Propagation of tremors over the surface of an elastic solid

Abstract

Wave phenomena which are seen along the surface of a semi-infinite elastic solid when subjected to an impulsive line force in the direction normal to its surface have been studied. The results obtained are as follows. (1) Immediately after the impulsive force is removed, the vertical displacement is downward in the neighbourhood of the origin, and it is upward outside that downward domain. (§3) (2) In the downward (upward) domain, the horizontal displacement is toward (away from) the origin. (§4) (3) The surface deformations thus produced are propagated with the velocity of Rayleigh wave without conspicuous changes in form. (§3 and §4) (4) The wave length of the Rayleigh wave is proportional to the time of duration of the impulse, and is of the same order of extent as that of the downward domain at the moment when the force is removed. (§3). © 1954, The Seismological Society of Japan, The Volcanological Society of Japan, The Geodetic Society of Japan. All rights reserved.