Abstract
Recently, the speeds of the records in the observations of the crustal strains are being increased higher and higher. So, the present author has devised the method of the tidal analyses in which the tidal heights in every 30 minute are used. The drift of the tidal heights is eliminated by means of the process which is derived from an amendment of Pertsev's selective means to adapt for the series of every 30 minute's reading values. The process of the tidal analysis for this series is derived from rearrangement of Darwin's one.
The recording-curves of the linear strain which are observed with a highly sensitive extensometer in the direction of S52°E at Osakayama are analyzed by means of the author's method (every 30 minute's height method) and by the combined method of Pertsev's driftelimination-process and Darwin's tidal analysis one, and then the both results are studiedcomparatively.
According to the results, the differences of the amplitudes are 2.5% in M2-tide, 15.6%O1-tide, and the differences of the phase lags are 32' and 2°54' in M2-tide and O1-tide, respectively, in these both processes. And the values of the higher orders are hardly able to believe in the process by using the every hourly height only.
The addition of the labour due to the use of the every 30 minute's height in these analyses is only about 40% of that of the every hourly one.
