129 



PROFILE NO. 11— STATIONS 320-324. 



The section runs from in on the Bank southwesterly offshore into 

 the warm salt water of the Gulf Stream. It was occupied June 4. 



Salinity. — Water less than 33°/oo lay in over the Bank. Water 

 between 337oo and 347oo extended 45 miles off the slope and to a 

 mean depth of 450 meters (246 fathoms). Proceeding offshore a 

 sudden transition was found from 33°/oo to much more saline water > 

 35" /o„. These two water masses, so diametrically opposed physically, 

 abutted each other with a sudden transition and a Avell-defmed boun- 

 dary, as shown by the 34.9''/oo isohaline, 60 miles seaward from the 

 slope. 



Temperature. — The coldest water was found on the slope between 

 the 100 and 300 meter depths (55 and 164 fathoms), projecting sea- 

 ward as a shelf, with its base resting on the slope and its outer 

 bt)unds extending 42 miles offshore, abutting against the mass of 

 warm salt water which completely flooded the outer two stations. 

 The saltness and the warmth of the latter identifies it as the inner 

 edge of the Gulf Stream, which had worked inshore toward the 

 slope, west of the Tail, .during the interim since the last investiga- 

 tion on May 2-4. 



Since profile No. 11 represents the last of three sections which were 

 taken in this locality for the ice season of 1923, it is appropriate to 

 review the data thus secured. 



April 14 : A large amount of Arctic water was found on the south- 

 west slope, which extended 68 miles out from the slope and down- 

 ward to the depth of inves oigation, 750 meters (410 fathoms). 



May 4 : A decided shrinkage had occurred in the amount of frigid 

 water on the slope, it now extending offshore a distance of only 50 

 miles and downward 350 meters (191 fathoms), adjacent to the Bank. 



Jmie 4: There was very little change in the amount of Arctic 

 water at this place on the southwest slope over an interval of one 

 month, but its position had changed. It was restricted to the 100-300 

 meter (55-164 fathoms) levels, extended offshore 42 miles, and had 

 become effaced in over the bottom of the Bank. These successive 

 observations taken at frequent intervals furnish conclusive evidence, 

 with respect to both salinities and temperatures (see p. 146), of 

 the presence of the Labrador Current, which was continually bathing 

 the southwest slope of the Grand Bank, 50 miles west of the Tail, 

 throughout the months of April, May, and June. 



