Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 106454 10.2205/2026es001131 cykdqr KAMCHATKA EARTHQUAKE M 8.8 ON JULY 29, 2025 KAMCHATKA EARTHQUAKE M 8.8 ON JULY 29, 2025 KAMCHATKA EARTHQUAKE M 8.8 ON JULY 29, 2025 Ionospheric Response to the Seismic Wave Induced by the Kamchatka Earthquake on July 29, 2025 Ionospheric Response to the Seismic Wave Induced by the Kamchatka Earthquake on July 29, 2025 https://orcid.org/0000-0002-1120-870X Ойнац Алексей Владимирович Oinats Aleksey Vladimirovich oinats@iszf.irk.ru

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 https://orcid.org/0000-0002-8732-511X Цедрик Марк Владиславович Cedrik Mark Vladislavovich mark7cedrick@gmail.com https://orcid.org/0009-0000-4910-9902 Дюков Илья Юрьевич Dyukov Il'ya Yur'evich https://orcid.org/0000-0002-9112-6535 Подлесный Алексей Витальевич Podlesnyi Aleksey Vitalyevich pav1986@rambler.ru https://orcid.org/0000-0003-2254-6138 Белинская Анастасия Юрьевна Belinskaya Anastasiya Yuryevna belinskayaay@ipgg.sbras.ru

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 https://orcid.org/0009-0001-8499-3737 Боровко Александра Антоновна Borovko Aleksandra A BorovkoAA@ipgg.sbras.ru https://orcid.org/0000-0001-5446-9697 Сорокин Александр Григорьевич Sorokin Aleksandr Grigoryevich sor@iszf.irk.ru

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 https://orcid.org/0009-0001-9860-8537 Добрынин Василий Андреевич Dobrynin Vasiliy Andreevich dobrynin@iszf.irk.ru https://orcid.org/0000-0001-5672-7813 Дергач Петр Александрович Dergach Petr Aleksandrovich DergachPA@ipgg.sbras.ru Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Россия Institute of Solar-Terrestrial Physics SB RAS Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation Институт нефтегазовой геологии и геофизики им. А.А. Трофимука СО РАН Новосибирск Россия Trofimuk Institute of Petroleum Geology and Geophysics SB RAS Novosibirsk Russian Federation Институт нефтегазовой геологии и геофизики им. А.А. Трофимука СО РАН Россия Trofimuk Institute of Petroleum Geology and Geophysics SB RAS Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation Институт нефтегазовой геологии и геофизики им. А.А. Трофимука СО РАН Россия Trofimuk Institute of Petroleum Geology and Geophysics SB RAS Russian Federation 01 07 2026 01 07 2026 26 2 ES2021 02 02 2026 25 05 2026 https://rjes.ru/en/nauka/article/106454/view

The July 29, 2025 earthquake near the eastern coast of the Kamchatka Peninsula induced a high-amplitude seismic wave that propagated thousands of kilometers from the epicenter. Ground vibrations caused variations in surface air pressure with periods in the infrasonic range, which propagated almost vertically into the upper atmosphere and modulated the ionospheric plasma. The resulting ionospheric disturbances were, in turn, recorded by a number of radiophysical facilities monitoring the ionosphere. In this paper, we provide an overview of the effects caused by the passage of the seismic wave, which were observed during ionospheric monitoring using vertical, oblique, and sky-wave backscatter sounding techniques in the Asian part of Russia.

The July 29, 2025 earthquake near the eastern coast of the Kamchatka Peninsula induced a high-amplitude seismic wave that propagated thousands of kilometers from the epicenter. Ground vibrations caused variations in surface air pressure with periods in the infrasonic range, which propagated almost vertically into the upper atmosphere and modulated the ionospheric plasma. The resulting ionospheric disturbances were, in turn, recorded by a number of radiophysical facilities monitoring the ionosphere. In this paper, we provide an overview of the effects caused by the passage of the seismic wave, which were observed during ionospheric monitoring using vertical, oblique, and sky-wave backscatter sounding techniques in the Asian part of Russia.

