High precision 14C measurements and wiggle-match dating of tree rings at Nagoya University

An AMS system dedicated to 14C measurement (486-AMS) built by HVEE B.V. The Netherlands, was delivered to Nagoya University in 1996, and is in use for routine 14C measurements. The relative error of the standard deviation (1σ) of 14C/12C ratios is ±0.3% to ±0.5% (somewhat larger than the uncertainty of ±0.3% from 14C counting statistics) and that of the corresponding 13C/12C ratios is ±0.03% to ±0.07%, as measured for HOxII standards. By using this AMS system, we are now testing whether the recommended IntCal04 14C calibration data set is consistent with the natural 14C-concentration variations as recorded in Japanese trees. Here we report the results of these consistency tests and accurate age determination of tree rings grown in Japan, using the 14C wiggle matching technique.