PHYSICAL OCEANOGRAPHY OF THE GULP OF MAINE 521 



able but much broken area shallower than 20 fathoms (37 meters), culmmating in the 

 dangerous "Georges" and Cultivator Shoals, the former with only 2J^ to 10 fathoms 

 (41/^ to 18 meters), the latter with 3 to 10 fathoms (6 to 18 meters). Both of these 

 shoals break heavily in stormy weather, and both have proved graveyards for many 

 fishing vessels. According to early rumor (Mitchell, 1881), Georges Shoal has been 

 awash or even dry within historic times; but even as early as 1776 Hollingsworth 

 decided that this tradition had no basis. It is worth noting that there is one well- 

 marked sink situated on the northeast part of Georges Bank, centering at latitude 

 41° 59' N., longitude 67° W. Prior to the spring of 1920 this was known (at least 

 ofBcially) from one sounding of 83 fathoms (152 meters) only, with neighboring 

 depths of 30 to 40 fathoms (55 to 73 meters). On March 11 of that year the U. S. 

 S. Albatross developed the region by a series of soundings, finding a maximum depth 

 of 120 fathoms (220 meters) and an area of about 27 square mUes deeper than 75 

 fathoms (about 140 meters). 



Inside the 50-fathom (90-meter) contour Browns Bank is about 55 miles long 

 from east to west, with an area about 700 square miles and a general depth of 30 to 

 50 fathoms. 



Around most of the periphery of the basin of the gulf the slope is gradual, the 

 100-fathom (183-meter) curve lying about 12 miles from shore at its closest (off Cape 

 Cod and about as near the outer islands in the northeast corner). The northern 

 slope of Georges Bank is much more abrupt, falling from about 40 fathoms (73 meters) 

 to 100 fathoms (183 meters) in a distance of only 3 to 5 miles. 



The Gulf of Maine, with its southern sill, occupies the whole breadth of the 

 Continental Shelf off northern New England and western Nova Scotia, with the 

 south slopes of Georges and Browns Banks falling so steeply to the abyss of the 

 North Atlantic that the zone between the 100 and 1,000 fathom contours (the " Con- 

 tinental Slope") is at one point (longitude about 66° W.) only 4 or 5 miles broad 

 and not more than 20 miles anywhere abreast the mouth of the gulf between the 

 longitudes of 65° and 71°. 



WATERSHED 



In more or less inclosed coastal seas, where the salinity of the water is influenced 

 greatly by the amount of inflow from rivers and smaller streams, the extentof the water- 

 shed and amount of run-off of fresh water demand consideration. The land area tribu- 

 tary in this way to the Gulf of Maine includes something over one-third of the State of 

 Massachusetts, two-thirds of New Hampshire, the entire State of Maine, half of the 

 Province of New Brunswick, a small part of the Province of Quebec, and the north- 

 western and western coastal strips of Nova Scotia — altogether, in round numbers, some 

 61,300 square miles. No large rivers empty into the gulf south of Cape Ann; north 

 of that point the chief tributaries, with their approximate drainage areas in square 

 miles, are (1) the Merrimac, 4,553; (2) the Saco, 1,753; (3) the Presumpscot, 470; 

 (4) the Androscoggin, 3,700; (5) the Kennebec, 6,330; (6) the Penobscot, 8,550; 

 (7) the Machias, 800; (8) the St. Croix, 1,630; and (9), chief of all, the St. John, 

 draining no less than 26,000 square miles. That is to say, the nine principal tribu- 

 taries drain together over 53,000 square miles, or five-sixths of the total watershed. 



