OCEANOGRAPHIC SUMMARY 



Lieurenant CoinniaiKlfr Edward H. Smith. United States Coast (iuard 



The absence of ice thiring the sprino; of ld'24- permitted the patiol 

 ^•essels to extend their oceanographic observations ovei' a greater area 

 :han in any previous season. This excellent diversification of sta- 

 tions has brought out in clearer detail than ever before the general 

 :listribution of salinity and temperature of the water masses in the 

 ice regions during the danger season. Sketches Nos. 6 to 19, which 

 are carried on subsequent pages, will give the reader the best idea of 

 sucli distribution. 



The most striking feature from an oceanographic point of view 

 was the presence of water warmer than normal which lay over the 

 Newfoundland shelf, and this was attributed both to the mildness of 

 the 1923-24 winter and the absence of ice in the western North 

 Atlantic.^^ As has been previously pointed out in the chapter on 

 subsurface discussion, it was necessary to apply different standards 

 of temperature criteria this spring tlian in former years. 



THE ICY CURRENT 



Three different times, viz, March 22. April 23, and May S, the 

 patrol investigated the water mass around the Atlantic faces of the 

 Grand Bank, and from tlie data collected it was definitely ascer- 

 tained that arctic water was continually present tltere throngliout 

 the season. 



The heart of the icy current which bears icebergs to menacing posi- 

 tions in the North Atlantic bathed tlie steepest part of the slope, 50-110 

 meters, continually swelling and shrinking upon this base. Similar 

 to previous years, this water at various localities along the slope was 

 subjected not only to oft'shore intrusions of salty Atlantic water 

 working up the grade in the deeper layers, but also to dilution from 

 inshore points, as fresh coastal water spread seaward in the surface 

 layers. Such a flanking of dissimilar Avater masses from either side 

 restricted the frigid zone to a band whose width south of latitude 

 45° 00' north, was not greater than 10 miles. This icy attenuation, 

 however, maintained a continual connection which stretched south- 

 ward as far as the Tail, where it discharged its supply into the mixed- 

 water zone. (Treat variations in the rate of flow of the icy current 



=>' See Oceanographei's report, March, pp. 63-69. 



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