Rayleigh wave magnitude scaleM s

Summary TheM _s Rayleigh wave magnitude formula is revised for purposes of eliminating the variable effects of near distances and propagation pats on the values computed from standard long period seismograms. The improved formulation employs a revised distance correction function and period dependent path correction that normalisesM _s to large teleseismic distance, 20 second values. The method for computing the path corrections is described. The magnitude scale presented here givesM _s values which are within ±0.1 magnitude units of the Gutenberg and Prague magnitude formulae.