Abstract:
The sea level observations in Bulgaria was started in 1928, when the main tidal stations Burgas and Varna were built. They were built in connection with the completion of the Main Precision Leveling of Bulgaria and the need to determine the starting level of the surface for determining the heights of the benchmarks. On a global scale, networks of tide gauge stations serve to continuously monitor sea level. Determining mean sea level and its change is of particular importance when assessing climate change. Mean sea level has an important role for shipping, in the construction of port facilities. In geodesy, the mean sea level determined by a long period of observations served as a reference surface, in calculating the heights of points on the earth’s surface, as well as in determining the depths of seas and oceans. Sea level observations were conducted with a mechanical type tide gauge with a float. In 2013, radar devices were installed to continue the series of observations. The radar tide gauge at Varna station is located in the well of the station. It is placed above the tide gauge bar – as the excess between the contact point of the tide gauge and control, NR11 is 32.63 m.