Radiocarbon in annual coral rings from the eastern Tropical Pacific Ocean

• Published in: Geophysical Research Letters
• Main Author: Druffel, Ellen M
• Format: Article in Journal/Newspaper
• Language: English
• Published: eScholarship, University of California 1981
• Subjects: Physical Sciences and Mathematics; oceanography; Pacific; North Atlantic
• Online Access: http://www.escholarship.org/uc/item/4mm0f43n

Sixty radiocarbon measurements were performed on aragonite from annually banded corals collected from three sites in the Galápagos Islands. Preanthropogenic Δ14C values of coral that grew around A.D. 1930 averaged −70‰. This is substantially lower than average values previously reported (−51‰) for corals from Florida and Belize in the western North Atlantic Ocean. A decrease of 6‰ was noticed in coral that grew from 1930 to 1954. This decrease could be interpreted as a Suess effect in surface ocean water. The 100‰ increase in Δ14C for coral that grew from 1954 to 1973 is the result of bomb-produced 14C that was introduced to the surface ocean waters. The 14C levels in corals that grew during El Niño years were considerably higher than those for normal years. These higher values are attributed to the absence of up welling at the equator during El Niño events.