Background Of Gravitational Wave Antennas Of Possible Terrestrial Origin. 3

In two previous papers we have presented evidence for a correlation between a part of the background of a gravitational-wave antenna (M=390 kg) and the free oscillations of the Earth. These results are suggestive of a similar study of the forced oscillations of the Earth. In this paper we present the results of the Fourier analysis for periods between ℱ=100 and 1667 min of the data collected on the occasion of two runs: one in 1978, the other in 1980. They show a few frequencies, some of which are in very good agreement with tidal frequencies. The probability for these «overlappings» to be accidental is of the order of 10−2 or less.