PHYSICAL OCEANOGRAPHY OF THE GULF OF MAINE 



601 



Dawson's (1922) records for 1904 and 1907 show only a slightly greater vertical 

 range of temperature close in to the west Nova Sootian coast, with little change dur- 

 ing the month of August. 



Tidal currents keep the water as thoroughly stirred near Cape Sable as they do 

 on German Bank, so that Dawson (1 922, station Q) found the temperature virtually 

 uniform (about 4°) from surface to botto m 12 miles south of the cape on July 2, 1907. 

 Observations taken by Dawson in this neighborhood later in the summer, however, 

 in three different years, and from the Grampus in 1914 and 1915, show that the 

 surface then warms rapidly enough to produce a considerable range of temperature 

 by the end of August, except when temporarily disturbed by the tide, as just des- 

 cribed (p. 593). 



Temperatures 12 miles south of Cape Sable, °C. (From Dawson, 19SS, station Q) 



' High tide. ' Low tide. 



Grampus temperatures near Cape Sable, °C. 



A wide vertical range of temperature also has been recorded across the whole 

 breadth of the continental shelf, in the offing of Shelburne, for the last week of July, 

 both in 1914 and in 1915, with the surface averaging about 7.3° warmer than the 

 50-meter level for all these stations^' (maximum difference about 11°, minimum 

 4.6°). This thermal contrast continues to develop during the summer near the land 

 off Shelburne, where the surface (15°) was nearly 13° warmer than the bottom (2.2°) 

 at a depth of 70 to 80 meters on September 6, 1915 (station 10313). 



"Qrampm stations 10230 to 10232; Acadia stations 37 to 40 (Bjerkan 1919). 



