ABSTRACT The objective of this project was to measure and correlate with existing data the physical characteristics of craters (radius, depth, lip height and width, throwout, and permanent vertical ground-surface displacement surrounding the crater) resulting from near-surface nuclear detonations. Primary participation was on Shots Koa, Cactus, and Fig, the only land-surface bursts of Operation Hardtack. Dimensions of the craters were determined by topographic, lead-line, and aerial-stereographic surveys. Secondary participation included fathometer surveys of barge shots Linden, Oak, Yellowwood, Butternut, and Holly. Whenthe crater dimensions of the above shots were compared to adjusted dimensions taken from the crater curves of TM 23-200 it was found that Shot Cactus and Shot Fig crater data compared favorably, but the Shot Koa crater dimensions were enlarged because the device was emplaced in a water tank. TM 23-200. The barge-shot craters were larger than values calculated from :