Earth tides

The tidal variations of gravity have been observed throughout intervals of several weeks to several months at Los Angeles, Pasadena, Hawaii and Attu. The term produced solely by the yielding of the Earth (including its oceans) may conveniently be characterized by two parameters. One parameter expresses the time‐phase, the other the amplitude. In the most extensive and reliable series of observations, at Pasadena and Los Angeles, these parameters were found to be nearly constant in time. Geographically, however, the phase shifts differ greatly at widely separated stations. Knowledge of the phase and amplitude parameters (when constant) enables the classical harmonic tidal constituents to be easily computed. Computation of the gravity tidal constituents for the Pasadena and Los Angeles data were carried through by the proposed simplified method, and compared with corresponding results obtained with the standard U.S. Coast and Geodetic Survey and British Admiralty computational procedures. Satisfactory agreement was obtained among the three methods.