.\N OCEANOGRAPHIC MODEL OF PUGET SOUND* 



By Clifford A. Barnes, John H. Lincoln and Maurice Rattray, Jr. 



Department of Oceanography, University of Washington 

 Seattle, Wasliington, U.S.A. 



Introduction 



Oceanogiaphic observations must be made in great numbers and 

 extend over long periods, in many cases years, in order to obtain a re- 

 latively complete understanding of the conditions existing in even a 

 small estuary or bay. Resolution of the mass of data to provide the 

 desired information is further complicated by the fact that none can 

 be obtained under controlled conditions. Data obtained at different 

 tim.es are not directly comparable since the natural conditions neither 

 remain constant nor precisely repeat. Thus a synoptic picture of the 

 oceanography of an area may be considered only in general terms at 

 best, and as the size of the area is increased the generalities must of 

 necessity become broader. 



In treating an area as large and complex as Puget Sound, the prob- 

 lems of obtaining a complete understanding of the over-all oceanogra- 

 phy, under either normal or extreme conditions, from field observations 

 alone are almost insurmountable. In recent years, hydraulic models of 

 tidal estuaries have been used in increasing numbers as a guide in in- 

 terpreting the conditions within the prototype. It is recognized that 

 it is impossible to construct a reduced scale model rigorous of the pro- 

 totype and that distortion and scale effects may easily lead to misin- 

 terpretation. Nevertheless, these small-scale models are useful in clari- 

 fying the nature of existing conditions and in planning more efficient 

 field programs. Observations may be made under controlled conditions 

 and, of utmost importance, a particular set of conditions may be set 

 up in the model and repeated at will until all pertinent information 

 is collected. 



Description of the Area 

 Puget Sound (Fig. 1) branches to the south from the eastern ter- 

 minus of the Strait of Juan de Fuca, between the Olympic and Cascade 

 mountains of Washington. Its various arms, averaging less than 3 miles 

 wide, have a total area of 767 square nautical miles at mean high water. 



♦Contribution numle'- 195 from the Department of Oceanography of the University of 

 Washington. Technical Report No. 19, University of Washington and Office of Naval Re- 

 .search, Contract NSonr-520/IJI, Project 083-012. 



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