Shallow Fault Structure
Shown is the xz-plane of the model and the y-component of seismic velocity.
The seismic properties of the model are
In the lower part of the model a direct S-wave (body waves) emerges. When the wave front touches the bottom part of the fault, some energy enters the FZ and converts into a trapped wave.
The direct S-wave touching the FZ boundary while traveling towards the surface causes a head wave within the FZ.