Mechanism of significant Antarctic ice sheet collapse events during the Last Interglacial

2020 Fiscal Year Final Research Report

• Project/Area Number: 17H01166
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Stratigraphy/Paleontology
• Research Institution: Hokkaido University
• Principal Investigator: Seki Osamu 北海道大学, 低温科学研究所, 准教授 (30374648)
• Co-Investigator(Kenkyū-buntansha): 池原 実 高知大学, 教育研究部自然科学系理工学部門, 教授 (90335919) ; 堀川 恵司 富山大学, 学術研究部理学系, 准教授 (40467858) ; 山本 正伸 北海道大学, 地球環境科学研究院, 准教授 (60332475) ; 菅沼 悠介 国立極地研究所, 研究教育系, 准教授 (70431898)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 南極氷床 / ウィルクス海盆 / 最終間氷期

Outline of Final Research Achievements

During the Last Interglacial, when global mean temperatures were +1 degree C higher than pre-industrial levels, sea levels were estimated to have been +6-9 m higher than the present level. A better understanding of the dynamics of the Antarctic ice sheet during the Last Interglacial provides important insights for predicting sea-level changes in future warming scenarios. In this study, we reconstructed the ice sheet dynamics of the Wilkes Subglacial Basin Ice Sheet (WBIS) during the Last Interglacial based don analyses of neodymium isotope and beryllium in a marine sediment core (GC1407) collected near East Antarctica to reconstruct the dynamics of WBIS during the Last Interglacial. We found, for the first time, that significant WBIS retreat occurred not only in the early part of the Last Interglacial but also in the late stage of the Last Interglacial.

Free Research Field

古気候学

Academic Significance and Societal Importance of the Research Achievements

本研究は全球気温が現在（２０２１年）と同等であった最終間氷期（１３－１１．５万年前）に東南極のウイルクス海盆氷床がどの程度後退したのかを調べた結果、ウイルクス海盆氷床の著しい後退が２度ほど起こっていたことが明らかになった。このことは現在の気候状態（産業革命前よりも＋１℃暖かい）が長時間継続した場合にやがてウイルクス海盆氷床の後退が起こる可能性を示唆する重要な成果である。