Distribution of ejecta from cratering explosions in soils

Abstract

A study of the deposition of ejecta from two nuclear and five chemical cratering events in alluvial mediums indicates that 80% of the ejected material is deposited within a radial distance of 5.5 crater radii and 50% of the total ejected material is distributed within 2 crater radii. The ratio of total ejected mass to the missing mass as represented by the apparent crater averaged 0.53 for nuclear craters and 0.74 for chemical craters, charge burst depth having little or no effect. Two cratering devices (one nuclear and the other chemical) detonated at the same scaled burst depth but differing in energy release by over two orders of magnitude exhibited mass distributions of ejecta relative to their respective craters which were almost identical. The ratio of true lip mass to missing mass is inversely proportional to the scaled burst depth, ranging from 0.03 at depth to more than 0.25 near the surface for both chemical and nuclear charges. The part of the apparent crater due to compaction of the material surrounding the crater appears to be directly proportional to scaled burst depth, but the absolute value of this quantity is less for chemical shots than for nuclear shots.