Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 106694 10.2205/2026es001132 vtivbr 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 Using Open GNSS Stations to Determine Earth Surface Displacements and Ionospheric Response Following the Kamchatka Earthquake of July 29, 2025 Using Open GNSS Stations to Determine Earth Surface Displacements and Ionospheric Response Following the Kamchatka Earthquake of July 29, 2025 https://orcid.org/0000-0003-2429-8000 Загретдинов Ренат Вагизович Zagretdinov Renat Vagizovich renatz@mail.ru https://orcid.org/0009-0008-3923-8207 Бахтиаров Вилорий Фаритович Bakhtiarov Vilory Faritovich https://orcid.org/0000-0001-6382-2309 Калинников Владислав Валерьевич Kalinnikov Vladislav Valer'evich https://orcid.org/0000-0002-3177-0791 Когогин Денис Александрович Kogogin Denis Aleksandrovich https://orcid.org/0000-0001-8082-2546 Максимов Денис Сергеевич Maksimov Denis Sergeevich https://orcid.org/0000-0002-1316-0009 Насыров Игорь Альбертович Nasyrov Igor Al'bertovich https://orcid.org/0009-0000-6587-5308 Загретдинов Айдар Анисович Zagretdinov Aidar Anisovich Казанский (Приволжский) федеральный университет Россия Kazan (Volga Region) Federal University Russian Federation Казанский (Приволжский) федеральный университет Россия Kazan (Volga Region) Federal University Russian Federation Университет Иннополис Россия Innopolis University Russian Federation Казанский (Приволжский) федеральный университет Россия Kazan (Volga Region) Federal University Russian Federation Казанский (Приволжский) федеральный университет Россия Kazan (Volga Region) Federal University Russian Federation Казанский (Приволжский) федеральный университет Россия Kazan (Volga Region) Federal University Russian Federation Казанский (Приволжский) федеральный университет Россия Kazan (Volga Region) Federal University Russian Federation 01 07 2026 01 07 2026 26 2 ES2022 02 02 2026 25 05 2026 https://rjes.ru/en/nauka/article/106694/view

This study analyzes crustal movements and ionospheric response triggered by the powerful MW 8.8 earthquake of July 29, 2025, using continuous GNSS observations from open geodetic network stations located on the Kamchatka Peninsula, Sakhalin Island, the coast of the Sea of Okhotsk, and the Kuril Islands. Significant coseismic horizontal and vertical coordinate changes were detected at GNSS stations on the Kamchatka Peninsula near Petropavlovsk-Kamchatsky (up to 65 cm horizontally and 8 cm vertically), in Severo-Kurilsk city (168 cm horizontally and 19 cm vertically), and on Sakhalin Island (up to 3 cm horizontally). The time delay of surface deformation propagation was estimated for stations in Petropavlovsk-Kamchatsky and Severo-Kurilsk. The ionospheric response to the earthquake was investigated, revealing concentric ionospheric disturbances propagating southwestward from the earthquake epicenter. Two modes of this disturbance were identified: a fast mode with a propagation velocity of 800–1300 m/s detectable during the first ~20 minutes, and a slow mode with velocity of 180–330 m/s observed approximately 40 minutes after the main shock.

This study analyzes crustal movements and ionospheric response triggered by the powerful MW 8.8 earthquake of July 29, 2025, using continuous GNSS observations from open geodetic network stations located on the Kamchatka Peninsula, Sakhalin Island, the coast of the Sea of Okhotsk, and the Kuril Islands. Significant coseismic horizontal and vertical coordinate changes were detected at GNSS stations on the Kamchatka Peninsula near Petropavlovsk-Kamchatsky (up to 65 cm horizontally and 8 cm vertically), in Severo-Kurilsk city (168 cm horizontally and 19 cm vertically), and on Sakhalin Island (up to 3 cm horizontally). The time delay of surface deformation propagation was estimated for stations in Petropavlovsk-Kamchatsky and Severo-Kurilsk. The ionospheric response to the earthquake was investigated, revealing concentric ionospheric disturbances propagating southwestward from the earthquake epicenter. Two modes of this disturbance were identified: a fast mode with a propagation velocity of 800–1300 m/s detectable during the first ~20 minutes, and a slow mode with velocity of 180–330 m/s observed approximately 40 minutes after the main shock.

 Aftershock displacements surface movements Precise Point Positioning (PPP) InnoGNSS Total Electron Content (TEC) Kamchatka megathrust earthquake Aftershock displacements surface movements Precise Point Positioning (PPP) InnoGNSS Total Electron Content (TEC) Kamchatka megathrust earthquake The authors sincerely thank the Center for Geodesy, Cartography, and Spatial Data Infrastructure of PLC “Roskadastr”, companies JSC “PRIN” (PRINNET), LLC “GEOSTROYIZYSKANIYA” (TopNETlive), LLC “Smartnet Geosystems” (SmartNet), SONEL and SOPAC/UNAVCO centers, and the Federal Navigation Data Center for the open GNSS data used in this work. The study of the ionospheric response to the earthquake was supported by the grant from the Russian Science Foundation No. 23-77-10029, https: //rscf.ru/project/23-77-10029/. The authors sincerely thank the Center for Geodesy, Cartography, and Spatial Data Infrastructure of PLC “Roskadastr”, companies JSC “PRIN” (PRINNET), LLC “GEOSTROYIZYSKANIYA” (TopNETlive), LLC “Smartnet Geosystems” (SmartNet), SONEL and SOPAC/UNAVCO centers, and the Federal Navigation Data Center for the open GNSS data used in this work. The study of the ionospheric response to the earthquake was supported by the grant from the Russian Science Foundation No. 23-77-10029, https: //rscf.ru/project/23-77-10029/.

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