PHYSICAL OCEANOGRAPHY OP THE GULP OP MAINE 
667 
autumnal data for the deeper levels (100 and 150 meters) were for October and 
November of the very cold year 1916, when these underlying strata certainly had not 
warmed to the temperature usual for the date, although the superficial strata had 
(p. 642 ) ; but warming is probably to be expected here at 100 meters until some 
time in December. However, no rule can be laid down for depths greater than 100 
to 150 meters in the basin. Thus, the lowest temperature so far recorded in the 
Fig. 89.— Normal seasonal variations in temperature at the surface, 20 meters, and 100 meters in the west- 
ern side of the basin of the gulf, in the offing of Cape Ann, combined from the data for the several 
years and months. The curves are smoothed 
western side of the basin at 150 meters was for midsummer (1912) instead of at the 
end of the winter, as is the case off Gloucester only 30 miles to the westward. This 
lack of conformity between the season of the year and the temperature is still more 
notable at 200 meters, for which level the lowest as well as the highest temperatures 
for this locality have been recorded in summer, the latter (6.3° and 6.8°) in August, 
1914 and 1915, and the former (4.61°) on July 15, 1912. 
