Figure 21. — Temperature (°C.) and salinity {°D near the bottom at 55, 183, 914, and 1,829 m. 

 along the continental terrace, spring 1963. (The 183- and 1,829-m. depth contours are shown, 

 and the values in parentheses are interpolated. ) 



Thus, more uniformity of salinity values — 

 range from 31.6%o to 32.3%» — indicated absence 

 of upwelling. By fall, temperatures at 55 m. 

 had increased 3" C. off Vancouver Island, and 

 4° to 6= C. off the Washington coast. The 

 increase was about 0.6- C. even at 183 m. 



DISTRIBUTION OF WATER MASS 

 BELOW 200 METERS 



Analysis of distribution of temperature, 

 salinity, and dissolved oxygen indicated sig- 

 nificant changes in characteristics of water 

 mass in near-shore areas and also between 

 seasons. Water masses of different character 

 conventionally have been defined by the tem- 

 perature vs. salinity (T-S) curve plotted from 



serial oceanographic data (Sverdrup et al., 

 1942). All T-S curves from spring data were 

 grossly similar ; each had a characteristic 

 s-shape and occupied a narrow envelope. The 

 T-S curves of stations farthest offshore were 

 consistently displaced downward toward the 

 left, however. Waters here were colder and 

 less saline than near the coast. The T-S curves 

 from 10 stations within 500 km. of shore along 

 the Willapa Bay-Cobb Seamount line during 

 fall illustrate this displacement (fig. 23). The 

 heavy curves on the lower and right-hand sides 

 are general curves that represent the extreme 

 water masses in the North Pacific Ocean — the 

 Subarctic and Equatorial Pacific Water 

 Masses ; they indicate that the coastal water is 

 a mixture of two water masses. The separation 



244 



U.S. FISH AND WILDLIFE SERVICE 



