Tides in the Mediterranean and Adjacent Seas 



415 



is 22-6 h according to the Japanese method, 21 -7 h according to the 

 Chrystal method. The ratio v for the semi-diurnal tides is, therefore, 

 about 2-3, which for both tidal components causes the development of two 

 nodal lines. The step-wise computation gives these two nodal lines for the 

 co-oscillating tide, the first off Qais, the second a little south of Bushire. 

 In the Gulf of Oman, the tidal range is about 6-6 ft (200 cm), it increases 

 in the Strait of Hormuz to 8 2 ft (250 cm), and at the antinodes of the stand- 



Fig. 175. Phases (lunar hours) and amplitude (cm) of the spring tides in the Persian Gulf 



derived from observations. 



ing wave it attains values of about 5-6 ft (170 cm) at the southern end and 

 8-2 ft (250 cm), at the northern end of the gulf. 



The computation of the independent tide is somewhat complicated, due 

 to the bend of the longitudinal axis of the area of oscillation. According 

 to Fig. 176 the entire area can be schematized in three canal sections: (I). 

 The actual Persian Gulf with its main direction NW.-SE. (II). The south- 

 eastern shallow section of the Gulf, together with the Strait of Hormuz, 

 the main direction being SW.- NE. (III). The Gulf of Oman, whose longi- 

 tudinal direction is essentially similar to that of the first section. The tide 

 generating forces for (M^ + S^) can then be computed for each of the different 

 sections and we obtain: 



section I K x = 7-875 x 10- 7 cos?|(?- 10 h); 