 Lithosphere-atmosphere-ionosphere coupling ionosphere monitoring vertical sounding oblique sounding sky-wave backscatter sounding HF radar infrasound Kamchatka megathrust earthquake Lithosphere-atmosphere-ionosphere coupling ionosphere monitoring vertical sounding oblique sounding sky-wave backscatter sounding HF radar infrasound Kamchatka megathrust earthquake This study was supported by the Ministry of Science and Higher Education of the Russian Federation (projects FWSE-2026-0003, FWZZ-2026-0051, and FWZZ-2026-0052). The results were obtained using the Core Shared Research Facility “Angara” of ISTP SB RAS (https://ckp-rf.ru/catalog/ckp/3056/). This study was supported by the Ministry of Science and Higher Education of the Russian Federation (projects FWSE-2026-0003, FWZZ-2026-0051, and FWZZ-2026-0052). The results were obtained using the Core Shared Research Facility “Angara” of ISTP SB RAS (https://ckp-rf.ru/catalog/ckp/3056/).

Afraimovich E. L., Perevalova N. P., Plotnikov A. V., et al. The shock-acoustic waves generated by earthquakes // Annales Geophysicae. — 2001. — Vol. 19, no. 4. — P. 395–409. — https://doi.org/10.5194/angeo-19-395-2001 Afraimovich E. L., Perevalova N. P., Plotnikov A. V., et al. The shock-acoustic waves generated by earthquakes // Annales Geophysicae. — 2001. — Vol. 19, no. 4. — P. 395–409. — https://doi.org/10.5194/angeo-19-395-2001 Artru J., Farges T. and Lognonné P. Acoustic waves generated from seismic surface waves: propagation properties determined from Doppler sounding observations and normal-mode modeling // Geophysical Journal International. — 2004. — Vol. 158, no. 3. — P. 1067–1077. — https://doi.org/10.1111/j.1365-246x.2004.02377.x Artru J., Farges T. and Lognonné P. Acoustic waves generated from seismic surface waves: propagation properties determined from Doppler sounding observations and normal-mode modeling // Geophysical Journal International. — 2004. — Vol. 158, no. 3. — P. 1067–1077. — https://doi.org/10.1111/j.1365-246x.2004.02377.x Berngardt O. I., Kurkin V. I., Kushnarev D. S., et al. ISTP SB RAS decameter radars // Solar-Terrestrial Physics. — 2020. — Vol. 6, no. 2. — P. 63–73. — https://doi.org/10.12737/stp-62202006 Berngardt O. I., Kurkin V. I., Kushnarev D. S., et al. ISTP SB RAS decameter radars // Solar-Terrestrial Physics. — 2020. — Vol. 6, no. 2. — P. 63–73. — https://doi.org/10.12737/stp-62202006 Cedrik M. V., Oinats A. V., Podlesnyi A. V., et al. Modeling of the ionosphere response to the passage of the Rayleigh wave caused by the earthquake in Taiwan on April 2, 2024 // Radio Propagation: Proceedings of the XXIX All-Russian Open Scientific Conference. — Kazan : Kazan University Press, 2025. — P. 80–83. — https://doi.org/10.26907/rwp29.2025.80-83 — (In Russian). Cedrik M. V., Oinats A. V., Podlesnyi A. V., et al. Modeling of the ionosphere response to the passage of the Rayleigh wave caused by the earthquake in Taiwan on April 2, 2024 // Radio Propagation: Proceedings of the XXIX All-Russian Open Scientific Conference. — Kazan : Kazan University Press, 2025. — P. 80–83. — https://doi.org/10.26907/rwp29.2025.80-83 — (In Russian). Chum J., Hruska F., Zednik J., et al. Ionospheric disturbances (infrasound waves) over the Czech Republic excited by the 2011 Tohoku earthquake // Journal of Geophysical Research: Space Physics. — 2012. — Vol. 117, A8. — https://doi.org/10.1029/2012ja017767 Chum J., Hruska F., Zednik J., et al. Ionospheric disturbances (infrasound waves) over the Czech Republic excited by the 2011 Tohoku earthquake // Journal of Geophysical Research: Space Physics. — 2012. — Vol. 117, A8. — https://doi.org/10.1029/2012ja017767 Chum J., Liu J. Y., Laštovička J., et al. Ionospheric signatures of the April 25, 2015 Nepal earthquake and the relative role of compression and advection for Doppler sounding of infrasound in the ionosphere // Earth, Planets and Space. — 