11:15 AM - 11:30 AM
[MTT28-09] Δ14C variability obtained from high-resolution radiocarbon measurements in coral skeletons from the western Pacific
Keywords:Radiocarbon, Δ14C variability, ΔR, coral, sea surface water
In this study, we established a new 14C analytical method, which requires smaller amount of carbonate samples using the accelerator mass spectrometry (AMS) at the Atmosphere and Ocean Research Institute, The University of Tokyo (YS-AMS). Coral skeletons along the Kuroshio trajectory were used to understand the variations of Kuroshio, which were compared with published radiocarbon ratio (Δ14C) data in the western Pacific.
Our results showed that Δ14C in Luzon, Ishigaki and Kikai Is, along Kuroshio current, were similar after 1950 (Post-bomb period). Before 1950 (Pre-Bomb period), our data showed that Δ14C in 1940s were different from Δ14C in 1900s previously reported by Yoneda et al. (2007). It is suggested that sea surface Δ14C fluctuates during a short period of time in the western Pacific. This variability would influence significantly to the calibration of local marine reservoir effects when calibrating 14C ages to calendar ages.