Damping of S Waves

Abstract

THE modified Lomnitz law of imperfection of elasticity makes the strain under constant stress P: a is probably such that at is large for t = 1 second. For longer times the relevant constants are the rigidity μ, α, and qaa. The data used to estimate α and qaa are the damping of the 14-monthly variation of latitude and the fact that S at a distance of about 80° is clear and attains half the value for pure elasticity in about 2 sec. An alternative, possibly better, is to take the ratio as ¼. These lead to estimates as follows1: These lead to no contradictions with other data, such as have been found in attempts to apply the elastico-viscous law. Since estimates of damping have now been made from surface waves, it appears interesting to compare the results with those found from the foregoing law. In this communication values are found for S waves.