Annual samples from two Palmyra Atoll corals (Porites lutea) that lived during the past 110years were analyzed for radiocarbon (Δ 14C) and δ 18O. The Δ 14C values decreased 7.6‰ from 1896 to 1953, similar to other coral records from the tropical and subtropical Pacific. Δ 14C values rose from ~-60‰ to ~+110‰ by 1980 due to the input of bomb radiocarbon from the atmosphere. Elevated Δ 14C values were observed for the mid- to late-1950s, suggesting early input of bomb radiocarbon, possibly from the largest Marshall Islands bomb tests in 1954. Secondary aragonite precipitation was identified in a portion of one core using scanning electron microscopy and X-radiography, and was responsible for high δ 18O and δ 13C values and a correlation between them. The Δ 14C results were more resistant to alteration, except when contamination was from the bomb era (>1956). © 2011 Elsevier Ltd.
Druffel-Rodriguez, K. C., Vetter, D., Griffin, S., Druffel, E. R. M., Dunbar, R. B., Mucciarone, D. A., Ziolkowski, L. A., & Sanchez-Cabeza, J. A. (2012). Radiocarbon and stable isotopes in Palmyra corals during the past century. Geochimica et Cosmochimica Acta, 82, 154-162. https://doi.org/10.1016/j.gca.2010.11.028