Establishment of the oxygen isotopic tree-ring chronology in the past 3400 years in Northeast Japan

2020 Fiscal Year Final Research Report

• Project/Area Number: 17H04729
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Cultural assets study and museology
• Research Institution: National Museum of Japanese History
• Principal Investigator: HAKOZAKI Masataka 国立歴史民俗博物館, 大学共同利用機関等の部局等, 研究員 (30634414)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 酸素同位体比年輪年代法 / 標準年輪曲線 / 高精度年代測定 / 東北日本 / 産地推定 / 気候復元 / 遺跡出土木材

Outline of Final Research Achievements

The oxygen isotopic dendrochronology established in Japan has made it possible to determine the age of tree-rings across tree species, which has been difficult using conventional methods. The author has developed the foundation of the method in Tohoku Japan, and has constructed an oxygen isotopic tree-ring chronology from the 5th to the 16th century. The present study aims to extend this to the past 3400 years.
The author obtained oxygen isotope ratio data of Aomori cypress from the 16th century to the present from living trees and archeological woods. In addition, data from the 5th century BC to the 5th century AD were obtained from archeological woods in Niigata and Miyagi prefectures, which were connected with the oxygen isotopic tree-ring chronology of the 15th century BC to the 5th century BC constructed from the buried forest of Mt.Chokai.These studies have achieved the construction of the oxygen isotopic tree-ring chronologies network that is continuous for the past 3400 years.

Free Research Field

文化財科学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果によって、東北日本の過去3400年間の木材の年代を誤差なく求めることが可能になった。構築された標準年輪曲線ネットワークは気候復元や産地推定にも応用できる。東北日本は歴史時代において中央政権と距離があったことから、文書記録の乏しい地域である。したがって、東北日本の歴史はモノ資料の情報に重点をおいて構築しなければならない。正確な歴史を構築する上で、高精度な年代情報、背景にあった気候変動、木材の動きからみえる流通構造などは、非常に有用な情報となる。本研究の成果は、東北日本の歴史構築の新たな基盤として、大きな意義を有する。