DAVIS STRAIT AND LABRADOR SEA 5 



to 34.92%o whereas Knudsen at stations 38 and 37 obtained 34.60 

 and 34.63%o, respectively. At Knudsen's station no. 22, however, in 

 the bottom water southwest of Cape Farewell, 34.96%o appears fairly 

 accurate. 



Based upon ships' log book records filed at the Deutsche Seewarte, 

 Schott (1897) published an exposition of the waters of the Grand 

 Banks and surroundings. In spite of the fact that the basic data 

 were necessarily confined to observations that could be made from 

 passing ships, Schott's paper is noteworthy, as it marks the beginning 

 of oceanographic literature on this particularly interesting area. 



During the summers of 1908 and 1909 the Greenland Trading Co.'s 

 brig Tjalfe carried out fishery and hydrograpical work in west 

 Greenland waters between the sixty-third and seventy-first parallels 

 of latitude. The results of the physical observations, considered with 

 data from other sources, have been reported by the Tjalfe's hydro- 

 grapher. Dr. J. N. Nielsen (1928). This is the most detailed and 

 comjDlete oceanogi-aphic paper yet published on the northwestern 

 North Atlantic. The following conclusions are put forward, {a) The 

 Labrador and Denmark Seas, in mid-depths, are essentially of the 

 same physical character; {h) the West Greenland Current, with a 

 velocity of approximately 8 miles per day, leaves the coast in the 

 latitude of Godthaab to join the Labrador Current; (c) the tidal 

 Hood current increases the velocity of the West Greenland Current, 

 the ebb decreases the same; {d) the velocity of the surface currents 

 around Greenland are greatly affected by the winds; {e) the extension 

 of the East Greenland Current undergoes seasonal variation and along 

 the southwest coast of Greenland disappears during autumn; (/) the 

 effects of winter chilling of the surface layers of the Labrador Sea 

 probably extends all the way to bottom, producing there the greater 

 part of the bottom water of the North Atlantic; {g) the eastern part 

 of Baffin Bay, beneath the surface, is filled with warm water that 

 has come across Davis Strait Ridge from the Atlantic and this layer 

 is thickest where it is pressed, by earth rotation, against the Green- 

 land slope; {h) the surface layers of Davis Strait are negative in 

 temperature throughout the year, and the warm water underneath 

 can have no direct effect, therefore, to melt the ice which is super- 

 ficial in draft. Our own observations in 1928 and subsequent years 

 support with specific evidence many of the early conclusions and 

 theories advanced as above by Nielsen. 



In 1910 the waters of the northwestern North Atlantic in their 

 southern and eastern sectors were explored by the Michael Sars North 

 Atlantic Deep-Sea Expedition. Prof. B. Helland-Hansen (1930) was 

 in charge of the physical work. The Michael Sars approached north- 

 ward toward the Grand Banks running a line of stations near the 

 fiftieth meridian toward St. John's, Newfoundland, and thence east- 

 ward in that latitude across the Atlantic. Serial observations of tem- 

 perature and salinity taken surface to 3,000 meters portray in both 

 sections the abrupt transitions that prevail along the North American 

 slope. The large scale maps, as Helland-Hansen points out, will 

 require many corrections as more and more detailed observations are 

 compiled. This in fact has been proved as will be shown by our own 

 contributions herein. One of the most important questions dealt with 

 by Helland-Hansen is the source of supply of the North Atlantic 



