潮位観測による渡海水準測量について

抄録

One of the methods of sea-crossing leveling is how to get the difference in the height of sea level from the measurements of the sea level at the two points on both sides of a strait. This method is named the oceanographic leveling. In this case the dominant factors which possibly function over the observation of the sea level are oceanic current, wind and the atmospheric pressure difference on both sides of the strait. As the observation of the oceanic currents and the wind in and over a strait s a hard and laborious work, the calculation of the difference of sea level between the two points on the sides of a strait is often made out with the induced electric potential which occurs when water is running in place of the oceanic current speed, and with the atmospheric pressure gradient in place of the wind velocity. Here the author has figured out the regression equation (15) to explain the relations between the values of the difference of sea level and of the induced electric potential and the values of atmospheric pressure gradient. Then, applying the above theory to the Tsugaru Strait, the author tried to figure out the difference of sea level between the two points, Asamushi and Hakodate, on both sides of the strait, with the data from October 1959 to March 1960, and we get the result that the sea level is higher at Asamushi by 167 mm than at Hakodate.