and oppositeh- directed components in a northeast-southwest direction, 

 greater and less than those shown in figure 24 where the relative flow 

 indicated in that figure is northwest and southeast respectively. 



However little the assumed motion of the berg may have contributed 

 to the explanation of the surface dynamic topography, at least it does 

 not add problems to those which existed before its introduction. It does 

 assist in smoothing the salinity picture and reducing the horizontal 

 gradients in surface salinity. In figure 25 the surface isohalines have 

 been redrawn to conform to the station locations predicated on the 

 assumed berg motion discussed above. This presents a more reasonable 

 picture than does figure 20, since the typical section of the Labrador 

 Current is characterized by nearly horizontal isotherms over the shelf 

 and a marked increase in salinity with increasing distance off shore and 

 with increasing depth. At subsurface levels the horizontal sections of 

 salinity are characterized by an axis of maximum salinit\' extending in a 

 north-northeasterly direction across the middle of the area. Within the 

 limits imposed by the horizontal spacing of the stations the horizontal 

 salinity gradients are not symmetrical with respect to the berg and the 

 gradients indicated by these measurements cannot be said to be the 

 result of the presence of the berg. 



Referring again to figure 21 two maxima in Ao-, are noteworthy, one 

 in the temperature effect at 10 meters and one in the salinity effect 

 at 20 meters. The former is associated with the thermocline and the 

 latter is associated with the corresponding steep vertical gradient in 

 salinity. In each case the value is sensitive to slight changes in depth 

 whether those changes represent the effects of internal waves or errors 

 in depth determination. The feature of interest is that the thermocline 

 occurs at a slightly higher level than the corresponding steep vertical 

 gradient in salinity. 



After completion of the oceanographic stations a series of bathy- 

 thermograph casts were made in the form of a section extending from 

 a point 1,300 yards from one side of the berg to a point 2,000 yards from 

 the berg on the opposite side. The resulting vertical section of tempera- 

 ture is shown in figure 26. The course of the isotherms between the 

 thermocline and the deeper temperature minimum is not as smooth as 

 in figures 18 and 19, although it must be borne in mind that figure 26 

 cuts across the center of the pattern, whereas figures 18 and 19 each 

 represented measurements made at equal distances from the berg. 



From the foregoing it is concluded that under conditions of a brisk 

 wind a berg floating in cold water probable does not aft'ect the tempera- 

 ture, salinity or circulation of the surrounding water to any marked 

 degree beyond a radius of 500 yards, and that for satisfactory examina- 

 tion of the efl"ect of a berg on its surroundings the measurements of 

 temperature and salinity need to be synoptic to eliminate spatial changes 

 of the berg with respect to its surroundings and changes in the depth of 

 the isotherms and isohalines from internal waves. Other conditions 



30 



