This thesis embodies three separate studies on seismicwaves. The first one is concerned with the origin ofthe oscillatory nature of earthquake waves. Differentmodes 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 thenature of the seismic waves is also explained briefly.
The second is a short note dealing with the physicalbasis of two kinds of observations: the observation ofvelocity and the observation of period.
The third part is a study on the theory of FLANKWAVES. The basic difficulties of the old theory arepointed out and discussed. The phenomenon is explainedin the light of the wave theory, in considerable detailin the case of P waves and very briefly sketched for thecase of SH waves.
