526 



BULLETIN OF THE BUBEAU OF FISHERIES 



TEMPERATURE AT 100 METERS AND DEEPER 



In February and March, 1920, the entire basin of the gulf was warmer than 1.5° 

 at 100 meters (fig. 13); all but its northwestern margin was warmer than 2°. The 

 most noteworthy features of the chart for this level are the very striking contrast 

 between the cold inner waters of the guK (1° to 3°) and the high temperature (7° to 

 13°) outside the edge of the continent, with the clearly outlined tongue of compara- 

 tively warm (4° to 6°) water entering via the Eastern Channel (better defined at 

 this level than at 40 meters) to extend northward and northwestward along the east- 

 em branch of the trough, which deserves special attention. The influence of this 

 warm indraft also is made evident around the northern slope of Georges Bank, west- 



1° 2° 3° 4° 5° 6° 7° 8° 9° 10° IT 12° 13° 14° 15° 16° 17° 18° 19° 

 Meter 



10 



20 



30 



40 



50 



60 



70 



80 



90 

 100 

 110 

 120 

 130 

 140 

 150 

 160 

 170 



180 



Fig. 4.— Vertical distribution of temperature at the moutli of Massachusetts Bay, March to August. A, March 

 1, 1920 (station 20050); B, April 9, 1920 (station 20090); C, May 4, 1920 (station 20120); D, May 16, 1920 

 (station 20124); E, July 20, 1912 (station 10002); F, August 22, 1914; Q, August 31, 1915 (station 10306) 



ward to the Cape Cod slope, in readings of 3° to 3.6°. With this warm tongue as 

 clearly defined by high sahnity as it is by temperature, its nature as an actual cur- 

 rent flowing into the gulf via the Eastern Channel from outside the continental edge 

 is sufficiently established. Seldom, in fact, do the curves for salinity and for tem- 

 perature correspond as closely as they do in this case, even to the pooling of the 

 warm, saline water off the mouth of the Bay of FujEidy. This phenomenon, of which 

 we have had frequent evidence in other years and at other seasons, is discussed more 



