This thesis embodies three separate studies on seismic
waves. The first one is concerned with the origin of
the oscillatory nature of earthquake waves. Different
modes of generation have been discussed in some detail,
particularly the theory of Kawasumi and that of Sharpe.
The effect of the possible failure of Hooke's law on the
nature of the seismic waves is also explained briefly.
The second is a short note dealing with the physical
basis of two kinds of observations: the observation of
velocity and the observation of period.
The third part is a study on the theory of FLANK
WAVES. The basic difficulties of the old theory are
pointed out and discussed. The phenomenon is explained
in the light of the wave theory, in considerable detail
in the case of P waves and very briefly sketched for the
case of SH waves.</p
