An oceanographic survey of Puget Sound, Washington Sound, and 

 the Strait of Juan de Fuca is being conducted under the supervision of 

 Dr. Chfford A. Barnes, Associate Professor of Oceanography. This 

 survey is a continuation of a series of long-range studies of the inland 

 waters of the State of Washington and the coastal system. The objectives 

 of this survey are to obtain a rigorous picture of the circulation within 

 the Strait of Juan de.Fuca and Puget Sound and the exchange of these 

 waters with contiguous water masses, including the open ocean ; to 

 assess the effects on the system of external influences such as tides, 

 meteorological conditions, and river run off ; and, where possible, to 

 interpret the internal conditions, including the physical, chemical, and 

 biological regimes in the light of the overall ph^'sical oceanography. 

 Drs. Alfred C. Redfield and William L. Ford, of the Woods Hole Oceano- 

 graphic Institution, participated actively during the summer of 1948 

 in the surve\'. 



Research effort has been largely concentrated on obtaining three- 

 dimensional circulation patterns using the Salinity-Temperature-Depth 

 Recorder (S-T-D). This device, developed at W^oods Hole, will con- 

 tinuously record the temperature of the sea-water and depth of sub- 

 mersion of the sensitive element when towed or lowered from a ship. 

 Although the reliability of the measurements is somewhat less than 

 obtained from normal water-bottle techniques it is adequate to establish 

 local gross circulation patterns and to define temporal changes that 

 could not be readily observed by other means. The salinity of local 

 waters varies from about 34°/oo near the bottom of the Strait of Juan 

 de Fuca to near zero in the upper layers off mouths of rivers and provides 

 a most useful index for determining the limits and tracing the movement 

 of local water masses. 



Two fisherman type craft of 50 ft. and 55 ft. in length, operating out 

 of the laboratories at Seattle and Friday Harbour, have been used for 

 field-work. Continuous surface records ha\'e been made for approxi- 

 mately 4,000 miles cruising on seventy-eight trips, and in excess of 

 •one thousand lowerings have been made for vertical structure. Surface 

 circulation patterns for the period July to September have been charted 

 for flood and ebb tides in Washington Sound between the Straits of 

 Juan de Fuca and Georgia and in the immediately adjacent waters of 

 these Straits. An insight has been obtained of vertical structure and 

 processes in this primary mixing zone of Fraser River effluent with ocean 

 water. During September the area of investigation was extended sea- 

 ward in the Strait of Juan de Fuca to within 30 miles of the open Pacific, 

 and also to the head of Puget Sound. During the period October to 

 December investigations were largely confined to the Puget Sound - 

 Hood Canal system with numerous measurements being made in the 

 entrance to Puget Sound, Admiraltj' Inlet, a critical constriction and 

 mixing zone which restricts water exchange with the open Strait. 



The local circulation pattern is characterized by an incoming supply 

 of relativeh' dense saline water upwelled from moderate depths of the 

 Pacific entering the coastal system on the bottom of the Strait of Juan 

 de Fuca and b}' a surface current of relatively fresh water from riyer 

 run-off and precipitation flowing seaward on the surface. Wind and 

 oscillating tidal effects are superimposed on the circulator}^ system 

 to accelerate mixing and vary the net water exchange. Prime mixing 

 zones normally occur at or near vertical or lateral constrictions in the 



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