Abstract
Shizuoka Profecture has been promoted the project for effective usage of deep seawater in Suruga Bay. The intake pipes of the deep seawater at depths 397m and 687m were laid in Senoumi Basin off Yaizu in August 2000. In order to contribute the promoting of the project, JAMSTEC carried out the mooring observation to grasp the characteristcs of current variations in the deep seawater intake sea area off Yaizu for about 3 months from November 1999 to February 2000, when the construction laying of deep seawater had not started yet.
We analyzed the time series data obtained on the flow direction and velocity, and water temperature and salinity in the wide range of depths. The results indicated that strong tide variations occurred in the periods of half a day and one day and other variations occurred in the periods of order several or ten days in even the depths down to several hundred meters. Being averaged each velocity components over the whole period of the mooring observation, strong southwestward current was predominant in the surface layer of the depths up to about 250m, while weak northward counter current existed in the middle and deep layers. Being used mean and standard deviation of absolute velocity, it was suggested that periodic current variations in the deep layer were bigger than we had expected.
