Tides in the Mediterranean and Adjacent Seas 



367 



of the North Sea between the nodal lines should have a phase of 35 h and 

 the innermost part again the phase of 95 h. These nodal lines are transformed 

 into amphidromies by the rotation of the earth. If we keep these conditions 

 in view, the agreement between the observations and these assumptions is 

 not bad. The schematic presentation of the co-tidal lines of the North Sea 



9°E 



Fig. 153. 



Co-tidal lines (in degrees) and co-range lines (amplitudes in cm) of the M 2 tide 

 in the North Sea (Proudman and Doodson). 



given by Sterneck (1920, p. 131), in his paper on the tides of the oceans based 

 on the "vulgar establishment", shows also these two amphidromies; one in 

 the northern part at approximately 56° N. lat., the second in the southern 

 part, and which is slightly moved in the direction of the Deutsche Bucht. 



