This paper investigates in what manner the spectrum of body waves radiating from point sources in a multilayered medium over a homogeneous half-space is different from the spectrum of body waves from the same source in an infinite medium. The effect of the system consisting of a point source in a layered crust on the spectrum of P-waves observed at large distances in the half space is studied. Analytical expressions for the transfer function of this system are derived for three types of point sources: an explosive source, a single couple, and a double couple of arbitrary orientation within the crust.
Preliminary numerical computations for the explosive source at various depths in a realistic model of the earth's crust permit the study of the effect of: a) the angle of incidence into the homogeneous half-space, b) the source depth, c) minor variations of the crustal model. In the case of an explosive source the most influential parameter of the transfer function is the source depth. In shallow explosions the low frequency part of the spectrum of body waves is comparatively rejected.