Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 126201 10.2205/2026es001121 wkcccg 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 On the Features of the Kamchatka Earthquake on July 29, 2025 (The View of a Seismological Engineer) On the Features of the Kamchatka Earthquake on July 29, 2025 (The View of a Seismological Engineer) Алешин Александр Степанович Aleshin Aleksandr Stepanovich asa@ifz.ru Институт физики Земли им. О.Ю. Шмидта РАН Россия Schmidt Institute of Physics of the Earth, Russian Academy of Science Russian Federation 01 07 2026 01 07 2026 26 2 ES2011 02 02 2026 25 05 2026 https://rjes.ru/en/nauka/article/126201/view

The magnitude of the Kamchatka earthquake of July 29, 2025, was significantly higher than the estimated maximum possible earthquake in the region. At the same time, despite its high magnitude, the intensity of shaking in Petropavlovsk-Kamchatsky was significantly lower than predicted. This article explores one possible explanation for this phenomenon, which involves the nonlinear relationship between stress and deformation caused by seismic vibrations in the soil. The results of computer modeling of seismic processes in dispersed soils are presented. The calculations are based on assumptions about the properties of soils and the parameters of seismic impact. The obtained results have practical significance for seismic microzonation.

The magnitude of the Kamchatka earthquake of July 29, 2025, was significantly higher than the estimated maximum possible earthquake in the region. At the same time, despite its high magnitude, the intensity of shaking in Petropavlovsk-Kamchatsky was significantly lower than predicted. This article explores one possible explanation for this phenomenon, which involves the nonlinear relationship between stress and deformation caused by seismic vibrations in the soil. The results of computer modeling of seismic processes in dispersed soils are presented. The calculations are based on assumptions about the properties of soils and the parameters of seismic impact. The obtained results have practical significance for seismic microzonation.

 Strong seismic event nonlinear stress-strain relationship computer modeling hyperbolic dependence seismic microzonation Kamchatka megathrust earthquake Strong seismic event nonlinear stress-strain relationship computer modeling hyperbolic dependence seismic microzonation Kamchatka megathrust earthquake The author expresses his gratitude to D. V. Chebrov for the kindly provided accelerograms of the Kamchatka earthquake. The author expresses his gratitude to D. V. Chebrov for the kindly provided accelerograms of the Kamchatka earthquake.

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