Bomb‐produced radiocarbon in the western tropical Pacific Ocean: Guam coral reveals operation‐specific signals from the Pacific Proving Grounds

A coral core from Guam reveals unprecedented bomb-produced radiocarbon (14C) spikes, providing operation-specific signals from nuclear tests at Bikini and Enewetak atolls. The 1954–1959 peaks, with the first rising an extraordinary ∼700‰ above pre-bomb levels, far exceed typical marine 14C patterns attributed to air-sea diffusion alone. These spikes correlate with thermonuclear tests during Operations Castle (1954), Redwing (1956), and Hardtack I (1958). The study attributes the signals to vaporized coral reef material in nuclear fireballs, neutron activation of atmospheric nitrogen, and subsequent 14CO2 absorption. High-resolution analysis and ocean current modeling confirmed the timing and origin of these anomalies.

Andrews, A. H., Asami, R., Iryu, Y., Kobayashi, D. R., & Camacho, F. (2016). Bomb‐produced radiocarbon in the western tropical Pacific Ocean: Guam coral reveals operation‐specific signals from the Pacific Proving Grounds. Journal of Geophysical Research: Oceans, 121(8), 6351–6366. Portico. https://doi.org/10.1002/2016jc012043