1:45 PM - 3:15 PM
[SGL21-P01] Annual radiocarbon dating of Japanese tree rings over the past 1200 years.
Keywords:Radiocarbon dating, Dendrochronology, Calibration curve, regional effect, fine structure
The standard calibration curve for the northern hemisphere, IntCal20, adopted the radiocarbon ages of Japanese tree rings obtained from a total of 10 buried trees and building members, as well as the varve deposits of Lake Suigetu. However, most of these values were measured using five or three-year rings as one sample. Since Miyake et al. (2013) detected cosmic ray events in the annual rings of the Yakusugi cedar, radiocarbon dating of single annual rings for verification and detection of similar events has been rapidly advancing in various areas of the world. In the process, regional differences in radiocarbon concentration in the atmosphere and minute annual variations have become clear.
Presenters are working on the radiocarbon dating of single annual rings of Japanese tree rings to clarify the temporal and spatial variation of atmospheric radiocarbon concentrations around the Japanese archipelago and improve the accuracy of age calibration. In addition to the conventional method based on width, the determination of tree ring age has progressed with the practical application of the oxygen isotope dendrochronology, making it easier to obtain tree ring data at various locations and periods. The efficiency of the preparation of the measurement samples has been improved by applying the cellulose extraction method used for the oxygen isotope dendrochronology, and the radiocarbon dating of single annual rings by accelerator mass spectrometry is accumulating. This paper presents the single-ring radiocarbon ages of Japanese trees, which have been reported in fragments.
The radiocarbon age of tree rings in Japan has tended to fall between IntCal and SHCal, the calibration curve for the southern hemisphere, indicating the possibility of entering the southern hemisphere atmosphere. The present material shows the same behavior. However, the period along IntCal is also seen. Although the radiocarbon age in a single annual ring has not been measured, the wood member of Seiun-ji temple in Koshu City adopted for IntCal20 is relatively consistent with IntCal and behaves differently from that of the cedar of Ise Jingu sacred area approaching SHCal.
The shape of IntCal20 from the 1st century to the 3rd century was revised from the previous version, IntCal13, by adopting the radiocarbon era of Japanese cedar buried in Hakone and Japanese cypress buried in Toyamagawa, Iida City. However, the regional effects of the radiocarbon era may differ even within the Japanese archipelago, and the pros and cons of the revision must be thoroughly discussed.
Our work was supported by JSPS KAKENHI (23300325, 25282075, JP18H03594, JP22H00026), NIHU Multidisciplinary Collaborative Projects, NMJH Collaborative Research, RIHN Research Project of the Ecohistory Program (H-05), and RISH Collaborative Research Using Databases, Kyoto University.
Figure 1. The ranges of the radiocarbon age of Japanese tree rings over the past 1,200 years in this study. The blue line is the samples adopted for IntCal 20, where five or 3-year rings are measured as 1 sample. Samples of Enkyo-ji temple and Aoba-jinja shrine are the same wood member, respectively.
Presenters are working on the radiocarbon dating of single annual rings of Japanese tree rings to clarify the temporal and spatial variation of atmospheric radiocarbon concentrations around the Japanese archipelago and improve the accuracy of age calibration. In addition to the conventional method based on width, the determination of tree ring age has progressed with the practical application of the oxygen isotope dendrochronology, making it easier to obtain tree ring data at various locations and periods. The efficiency of the preparation of the measurement samples has been improved by applying the cellulose extraction method used for the oxygen isotope dendrochronology, and the radiocarbon dating of single annual rings by accelerator mass spectrometry is accumulating. This paper presents the single-ring radiocarbon ages of Japanese trees, which have been reported in fragments.
The radiocarbon age of tree rings in Japan has tended to fall between IntCal and SHCal, the calibration curve for the southern hemisphere, indicating the possibility of entering the southern hemisphere atmosphere. The present material shows the same behavior. However, the period along IntCal is also seen. Although the radiocarbon age in a single annual ring has not been measured, the wood member of Seiun-ji temple in Koshu City adopted for IntCal20 is relatively consistent with IntCal and behaves differently from that of the cedar of Ise Jingu sacred area approaching SHCal.
The shape of IntCal20 from the 1st century to the 3rd century was revised from the previous version, IntCal13, by adopting the radiocarbon era of Japanese cedar buried in Hakone and Japanese cypress buried in Toyamagawa, Iida City. However, the regional effects of the radiocarbon era may differ even within the Japanese archipelago, and the pros and cons of the revision must be thoroughly discussed.
Our work was supported by JSPS KAKENHI (23300325, 25282075, JP18H03594, JP22H00026), NIHU Multidisciplinary Collaborative Projects, NMJH Collaborative Research, RIHN Research Project of the Ecohistory Program (H-05), and RISH Collaborative Research Using Databases, Kyoto University.
Figure 1. The ranges of the radiocarbon age of Japanese tree rings over the past 1,200 years in this study. The blue line is the samples adopted for IntCal 20, where five or 3-year rings are measured as 1 sample. Samples of Enkyo-ji temple and Aoba-jinja shrine are the same wood member, respectively.