Gravitational waves (GWs) of astrophysical origin were detected for the first time in 2015 through strain deformation measured at the Earth's surface. The inertia tensor of the deformable Earth is also disturbed resulting in the perturbation of its rotation vector and excitation of the rotational normal modes. Using a linearized theory of gravitation and the linearized equations of conservation √ Hz for fg = 10 −4 Hz and h0 = 10 −16. The strain amplitudes of such centrifugal deformation are beyond the detectability of current laser strainmeters used to detect GWs. In the future, improvement in the sensitivities of geophysical instruments to measure Earth's rotation fluctuations, particularly at sub-daily periods, and the development of the Laser Interferometer Space Antenna would make the present quantifications worth considering.