Amplitudes of P, PP, and S and magnitude of shallow earthquakes

The determination of the magnitude of distant earthquakes has been based thus far on the amplitudes of Surface waves having periods of about 20 seconds, This method can be applied only to shallow earthquakes. The determination of the magnitude of shocks with a focal depth in excess of about 30 km. must be based on the amplitudes of the body waves. Before this can be accomplished, the relationship between amplitudes of body waves and the magnitude of shallow shocks must be studied. In the present paper the amplitudes of P, PP, and S, as a function of the magnitude M and the distance, Δ, are investigated as a first step in this direction