gtcrustГеодинамика и тектонофизикаGeodynamics & Tectonophysics2078-502XInstitute of the Earth's crust of the Russian Academy of Sciences, Siberian Branch10.5800/GT-2026-17-3-0894JNSTNMgtcrust-2295Research ArticleСОВРЕМЕННАЯ ГЕОДИНАМИКАRECENT GEODYNAMICSОБ АНИЗОТРОПИИ ЭФФЕКТИВНОЙ ТОКОВОЙ СТРУКТУРЫ В ЗОНЕ ПОДГОТОВКИ ЗЕМЛЕТРЯСЕНИЯ МАГНИТУДОЙ 8.8, ПРОИЗОШЕДШЕГО 29 ИЮЛЯ 2025 ГОДА У ПОБЕРЕЖЬЯ КАМЧАТКИON ANISOTROPY OF THE EFFECTIVE CURRENT STRUCTURE IN THE PREPARATION ZONE FOR THE JULY 29, 2025, Mw 8.8 EARTHQUAKE OFF THE COAST OF KAMCHATKAhttps://orcid.org/0000-0002-3839-3466ВольвачА. Е.VolvachA. E.

98688, Кацивели, Республика Крым

Katsiveli 298688, Republic of Crimea 

volvach@bk.ruКоганЛ. П.KoganL. P.

298688, Кацивели, Республика Крым

603000, Нижний Новгород, ул. Ильинская, 65 

Katsiveli 298688, Republic of Crimea 

65 Ilinskaya St, Nizhny Novgorod 603000 

https://orcid.org/0000-0001-6157-003XВольвачЛ. Н.VolvachL. N.

98688, Кацивели, Республика Крым

Katsiveli 298688, Republic of Crimea 

ШтенбергВ. Б.ShtenbergV. B.

603000, Нижний Новгород, ул. Ильинская, 65 

65 Ilinskaya St, Nizhny Novgorod 603000 

РевуноваЕ. А.RevunovaE. A.

603000, Нижний Новгород, ул. Ильинская, 65 

65 Ilinskaya St, Nizhny Novgorod 603000 

Крымская астрофизическая обсерватория РАНРоссияCrimean Astrophysical Observatory, Russian Academy of SciencesRussian FederationКрымская астрофизическая обсерватория РАН ; Нижегородский государственный архитектурно-строительный университетРоссияCrimean Astrophysical Observatory, Russian Academy of Sciences ; Nizhny Novgorod State University of Architecture and Civil EngineeringRussian FederationНижегородский государственный архитектурно-строительный университетРоссияNizhny Novgorod State University of Architecture and Civil EngineeringRussian Federation202618062026173894894Copyright © Вольвач А.Е., Коган Л.П., Вольвач Л.Н., Штенберг В.Б., Ревунова Е.А., 20262026Вольвач А.Е., Коган Л.П., Вольвач Л.Н., Штенберг В.Б., Ревунова Е.А.Volvach A.E., Kogan L.P., Volvach L.N., Shtenberg V.B., Revunova E.A.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://www.gt-crust.ru/jour/article/view/2295

В данной работе с использованием метода спектрально-вероятностного анализа исследованы статистические свойства вариаций Z-компоненты геомагнитного поля в течение 14 сут, предшествовавших землетрясению магнитудой 8.8, произошедшему 29 июля 2025 г. у побережья Камчатки. Дополнительно проанализированы аналогичные данные за 9 сут после начала события. Проведенный анализ выявил устойчивые различия статистической структуры геомагнитных вариаций на четырех пространственно разнесенных магнитовариационных станциях. Обнаруженные особенности воспроизводятся при варьировании параметров обработки (N1, M, h), что свидетельствует об их устойчивости. Полученные результаты согласуются с моделью направленной (анизотропной) эффективной токовой структуры, формирующейся в зоне подготовки землетрясения. Простая геометрическая оценка, основанная на законе Био – Савара – Лапласа, дает угловые ориентации, сопоставимые с направлением оси сейсмоактивной зоны. Выявленные различия не коррелируют с уровнем умеренной геомагнитной активности рассматриваемого периода и могут отражать крупномасштабную анизотропию магнитного отклика в предсейсмический интервал. Предложенный подход ориентирован на анализ статистической структуры геомагнитных вариаций и может быть использован для выявления пространственных особенностей процессов подготовки сильных землетрясений. Дальнейшая проверка метода на независимых событиях необходима для оценки его практической применимости.

