Recent measurements of Qβ-1 of S waves in the lithosphere for frequency range from 0.02 to 25 Hz show a remarkable frequency dependence and systematic variation from place to place depending on the current tectonic activity. In order to test the hypothesis that the attenuation of S waves may be caused by the loss of energy by scattering due to heterogeneity, the amplitudes of S and coda waves were measured simultaneously for 900 local earthquakes in the central Japan for various frequency bands. The data were interpreted using the S to S single-scattering theory for coda waves, which is now supported by the observed agreement between Q of coda and Qβ, and also by the observed identical local site effect on coda and S waves. The result shows that the loss of energy from S waves required to explain coda amplitudes agrees with the attenuation of S waves within the uncertainty of measurements. This conclusion is supported by several recent studies on Q of coda, Q of Lg, Aβ, and coda excitation by other workers. |