In the 1950s, US nuclear tests at Bikini and Enewetak left carbon-14 traces in Guam coral, revealing how nuclear fallout travelled across the Pacific

In the warm waters around Guam, a coral reef quietly recorded a series of events taking place thousands of kilometres away. During the 1950s, the United States carried out powerful thermonuclear tests at Bikini and Enewetak in the Pacific.