Project 1.9— Water Wave Studies - L. W. Kidd OBJECTIVES AND INSTRUMENTATION Studies of water wave action generated by the detonation of large yield (greater than 1 MT) nuclear devices are made at relatively close ranges and at several distant island stations by Project 1.9. Four shore recording wave measuring stations (of the Mark VIII type) were active in Bikini Lagoon fonJonerciee). Project 1,9 constructed In addition, and installed four new type long period wave recorders on Fniwetok, Ailinginae, Wake, and Johnston Islands. These recorders are designed to document long period, low amplitude deep ocean waves of the tsunami type. f The recorders operate continuously but only receive significant signals from the large shots at Bikini, In addition to the above instrumentation, a tide gage was active at Ailinginae Atoll, and Sandia Corporation microbarographic stations were operated by Project 1.9 at Wake and Johnston. RESULTS AND DISCUSSION The tide gage record has not yet been recovered from Ailinginae, All other stations yielded excellent data. The Bikini Lagoon stations indicate there was no significant wave action in the lagoon, Detailed analysis may show the presence of a background-level wave entering the lagoon through the Enyu (Nan) channel or possibly the presence of an air-coupled water wave ijisturbance within the lagoon. All shore re- cording stations in the Bikini area yielded data on overpressure, COPIED/DOE LANL pe -_ ?.