Earth tide observations and interpretation

Earth tide observations with gravimeters, tilt-and strainmeters were obtained at many stations on the globe. The original aim of the research was to determine the global response of the earth to the tidal forcing in the form of Love and Shida numbers. This goal could not be reached due to strong perturbations of the body tide signals by ocean tide loading and attraction and by local elastic effects for the two latter types of instruments. Higher accuracy is needed for the instruments and the corrections for these perturbations, before the true body tide signal can be gleaned from the observations and information about the elastic and anelastic threedimensional structure of the earth can be retrieved.