Response of Layer to Strike-Slip Vertical Fault

Horizontally polarized shear waves in an elastic layer perfectly bonded to a rigid half-space are considered. The layer is subjected to a steady-state horizontal displacement field. The displacement spectrum is evaluated in closed form. It consists of two types of waves: (1)Progressing waves; and (2)locally standing waves. The average ratio of progressing torsional spectra versus the product of the displacement spectra and frequency, remains constant for a wide range of frequencies. The same ratio is strongly frequency-dependent for locally standing waves. The contribution of locally standing waves to displacements is significant for distances from the source which are, at most, an order of one thickness of the layer.