Characterization of natural seiches in Lake Kinneret under fluctuating water level

Study region: Lake Kinneret (the Sea of Galilee), a subtropical, warm monomictic lake located in northern Israel, serves as the region’s primary freshwater reservoir and a critical component of the national water supply infrastructure. Study focus: High-frequency observations of surface water levels across the basin reveal low-frequency variability with periodicities on the order of tens of minutes, consistent with the generation of natural surface seiches. While historical frameworks identified these foundational basin-scale resonant modes, they have since been largely overlooked due to their low amplitudes and the masking effects inherent in standard temporal averaging. This study provides a comprehensive observational re-evaluation and physical characterization of these oscillations under conditions of highly dynamic baseline water levels. New hydrological insights for the region: By pairing high-frequency in situ hydrostatic pressure records from a perimeter network of littoral stations with numerical model results, ten discrete natural resonant modes ( M 0 – M 9 ) with periods ranging from 9 to 38 min were successfully verified. Spectral variance analysis reveals that while the longitudinal standing modes M 0 and M 2 drive the baseline variance, higher-order modes ( M 6 – M 9 ) experience episodic energy injections that can explain up to 20%–45% of the localized variance during specific temporal windows. Finally, a conceptual framework for seiche agitation is discussed, highlighting how meteorological forcing and relaxation can govern the excitation of these high-frequency basin oscillations.