348 



BosTwicK H. Ketchum and D. Jean Keen 



volume of water within the region considered. The discharge of all of these rivers is 

 already mixed with large volumes of sea water in the sounds and estuaries before 

 reaching the continental shelf. 



Table I 

 The total volume of water contained between depth contours for various areas of the 



continental shelf Cape Cod to Chesapeake Bay 



Table II 



The major gaged rivers discharging between Cape Cod and Chesapeake Bay 



Data from U.S. Geological Survey Water-Supply Paper 1051 



* The Taunton, Providence, Pawtuxet and Pawcetuck Rivers gaged flow for 1946-1947. 



Direct precipitation on the area would add 2-38 x 10^^ ft'' per year, but the loss 

 from evaporation would be 3-42 x 10^^ ft^ per year. Wust's data for 35° and 40° 

 North Latitude of the Atlantic Ocean (Sverdrup et al., 1942, Table 30) give a mean 

 precipitation of 2-29 feet and a mean evaporation of 3-29 feet per year. The excess 

 of evaporation over precipitation of one foot per year gives a net loss for the exchanges 

 across the sea surface of 1-04 x 10^^ cubic feet per year. This is equivalent to 20% of 



