Diversion of the Evergreen for surface vessel ice patrols prevented any 

 further oceanographio work during the 1957 season. A postseason 

 cruise, comprising 53 stations, made during late July, however, consisted 

 of occupations of the Bonavista triangle 22-25 July and the section across 

 the Labrador Sea from South Wolf Island, Labrador, to Cape Farewell, 

 Greenland, 26-29 July. Thus in 1957, a total 237 stations were occupied, 

 96 during the first survey, 88 during the second survey, 30 in the occupa- 

 tion of the Bonavista triangle and 23 on the Labrador Sea section. The 

 oceanographic work was under the supervision of Oceanographer Floyd 

 M. Soule who was assisted by Lt. R. M. Morse. During the two surveys 

 made during the season Lt. John E. Murray also assisted. Other 

 assistants in the observational work were Francis N. Brown, yeoman 

 first class; Elwood C. Gray, aerographer's mate first class; Lewis M. 

 Lawday, aerographer's mate second class; Hugh R. McCartney, Jr., 

 aerographer's mate second class; and Herbert A. Ashmore, aerographer's 

 mate third class. 



Temperature and salinity measurements were made at each of the 

 237 stations. At the 23 stations along the Labrador Sea section the 

 observations extended from the surface to as near bottom as was practi- 

 cable. At the other 214 stations the observations extended from the 

 surface to about 1,500 meters where the depth of water permitted. The 

 intended depth of observations, in meters, were 0, 25, 50, 75, 100, 150, 

 200, 300, 400, 600, 800, 1,000 and thence by 500-meter intervals. 



A sample of old water taken from a part of an ice berg located well 

 away from the original surface of the berg and away from old crevasse 

 lines, was collected for subsequent determination of tritium concen- 

 tration. 



Temperatures were measured with deep sea reversing thermometers. 

 Most of the thermometers used were of Richter & Wiese manufacture 

 but a small percentage were made by Negretti & Zambra, G. M. Manu- 

 facturing Co., and Kahl Scientific Inst. Corp. The depths of observation 

 were based on unprotected reversing thermometers made by Richter 

 & Wiese and by Kahl. As a control on the performance of the individual 

 thermometers and a guide in determining when and which thermometers 

 were in need of thermal manipulation for the removal of gas particles 

 to their small bulbs, a program of intercomparison of protected ther- 

 mometers was carried out as in previous years. The individual ther- 

 mometers used in pairs were periodically shifted so that each thermometer 

 eventually was paired with several other thermometers. From a total 

 of 1957 comparisons, the probable difference between the corrected 

 reading of a pair of protected thermometers was 0.011° C. Since many 

 of the thermometers used had recent laboratory comparisons with 

 thermometers tested by the National Bureau of Standards, and as in 

 most cases the temperatures are the mean of the corrected readings of a 

 pair of thermometers, it is considered that the observed temperatures 

 listed in the table of oceanographic data have a probable error of about 

 ±0.01° C. 



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