High resolution reconstruction of intermediate and deep water environment in the North Pacific since the last glacial maximum

2017 Fiscal Year Final Research Report

• Project/Area Number: 26400504
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Stratigraphy/Paleontology
• Research Institution: Kobe University
• Principal Investigator: Ohkushi Ken'ichi 神戸大学, 人間発達環境学研究科, 准教授 (10312802)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 底生有孔虫 / 北太平洋 / 最終氷期 / 酸素同位体比 / 海底コア / 北太平洋中層水

Outline of Final Research Achievements

1)　We analyzed foraminiferal oxygen and carbon isotopes from a sediment core sampled at a water depth of 777 m to evaluate the intensity and depth distribution of the origin water of NPIW since the last deglaciation in the Oyashio region. The benthic foraminiferal delta-O-18 in the core increased by 0.3‰ to 0.4‰ from the end of the Bolling/Allerod warm episode to the Younger Dryas cold episode, suggesting that benthic oxygen isotope recorded intermediate water cooling.
2)　We studied deep-sea benthic foraminiferal fauna during the last 187 kyr in core NGC108 (3390 m water depth) collected from the Shatsky Rise, central northwestern Pacific, to determine a relationship between benthic foraminifera and paleoproductivity in the transitional zone between the subtropical Kuroshio Extension and the subarctic current. Cassidulina reniforme, Eilohedra levicula, and Epistominella exigua were the abundant species.

Free Research Field

古生物学