The present paper deals with the use of a probabilistic spectral analysis in the study of statistical properties of the variations in Z-component of electromagnetic field during 14 days prior to the July 29, 2025, M 8.8 earthquake which struck off Kamchatka. Additional analysis has been made on similar data for 9 days after the event. The analysis showed persistent differences in the statistical structure of geomagnetic variations at four spatially spaced magnitovariational stations. The persistence of differences is evidenced by the fact that they re-arise during the variation of processing parameters (N1, M, h). The results obtained are consistent with the model of directed (anisotropic) effective current structure forming in the earthquake preparation zone. A simple geometric assessment based on the Biot – Savart – Laplace Law yields angular orientations comparable with an axial direction of seismic zone. The revealed differences do not correlate with the level of moderate geomagnetic activity of the period considered and may reflect large-scale anisotropy of magnetic response in the pre-seismic interval. The proposed approach is oriented at the analysis of statistical structure of geomagnetic variations and can be used to identify spatial features of strong earthquake preparation process. Further testing of the method on independent events is required to assess its practical applicability.

сейсмичностьгеодинамикаанизотропия направлений электрических токовпрогноз землетрясениягеомагнитное полефизика землетрясенийseismicitygeodynamicsanisotropy of current directionsearthquake predictiongeomagnetic fieldearthquake physicsReferencesCampbell W.H., 2003. Introduction to Geomagnetic Fields. Cambridge University Press, 303 p.Campbell W.H., 2003. Introduction to Geomagnetic Fields. Cambridge University Press, 303 p.Freund F., 2002. Charge Generation and Propagation in Igneous Rocks. Journal of Geodynamics 33 (4–5), 545–570. https://doi.org/10.1016/S0264-3707(02)00015-7.Freund F., 2002. Charge Generation and Propagation in Igneous Rocks. Journal of Geodynamics 33 (4–5), 545–570. https://doi.org/10.1016/S0264-3707(02)00015-7.Freund F., 2011. Pre-Earthquake Signals: Underlying Physical Processes. Journal of Asian Earth Sciences 41 (4–5), 383–400. https://doi.org/10.1016/j.jseaes.2010.03.009.Freund F., 2011. Pre-Earthquake Signals: Underlying Physical Processes. Journal of Asian Earth Sciences 41 (4–5), 383–400. https://doi.org/10.1016/j.jseaes.2010.03.009.Geller R.J., 1997. Earthquake Prediction: A Critical Review. Geophysical Journal International 131 (3), 425–450. https://doi.org/10.1111/j.1365-246X.1997.tb06588.x.Geller R.J., 1997. Earthquake Prediction: A Critical Review. Geophysical Journal International 131 (3), 425–450. https://doi.org/10.1111/j.1365-246X.1997.tb06588.x.Hayakawa M., 2015. Earthquake Prediction with Radio Techniques. John Wiley & Sons, Singapore, 294 p. https://doi.org/10.1002/9781118770368.Hayakawa M., 2015. Earthquake Prediction with Radio Techniques. John Wiley & Sons, Singapore, 294 p. https://doi.org/10.1002/9781118770368.Hayakawa M., Fujinawa Y., 1994. Electromagnetic Phenomena Related to Earthquake Prediction. Terra Scientific Publishing, Tokyo, Japan, 677 p.Hayakawa M., Fujinawa Y., 1994. Electromagnetic Phenomena Related to Earthquake Prediction. Terra Scientific Publishing, Tokyo, Japan, 677 p.Liu J.Y., 2009. Earthquake Precursors Observed in the Ionospheric F-Region. In: M. Hayakawa (Ed.), Electromagnetic Phenomena Associated with Earthquakes. Transworld Research Network, Trivandrum, p. 187–204.Liu J.Y., 2009. Earthquake Precursors Observed in the Ionospheric F-Region. In: M. Hayakawa (Ed.), Electromagnetic Phenomena Associated with Earthquakes. Transworld