Calibration curve from AD 1250 to AD 1650 by measurements of tree-rings grown on the Korean peninsula
详细信息   
摘要
A 1 MV AMS machine installed at Korea Institute of Geoscience and Mineral Resources (KIGAM) in 2007 has been dedicated to study on paleoclimate change and the environmental issues. Because the possibility of regional age offset has been suggested by several previous studies, the consistency of the data set of IntCal04, which is used to calibrate radiocarbon ages in our laboratory, with data obtained from 14C in tree rings grown in the Korean peninsula has been examined in this study. Tree-ring samples were collected from the building materials of Korean historical wooden buildings. Remaining historical records regarding the construction times of the buildings were consulted. The ages of the tree-ring samples ranged from AD 1250 to AD 1650 and were measured by dendrochronological method. After the samples were cut into single-year rings, alpha cellulose was extracted from each ring. Then, their annual 14C concentrations were measured by AMS. Accurate radiocarbon ages during the 400 year period were evaluated from the concentrations. The ages of the tree rings were compared with the IntCal04 calibration curve. The average deviation of 14C concentration was calculated to be ?2.14¡ë. By the Fourier transform of the single-year variation of the concentration, six major periodic components could be found. One of the components has a period of 10.9 years and it is thought to be related to a sunspot variation known as the Schwabe cycle, which has a period of 11 years.