ABSTRACT a ‘Photographic observation and fathometer measurements of CASTLE Shots 1, 3, and 4 were made to assist in the prediction of craters produced by megaton weapons. The.more important numerical data are as follows: Yield Location Crater Radius Estimated Max.Depth (ft) (ft) 1 (fabs ME no x Surface-reef Surface-island 3000 400 2ho 15 4 Surface-water (160 ft water depth) 1500 250 6.5 MI _ | 1 Be RG The Shot 1 crater could‘have been predicted satisfactorily from the IVY Mike Shot. Shot 3 grater was smaller than predicted on that pasis. Both craters were largerChan predictions based on simple scaling of the JANGLE surface shot,’(even if some allowance is made for the difference in soils. fhe Shot 4 crater, producedbye shot on the surface of water having a scaled depth 4, = 0.05, was detectable but relatively small. A tunm breached but no hazard to nel underneath it would probably have | navigation was produced. An extrapolation procedure based ba smaller TNT explosions permits the prediction of the radius of the crater produced by a nuclear explosion under a wide range of circumstances. mer range of uncertainty is believed to be larger than a factor of two. |