Reconstruction of Antarctic Ice Sheet changes during a glacial period using GIA modeling

• Project/Area Number: 18K13621
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 17030:Human geosciences-related
• Research Institution: National Institute of Polar Research
• Principal Investigator: Ishiwa Takeshige 国立極地研究所, 研究教育系, 特任研究員 (10811896)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2019: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2018: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 南極氷床 / GIAモデル / 古環境 / 南極氷床変動 / 最終氷期 / GIAモデリング / 最終氷期最盛期 / 氷期

Outline of Final Research Achievements

Understanding the Antarctic ice sheet changes in response to climate change is an important issue for both research and society, since the Antarctic ice sheet melting will mainly cause global sea level rising. In order to assess the long-term time scale of Antarctic ice sheet variability, this study aimed to reconstruct the Antarctic ice sheet history during the Last Glacial Maximum (LGM, about 20,000 years ago). Due to the lack of direct records of Antarctic ice sheet changes, the Antarctic ice sheet history in the LGM does not well constrain. This study reconstructs the Antarctic ice sheet changes using a numerical modeling and sea-level data far from Antarctica. The results show that it is possible to constrain the Antarctic ice sheet history using not only geological evidence in Antarctica but also regions far from Antarctica.

Academic Significance and Societal Importance of the Research Achievements

南極氷床変動の時間スケールは様々であるが，衛星をはじめとする観測データは数十年に限られている．現在の南極氷床変動はより長期的な時間スケールを含んでいるため，その評価が南極氷床の気候変動に対する応答を理解する上では重要である．長期的な時間スケールの変動の復元には地質学的試料が有用であるが，南極域における地質学的記録は時空間的に不足している．本研究により南極から離れた地域の地質学データを用いて，GIAモデルから南極氷床変動史の制約が可能であることが示されたことは，長い時間スケールの南極氷床変動の復元につながり，将来の気候変動に対する南極氷床の応答の理解に向けて重要な知見である．

Research Products

• [Int'l Joint Research] Durham University(英国)
• [Journal Article] Excess ice loads in the Indian Ocean sector of East Antarctica during the last glacial period (2021)
  • Author(s): Ishiwa, T., Okuno, J., Suganuma, Y.
  • Journal Title: Geology Volume: in press
  • Peer Reviewed
• [Journal Article] A sea-level plateau preceding the Marine Isotope Stage 2 minima revealed by Australian sediments (2019)
  • Author(s): Ishiwa Takeshige、Yokoyama Yusuke、Okuno Jun’ichi、Obrochta Stephen、Uehara Katsuto、Ikehara Minoru、Miyairi Yosuke
  • Journal Title: Scientific Reports Volume: 9 Issue: 1 Pages: 1-8
  • DOI: 10.1038/s41598-019-42573-4
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Gauging Quaternary Sea-Level Changes Through Scientific Ocean Drilling (2019)
  • Author(s): Yokoyama, Y., Purcell, A., Ishiwa, T.
  • Journal Title: Oceanography Volume: 32 Issue: 1 Pages: 64-71
  • DOI: 10.5670/oceanog.2019.121
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Sea-level reconstruction using GIA modeling and geological evidence at Lutzow-Holm Bay during the past 50,000 years. (2020)
  • Author(s): Ishiwa T., Suganuma, Y., Okuno, J., Tokuda, Y., Itaki, T., Sasaki, S., Yamasaki, S.
  • Organizer: The 11th Symposium on Polar Science
  • Int'l Joint Research
• [Presentation] GIAモデルを用いた東南極インド洋セクターおける氷期の氷床変動復元 (2020)
  • Author(s): 石輪健樹，奥野淳一，菅沼悠介
  • Organizer: 第四紀学会2020年オンライン学会
• [Presentation] The timing of Antarctic Ice Sheet glaciation evidenced by Marine Isotope Stage 3 sea-level highstand records. (2019)
  • Author(s): Ishiwa, T., Okuno, J., Whitehouse, P.L., Suganuma, Y.
  • Organizer: INQUA
• [Presentation] A sea-level plateau during Marine Isotope Stage 2 evidenced by the Bonaparte Gulf sediments, northwestern Australia, and glacial isostatic adjustment modeling. (2019)
  • Author(s): Ishiwa, T., Yokoyama, Y,. Okuno, J., Obrochta, S., Uehara, K., Ikehara, M., Miyairi, Y.
  • Organizer: EGU 2019
• [Presentation] GIA モデルから探る最終間氷期の海水準変動 (2019)
  • Author(s): 石輪健樹
  • Organizer: 「未来の温室地球の類型としての過去の温暖期の気候状態の解明(その 2) 」
• [Presentation] Late Pleistocene to Holocene sea-level change in East Antarctica revealed by glacial isostatic adjustment modeling. (2019)
  • Author(s): 石輪健樹、奥野淳一、菅沼悠介、三浦英樹
  • Organizer: 2019年度地球惑星科学連合大会
• [Presentation] Antarctic Ice Sheet change before Marine Isotope Stage 3 using a glacial isostatic adjustment model. (2018)
  • Author(s): Ishiwa, T., Okuno, J., Whitehouse, P.L., Suganuma, Y., Miura, H
  • Organizer: GRAntarctic-NIPR Joint International Symposium on Ice-Ocean Interaction
  • Int'l Joint Research
• [Presentation] Sea level fingerprinting as a reconstruction of AIS history during MIS 2. (2018)
  • Author(s): Ishiwa, T., Okuno, J.
  • Organizer: Polar 2018
  • Int'l Joint Research
• [Presentation] Potential Antarctic Ice Sheet volume during the Last Glacial Maximum by sea-level fingerprinting using glacial isostatic adjustment modeling. (2018)
  • Author(s): Ishiwa, T., Okuno, J.
  • Organizer: The EGU General Assembly 2018
  • Int'l Joint Research
• [Presentation] GIA モデルによる東南極氷床変動史の復元と浅海域の海底堆積物掘削に向けて． (2018)
  • Author(s): 石輪健樹、奥野淳一、菅沼悠介、三浦英樹
  • Organizer: 日本地質学会第125年学術大会
• [Presentation] A sea-level fingerprinting analysis by glacial isostatic adjustment modeling for the Antarctic Ice Sheet change from the Last Glacial Maximum to the Holocene. (2018)
  • Author(s): 石輪健樹、奥野淳一
  • Organizer: 2018年度地球惑星科学連合大会
• [Remarks] 海洋堆積物コアから解明された最終氷期における短期間の氷床変動
  • URL: https://www.nipr.ac.jp/info/notice/20190510.html