海岸にある栖原での地球潮汐歪の観測

抄録

Observations of the earth tidal strains in the directions of NS and EW at Suhara observatory which is located on the coast have been performed. The component tides (M₂, O₁ and S₂) of the strains are analyzed for the period of about 200 days. The direct tides and load tides caused by the ocean and the atmosphere are subtracted from the observed components, and their residual strains are obtained. M₂-components of the residual strains are obtained as 10.7×10^-9 cos (2t-35 .4°) in the NS-direction and 10.1×10^-9 cos (2t-10.4°) in the EW-direction. Where t is the local time of the M₂ tide. Their amplitudes and phases are almost equal each other in the orthogonal directions. Therefore, it is reasonable to presume that the residual strain is caused by tidal oscillation of the pressure of ground water under the observing site which is connected to the hydrostatic pressure at the sea floor near the Observatory.