2000 Fiscal Year Final Research Report Summary
Assessment of effects on sea-level changes due to recessions of large-scale temperate glaciers caused by global warming
| Project/Area Number |
11640422
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | HOKKAIDO UNIVERSITY |
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Principal Investigator |
NARUSE Renji Hokkaido University, Institute of Low Temperature Science, Associate Professor, 低温科学研究所, 助教授 (10002099)
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| Co-Investigator(Kenkyū-buntansha) |
SHIRAIWA Takayuki Hokkaido University, Institute of Low Temperature Science, Instructor, 低温科学研究所, 助手 (90235739)
SAWAGAKI Takanobu Hokkaido University, Graduate School of Environmental Earth Science, Instructor, 大学院・地球環境科学研究科, 助手 (70312410)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Patagonia / Glacier / Snow and ice core / core drilling / Calving / Flow / Accumulation rate / Glacier variation |
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| Research Abstract |
This study was conducted by analyzing mostly the samples and data obtained from the field surveys at glaciers in Patagonia, South America, made in 1999 and 2000. Ice-core drilling was carried out in December 1999 near the head(1756m a.s.l.)of the accumulation area of Tyndall Glacier. Analyses of stable oxygen and hydrogen isotopes as well as major ions and biomass along a 46-m-long ice-core were made in laboratories to estimate accumulation rates over the Patagonia Icefield. Annual net accumulation rate was estimated as 17.8m a^<-1> w.e.in the balance year of 1997/98-1998/99, whereas 11.0m a^<-1> in 1998/99-1999/00. This high net-accumulation rate ranks Tyndall Glacier as one of the more extreme maritime glaciers in the world. Almost all large-scale glaciers in Patagonia calve into fjords to the west and into lakes to the east. Dynamic behavior of the lacustrine calving Upsala Glacier was studied, and it was found that the frontal variations should be affected by the bed topography and longitudinal stretching of the glacier. A linear relationship between calving velocity and water depth near the calving terminus was derived from freshwater calving glaciers in Patagonia. Measurements of flow velocities and calving events were carried out in December 1999 near the terminus of Glaciar Perito Moreno. The largest velocity was obtained as 2.7m d^<-1> at the front tip. A dynamic glacier model was constructed on the basis of measurements of flow velocity and ablation rates at Soler Glacier and others.
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