2 MARION AND GENERAL GREENE EXPEDITIONS 



The waters of the northwestern arm of the Labrador Basin 

 usually referred to as Davis Strait, has often raised a doubt as to 

 the extent of this body of water. Some maps, for example, print the 

 legend Davis Strait from the southern entrance of Baffin Bay to a 

 line from Cape Farewell to Newfoundland. The majority of car- 

 tographers, however, on recent maps, confine the name to the waters 

 on the submarine ridge between Greenland and Baffin Land. The 

 United States Geographic Board is also of the opinion that, strictly 

 speaking, the waters of Davis Strait refer only to the narrowest 

 part of the above waterway. If this definition be observed, and 

 such appears to be best practice, there remains a relatively large 

 sea expanse, bounded on the northeast by Greenland and on the 

 southwest by Labrador and Newfoundland, for which no name pre- 

 vails. The suggestion that this body of water be called the Labrador 

 Sea appears both logical and of good precedent, and so this usage 

 has been followed throughout the present paper. 



Nearby waters to which occasional references are made include: 

 Irminger Sea, Denmark Strait, and Greenland Sea. The prevailing 

 circulation of the waters also requires frequent reference to the 

 Irminger Current, East Greenland Current, West Greenland Cur- 

 rent, Baffin Land Current, Labrador Current, Gulf Stream, and At- 

 lantic Current. The fanning out of the Gulf Stream on reaching the 

 longitude of the Grand Banks has necessitated another designation 

 for the flow east of the fiftieth meridian — Atlantic Current. 



Knowledge regarding the submarine configuration of the north- 

 western North Atlantic in its deepest parts, especially where it con- 

 nects through the Labrador and Newfoundland Basins with the 

 North American Basin, helps to explain broad questions of deep- 

 water and bottom-water circulation. As a result of the echo sound- 

 ings obtained by the Meteor^ 1929-33, it was found that Reykjanes 

 Ridge (Defant, 1931) extends much farther to the southwest of 

 Iceland than had previously been believed. The configuration, as 

 shown by the trend of the 4,000-meter isobath in the lower right- 

 hand side of the frontispiece, suggests a topographic connection 

 between Reykjanes Ridge and Flemish Cap. Wiist (1935), for one, 

 was of the opinion that the deep water of the Labrador Basin was 

 partially barred from the Newfoundland Basin and the North Amer- 

 ican Basin by a Newfoundland Ridge (i. e., a connection between 

 the Reykjanes Ridge and Flemish Cap) at a depth of about 3,600 

 meters.^ The Meteor^ however, which in February and INIarch 1935 

 ran a line of soundings from Cape Farewell southward to the 

 fiftieth parallel as stated in a preliminary report by Dr. Bohnecke 

 dated April 8, 1935, found only one isolated sounding of about 

 3,800 meters near the position of the suspected ridge. 



In the summer of 1935 Soule (1936) on the United States Coast 

 Guard cutter General Greene collected a total of 2,036 sonic sound- 

 ings from the Labrador Basin and in the region of the Newfound- 

 land Ridge hypothesized by Wiist (1933) . A bathynietric map based 

 upon all available soundings has been published by Soule (1936) and 



8 His assumption of a Newfoundland Ridge was based on a difference in temperature 

 of tho bottom water as shown by the two following: observations : British ship Cambria, 

 latitude 51<'34' N., longitude 41*43'.S0" W., depth 4,2:U meters; ts 1.83° C, tp 1.46° C. : 

 and an unnamed ship, from the records of the British Admiralty, latitude 49°49' N., longi- 

 tude 38°00' W. ; depth 4,005 meters; ts 2.22° C, tp 1.85° C, (where U is the temperature 

 in situ and tp is the potential temperature). 



