PHYSICAL OCEANOGRAPHY OF THE GULF OF MAINE 



643 



The whole column, however, cools nearly uniformly on the shoals during October, 

 whether the surface be slightly cooler than the bottom or slightly warmer at this 

 season depending on the wind as the latter moves the surface water in or offshore. 



Fig. 72. — Vertical distribution of temperature in the western arm of tlie basin of the gulf in 

 autumn and winter. A, August 31, 1915 (station 10307); B, November 1, 1916 (station 

 10401); C, December 29, 1920 (station 10490); D, January 9, 1921 (station 10503) 



The upper 40 meters of water over the continental shelf, south of Marthas 

 Vineyard and out to the edge of the continent, was vertically homogeneous in tem- 

 perature at 13° to 14.5° by October 22, 1915 (stations 10331 to 10333, fig. 73). 



