An empirical study of acoustic/infrasonic source and propagation effects using a large dataset of explosions

Abstract

In May 2013 we performed a series of seventy explosion tests, varying the mass, shape, and height of the explosives. Shots were comprised of 11.6 kg, 4.9 kg, and 1.7 kg cylinders and 14.9 kg spheres, all of Comp-B. Explosive heights varied between 4, 2, 1, and 1/2 m above the surface, at the surface, and buried 1 m below the surface. Explosives above the surface were suspended by rope between two concrete pillars. In addition, ground surfaces were altered between dry sand, chicken wire, and concrete blocks. We monitored the explosions on 13 acoustic stations. Four temporary stations were deployed surrounding the shot site at less than 1 km distance. Eight additional stations were at distances of 1 to less than 9 km, and one at ~23 km from the shot site, 4 of which were temporary stations, and 5 are part of the Los Alamos Seismo-acoustic Network. We report on a detailed analysis of signal differences related to explosive and meteorological variations. The large quantity of data from repeating shots enables us to formally characterize the relative importance of source and path variations.