PHYSICAL OCEAN OGEAPH Y OF THE GULF OF MAINE 
763 
Salinity on the bottom, of the trough, June, 1915. 
Locality 
Depth 
Salinity 
Locality 
Depth 
Salinity 
Fundy Deep, station 10282 
Northeastern corner, station 10283 
Eastern basin, station 10288 
Meters 
180 
180 
220 
Per mille 
33. 06 
33. 66 
33. 95 
Eastern Channel, station 10297 
Southeastern corner, station 10298 
Western basin, station 10299 
Meters 
275 
225 
210 
Per mille 
34. 92 
34.60 
33. 82 
The fact that the whole trough of the gulf was nearly as saline in the last half 
of June, 1915, as we found it in April, 1920 (p. 737), suggests a recovery of the indraft 
of slope water during the last half of May and first days of summer; but if such 
a recovery actually took place in 1915 it seems soon to have slackened again, judging 
from the rather abrupt transition from higher salinities in the Eastern Channe 
to lower ones just within the basin of the gulf recorded during the third week of 
that June (see the preceding tables). 
The expansions and contractions of 34 per mille water over the floor of the gulf > 
and the depth at which its upper limit lies below the surface of the water at any 
given time, more clearly reflect the recent activity of the indraft through the East- 
ern Channel than does the distribution of salinity at any given level in the water. 
In April, 1920, water as salt as this flooded the bottom of both arms of the 
basin, rising up to within about 140 to 175 meters of the surface along the eastern 
slope of the gulf (fig. 118). In June, 1915, however, 34 per mille water was confined 
to the southeastern corner of the basin (station 10298) close to the entrance of the 
Eastern Channel. 
SALINITY IN JULY AND AUGUST 
SURFACE 
If the readings taken in the western side of the gulf in July of 1912, 1913, and 
1916 represent the normal succession to the June state of 1915 and 1925 (just 
described), the surface of this part of the area suffers a second freshening from 32 to 
32.5 per mille in June to 31.4 to 31.9 per mille in July, but with little or no change from 
the one month to the next along the coast of Maine (31.5 to 31.8 per mille in July as 
well as in June) . If this represents the regular seasonal progression it probably reflects 
the anticlockwise surface drift, carrying the discharges of the eastern rivers around the 
gulf to the Massachusetts Bay region a month or more after their freshening effect has 
been entirely obscured off the coast of Maine by tidal stirrings. This explanation is 
supported by the fact that the July values for the surface of the bay were lowest in 
1916 (30.5 to 31.2 per mille), when a very tardy spring, with unusually heavy snow- 
fall, would make a seasonal sucession of this sort the most likely. The surface water 
of the western part of the basin of the gulf, in the offing of Cape Ann, has proved 
less saline in every August of record (1913, 1914, and 1915) than it is in May (p. 741) 
or June (p. 756), in the following seasonal sequence and for the same reason: 
Surface salinity, western basin 
Date 
Station 
Salinity 
Date 
Station 
Salinity 
May 4, 1915 
10267 
10299 
10007 
Per mille 
33.03 
32. 50 
31. 62 
Aug. 9, 1913 
10088 
10254 
10307 
Per mille 
32. 21 
31. 55 
32.47 
June 26, 1915 
Aug. 22, 1914 
July 16, 1912 
Aug. 31, 1915 
