143 



of the water, considering its contact witli other waters, and on 

 atmospheric influences, depends largely on the time interval. 



The highest temperature and sahnit}'^ ever recorded by the patrol 

 was observed May 27, 75 miles south of the Tail, where water of 

 20° and of 36.44 salinity was found, wliich would be normal for the 

 water between Bahama and Florida, one of the fountain heads of the 

 Gulf Stream.^ 



The latter part of May the Labrador Current extension had 

 dwindled to its lowest ebb for the season. It was instructive to 

 observe such a contrast between its size on May 27-30 — a weak, 

 attenuated extension — -and on April 13-14, when it was a voluminous 

 current flowing at record strength. 



Early in June the cold current exhibited a tendency to swell from 

 its low ebb just mentioned. The pool of water left on the southwest 

 slope by the failure of the northern supply was, by June 4, entirely 

 absorbed by warm saUne intrusions in the deep oceanic triangle west 

 of the Tail. This was the first appearance of Gulf Stream water 

 tliis far north and this far inshore for 1923. 



The boundary of the cold Arctic discharge, on June 4-14, curled 

 around and somewhat across the Tail of the Bank, extending about 

 60 miles to the westward and 48 miles to the southward. Several 

 bergs were freighted southward by it around the Tail, and set in on 

 the southwest slope during this period as shown by chart "C." 



During the latter part of June the cold current again weakened to 

 an attenuated streak across the extreme edge of the Tail as shown 

 by Sketch No. 7. 



The circulation of the water over the Grand Bank itself was sub- 

 jected to examination during May and June, as shown by profiles 

 No. 9 and No. 14. Early in May icy water was found fiUing the gulley 

 south of Cape Race and completely flooding the northern part of the 

 Grand Bank to a distance of 150 miles from Cape Race on the surface, 

 and 110 miles on the bottom, the latter condition being shown on 

 sketch No. 8. The water over the south central part of the Bank, 

 especially in the surface layers, was constantly too warm and of too 

 low a saUnity to have had a far northern source. A decided shrink- 

 age in volume of the Arctic water occurred between May 9 and 

 June 19, when it completely receded from the south central part of 

 the Bank, where it had been replaced by decidedly warmer and fresher 

 water, a change especially well marked in the surface layers. 



Several interesting facts have been brought out in connection with 

 oceanographic developments as disclosed by the series of observa- 

 tions carried out during the ice season of 1923, one of the most 



3 Bigelow (1917), on an exploration of the western Atlantic on Mar. 21, 1914, midway between Bahama 

 and Florida, found the water to be 20.13° in temperature and 3(3.55 in salinity. Although separated by 

 several years, the time interval of two months is approximately the period required to transport any in- 

 dividual water mass from Florida to the Tail of the Grand Bank. 



