Abstract
The effect of fluid-core resonance on strain tides has a different feature from that of gravity and tilt tides. We first studied the method to verify the fluid-core dynamic effect on strain tides and then calculated its spatial and azimuthal distributions varying with the station latitude and baseline orientation. The effect theoretically estimated for the laser strainmeter at the Rokko-Takao station, Kobe, Japan can reach -20% and+80% for K1 and Ψ1 constituents, respectively. Next, we analyzed two year observational data from March 1989 to February 1991 obtained from the laser strainmeter at Rokko-Takao by applying Venedikov's harmonic analysis method. Comparing the results obtained by harmonic analysis with those theoretically expected, precision of analytical results is good enough to be used in searching for the fluid-core dynamic effect. As a result, frequency dependence of straintidal factors obtaine from the laser strainmeter at Rokko-Takao is fairly well consistent with that theoretically predicted, except for the S1 constituent which would be disturbed by meteorological effects.
