What do you suggest that implications of more stations to record earthquake data in Saudi Arabia will help in imaging the crustal structures? And what do you think that the crustal model suggested by the author and described in Table2 can be improved as it already shows a lot of velocity variations in the crustal layers?

When do the Nyquist frequency cause aliasing while digitization? What do you think?

 If we consider the assumptions regarding the vertical velocity gradient and lateral velocity variations, the solutions to elastodynamic equation becomes easy or very difficult?

 Are GPS readings alone appropriate to determine plate motions?

How would we be able to construct a reliable model for plate movement when geodetic coverage is not equally distributed over the earth?