task АААА-А21-121011290003-0. The work was realized by the means of the Common Use Center ”NorthEastern Heliogeophysical Center” CKP 558279, USU 351757.

Competing interests. There are no conflicts of interest regarding authorship and publication.

Contribution and Responsibility. All authors contributed to this article. Authors are solely responsible for providing the final version of the article in print. The final version of the manuscript was approved by all authors.

^\astCorrespondence: E-mail:

The content is published under the terms of the Creative Commons Attribution 4.0 International License

© Bogdanov V. V., Pavlov A. V., 2023

© Institute of Cosmophysical Research and Radio Wave Propagation, 2023 (original layout, design, compilation)


  1. Liperovskiy V. A., Pokhotelov O. A., Shalimov S. L. Ionosfernye predvestniki zemletryaseniy [Ionospheric precursors of earthquakes]. Moscow, Nauka, 1992, 304 pp. (In Russian)
  2. Pulinets S.A., Boyarchuk K.A. Ionospheric Precursors of Earthquakes. Berlin, Springer, 315 p, 2004
  3. Pulinets S. A., Uzunov D.P., Davidenko D. V., Dudkin S. A., Tsadikovskiy E. I. Prognoz zemletryaseniy vozmozhen?! [Earthquake forecast is possible?!]. Moscow, Trovant, 2014, 144 pp. (In Russian)
  4. Khegay V. V., Legen’ka A. D., Kim V.P., K. Georgieva K. Ionosfernyy predvestnik razrushitel’nogo zemletryaseniya, proizoshedshego 6 aprelya 2009 g. v L’Akvile (Italiya) [Ionospheric precursor of a destructive earthquake that occurred on April 6, 2009 at L’Aquila (Italy)], Geomagnetizm i aeronomiya, 2011, vol. 51, no. 1, pp. 73-79 (In Russian)
  5. Khegay V. V., Legen’ka A. D., Kim V.P. Anomal’noe uvelichenie kriticheskoy chastoty foF2 pered ispanskim zemletryaseniem 11.05.2011 g. [Anomalous increase in the fof2 critical frequency prior to the spanish earthquake of May 11, 2011], Geomagnetizm i aeronomiya, 2014, vol. 54, no. 1, pp. 89-93 (In Russian)
  6. Legen’ka A. D., Khegay V. V., Kim V.P. Vozmushcheniya kriticheskoy chastoty F2-sloya pered zemletryaseniem v Yaponii v rayone ostrova Khokkaydo 11.09.2008 g. i v period umerennoy magnitnoy buri po dannym stantsiy nazemnogo vertikal’nogo zondirovaniya ionosfery [Disturbances in the F2 region critical frequency before the earthquake of September 11, 2008 off the coast of Hokkaido, Japan, and during a moderate magnetic storm based on data from ground-based vertical ionosphere sounding stations], Geomagnetizm i aeronomiya, 2016, vol. 56, no. 3, pp. 353-364 (In Russian)
  7. Pulinets S. A., Legen’ka A. D., Khegay V. V., Kim V.P., Korsunova L.P. Vozmushcheniya ionosfery, predshestvuyushchie zemletryaseniyam, po dannym nazemnoy stantsii vertikal’nogo zondirovaniya ionosfery WAKKANAI, Geomagnetizm i aeronomiya [Ionosphere disturbances preceding earthquakes according to the data of ground based station of the vertical ionospheric sounding WAKKANAI], 2018, vol. 58, no. 5, pp. 713-719 (In Russian)
  8. Dobrovolsky I.P., Zubkov S. I., Miachkin V. I. Estimation of the size of earthquake preparation zones, Pure Appl. Geophys., 1979, vol. 117. no 5, pp. 1025-1044
  9. Parrot M. Statistical analysis of Ionospheric Perturbations Observed by DEMETER in Relation with the Seismic Activity, Earthquake Science, 2011, vol. 24, no. 6, pp. 513-521
  10. Loewe C. A., Pr¨olss G. W. Classification and mean behavior of magnetic storms, J. Geophys. Res., 1997, vol. 102, no 7, pp. 14209-142013
  11. Klotz, S., Johnson, N.L. Encyclopedia of Statistical Sciences. Hoboken, John Wiley, 1983
  12. Forbes J. M., Palo S. E., Zhang X. Variability of the ionosphere, J. Atmos. Solar Terr. Phys., 2000, vol. 62, no. 8, pp. 685-693
  13. Sidorin A.Ya. Predvestniki zemletryaseniy [Earthquakes precursors]. Moscow, Nauka, 192 p., 1992.

Information about authors

Bogdanov Vadim Vasil’evich – Dr. Sci. (Phys. & Math.), Chief Researcher, Institute of Cosmophysical Research and Radio Wave Propagation FEB RAS, Paratunka, Russia, ORCID 0000-0002-9267-0401.

Pavlov Aleksey Vladimirovich – Cand. Sci. (Phys. & Math.), Researcher, Institute of Cosmophysical Research and Radio Wave Propagation FEB RAS, Paratunka, Russia, ORCID 0000-0001-5718-1429.