curve roughly follows the curve of the more accurately determined 

 volume of flow at section U, showing the same long period increase in 

 volume of flow. In the discussion of figure 13, it was pointed out that 

 the long-period trends in density of the upper and lower la\'ers were 

 oppositely directed and that while the full significance of these trends 

 was as yet obscure they would have far reaching efi^ects. It will be noted 

 that although the trend in the shallower layers, where the higher veloci- 

 ties exist, is toward greater densxcy and consequently smaller volume of 

 flow, in the deeper water the smaller trend toward lighter water out- 

 weighs the former and a net increase in volume of flow results. Thus is 

 emphasized the importance of comparativeh" slight changes in the 

 deeper levels. 



One of the unfortunate results of the war was the break in the series 

 of oceanographic observations from the Grand Banks region. The 

 season of 1941 brought to a close the 8-year series which has been 

 discussed here. With data missing for the war years, this series is 

 separated from later data collected with the resumption of oceano- 

 graphic work in the postwar period. 



The details of circulation and of the distribution of temperature 

 and salinity in the immediate vicinity of an iceberg have long been 

 subjects of speculation with little in the way of factual support avail- 

 able for such pictures as have been proposed. One school held that the 

 melt water from a berg being fresh would be of low density and spread 

 out from the berg upon the surface of the sea and might permit the 

 detection of the presence of the berg b>' means of a microthermograph 

 installed on a ship approaching the berg since the melt water would have 

 a difi^erent temperature than that of the surrounding sea. Early trials 

 of such microthermographs indicated that an\' such temperature efi^ect, 

 if present, was masked by other variations in seasurface temperature 

 to within practical distances of approach to a berg. Another school held 

 that the water immediately adjacent to a berg would be cooled b\- 

 the berg and the resulting increase in density would cause the water to 

 sink so that surface water would move toward the berg.^ 



It was hoped that during 1941 opportunities would permit the invest- 

 igation of the horizontal and vertical distribution of temperatures and 

 salinity near a berg under one or more of the four elementary conditions 

 combining calm and windy atmospheric conditions each with bergs 

 floating in warm and frigid water. The absence of bergs, however, 

 limited the observations to the one set of conditions combining a brisk 

 wind and cold water. This opportunity did not arise until the post- 

 season cruise, when on 23 July, stations 3540 to 3551 were occupied at 

 distances of from 300 to 2,200 yards from a berg found on the continental 

 shelf off the eastern approach to the Strait of Belle Isle. The approxi- 

 mate mean position of the berg during the observations was 52°18 ' N., 



« Smith, Ed. H. Marion. Expedition to Davis Strait and Baffin Bay. U. S. Coast Guard Bull. No. 

 pt. 3. pp. 124-127 (1931), Washington. 



25 _ 



