Figure 2.

Hawaii coral cores provide a valid local bomb ¹⁴C reference series. (a) The Baker nuclear detonation at Bikini lagoon in 1946, a 23 kt Mark III ‘Fat Man’ plutonium core bomb was one of the first in a series of tests that reached yields in megatons of TNT. The dark shape in the central water pillar is the silhouette from the battleship USS Arkansas. Later mid-twentieth century atmospheric nuclear detonations dispersed large amounts of ¹⁴C across the biosphere, which accrued regionally at different rates and timelines. Image credit: US Government, public domain. (b) Sample sites in the Hawaiian archipelago providing Porites coral cores with date ranges. (c) Radiocarbon chronologies for Porites records. Black line is an ensemble model; dotted line is the linear extension through contemporary period.