The present invention provides a method of logging a subterranean formation through a wellbore containing a fluid, wherein no shear wave signal is obtainable utilizing conventional sonic well logging tools suspended in the wellbore. The shear wave signal is not obtainable usually because the acoustic velocity of the wellbore fluid is greater than the shear wave velocity of the formation to be logged. In the present method, the acoustic velocity of the wellbore fluid is adjusted until a shear velocity signal is obtainable by lowering the acoustic velocity of the wellbore fluid until it is less than the shear wave velocity of the formation. Thereafter, the formation is logged through the wellbore to obtain a shear wave signal.