ROCK DEFORMATIONS DEDUCED FROM ADIT-BASED MEASUREMENTS ON THE SHIKOTAN ISLAND (LESSER KURIL RIDGE) IN 2024–2025

The paper presents the results of rock deformation measurements conducted in 2024–2025 on the Shikotan Island (Lesser Kuril Ridge). The measurements were conducted using strainmeters installed in the adit of the former Shikotan geophysical observatory, now the Shikotan seismic station of the Sakhalin Branch of the Geophysical Survey. The research was conducted by means of an instrumental complex developed specially for monitoring rock deformation. The goal of the work is to provide a comprehensive analysis of the variations of deformations of rocks depending on various natural processes.

The first results of the analysis showed the correctness of the employed deformation measurement technique. An important finding was the relationship between deformation rate changes and the local seismic regime. There has been a reaction from both components (alternating impulse) to strong remote earthquakes on July 20 and 30, 2025, in Kamchatka. It was shown that both components of soil deformation consistently reflect the passage of cyclones, which is expressed in short-term variations of an impulsive nature.

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