Spectral Analysis of Seismic Instruments from Explosions in Southern Mississippi

ABSTRACT

Twenty-one surface seismic recordings were made by the U.S. Geological Survey in southern Mississippi for Projects STERLING and SALMON which provided for the detonation of two nuclear devices and one chemical charge. Relative-amplitude spectral ratios from the first 10 seconds of the SALMON and STERLING nuclear recordings indicate that in the predominant teleseismic frequency band, 1 to 5 cps, the SALMON signal amplitudes were about 1,000 times as large as the STERLING signal amplitudes, but in the frequency band 10 to 25 cps, they were less than 200 times as large. Comparison of the amplitude spectral ratios for the SALMON to STERLING-nuclear recordings with similar ratios for the STERLING-chemical to STERLING-nuclear recordings indicates that the ratios are primarily dependent upon the properties of the seismic sources and independent of the propagation media.

First posted January 13, 2010