Comparison of amplitudes of seismic waves from nuclear explosions in four mediums

Abstract

Particle velocity measurements just beyond the region of pisstic deformation have been used in calculating the reduced displacement potential of the nuclear explosions-Rainier, 1.7 kt in tuff; Fisher, 13•5 kt in alluvium; Hardhat, 5 kt in granite; and Gnome, 3.5 kt in salt. After scaling to 5 kt, the potentials are convolved with the response of the Benioff instrument and with an attenuation operator appropriate for distances of approximately 500 km. The resultant amplitudes normalized to tuff are tuff 1, alluvium 0.25, granite 1.11, and salt 1.61. Models of the crust of the earth are developed for the four explosions, and the amplitudes of the arrivals from the Mohorovicic discontinuity are calculated using methods previously developed by the authors. The ratios then become tuff 1, alluvium 0.18, ganitc 226, and salt 2.11. These ratios are for the amplitude of the first half-cycle of motion. The theoretical amplitude-distance curves for explosions in tuff, alluvium, granite, and salt for the first 500 km are in agreement with the experimental values recorded by the Air Force Technical Applications Center for the nuclear explosions Antler, Logan, Blanca, Fisher, Hardhat, and Gnome.

Elastic Displacement of Primary Waves From Explosive Sources

“…Figures 6A, 6B of a between 80 and 600 m. This is not a large variation of n. This method of relating the peak displacement amplitude to the size of the source is equivalent to using the peak displacement from the first half eycle of a displacement-type seismogram. These results are comparable to those of Werth and Herbst (1963). It must be realized that frequency shifts with different charge sizes.…”

Estimation of the power of underground nuclear explosions, taking account of their actual seismic efficiency

“…The existing models of the selsmic-source function use an approximation, or else the physically real description, of Reduced potentials and amplitude spectra of displacements for underground nuclear explosions in various media: a) reduced shift potentials for granite (1), alluvium (2), tufa (3), and modified tufa (4); b) relative amplitude spectra of displacements; c) normalized spectra of displacements according to the model of [7] for m = 5,0. the pressure, the reduced shift potential, and the maximum shift at the elastic-zone boundary. Thus in [5], a dependence of the following form was proposed to approximate the experimental reduced shift potential obtained in [6] …”

Accuracy of determining the power of underground nuclear explosions by a seismic method with known conditions of explosion

“…SAccording to [16]. **According to [7]. of basic parameters characterizing the geological conditions of expolsion in the first approximation may be reduced.…”