Uploaded April 2024 | Updated September 2026, 2 weeks ago
At 0630 on May 13, the Koa surface device was detonated at the western side of Dridrilbwij. The size of the blast was 1.37 megatons of TNT (5.7 PJ), around 76 times larger than the yield of the previous surface test, Cactus. The test was conducted in a large water tank. Within 17 minutes of the blast, surface clouds reached approximately 60,000 feet (18 km). Nuclear fallout predictions for Koa were larger and covered a broader range than Cactus, with significantly higher radiation levels, an order of magnitude larger, in the immediate region surrounding the blast. There had been a larger nuclear barge detonation, the 1.85 megatons of TNT (7.7 PJ) Apache test, off the island of Dridrilbwij two years prior in 1956, during which the island survived.The detonation of the Koa device, however, caused complete destruction of the island
At 0630 on May 13, the Koa surface device was detonated at the western side of Dridrilbwij. The size of the blast was 1.37 megatons of TNT (5.7 PJ), around 76 times larger than the yield of the previous surface test, Cactus. The test was conducted in a large water tank. Within 17 minutes of the blast, surface clouds reached approximately 60,000 feet (18 km). Nuclear fallout predictions for Koa were larger and covered a broader range than Cactus, with significantly higher radiation levels, an order of magnitude larger, in the immediate region surrounding the blast. There had been a larger nuclear barge detonation, the 1.85 megatons of TNT (7.7 PJ) Apache test, off the island of Dridrilbwij two years prior in 1956, during which the island survived.The detonation of the Koa device, however, caused complete destruction of the island
