Pacific Enewetak Atoll Crater Exploration (PEACE) program, Enewetak Atoll, Republic of the Marshall Islands. Part 1: Drilling operations and descriptions of boreholes in vicinity of KOA and OAK craters

Abstract

From mid-1984 through mid-1985, the United States Geological Survey engaged in an investigation of two craters formed from high-yield, near surface nuclear bursts at Enewatak Atoll. The craters studied, KOA and OAK, resulted from 1.4- and 8.9-megaton, near-surface bursts detonated near the northern perimeter of the Enewetak lagoon on May 12 and June 28, 1958, respectively. At that time, Enewetak was a part of the Pacific Proving Grounds (PPG). OAK and KOA are among the only high-yield nuclear explosion craters available for studies of cratering processes and crater-related effects. The objects of this program were: (1) to identify major crater dimensions, morphology, and structures; (2) to provide a data base for material-properties, shock-metamorphic, and other types of related studies; and (3) to gain a better understanding of both the process that formed the excavational crater and that altered that initial feature to its present form. These data from the Enewetak craters are needed for verification of cratering prediction models (code validation), which is important to the analysis of survivability of various strategic defense systems.