Browsing Radiocarbon, Volume 46, Number 2 (2004) by Authors
Marine Reservoir Correction for the Cocos (Keeling) Islands, Indian OceanHua, Quan; Woodroffe, Colin D.; Barbetti, Mike; Smithers, Scott G.; Zoppi, Ugo; Fink, David (Department of Geosciences, The University of Arizona, 2004-01-01)Known-age corals from the Cocos (Keeling) Islands, Indian Ocean, have been analyzed by accelerator mass spectrometry (AMS) for radiocarbon to determine marine reservoir age corrections. The R value for the Cocos (Keeling) Islands is 66 +/12 yr based on the analyses undertaken for this study. When our AMS and previously published dates for Cocos are averaged, they yield a R of 64 +/15 yr. This is a significant revision of an earlier estimate of the R value for the Cocos (Keeling) Islands of 186 +/66 yr (Toggweiler et al. 1991). The (revised) lower Delta-R for the Cocos (Keeling) Islands is consistent with GEOSECS 14C data for the Indian Ocean, and previously published bomb 14C data for the Red Sea, Gulf of Aden, and Cocos Islands. The revised Delta-R is also close to values for the eastern Indian Ocean and adjacent seas. These suggest surface waters that reach the Cocos Islands might be partly derived from the far western Pacific, via the Indonesian throughflow, and might not be influenced by the southeast flow from the Arabian Sea.