Research Network, Trivandrum, p. 187–204.Masci F., Thomas J., 2015. Are There Any New Findings in the Search for ULF Magnetic Precursors to Earthquakes? Journal of Geophysical Research: Space Physics 120 (12), 10289–10304. https://doi.org/10.1002/2015JA021336.Masci F., Thomas J., 2015. Are There Any New Findings in the Search for ULF Magnetic Precursors to Earthquakes? Journal of Geophysical Research: Space Physics 120 (12), 10289–10304. https://doi.org/10.1002/2015JA021336.Masci F., Thomas J.N., Villani F., Secan J.A., Rivera N., 2015. On the Onset of Ionospheric Precursors 40 min Before Strong Earthquakes. Journal of Geophysical Research: Space Physics 120 (2), 1383–1393. https://doi.org/10.1002/2014JA020822.Masci F., Thomas J.N., Villani F., Secan J.A., Rivera N., 2015. On the Onset of Ionospheric Precursors 40 min Before Strong Earthquakes. Journal of Geophysical Research: Space Physics 120 (2), 1383–1393. https://doi.org/10.1002/2014JA020822.Ouzounov D., Pulinets S., Hattori K., Taylor P. (Eds), 2018. Pre-Earthquake Processes: A Multidisciplinary Approach to Earthquake Prediction Studies. American Geophysical Union, 384 p. https://doi.org/10.1002/9781119156949.Ouzounov D., Pulinets S., Hattori K., Taylor P. (Eds), 2018. Pre-Earthquake Processes: A Multidisciplinary Approach to Earthquake Prediction Studies. American Geophysical Union, 384 p. https://doi.org/10.1002/9781119156949.Pulinets S.A., Ouzounov D., 2011. Lithosphere – Atmosphere – Ionosphere Coupling (LAIC) Model – An Unified Concept for Earthquake Precursors Validation. Journal of Asian Earth Sciences 41 (4–5), 371–382. https://doi.org/10.1016/j.jseaes.2010.03.005.Pulinets S.A., Ouzounov D., 2011. Lithosphere – Atmosphere – Ionosphere Coupling (LAIC) Model – An Unified Concept for Earthquake Precursors Validation. Journal of Asian Earth Sciences 41 (4–5), 371–382. https://doi.org/10.1016/j.jseaes.2010.03.005.Thomas J.N., Love J.J., Johnston M.J.S., 2009. On the Reported Magnetic Precursor of the 1989 Loma Prieta Earthquake. Physics of the Earth and Planetary Interiors 173 (3–4), 207–215. https://doi.org/10.1016/j.pepi.2008.11.014.Thomas J.N., Love J.J., Johnston M.J.S., 2009. On the Reported Magnetic Precursor of the 1989 Loma Prieta Earthquake. Physics of the Earth and Planetary Interiors 173 (3–4), 207–215. https://doi.org/10.1016/j.pepi.2008.11.014.Volvach A., Celik C., Kogan L., Volvach L., 2025a. On the Extreme Values of the Correlator of Topological Similarity of Functionals from the Statistics of Geomagnetic Field Measurements for Spatially Separated Magnetometers in the Period Before the 06/02/2023 Earthquake of Magnitude 7.8 in Eastern Turkey. Romanian Reports in Physics 77 (1), 704. https://doi.org/10.59277/RomRepPhys.2025.77.704.Volvach A., Celik C., Kogan L., Volvach L., 2025a. On the Extreme Values of the Correlator of Topological Similarity of Functionals from the Statistics of Geomagnetic Field Measurements for Spatially Separated Magnetometers in the Period Before the 06/02/2023 Earthquake of Magnitude 7.8 in Eastern Turkey. Romanian Reports in Physics 77 (1), 704. https://doi.org/10.59277/RomRepPhys.2025.77.704.Volvach A., Kogan L., Volvach L., Kanonidi K., Bubukin I., Revunova E., 2023. On the Topological Similarity of the Functionals from the Statistics of Magnetic Field Measurements Before the Earthquake on November 3, 2022 in the Gura Teghii, Romania Region. Romanian Reports in Physics 75 (4), 707. https://doi.org/10.59277/RomRepPhys.2023.75.707.Volvach A., Kogan L., Volvach L., Kanonidi K., Bubukin I., Revunova E., 2023. On the Topological Similarity of the Functionals from the Statistics of Magnetic Field Measurements Before the Earthquake on November 3, 2022 in the Gura Teghii, Romania