Tides and sea-level variability at the Strait of Euripus

The strong tidal currents in the Strait of Euripus are one of the first recorded observations of tidal phenomena. The analysis of sea-level time series from tide gauges located near the narrowest part of the Strait show that the amplitude of the semi-diurnal tides at the north side of the Strait is four times the amplitude at the south side of the Strait. The two tide gauges are located a few hundred metres apart. Two-dimensional depth-averaged tidal modelling of the area shows that the M₂ and S₂ tides are enhanced as they travel through the Straits of Oreon and Trikeri, which are the communication of the North Evvoikos Gulf to the Aegean Sea. The tidal propagation through the Strait of Euripus itself is severely restricted owing to its small cross-section. Therefore, the tides measured at the two tide gauges represent the independent propagation of the tide from the Aegean Sea through the North and South Evvoikos Gulfs, respectively, to the north and south sides of the Strait. The strong currents are driven by the gradient in sea level across the Strait. The natural modes of the basins are determined but are not detectable in the records.