wt between 50 pei and 9000 psi, 2-6 Peak pressures were in agreement with theoret~ ical predictions and high explosive work. Peak pressures decayed with dis- tance at a significantly higher rate than vould occur in free water. The main shock was preceded by a small gradual increase in pressure which was induced by ground shock. At close-in stations, near ideal wave forms were observed; at 3000' range and beyond, wave forms were complex, A cavitation pulse was observed at all stations eat 755' range and beyond; masciumum cavita~ tion pressure measured was 314 psi at 188.' ranze, Air Overpressures, NOL used a combinatior of 32 rockets, five balloon sta-= tions, and seven surface stations to decunent the air overpressure-time field at ranges to 8000! from surface zer2 anc to altitudes of 15,000'. Nine of twenty rockets recovered yielded usable deta; eight additional rocket records may yield usable data after further ev-luition. Five cf the seven surface stations and one balloon station produced good records. Surface data show good agreement with predictions based on i res.lts and indicate the use of 1003 effieienty in scaling HE data to the nuclear case is reasonable. pressures from rocket records were lo. conpared to Ho predictions, Peak Maximum pressure recorded, 1.88 psi, was at ©5C0' altitude at range of 2000 feet fron surface zero, Surface Phenomena, NGL investigated surface ohenomena in general while SIO concentrated on water waves, 2G provided excellent photographic coverage of surface phenomena from 4 aircraft and several surface stations. NOL ob- tained good records of temperature and humidity changes at 5 stations within the base surge. These records show well defined temperature changes which correlate well with arrival of base surge es visually observed. SIO success~= fully measured the waterwaves from a number of stations and by 2 variety of means, The most interesting of these were three stations about 1700! from surface geo which “ndicated the hizhest wave was the first of the wave train. Mie pores wae PAGE OQ ¢