Summer climate information recorded in tree-ring oxygen isotope chronologies from seven locations in the Republic of Korea

The Republic of Korea is characterized by its north-to-south stretch and high mountain ranges along the eastern coast, resulting in terrain with higher elevation in the east and lower in the west. These geographical features typically lead to regional climate differences, either based on latitude or from east to west. In the present study, for effectiveness, the entire Korean peninsula was divided into four regions based on the geographical features: The Northeast Coast (NEC), Central Inland (MI), Southeast Coast (SEC), and South Coast (SC). Two test sites were chosen from each region, except for the SC. The linear relationship between the altitude of sites and the mean oxygen isotope ratio (δ18O) revealed a negative correlation; the highest (1,447 m a.s.l.) and the lowest altitude (86 m a.s.l.) sites had a mean δ18O of 27.03‰ and 29.67‰, respectively. The sites selected from the same region exhibited stronger correlation coefficients (0.75–0.79) and Glk (Gleichläufigkeit) (74–83%) between the tree-ring oxygen isotope chronologies (δ18OTR chronologies) than those from different regions (0.60–0.69/70–79%). However, subtle variations in pattern were observed in the comparison period during a few selected intervals (approximately 10 years). All the regional δ18OTR chronologies exhibited positive correlations with either June or July temperatures over Korea, whereas negative correlations with regional summer precipitation and SPEI-3. Moreover, the chronologies showed notable negative correlations with the water condition of western Japan. The findings of this study can be used as a scientific reference for the study of variations of rainfall in East Asia using δ18OTR chronology

[論文] 酸素同位体比年輪年代法による韓国南部古代資料の高精度年代測定

年輪年代法は，誤差0年の暦年代を木材資料に付与できる優れた年代測定法である。欧米で広く利用されている同法であるが，日本を含めた北東アジア地域では限定的な利用に留まっている。その最大の理由は，年代測定の物差したる「標準年輪曲線」が限られた樹種でしか構築できていない点にある。2010年代に日本で飛躍的に発展し，実用化に至った「酸素同位体比年輪年代法」は，一つの標準年輪曲線で理論上あらゆる樹種の木材資料の年代決定を可能にし，この状況を打破した。本論では，韓国南部の低湿地遺跡から出土した広葉樹の木材資料に，酸素同位体比年輪年代法を適用し，年代決定に至った事例についてレビューする。金海市退来里1057-1遺跡建物遺構群では，木柱6点の年代が西暦287〜333年と決定した。慶州市月城垓子（堀）跡では，木柱5点の年代が西暦424〜433年と決定した。これらの木材資料に暦年代を与えたのは日本の針葉樹から構築された標準年輪曲線であった。これらの研究によって，韓国の三国時代の木材資料に初めて誤差のない暦年代が付与された。また，日韓の年輪年代学者，考古学者の交流が深まり，研究協力体制の構築にも繋がった。Dendrochronology can determine the absolute age of archaeological wood materials with annual accuracy. Although this method is widely used in Europe and the United States, its use is limited in the Northeast Asian region. The main reason for limited using is that the master chronology required for dating has been constructed for a limited number of tree species due to various historical backgrounds. The oxygen isotopic dendrochronology, recently developed in Japan, has made it possible to date all wood materials with a single master chronology.This paper show that a review for case studies of the application of oxygen isotopic dendrochronology to archaeological wood materials excavated from lowland sites in southern Korea. At the Tereri 1057–1 site of Gimhae, six wooden pillars were dated, which were found to have been cut down around 287–333 AD. At the Wolseong site of Gyeongju, we successfully dated five wooden pillars and found that they were around 424–433 AD. These studies showed that the oxygen isotopic dendrochronology can accurate dating for Korean wood materials of the Three Kingdoms period. In addition, the two surveys deepened the exchange between Japanese and Korean dendrochronologists and archaeologists, and led to the establishment of a cooperative research system

Tree-Ring Dating and AMS Wiggle-Matching of Wooden Statues at Neunggasa Temple in South Korea

From the 20th International Radiocarbon Conference held in Kona, Hawaii, USA, May 31-June 3, 2009.This paper reports the results of tree-ring dating and accelerator mass spectrometry (AMS) wiggle-matching for wooden Buddhist statues stored at the Eungjindang Hall of Neunggasa Temple, South Korea. Among 23 statues, 10 were successfully dated by tree rings. The cutting date of logs used for the statues was determined as some time between late fall 1684 and early spring 1685 when the bark ring (AD 1684) completed latewood formation. The 95.4% confidence interval of a radiocarbon date (cal AD 1688-1713, 2 ), which was obtained by wiggle-matching 7 samples of a statue, is similar to the dendro-date (AD 1684). A historical document recorded that the statues in the Eungjindang of Neunggasa were dedicated in July 1685. The dendro-date and written record indicate that Eungjindang statues were made within 3-8 months after log cutting. This seems rather short if we consider the period required for natural drying to avoid defects such as cracking and crooking.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202

Tree-Ring Dating and AMS Wiggle-Matching of Wooden Statues at Neunggasa Temple in South Korea

From the 20th International Radiocarbon Conference held in Kona, Hawaii, USA, May 31-June 3, 2009.This paper reports the results of tree-ring dating and accelerator mass spectrometry (AMS) wiggle-matching for wooden Buddhist statues stored at the Eungjindang Hall of Neunggasa Temple, South Korea. Among 23 statues, 10 were successfully dated by tree rings. The cutting date of logs used for the statues was determined as some time between late fall 1684 and early spring 1685 when the bark ring (AD 1684) completed latewood formation. The 95.4% confidence interval of a radiocarbon date (cal AD 1688-1713, 2 ), which was obtained by wiggle-matching 7 samples of a statue, is similar to the dendro-date (AD 1684). A historical document recorded that the statues in the Eungjindang of Neunggasa were dedicated in July 1685. The dendro-date and written record indicate that Eungjindang statues were made within 3-8 months after log cutting. This seems rather short if we consider the period required for natural drying to avoid defects such as cracking and crooking.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202