2016. — Vol. 68, no. 1. — https://doi.org/10.1186/s40623-016-0401-9 Chum J., Liu J. Y., Laštovička J., et al. Ionospheric signatures of the April 25, 2015 Nepal earthquake and the relative role of compression and advection for Doppler sounding of infrasound in the ionosphere // Earth, Planets and Space. — 2016. — Vol. 68, no. 1. — https://doi.org/10.1186/s40623-016-0401-9 Davis K. and Baker D. M. Ionospheric effects observed around the time of the Alaskan earthquake of March 28, 1964 // Journal of Geophysical Research. — 1965. — Vol. 70, no. 9. — P. 2251–2253. — https://doi.org/10.1029/jz070i009p02251 Davis K. and Baker D. M. Ionospheric effects observed around the time of the Alaskan earthquake of March 28, 1964 // Journal of Geophysical Research. — 1965. — Vol. 70, no. 9. — P. 2251–2253. — https://doi.org/10.1029/jz070i009p02251 Leonard R. S. and Jr. R. A. Barnes. Observation of ionospheric disturbances following the Alaska earthquake // Journal of Geophysical Research. — 1965. — Vol. 70, no. 5. — P. 1250–1253. — https://doi.org/10.1029/jz070i005p01250 Leonard R. S. and Jr. R. A. Barnes. Observation of ionospheric disturbances following the Alaska earthquake // Journal of Geophysical Research. — 1965. — Vol. 70, no. 5. — P. 1250–1253. — https://doi.org/10.1029/jz070i005p01250 Lighthill M. J. Waves in fluids. — Cambridge, UK : Cambridge University Press, 2001. Lighthill M. J. Waves in fluids. — Cambridge, UK : Cambridge University Press, 2001. Liu J. Y., Chen C. H., Sun Y. Y., et al. The vertical propagation of disturbances triggered by seismic waves of the 11 March 2011 M9.0 Tohoku earthquake over Taiwan // Geophysical Research Letters. — 2016. — Vol. 43, no. 4. — P. 1759–1765. — https://doi.org/10.1002/2015gl067487 Liu J. Y., Chen C. H., Sun Y. Y., et al. The vertical propagation of disturbances triggered by seismic waves of the 11 March 2011 M9.0 Tohoku earthquake over Taiwan // Geophysical Research Letters. — 2016. — Vol. 43, no. 4. — P. 1759–1765. — https://doi.org/10.1002/2015gl067487 Maruyama T. and Shinagawa H. Infrasonic sounds excited by seismic waves of the 2011 Tohoku-oki earthquake as visualized in ionograms // Journal of Geophysical Research: Space Physics. — 2014. — Vol. 119, no. 5. — P. 4094– 4108. — https://doi.org/10.1002/2013ja019707 Maruyama T. and Shinagawa H. Infrasonic sounds excited by seismic waves of the 2011 Tohoku-oki earthquake as visualized in ionograms // Journal of Geophysical Research: Space Physics. — 2014. — Vol. 119, no. 5. — P. 4094– 4108. — https://doi.org/10.1002/2013ja019707 Maruyama T., Tsugawa T., Kato H., et al. Rayleigh wave signature in ionograms induced by strong earthquakes // Journal of Geophysical Research: Space Physics. — 2012. — Vol. 117, A8. — https://doi.org/10.1029/2012JA017952 Maruyama T., Tsugawa T., Kato H., et al. Rayleigh wave signature in ionograms induced by strong earthquakes // Journal of Geophysical Research: Space Physics. — 2012. — Vol. 117, A8. — https://doi.org/10.1029/2012JA017952 Nishitani N., Ogawa T., Otsuka Y., et al. Propagation of large amplitude ionospheric disturbances with velocity dispersion observed by the SuperDARN Hokkaido radar after the 2011 off the Pacific coast of Tohoku Earthquake // Earth, Planets and Space. — 2011. — Vol. 63, no. 7. — P. 891–896. — https://doi.org/10.5047/eps.2011.07.003 Nishitani N., Ogawa T., Otsuka Y., et al. Propagation of large amplitude ionospheric disturbances with velocity dispersion observed by the SuperDARN Hokkaido radar after the 2011 off the Pacific coast of Tohoku Earthquake // Earth, Planets and Space. — 2011. — Vol. 63, no. 7. — P. 891–896. — https://doi.org/10.5047/eps.2011.07.003 Ogawa T., Nishitani N., Tsugawa T., et al. Giant ionospheric disturbances observed with the SuperDARN Hokkaido HF radar and GPS network after the 2011 Tohoku earthquake // Earth, Planets and Space. — 2012. — Vol. 64, no. 12. — P. 