Region. Romanian Reports in Physics 75 (4), 707. https://doi.org/10.59277/RomRepPhys.2023.75.707.Volvach A.E., Kogan L.P., Kanonidi K.H., Bubukin I.T., Shtenberg V.B., Volvach L.N., Biazitov D.T., 2022а. Statistical Precursors of a Strong Earthquake on April 6, 2009 on the Apennine Peninsula. Heliyon 8 (8), e10200. https://doi.org/10.1016/j.heliyon.2022.e10200.Volvach A.E., Kogan L.P., Kanonidi K.H., Bubukin I.T., Shtenberg V.B., Volvach L.N., Biazitov D.T., 2022а. Statistical Precursors of a Strong Earthquake on April 6, 2009 on the Apennine Peninsula. Heliyon 8 (8), e10200. https://doi.org/10.1016/j.heliyon.2022.e10200.Вольвач А.Е., Коган Л.П., Канониди К.Х., Надежка Л.И., Бубукин И.Т., Боборыкина О.В., Штенберг В.Б., Вольвач Л.Н., Биазитов Д.Т. О возможной связи совокупности статистически выявляемых квазилинейных локальных трендов в вариациях параметров магнитного поля перед землетрясениями в сейсмоактивных зонах Черного моря, Кавказа и Западной Азии // Геодинамика и тектонофизика. 2022. Т. 13. № 5. 0680. https://doi.org/10.5800/GT-2022-13-5-0680.Volvach A.E., Kogan L.P., Kanonidi K.H., Nadezhka L.I., Bubukin I.T., Boborikina O.V., Shtenberg V.B., Volvach L.N., Biazitov D.T., 2022b. A Possible Relationship Between the Sets of Quasi-Linear Local Trends Statistically Detected in the Variations of the Magnetic Field Parameters Before Earthquakes in Seismicly Active Zones of the Black Sea, Caucasus, and Western Asia. Geodynamics & Tectonophysics 13 (5), 0680 (in Russian) https://doi.org/10.5800/GT-2022-13-5-0680.Volvach A.E., Kogan L.P., Kanonidi K.H., Nadezhka L.I., Bubukin I.T., Shtenberg V.B., Gordetsov A.S., Krasnikova O.V., Kislitsyn D.I., 2022с. Changes in the Properties of the Statistics of Physical and Biophysical Fields as Earthquake Precursor. Communications in Nonlinear Science and Numerical Simulation 108, 106200. https://doi.org/10.1016/j.cnsns.2021.106200.Volvach A.E., Kogan L.P., Kanonidi K.H., Nadezhka L.I., Bubukin I.T., Shtenberg V.B., Gordetsov A.S., Krasnikova O.V., Kislitsyn D.I., 2022с. Changes in the Properties of the Statistics of Physical and Biophysical Fields as Earthquake Precursor. Communications in Nonlinear Science and Numerical Simulation 108, 106200. https://doi.org/10.1016/j.cnsns.2021.106200.Volvach A.E., Kogan L.P., Volvach L.N., Kanonidi K.H., 2026. Precursors the Earthquake on February 6, 2023 on the Turkey. Natural Hazards 122 (2), 68. https://doi.org/10.1007/s11069-025-07754-7.Volvach A.E., Kogan L.P., Volvach L.N., Kanonidi K.H., 2026. Precursors the Earthquake on February 6, 2023 on the Turkey. Natural Hazards 122 (2), 68. https://doi.org/10.1007/s11069-025-07754-7.Volvach A.E., Kogan L.P., Volvach L.N., Kanonidi K.Н., Bubukin I.T., Shtenberg V.В., 2024. The Group of Statistical Precursors of 7.3 and 6.6 Magnitude Earthquakes in the Region of Indonesia. Natural Hazards 120 (6), 5601–5616. https://doi.org/10.1007/s11069-024-06439-x.Volvach A.E., Kogan L.P., Volvach L.N., Kanonidi K.Н., Bubukin I.T., Shtenberg V.В., 2024. The Group of Statistical Precursors of 7.3 and 6.6 Magnitude Earthquakes in the Region of Indonesia. Natural Hazards 120 (6), 5601–5616. https://doi.org/10.1007/s11069-024-06439-x.Volvach A.E., Kurbasova G.S., Volvach L.N., 2025b. Parametric Resonance of Surface Geomagnetic Waves as a Precursor of Local Earthquakes. Physics and Chemistry of the Earth, Parts A/B/C 137, 103802. https://doi.org/10.1016/j.pce.2024.103802.Volvach A.E., Kurbasova G.S., Volvach L.N., 2025b. Parametric Resonance of Surface Geomagnetic Waves as a Precursor of Local Earthquakes. Physics and Chemistry of the Earth, Parts A/B/C 137, 103802. https://doi.org/10.1016/j.pce.2024.103802.

The authors declare that there are no conflicts of interest present.