Development of quantitative technology of dislocations in artificial ice containing microparticles and Greenland EGRIP ice core

• Project/Area Number: 17H02957
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Nagaoka University of Technology
• Principal Investigator: Nobuhiko Azuma 長岡技術科学大学, 工学研究科, 学長 (70182996)
• Co-Investigator(Kenkyū-buntansha): 本間 智之 長岡技術科学大学, 工学研究科, 准教授 (50452082) ; 高田 守昌 長岡技術科学大学, 工学研究科, 助教 (50377222) ; 東 久美子 国立極地研究所, 研究教育系, 教授 (80202620)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥18,070,000 (Direct Cost: ¥13,900,000、Indirect Cost: ¥4,170,000); Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2017: ¥14,300,000 (Direct Cost: ¥11,000,000、Indirect Cost: ¥3,300,000)
• Keywords: 氷床 / 海面上昇 / クリープ / レオロジー / 人工氷 / 転位 / 不純物 / X線 / 氷床流動 / X線回折 / 微細粒氷 / アイスコア / 転位密度測定 / 氷 / 転位密度 / 雪氷 / 地球変動予測 / 力学特性 / 環境

Outline of Final Research Achievements

The sea level rise accelerates due to plastic deformation of ice sheets in polar regions, and hence we have evaluated such rheology of ice, which contains solid impurities, in view of dislocation assisted deformations. For this purpose, we developed an X-ray diffraction apparatus in conjunction with its stage holder at low temperature, and then the dislocation densities in crept ice samples containing an impurity are measured. Based on modified Williamson-Hall and Warren-Averbach methods are simultaneously used for the measurements of the dislocation densities, and then it is found that the impurities promotes pile-ups of dislocations, leading to recrystallization during the creep; consequently, a rapid deformation occurs in the impurity containing ice sample.

Academic Significance and Societal Importance of the Research Achievements

氷の変形が転位を介した塑性変形により生じることは古くから知られていたが、クリープ変形にともなう転位密度を測定した例は報告されていない。我々は氷床を模擬した人工氷の作成技術を確立しており、更にシリカを不純物とみなした不純物氷も人工氷として作成する技術も確立している。氷は六方構造を基本とした多結晶組織を有し、極地の降雪がやがてその自重により氷へと変化し、氷床を作る。氷床には鉱物、塩、生物起源の不純物も含有されており、比較的大きな不純物の影響はこれまで知られていたが、我々は500nm以下の微細な不純物が氷床流動に及ぼす影響をin-houseの加速試験装置を用いて評価し、その役割を明らかにした。

