An intense pycnocline at about 4 m. depth existed in Bute Inlet in August, 1967. This corresponded to the largest observed fresh water runoff into the head of the inlet. A major pycnocline above 10 m. depth was not observed in January, 1968, corresponding to small fresh water runoff. Correlating information derived from near-surface transverse and longitudinal sigma-t sections and drift pole plots with wind and tide data, the curvature of the inlet's lateral boundaries was found to influence the disposition of fresh water in any given transverse section. The direction of the surface layer flow was best related to the wind direction except in cases of high runoff when the wind only modulated the speed of outflow. The tide had remarkably little effect. Distinct changes in depth of the pycnocline along inlet were observed.Suggestions for future experiments are presented. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Distributions of salinity, temperature, and oxygen of Bute Inlet based on eleven oceanographic surveys between the period August 1950 to August 1952 have been examined. The shallow salinity structures of the various seasons can be classified under two main groups, those occurring at periods of small river runoff and the others occurring at periods of large river runoff. In general, the surface salinity increases to seaward and with depth during all seasons. The surface water along the western shore is almost always observed to be less saline than along the eastern shore. The salinity of the deep water is 30.6 % during both periods. The seasonal fluctuation of salinities at the surface is well-marked but below a depth of 60 feet no normal cycle exists. The temperature distributions of both seasons can also be grouped under two main seasons, namely, Winter and Summer. During both seasons the surface temperature generally increases to seaward. The temperature gradients in the upper layers during the Winter and Summer are positive (increasing vertically downward) and negative (decreasing vertically downward) respectively. From the Spring Transitional to the late Autumn, a well-defined temperature minimum, which becomes indistinguishable at the mouth, is evident in the intermediate depths. The water in the greater depths has a temperature of 8°C and remains almost unchanged throughout the seasons. The seasonal temperature variation of the surface and sub-surface water down to a depth of 150 feet is in phase with the air temperature cycle but below this it is less noticeable. Insolation and cold runoff water from the rivers are predominant factors in determining the fluctuation in the temperature. The concentration of dissolved oxygen is usually high in the surface layer. The water at the greater depth is not stagnant as evidenced by the oxygen concentration. The characteristic water types of this inlet are: the Deep Water, Runoff Water, Intermediate Water and Winter Surface Water. The three distinct layers in the oceanographic structures are: the upper brackish layer, mixed layer, and lower layer. The main circulation of this inlet is estuarine. Eddy coefficient of diffusivity of values 0.65 and 0.58 g./cm./ sec., have been determined for the water above and below the layer of minimum temperature respectively. / Science, Faculty of / Physics and Astronomy, Department of / Graduate