The observation of the tidal tilting in the direction of N 38° E at Osakayama Observatory has been performed with a recording water-tube tiitmeter whose base length is 60 meters and sensitivity is 0.00173"/mm and 0.00346"/mm. From the analyses of two periods of one month and a period of six months of ist observation, we have obtained some tidal com-ponents (M
2, S
2, K
1, O
1, P
1, J
1 and K
2), and have calculated the period range of the daily variation.
According to our analyses, we have the following results,
(1) the ratios O
1/K
1 and P
1/K
1 of the observed values are almost equal to those of the theoretical values. But the ratios K
1/M
2, O
1/M
2 of the observed values are about 16 times as large as those of the theoretical ones; the observed semi-diurnal components are very smaller than those of the theoretical ones which are direct effect of the ground tilt due to the tide generating force. It is the reason why that the difference between the phase of the direct effect of the semidiurnal component and that of the load tilt due to the oceanic tide is almost 180: Assuming the diminishing factor D is equal to 0.70, we are able to estimate adequately that the amplitude of the M
2-component of the load tilt is 0.97 times as large as that of the direct effect. On the contrary, the difference between the phases of the diurnal components of the direct effect and those of the load tilts are small, and their amplitude of the load tilt are from 1.1 to 1.7 times as large as those of the direct ones. So it seems that the observed amplitudes of the diurnal tides are emphasised.
(2) the ratio S
2/M
2 of the observed values is about 2.5 times as large as that of the theoretical ones. It shows that the solar tide has an another effect than that of the lunar tide. The residual of the observed value which is subtracted the direct effect and the estimated load tilt for S
2-component is as follow
0.0012" cos (2t-266°) .
On the other hand, the ground tilt due to the air-tide is calculated as
0.00054" cos (2t-163.6°) .
(3) the period of the daily variation is equal to 24 hours exactly. It seems that the effect of the air tide for S1-component is smaller than 19% of it, and the greater part of the S
1-component is caused by the solar radiation.
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