414 



Tides in the Mediterranean and Adjacent Seas 



a rough picture of the semi-diurnal tide. For a series of localities these values 

 are compiled in Table 56; Table 57 gives the harmonic constants of the two 

 afore-mentioned localities, together with those of Karachi, on the Indian 

 Ocean. The tidal picture resulting from these observations is briefly the 

 following (Fig. 175). 



Table 57. Harmonic constants 



High water occurs simultaneously over the entire area of the Gulf of 

 Oman, whereas the range increases slightly inside the Gulf. Consequently, 

 the water surface rises and falls almost simultaneously up till the opening 

 off the Strait of Hormuz. In this Strait there is then a regular increase of 

 the establishment from 9-5 h till h at the southern end of the Persian 

 Gulf; the tidal range increasing in the middle of the Strait up till 12 ft (3-7 m), 

 then decreasing again to 7-2 ft (2-2 m). The establishment in the Persian Gulf 

 itself can be explained by assuming two amphidromies rotating to the left, 

 one in the southern section, the other one in the northern section of the Gulf. 

 The distribution of the ranges is then also in agreement. 



Beside the important semi-diurnal tides, the diurnal tides must also be 

 well developed in the Persian Gulf, according to the harmonic constants 

 of Bushire. 



The explanation given by Krummel (1911, vol. II, p. 384) of the tides of 

 this adjacent sea is entirely based on the previous conception of the ex- 

 planation of the tides by progressive waves. The tide wave penetrates through 

 the Strait of Hormuz and, clinging to the land on the right side, it travels 

 counter-clockwise around the entire gulf. This is the only way to explain, 

 in agreement with the water depths, the "otherwise incomprehensible es- 

 tablishments". The tidal ranges do fit this picture less well. Defant (1919) 

 has given a hydrodynamical theory which explains from the orographical 

 configuration of the sea area the two amphidromies as the main feature 

 within the Gulf, and also the remarkable distribution of the establishment 

 and the range in the Strait of Hormuz. 



The natural period of the Persian Gulf, including the Strait of Hormuz, 



