Characterization of Seiche in a Relatively Small Artificial Basin

A seiche is effectively a standing wave that forms in the water surface of an enclosed (or partially enclosed) basin such as a lake. The frequency of seiche oscillations is primarily determined by the geometric characteristics of the enclosed basin. In this poster, we describe the observation and characterization of seiche occurring in artificial basins of simple geometry. Additionally, we examine similarities and differences between seiche that are driven by a temporal variation of the water surface and those excited by spatial variation of the surface. Using an ultrasonic sensor, the surface water height at a specific location was measured over time during the occurrence of seiche in an artificial basin, namely a rectangular tub. A discrete Fourier analysis applied to the surface height time series is used to determine the frequencies of the seiche modes present. Using these observations, we construct dispersion relationships for temporally and spatially excited seiche at three different depths. The dispersion relationships for the temporally driven seiche are in strong agreement with the general surface gravity wave dispersion relationship. However, the dispersion relationships for seiche produced by a spatial variation in the surface position are not well modelled by the general surface gravity wave dispersion relationship.