Spatial Variations of Sea Level along the Egyptian Mediterranean Coast
Tarek M. El‐Geziry, Mohamed Ahmed Said
Abstract
This paper is based on hourly sea level data from six tide-gauges distributed over the Egyptian Mediterranean coast. These data are used to calculate the tidal characteristics, the spatial variations of the mean sea level, its annual rates of increase and seasonal variations. Twelve astronomical tidal constituents are constructed using the T_TIDE package. Along the coast, tides are of semidiurnal type, and the mean sea level increases from west to east with a difference of 35 cm between the two extremities. The sea level rate of increase varied between 1.0 mm/yr (west) and 6.4 mm/yr (east), with an overall average rate of 3.4 mm/yr. This is higher than the rates of the global and whole Mediterranean basins, but meanwhile is less than the rate of the eastern Mediterranean basin. The sea level examines a seasonal trend with usual lows in spring and highs in summer. The seasonal variations tend to be mostly affected by the air pressure scheme and wind regime over the coast. Land subsidence is another factor, which must be considered upon investigation of sea level variability along the Egyptian Mediterranean coast. However, this needs to be verified and concluded through more robust actual geological observations and analyses.