Two New Millennium-Long Tree-Ring Oxygen Isotope Chronologies (2349–1009 Bce and 1412–466 Bce) From Japan

Abstract

We present two new millennium-long tree-ring oxygen isotope chronologies for central and northern Japan, based on 9693 annually resolved measurements of tree-ring oxygen isotopes from 39 unearthed samples consisting mainly of Japanese cedar (Cryptomeria japonica). These chronologies were developed through cross-dating of tree-ring widths and δ18O data from multiple samples covering the periods 2349–1009 BCE (1341 yr) and 1412–466 BCE (947 yr) for central and northern Japan, respectively. In combination with our published chronology for central Japan, the tree-ring δ18O dataset currently available covers the past 4354 yr (2349 BCE to 2005 CE), which represents the longest annually resolved tree-ring δ18O dataset for Asia. Furthermore, the high-resolution temporal record of 14C contents independently developed by Sakurai et al. (2020) was reproduced by our 14C measurements of earlywood and latewood in annual rings for the period 667–660 BCE.

Reconstruction of drought and long-rain chronologies since the 17th century in Central Japan using intra-annual tree-ring oxygen isotope ratios and documentary records

“…The mean standard deviation of multiple measurements for the same segment of the same tree ring was ± 0.38‰ (n = 816). This is larger than the typical analytical uncertainties for annual tree-ring samples of ± 0.2‰ (Sano et al, 2023;Zhao et al, 2023) because the value of 100 standard deviation for this study includes the influence of variability in δ 18 O within tree-ring in addition to the error in isotope measurement. However, this value is sufficiently smaller than the typical range of intra-ring δ 18 O variation of 4-6‰ (Fig.…”