Observations 

 in the Medi- 

 terranean. 



292 DEPTHS OF THE OCEAN chap. 



Gibraltar, the "Michael Sars " entered the Mediterranean, and 

 took observations at Station 19, the hydrographical conditions 

 being shown in Fig. 197. The surface temperature varied from 

 1 6° to 1 7' C, and the salinity was nearly 36.4 per thousand. The 

 temperature decreased and the salinity increased downwards, 

 until we struck the Mediterranean deep water at a depth of 

 about 160 metres ; from this point downwards we found exactly 

 the same temperatures and salinities as in the undercurrent in 

 the straits. This was on the 2nd May, between 10 a.m. and 

 I P.M. ; the observations in the uppermost 300 metres were 

 made between 10.30 and 11. 30 a.m. Judging from the previous 



measurements the in- 

 flow in the straits 

 should then be about 

 its strongest. Be- 

 tween 5 and 6 p.m. 

 some of the observa- 

 tions were repeated, 

 and the boundary be- 

 tween the surface- 

 layers and the deep 

 water then lay some- 

 what higher; it might 

 be a matter of 10 or 

 15 metres. The 

 under current setting 

 out of the straits was 

 then very strong and 

 the surface current 

 comparatively feeble. 

 So there were fluctua- 

 in the Mediterranean 

 the fluctuations in the 



Fig. 198. — "Michael Sars" Stations in the Spanish 



Bay between Spain and Morocco in May 1910. 



The lines indicate the positions of the two sections represented 



in the two following figures. 



tions in the position of the boundary 



eastward of the straits corresponding to 



straits, only considerably smaller, because the current-velocities 



naturally would be much smaller where the basin was broad. 



A few days later a number of observations were taken in 

 the Spanish Bay westward of the straits. The positions of the 

 stations are indicated in Fig. 198, and the salinities and tempera- 

 tures are shown in the two sections: Fig. 199, in an east and 

 west direction, and Fig. 200, in a north and south direction. In 

 the east to west section the salt Mediterranean water with a 

 salinity exceeding '}y^ per thousand is seen stretching out through 

 the Straits of Gibraltar, its salinity, however, soon decreasing 



