2000 Fiscal Year Final Research Report Summary
Bi-polar studies on physical and mechanical properties of deep ice cores
| Project/Area Number |
10440130
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Meteorology/Physical oceanography/Hydrology
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| Research Institution | Kitami Institute of Technology |
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Principal Investigator |
SHOUI Hitoshi Fac, Eng., Kitami Institute of Technology Prof., 工学部, 教授 (50201562)
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| Co-Investigator(Kenkyū-buntansha) |
NARITA Hideki Inst, Low Temp.Sci., hokkaido univ, Assoc.Prof., 低温科学研究所, 助教授 (20001662)
KAMEDA Takao Fac, Eng., Kitami Institute of Technology Lecturer, 工学部, 講師 (00233974)
SUZUKI Teruguki Fac, Eng., Kitami Institute of Technology Prof., 工学部, 教授 (30003205)
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| Project Period (FY) |
1998 – 2000
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| Keywords | ice core / deep ice sheet / ice sheet flow / ice crystal / Gneenland / Antarctica / cloudy band / mechanical test |
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| Research Abstract |
Polar ice sheets contain palaeo-environmental variation records on the Earth. This study aims to investigate physical and mechanical characteristics of ice sheets by conducting comparative studies of Greenland (GRIP and NGRIP cores) and Antarctic (Dome Fuji core) ice sheets, which serve as a foundation to retrieve environmental signals from deep ice cores. Major outcomes are summerized as below.
1) To investigate slip systems of ice crystal, a growth apparatus for a large single ice crystal was designed and constructed in a laboratory in reference to the Czochralski method. Uniaxial compression tests were carried out with ice samples obtained. Flow stress for pyramidal plane sliding is much higher than those hitherto assumed. This suggest that pyramidal plane sliding may not be contributing to ice sheet flow.
2) Uniaxial compression tests on deep core samples from GRIP, Greenland and Dome Fuji, Antarctica revealed that ice flow strength depends only on c-axis distribution, and not on impurity contents. This suggests that ice sheet flow strength may be calculated by adopting some models for fabric evolution in ice sheets.
3) Microscopic observations on cloudy band structures in ice core samples from NGRIP and GRIP, Greenland revealed that major sources for light scattering are micro-bubbles and the number density and size distribution were measured for the first time.
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