Wave Groups Generated by a Very Small Explosion.

Abstract

Generation mechanisms of wave groups by a small explosion are studied from a wave theoretical point of view. We see all waves predominant in the seismic records obtained are some kind of surface waves, especially of dispersive RAYLEIGH and SEZAWA waves. These wave groups are shown to satisfy the quarter wave length law which has been established theoretically in the present paper. Owing to shielding effects of a superficial layer, not very many kinds of surface wave groups can grow. This makes our seismograms rather simple.
In seismic prospectings, the surface waves studied in the present paper may be useful, at least, in some cases.