ad. Within the ranges instrumented (7,500 to 20,000 ft), underwater shock pressures were not appreciably larger than the air pressure at the corresponding distance, Approximately equal peak pressure inducing signals were transmitted through the earth and air, and these induced peak pressures were approximately equal to those of the air shock wave at corresponding distances. €. The heights of the water waves induced within the Bikini lagoon can be approximated by the empirical relationship: H,R = 2.25 wi/2 (85)? p Range in feet Angular breach width in degrees in a semicircle into the i = Equivalent charge weight in Mt ea i & Shallow water crest height in feet FW Where: lagoon p = Relative density of media beneath fireball 2.3.2 Program 2, Nuclear Radiation Effects The general objective of this program was the determination of the militarily significant nuclear radiation effects of high yield surface detonations. Of primary interest was the determination of the nature, intensity and distribution of radioactive fall-out re-~- sulting fram surface-land and surface-water detonations of high-yield devices. In addition, the effects of initial gamma radiation and the flux and spectrum quality of neutrons were investigated. Gamma film and chemical dosimetry techniques and gamma scintil- i A Mac RAPins te OF ye tAT Et NAH Or lation counter equipments were employed to evaluate initial and resi- dual gamma rediation exposure and to provide information on arrival time and early field decay characteristics of gamma radiation from fall-out, Neutron detection techniques, including the use of a variety of x