Author(s): Tomoyuki Takeuchi; Toshitaka Sakata; Yoshihiro Fujiyoshi
Linked Author(s): Tomoyuki Takeuchi
Keywords: No Keywords
Abstract: Lake Saroma is a lagoon with two tidal inlets, facing the Okhotsk sea in north-eastern Hokkaido, Japan. This lagoon is covered with ice in winter. Since 1928 investigations of physical and chemical conditions of the lagoon were carried out. but most of them were fragmental studies. Nonetheless, for these investigations, seasonal change has not been cleared enough, not to speak of conditions under the ice. So we have been executing comprehensive study of them since 1985. The items of the observation are tidal levels, current velocity and direction, water temperature. salinity and nutrients. The main results of this study at this stage are as follows: 1. The whole surface of the lagoon rises and falls almost simultaneously. 2. The amplitude of the tide inside the lagoon was less than that of outside and the time lag between them was 1-3 hours. 3. The boundary of the ranges affected by the first and second inlets may be the line connecting Fukushima-Banya and Cape Kimuaneppu. 4. Vertical distribution of nutrients were almost uniform except the unusual values near the bottom which were significant in summer and autumn. 5. When the amplitude of tide was about one meter, the mass of sea water interchange in a tide was the order of a hundred million cubic meters through the first inlet and ten million cubic meters through the second one. 6. There are no wind effect and no stratification in the water under the ice, therefore current speed was very slow except the area in which the strong effect of tidal flow extends through the inlets.
Year: 1988