A WIGGLE-MATCHED 297-YR TREE-RING OXYGEN ISOTOPE RECORD from THAILAND: INVESTIGATING the <sup>14</sup>C OFFSET INDUCED by AIR MASS TRANSPORT from the INDIAN OCEAN
Issued Date
2023-04-23
Resource Type
ISSN
00338222
Scopus ID
2-s2.0-85151570841
Journal Title
Radiocarbon
Volume
65
Issue
2
Start Page
505
End Page
519
Rights Holder(s)
SCOPUS
Bibliographic Citation
Radiocarbon Vol.65 No.2 (2023) , 505-519
Suggested Citation
Sano M., Pumijumnong N., Fujita K., Hakozaki M., Miyake F., Nakatsuka T. A WIGGLE-MATCHED 297-YR TREE-RING OXYGEN ISOTOPE RECORD from THAILAND: INVESTIGATING the <sup>14</sup>C OFFSET INDUCED by AIR MASS TRANSPORT from the INDIAN OCEAN. Radiocarbon Vol.65 No.2 (2023) , 505-519. 519. doi:10.1017/RDC.2023.14 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/81310
Title
A WIGGLE-MATCHED 297-YR TREE-RING OXYGEN ISOTOPE RECORD from THAILAND: INVESTIGATING the <sup>14</sup>C OFFSET INDUCED by AIR MASS TRANSPORT from the INDIAN OCEAN
Other Contributor(s)
Abstract
Regional offsets from Northern Hemisphere radiocarbon (14C) calibration curves are widely recognized for monsoon Asia and often hinder accurate 14C dating. In this paper, we explore the possible linkage between summer monsoon intensity and 14C offsets using tree-ring δ18O and 14C data from Thailand. We developed a 297-yr floating tree-ring δ18O chronology comprising seven teak log-coffin samples from the Ban Rai rock shelter site, northwestern Thailand. The outermost ring of our chronology was estimated to date from 358-383 CE, within a 95.4% (2σ) probability range, based on a total of 10 14C measurements that were wiggle-matched against a mixed calibration curve evenly weighted from the IntCal20 and SHCal20 curves. Backward trajectory analysis showed that an intensified (weakened) summer monsoon detected in a modern tree-ring δ18O chronology was most likely to be induced by increased (decreased) air mass transport from the tropical Indian Ocean, which is an area of intense upwelling where the 14C concentration is lower than the atmospheric 14C level. However, partly because of the limited sample size and dating uncertainty, the direct linkage between the tree-ring δ18O series and 14C records obtained from our teak log-coffin samples could not be statistically verified.