edge of the continental shelf but are found in the main basin at distances 
of less than 1 mile from the beach. Measured net fluxes in the main basin 
are variable over the annual cycle. Observed values range between 
0.7 X 10® ft.^/sec. and 2.9 x 10® ft.^/sec. (Cannon, 1983) (Fig. 3). 
Figure 3. Measured fluxes in the middle of the main basin 
After Cannon and Ebbesmeyer (1978) 
The seaward surface flux should exceed the landward flux at depth by the 
freshwater inflow which has an annual average value of about 
3 3 
39 X 10 ft. /sec. The magnitude of these net fluxes can be put in per¬ 
spective by comparing them with the annual mean discharge of the Columbia 
River which is about 0.26 x 10^ ft.^/sec. (Pruter and A1verson, 1972). 
Considerable interest has been generated in the fact that a portion of the 
seaward surface layer flux is mixed with the oceanic water in the Strait 
of Juan de Fuca at the entrance sill in Admiralty Inlet. It is this 
mixture that then enters at depth to produce the landward-moving flux in 
the main basin. This process recycles some of the surface flow. Present 
estimates of the percent of recycling of surface water are between 50 to 
60 percent (Barnes and Ebbesmeyer, 1978, Cannon and Ebbesmeyer, 1978 and 
Ebbesmeyer and Barnes, 1980). The percent of recycling and rates of in¬ 
flow of mixed water are believed to be related to stability of the water 
column and spring and neap tide cycles. However a clear understanding of 
the process has not yet evolved (Geyer and Cannon, 1982). 
If 50 percent recycling of the net seaward surface flow is assumed then 
the flux of water escaping the Sound is one-hcflf the main basin surface 
flux rate. This escaping flux rate when divided into the Sound's volume 
yields a flushing time for the whole Sound of approximately 155 days. 
At the sound end of the main basin the orientation and dimensions of the 
6 
