日本地球惑星科学連合2019年大会

講演情報

[J] ポスター発表

セッション記号 M (領域外・複数領域) » M-IS ジョイント

[M-IS14] 南大洋・南極氷床が駆動する全球気候変動

2019年5月27日(月) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:関 宰(北海道大学低温科学研究所)、岡 顕(東京大学大気海洋研究所)、植村 立(琉球大学 理学部)、真壁 竜介(国立極地研究所)

[MIS14-P09] Reconstruction of Antarctic ice sheet dynamics in the Last Interglacial

*飯塚 睦1関 宰1板木 拓也2入野 智久1池原 実4杉崎 彩子2山本 正伸1堀川 恵司5菅沼 悠介3 (1.北海道大学、2.産業技術総合研究所、3.国立極地研究所、4.高知大学海洋コア総合研究センター、5.富山大学)

キーワード:南大洋、最終間氷期、南極氷床

Ongoing global warming could cause various problems in the future. One of the serious concerns is a sea level rise due to the melting of the ice sheet. Antarctic ice sheet, which hold a massive amount of fresh water was considered to be stable even if global warming progresses in the future. However, recent studies have shown that Antarctic ice sheet is more sensitive to global warming than previously thought. Therefore, it is an important to better understand extent to which Antarctic ice sheet is sensitive to global warming.

Study of past warm period proves an useful insight into the prediction of sea level rise in a future. Especially, Sea level in the last interglacial (MIS 5e), which was ~1°C warmer than the preindustrial was estimated to be several meters higher than that of the present with the sudden and abrupt rises in sea level. This suggests significant loss of Antarctic ice sheet during MIS 5e. However, Antarctic ice sheet variability during the MIS 5e has been poorly understood. In this study, we reconstruct dynamics of Antarctic ice sheet during MIS 5e from the marine sediment core GC1407 collected from Dumont d'Urville Sea, East Antarctica (130.518°E, 63.74°S).

Interval of MIS 5e has been determined based on abundance of radiolaria in GC1407. Variability of iceberg discharge is reconstructed by measurement of iceberg rafted debris (IBRD) in sediments. IBRDs are found to be recognized only during MIS 5e. This suggests that the significant discharge of large icebergs possibly from Wilkes Land basin, East Antarctica happened only during warmer than present climate condition.