PHYSICAL OCEANOGBAPHY OF THE GULF OF MAINE 



721 



tion at greater depths from about 34 per mille at the bottom of the western and 

 northeastern parts of the trough to about 34.8 per mille in the southeastern part, 

 irrespective of slight differences in depth. 



Fig. 100.— Depth below tile surface of the isohalobath of 34 per mille, February to March, 1920 



Thanks to the vertical homogeneity of the water at this season at depths less 

 than 100 meters, the bottom salinity of the coastal zone was then very uniform from 

 station to station (about 32.3 to 32.6 per mille at most of the stations) in depths of 

 40 to 100 meters. The bottom water proved equally uniform on Georges Bank, 

 where the extremes recorded (32.6 and 32.8 per mille) were only 0.2 per mille apart 



