On the Features of the Kamchatka Earthquake on July 29, 2025 (The View of a Seismological Engineer)

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.