426 



Tides in the Mediterranean and Adjacent Seas 



Water transport during 6 h of the M 2 tide through : 



the canals of the Ryu-Kyu islands 350 km 3 



the northern entrance of the Formosa Strait 1 30 km 3 



the south-western entrance into the Strait of Tsushima 20 km 3 

 This proves that the tides of the boundary sea are essentially of Pacific origin. 

 Concerning the tidal currents in the different sections, see Ogura (p. 424). 

 Table 59 gives the ratio of the diurnal to the semi-diurnal tides. The ratio 

 indicating the character of the tide is generally smaller than 05; the tides, 

 therefore, are mixed, preponderantly semi-diurnal, increasingly so with a fur- 

 ther penetration into the boundary sea, where they become almost exclusively 

 semi-diurnal. Excepted are only the areas in the vicinity of the centres of the 

 amphidromies, where of course, the diurnal tides are predominant. 



Fig. 182. Co-tidal lines of the A/ 2 tide (referred to the 135°E. L. meridian) and range 

 2(M 2 + 5 2 ) in m for the Sea of Japan (Ogura). 



14. The Tides of the Sea of Japan and the Sea of Okhotsk 



The Sea of Japan is connected with other seas by four straits, the most 

 important of which is the Strait of Korea or of Tsushima, whereas the Strait 

 of Tsugaru between Honshu and Hokkaido and the Strait of Soya (La Perouse 

 Strait) are of lesser importance, and still less so is the Gulf of Tatary between 



