Seven 1000-lb nitromethane spheres were detonated at different height/depths of burst with respect to the surface of a sandstone rock mass near Grand Junction, Colorado. The purpose of the tests was to study the effects of burst position on airblast, ground shock (the primary interest), and cratering phenomena. Ground motions were measured directly beneath the charges to maximum depths of 60 ft and at several locations near the ground surface within horizontal distances of 100 ft. Airblast pressure-time histories were determined along the rock surface at five stations extending to the 10-psi level.