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

Particle velocity measurements just beyond the region of plastic 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, granite 2.26, 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.