What is the tide and dryness?
Tides are the periodic rise and fall of the water surface, caused by the attraction forces of the moon and the sun on the rotating earth. The tidal movement is a wave movement. People speak of high tide or rising tide and ebb or waning tide. The maximum water level during this cycle is called high water, the minimum water level is low water. The tides are brought about by tidal currents, divided into ebb and flow currents. The tide enters the North Sea through two entrances: to the north between Scotland and Norway and to the south via the Strait of Calais.