Frequency-dependent attenuation of Love waves and its estimation

A modification of the spectral ratio method is presented to invert the frequency-dependent quality factor of Love-waves as the classical spectral ratio method can only be valid for a constant quality factor. A simple symmetric three-layered linear elastic model is used because its frequency-dependent attenuation relation can be given explicitly assuming that the quality factor of the coal and the country rock is constant. Synthetic seismograms are computed for this simple three-layered model to demonstrate the superiority of the modification to the classical spectral ratio method.