84 



force 5 or greater, 1 station being taken in a force 9 wind. The 

 current map, figure 20, was completed and delivered aboard the cutter 

 on patrol 25 hours after the occupation of the last station. The 

 General Greene then returned to St. John's where she arrived on 

 May 21. 



Departure was taken from St. John's on June 3 to make a third 

 current survey. As very little ice was present in the critical area 

 south of latitude 47° N., interest centered in the current situation 

 between latitudes 43° N. and 46° N., where in some years an intrusion 

 of Gulf Stream water blocks off the ice-carrying Labrador current 

 and insures freedom from ice in the steamer lanes to the south. 

 Accordingly, the oceanographic work of this cruise was concentrated 

 between these latitudes, the work of collection of data commencing 

 on June 4 at station 1896 and ending on June 10 at station 1937. 

 The 42 stations thus occupied were used to construct a current map, 

 figure 21, which was delivered aboard the Mendota 32 hours after the 

 last station had been completed. The General Greene then proceeded 

 to St. John's, where she arrived on June 12. 



Thus a total of 167 oceanographic stations were occupied during the 

 ice-patrol season. An additional 110 oceanographic stations were 

 occupied on an intensive post-season cruise in the region of the 

 Labrador Deep and the supposed location of the Newfoimdland 

 Ridge, hypothesized by Wiist.^ These 110 oceanographic stations of 

 the post-season cruise were occupied between July 10 and August 23. 

 A track chart is shown in figure 22, the oceanographic stations being 

 indicated as small circles. A dynamic topographic chart based on 

 this cruise is shown in figure 23. At 12 stations selected to form a 

 section from Cape Farewell southwestward to deep water and thence 

 south-southeastward to a point south of the supposed Newfoundland 

 Ridge, a total of 95 s'lmples were taken for oxygen determinations 

 and an equal number of helium samples were taken. Most of these 

 samples were taken from depths of 600 meters and deeper, only a 

 few stations having oxygen and helium samples from the surface to 

 600 meters. The oxygen titrations were performed by Mr. Henry E. 

 Mahncke, at the Woods Hole Oceanographic Institution, after the 

 return of the General Greene. The temperature, salinity, and oxygen 

 data collected at the 277 oceanographic stations occupied during the 

 season and on the post-season cruise are presented in the oceano- 

 graphic table in this bulletin. 



On the post-season cruise 2,036 sonic soundings were made with 

 the fathometer. These have been corrected for soimding velocity 

 by means of the concurrently collected temperature and salinity data 

 in accordance with the temperature-salinity-pressure-velocity rela- 



. ' jO«org Wiist, Wissenschaftliche Ergebnisse der Deutschen Atlantischen Expedition Aut Dem Forschungs 

 und Vermessungsschifr Meteor, 1925-27. Band VI, Erster Teil. pp. 73-74, Berlin. 1933. 



