Seiches in Kuril Lake Stimulated by the 2025 Mw 8.8 Kamchatka Earthquake

Abstract

Using wave phenomena initiated in Kuril Lake (Kamchatka Peninsula, Russia) by the 8.8 Mw Kamchatka earthquake as an example, the formation of seismogenic seiches in enclosed bodies of water on land is analyzed. Within the framework of linear potential wave theory, it is shown that the primary contribution to the amplitude of seiche oscillations comes from the first few eigenmodes, which can be considered long-wavelength. The contribution of higher eigenmodes decreases inversely proportional to the square of the frequency. Seiches generated by the 8.8 Mw Kamchatka earthquake in Kuril Lake were numerically simulated using linear shallow-water equations. It was shown that in narrow bays and straits, lake level fluctuations could reach 5 m, and current velocities could reach 2 m/s. The numerical results for the ‘‘Kordon Ozerny’’ point (2.3 m, 1.1 m/s) are consistent with eyewitness accounts.