Seismic waves from finite faults in layered media

The time-dependent solution for a multipolar source in a structure consisting of a homogeneous layer over a homogeneous half-space is obtained as a sum of generalized rays. Numerical seismograms are calculated for a horizontal strikeslip and a horizontal dip-slip for a point-source, a finite line-source, and a finite two-dimensional source in the form of a rectangle. For comparison, the displacements in a homogeneous space and half-space are also calculated.

The seismograms for finite sources are similar to those for a point-source but show less conspicuous phases, the arriving pulses being wider and less sharp.