Attenuation of dispersed wave trains

Abstract

It is shown that groups of seismic waves are attenuated by the factor exp − $exp⁡−πXQUT$ where X is the distance, U the group velocity, T the period and Q⁻¹ is a measure of the damping of free oscillations. Accordingly, observations of Q given by Ewing and Press (1954 a, b) and Sato (1958) are revised by the ratio of the phase velocity to the group velocity.