115 



information regarding the currents south of the Tail of the Grand 

 Banks the survey was begun at the southern end of the area and pro- 

 ceeded from south toward north. The work of collection of data 

 began at station 2732 located at 43°30' N., 50°13' W., and, continuing 

 without incident, was completed at station 2808 at 47°20' N.,47°15' W., 

 on July 3, a total of 77 stations having been occupied. 



As soon as possible after completing the stations south of latitude 

 43° N., the currents in this vicinity were mapped and the situation 

 was described to the patrol cutter by radio. It should be remarked 

 here that in spite of an unusually high percentage of fog experienced 

 during this survey, occasional sights and sounding fixes at fortunate 

 times and intervals served to locate the stations with sufficient accu- 

 racy to produce a map of average reliability. The current map was 

 delivered aboard the patrol cutter Tahoe lb)i hours after completion 

 of the work of collection of data. The General Greene then proceeded 

 to St. John's, arriving there on July 4. 



Thus a total of 268 oceanographic stations were occupied during 

 the ice patrol season. From July 22 to August 17 an additional 39 

 stations were occupied during a post-season cruise in the Labrador 

 Sea and Davis Strait. These stations were disposed in the form of 

 three sections, namely, {a) from South Wolf Island, Labrador, to 

 Cape Farewell, Greenland, (6) a longitudinal section from section (a) 

 to Davis Strait Ridge, and (c) on Davis Strait Ridge from the "west 

 ice" to Holsteinsborg, Greenland. In addition to the usual tempera- 

 ture and salinity observations, samples were collected for the deter- 

 mination of dissolved helium and oxygen from the deeper levels at 

 the stations forming section (6) and from three stations in the middle 

 of section {a). The temperature, salinity, and oxygen data collected 

 at the 307 oceanographic stations occupied during the season and on 

 the post-season cruise are presented in the oceanographic table in this 

 bulletin. 



On the post-season cruise 451 sonic soundings were made with the 

 fathometer along the above-mentioned sections. These soundings 

 have been corrected for sounding velocity by means of the con- 

 currently collected temperature and salinity data in accordance with 

 the temperature-salinity-pressure-velocity relations given in the 

 British Admiralty tables (H. D. 282). The corrected soundings have 

 been tabulated and supplied to the United States Hydrographic Office 

 and to the International Hydrographic Bureau. In addition to these 

 soundings a continuous sonic sounding section was made along the 

 continental shelf from Davis Strait to the Strait of Belle Isle. This 

 section was mcidental to ice observation along the route and was 

 intended to shed light on the question of whether or not any submarine 

 canyons of the type found in other parts of the world exist in the 

 Labrador shelf. The best location for such a section would have been 



