“…An S R value of 1.3 can be used for both the tuff and alluvium found at the Nevada Test Site. Equation (12) can be rewritten to more clearly show its dependence on initial porosity if we first no*e that 1-$-(1 -W)p 0 (13) "g where <f is the total porosity of the me dium. Equation (12) A shock wave which represents the ground shock will then propagate outward from this explosion point.…”