152 



of circulation at each particular place. (See oceanographic station 

 chart ''A.") 



A severe gale was experienced on the passage eastward, tut the 

 Seneca arrived without noteworthy event at station 351, lat. 43° 11', 

 long. 53° 50', at 2.15 p. ra., October 21. Favorable weather condi- 

 tions prevailed, affording an opportunity for accurate and rapid work, 

 and the entire investigation was completed at 12.50 p.m., October 26. 

 The Seneca cruised about 850 miles and occupied 26 stations, at 

 which 151 records for both salinity and temperature were secured 

 to a depth of 750 meters (410 fathoms). 



The Seneca collected the only oceanographic data ever secured at 

 this time of year — October — in the region of the Grand Banks. 

 These data are available for the use of scientists, and also are of 

 practical use to the ice patrol, as they increase its general knowledge 

 of the ice regions. A detailed discussion with reference to the 

 salinity and temperature of the profiles of the four radial sections 

 taken October 21-26 follows: 



DISCUSSION OF PROFILES 16-19. 

 PROFILE NO. 16— STATIONS 363 369. 



The section runs from just inside the continental edge across the 

 slope and eastward into deep water. The stations were taken 

 October 24-25. 



Salinity. — A shelf of water salter than 35 7oo ^^y between the 45 

 and 150 meter (25-S2 fathoms) depths at the outer stations, but it 

 did not reach to station 365. At this point, 70 miles seaward from 

 the slope, an abrupt transition occurred in the intermediate layers 

 from the highly saline water offshore to decidedly lower salinities, 

 <34 7oo> which occupied the remainder of the section above the 125- 

 meter (68 fathoms) depth. Water between 34 7oo and 33,5 Voo 

 bat-hed the slope and the bottom of the Bank. A still fresher surface 

 film, 32.8 °/oo> 15 meters (8 fathoms) in thickness, spread 12 miles 

 seaward from the edge, and right across the whole section in the 

 upper 30 meters (IS fathoms) the water was fresher than 34 7oo- 



Temperature.— T\\e most interesting feature of the profile is the 

 demonstration of the presence of a narrow band of water of Arctic 

 temperature, —0.4°, hugging the upper part of the slope between the 

 6.0 and 160 meter (33-86 fathoms) levels, but not encroaching at all 

 on the bottom of the Bank, nor more than 9 miles in width. The 

 bottora water on the Bank was more than 2° warmer (2.05°) than 

 that on the slope. The curve for 4° at the 150-meter (82 fathoms) 

 depth suggests that the temperature at this level had been influenced 

 b}'^ this Arctic band 44 miles out, but somewhere between stations 

 365 and 364 there was a sudden transition between temperature 



