PHYSICAL OCEANOGRAPHY OF THE GULF OF MAINE 
591 
On August 17, 1912, and again on the 19th, we had readings of 10 to 11.7° as 
the Grampus sailed lengthwise through the Grand Manan Channel; and it is proba- 
ble that t his is about the highest temperature attained in the tide-swept Lubec 
Channel, because the highest 10-day average was about 10° there during the last of 
August and first of September of 1920 (fig. 31). The highest mean temperature 
recorded at Eastport for a 10-day period for the years 1878 to 1887 was 10.7° (Moore, 
1898) in the second week of September. 
The surface temperature of the greater part of the open Bay of Fundy likewise 
ranges from 10° to 12° in August, rising above 12° only exceptionally and locally 
(Huntsman, 1918; Vachon, 1918). Thus, Mavor (1923) records a range from 9.44° 
to 12° at 19 stations on three traverses of the bay inward from Grand Manan on 
August 22 to 27, 1919, warmest along the New Brunswick shore, coldest (9° to 10°) 
near Digby Neck on the Nova Scotian side. A similar gradation is described by 
Dawson (1922) for the first half of August, 1907. The records given by Craigie 
(1916), Craigie and Chase (1918), and Vachon (1918) for the open bay, with a maxi- 
mum of 12.68°, a minimum of 8.93°, in July and August, are consistent with this 
on the whole. 
Dawson (1922, p. 92) records surface temperatures somewhat higher (14.17° to 
13.33°) than this on a run from Digby to the middle of the bay on the meridian of 
St. John, New Brunswick (his station A), for July 22, 1907, but this may have been 
an unusually warm summer in the bay. At any rate, temperatures so high were 
briefly transitory, for the surface at his outer station had cooled to 13.6° by the next 
day and to 12.8° three days later (Dawson, 1922, pp. 88-92), when the surface tem- 
perature along the land from Digby Gut to Brier Island was only 8° to 9°. With a 
variation from 10° to 11.7° over the Fundy Deep for the three-day period, August 
23 to 25, 1904, independent of the stage of the tide (Dawson, 1922, p. 95), slight 
changes evidently are to be expected in the bay from day to day, perhaps governed 
by the roughness of the sea. 
Many records of temperature, surface and subsurface, have been published for 
the Passamaquoddy Bay region by Copeland (1912), by Craigie and Chase (1918), 
and by Vachon (1918), showing a considerable regional variation in the temperature 
to which the surface attains by the end of the summer. Copeland found the surface 
warmest (13.9° to 15.6°) in the northern part of the bay, coldest (10.4° to 11°) near 
Deer Island and in Letite Passage, with the central and western parts of the bay 
ranging from 11.1° to 15°. Vachon (1918, station 4), likewise records the surface of 
the center of the bay as warming from 11.4° on July 20 to 15.9° on July 27 in 1916. 
cooling to 11° on August 3 and 17, but warming again to 12.48° on the 25th and 
to 14.91° on the last day of the month. In the mouth of the St. Croix River, how- 
ever, the water is kept so thoroughly stirred by the strong tides that Vachon’s 
highest reading was 13.4°, the lowest 10.95°, for the period July 17 to August 31, 
coolest after northwest winds. Low surface temperatures also rule in Friar Roads 
between Campobello Island and Eastport, where Vachon reports 8.7° to 10.3° 
between August 2 and September 17, with 9.5° to 12.62° in the western passage 
between Deer Island and the coast of Maine, and with about this same range of 
temperature at a station near St. Andrews. 