Research Products

• [Int'l Joint Research] Basque Centre for Climate Change(スペイン)
• [Int'l Joint Research] コペンハーゲン大学(デンマーク)
• [Int'l Joint Research] AWI(ドイツ)
• [Journal Article] Studies on the variability of the Greenland Ice Sheet and climate (2021)
  • Author(s): Kumiko Goto-Azuma, Tomoyuki Homma, Tomotaka Saruya, Fumio Nakazawa, Yuki Komuro, Naoko Nagatsuka, Motohiro Hirabayashi, Yutaka Kondo, Makoto Koike, Teruo Aoki, Ralf Greve, Jun'ichi Okuno
  • Journal Title: Polar Science Volume: 27 Pages: 100557-100557
  • DOI: 10.1016/j.polar.2020.100557
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Temporal and spatial variabilities in surface mass balance at the EGRIP site, Greenland from 2009 to 2017 (2021)
  • Author(s): Yuki Komuro, Fumio Nakazawa, Motohiro Hirabayashi, Kumiko Goto-Azuma, Naoko Nagatsuka, Wataru Shigeyama, Sumito Matoba, Tomoyuki Homma, Jørgen Peder Steffensen, Dorthe Dahl-Jensen
  • Journal Title: Polar Science Volume: 27 Pages: 100568-100568
  • DOI: 10.1016/j.polar.2020.100568
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Studies on Arctic aerosols and clouds during the ArCS project (2021)
  • Author(s): M. Koike, K. Goto-Azuma, Y. Kondo, H. Matsui, T. Mori, N. Moteki, S. Ohata, H. Okamoto, N. Oshima, K. Sato, T. Takano, Y. Tobo, J. Ukita, and A. Yoshida
  • Journal Title: Polar Science Volume: 27 Pages: 1-11
  • DOI: 10.1016/j.polar.2020.100621
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Variation in recent annual snow deposition and seasonality of snow chemistry at the east Greenland ice core project (EGRIP) camp, Greenland (2021)
  • Author(s): Fumio Nakazawa, Naoko Nagatsuka, Motohiro Hirabayashi, Kumiko Goto-Azuma, Jørgen Peder Steffensen, Dorthe Dahl-Jensen
  • Journal Title: Polar Science Volume: 27 Pages: 100597-100597
  • DOI: 10.1016/j.polar.2020.100597
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Continuous flow analysis of iron oxide in a Greenland ice core using a modified single-particle soot photometer (2020)
  • Author(s): K. Goto-Azuma, N. Moteki, Y. Ogawa-Tsukagawa, K. Fukuda, S. Ohata, A. Yoshida, T. Mori, Y. Kondo, M. Koike, M. Hirabayashi, R. Dallmayr, J. Ogata, K. Kitamur, S. Matoba, T. Aoki
  • Organizer: The 11th Symposium on Polar Science
  • Int'l Joint Research
• [Presentation] Temporal and spatial variabilities in recent surface mass balance at EGRIP, Greenland (2020)
  • Author(s): Y. Komuro, F. Nakazawa, N. Nagatsuka, M. Hirabayashi, W. Shigeyama, S. Matoba, T. Homma, K. Goto-Azuma
  • Organizer: The 11th Synmposium on Polar Science
  • Int'l Joint Research
• [Presentation] Analysis of solid microparticles and metal components contained in snow at EGRIP, Greenland (2020)
  • Author(s): Y. Komuro, F. Nakazawa, N. Nagatsuka, M. Hirabayashi, W. Shigeyama, S. Matoba, T. Homma, K. Goto-Azuma
  • Organizer: The 11th Synmposium on Polar Science
  • Int'l Joint Research
• [Presentation] グリーンランドEGRIPのピット試料に含まれる固体微粒子および金属成分の解析 (2020)
  • Author(s): 小室悠紀、中澤文男、永塚尚子、平林幹啓、繁山航、的場澄人、本間智之、東久美子
  • Organizer: ：雪氷研究大会オンライン
• [Presentation] グリーンランドEGRIP計画における2016～2018年の日本の観測活動及び氷床コア解析 (2018)
  • Author(s): 東久美子，川村賢二，中澤文男，平林幹啓，永塚尚子，繁山航，尾形純，福田かおり，本間智之
  • Organizer: 日本地球惑星科学連合2018年大会
  • Int'l Joint Research
• [Presentation] グリーンランド深層アイスコアに含まれる固体微粒子のその場観察 (2018)
  • Author(s): 繁山航，永塚尚子，本間智之，高田守昌，東久美子，Weikusat, I.，Drury, M.，Kuiper, E.，Pennock, G.，Mateiu, R.，東信彦，Dahl-Jensen, D.
  • Organizer: 日本地球惑星科学連合2018年大会
  • Int'l Joint Research
• [Presentation] 微細結晶粒氷のクリープ変形における結晶粒径と含有不純物の影響 (2018)
  • Author(s): 猿谷友孝，中島甲葵，高田守昌，本間智之，東信彦，東久美子
  • Organizer: 日本地球惑星科学連合2018年大会
  • Int'l Joint Research
• [Presentation] 氷期のグリーンランド氷床コアにおける固体微粒子のその場観察 (2018)
  • Author(s): 繁山航，永塚尚子，本間智之，高田守昌，東久美子，Mateiu, R. V.，東信彦，Dahl-Jensen, D.
  • Organizer: 雪氷研究大会
• [Presentation] 多結晶氷の力学特性・組織変化における結晶粒径の影響 (2018)
  • Author(s): 猿谷友孝，高田守昌，本間智之，東信彦，東久美子
  • Organizer: 雪氷研究大会