1295–1307. — https://doi.org/10.5047/eps.2012.08.001 Ogawa T., Nishitani N., Tsugawa T., et al. Giant ionospheric disturbances observed with the SuperDARN Hokkaido HF radar and GPS network after the 2011 Tohoku earthquake // Earth, Planets and Space. — 2012. — Vol. 64, no. 12. — P. 1295–1307. — https://doi.org/10.5047/eps.2012.08.001 Podlesnyi A. V., Brynko I. G., Kurkin V. I., et al. Multifunctional LFM ionosonde to the ionosphere monitoring // Heliogeophysical Research. — 2013. — Vol. 4. — P. 24–31. — (In Russian). Podlesnyi A. V., Brynko I. G., Kurkin V. I., et al. Multifunctional LFM ionosonde to the ionosphere monitoring // Heliogeophysical Research. — 2013. — Vol. 4. — P. 24–31. — (In Russian). Pokhotelov O. A., Parrot M., Fedorov E. N., et al. Response of the ionosphere to natural and man-made acoustic sources // Annales Geophysicae. — 1995. — Vol. 13, no. 11. — P. 1197–1210. — https://doi.org/10.1007/s00585-995-1197-2 Pokhotelov O. A., Parrot M., Fedorov E. N., et al. Response of the ionosphere to natural and man-made acoustic sources // Annales Geophysicae. — 1995. — Vol. 13, no. 11. — P. 1197–1210. — https://doi.org/10.1007/s00585-995-1197-2 Ponomarchuk S. N., Grozov V. P. and Kotovich G. V. Technique of ionospheric parameters automatic determination from data of vertical sounding with a continuous chirp signal. — 2023. — https://doi.org/10.1117/12.2688438 Ponomarchuk S. N., Grozov V. P. and Kotovich G. V. Technique of ionospheric parameters automatic determination from data of vertical sounding with a continuous chirp signal. — 2023. — https://doi.org/10.1117/12.2688438 Rolland L. M., Lognonné P., Astafyeva E., et al. The resonant response of the ionosphere imaged after the 2011 off the Pacific coast of Tohoku Earthquake // Earth, Planets and Space. — 2011. — Vol. 63, no. 7. — P. 853–857. — https://doi.org/10.5047/eps.2011.06.020 Rolland L. M., Lognonné P., Astafyeva E., et al. The resonant response of the ionosphere imaged after the 2011 off the Pacific coast of Tohoku Earthquake // Earth, Planets and Space. — 2011. — Vol. 63, no. 7. — P. 853–857. — https://doi.org/10.5047/eps.2011.06.020 Sorokin A. G., Dobrynin V. A., Oynats A. V., et al. On the effect of the Rayleigh seismic wave in the atmosphere from the earthquake in Taiwan on April 3, 2024 // Collection of Proceedings of the XXXVII session of the Russian Acoustic Society. — Moscow : GEOS, 2025. — P. 84–90. — https://doi.org/10.34756/GEOS.2025.17.39225 — (In Russian). Sorokin A. G., Dobrynin V. A., Oynats A. V., et al. On the effect of the Rayleigh seismic wave in the atmosphere from the earthquake in Taiwan on April 3, 2024 // Collection of Proceedings of the XXXVII session of the Russian Acoustic Society. — Moscow : GEOS, 2025. — P. 84–90. — https://doi.org/10.34756/GEOS.2025.17.39225 — (In Russian). Tsugawa T., Saito A., Otsuka Y., et al. Ionospheric disturbances detected by GPS total electron content observation after the 2011 off the Pacific coast of Tohoku Earthquake // Earth, Planets and Space. — 2011. — Vol. 63, no. 7. — P. 875–879. — https://doi.org/10.5047/eps.2011.06.035 Tsugawa T., Saito A., Otsuka Y., et al. Ionospheric disturbances detected by GPS total electron content observation after the 2011 off the Pacific coast of Tohoku Earthquake // Earth, Planets and Space. — 2011. — Vol. 63, no. 7. — P. 875–879. — https://doi.org/10.5047/eps.2011.06.035 Yusupov K. M., Mathews J. D., Maruyama T., et al. Amplitude variations of the reflected signal during vertical sounding of the ionosphere at middle latitudes // Solar-Terrestrial Physics. — 2020. — Vol. 6, no. 3. — P. 72–80. — https://doi.org/10.12737/stp-63202010 Yusupov K. M., Mathews J. D., Maruyama T., et al. Amplitude variations of the reflected signal during vertical sounding of the ionosphere at middle latitudes // Solar-Terrestrial Physics. — 2020. — Vol. 6, no. 3. — P. 72–80. — https://doi.org/10.12737/stp-63202010