G02_P12

Bomb-pulse radiocarbon record for a well-dated Caribbean coral core

Winkler S^1,2,  Steier P², Carilli J³

¹Helmholtz-zentrum Dresden-Rossendorf, Dresden, Germany, ²Universität Wien, Wien, Austria, ³ University of California San Diego, La Jolla , USA

The radiocarbon bomb-pulse created by nuclear weapons testing in the 1950s and 1960s has created a massive spike of atmospheric ¹⁴C, which has been used in the study of the global carbon cycle in many subsystems including the marine environment. Coral records of bomb-pulse era ¹⁴C have been studied over the past decades to gain insight into the uptake and mixing of atmospheric CO₂ in the ocean. The ¹⁴C level seen in surface waters is specific to the origin of the water masses and ocean-atmosphere exchange of CO₂.

We present results for radiocarbon levels in coral aragonite with yearly resolution for a coral core from Belize. The core has a well-established stratigraphy, stretching from the onset of atmospheric testing of thermonuclear devices to 2007. The core has previously been analyzed for and trace metal content in relation to environmental impacts and the bomb-pulse of ²³⁶U. We compare the results with existing results and model expectations for the Caribbean Sea. We further discuss the close agreement for the prior results in terms of feasibility and the achievable accuracy of cross-dating of cores using the rise of radiocarbon by the atmospheric bomb-pulse.