| Project/Area Number |
13490013
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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 |
広領域
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| Research Institution | Nagoya University |
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Principal Investigator |
KITAGAWA Hiroyuki Nagoya University, Graduate School for environmental studies, Associate Professor, 大学院・環境学研究科, 助教授 (00234245)
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| Co-Investigator(Kenkyū-buntansha) |
OKUNO Mirsuru Fukuoka University, Faculty of Science, Lecture, 理学部, 講師 (50309887)
MASUZAWA Toshiyuki Nagoya University, Graduate School for environmental studies, Professor, 大学院・環境学研究科, 教授 (40023858)
NAKAMURA Toshio Nagoya University, Nagoya University Center for Chronological Research, Professor, 年代測定総合センター, 教授 (10135387)
NISHIMURA Mitsugu Nagoya University, School of marine science and technology, Professor, 海洋学部, 教授 (70167568)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥12,200,000 (Direct Cost: ¥12,200,000)
Fiscal Year 2003: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2002: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2001: ¥7,000,000 (Direct Cost: ¥7,000,000)
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| Keywords | consmogenic isotope / cosmic ray / ^<10>Be / radiocarbon / peat deposit / carbon cycle / Holocene / paleoenvironmental changes / 宇宙線生成核種 / 湖沼堆積物 / 宇宙線生成同位体 |
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| Research Abstract |
The cosinogenic radionuclide ^<14>C is produced in the Earth's atmosphere mainly by the interaction of cosmic rays with nitrogen. Since the cosmic ray flux is modulated by geo-and heliomagnetic shieldings, records of ^<14>C provide information on variations in the solar activity and the geomagnetic field intensity in the past, After oxidation to ^<14>CO_2 (radiocarbon) becomes a constituent of the global carbon cycle, and exchanges between atmosphere, biosphere and the ocean. The analysis of the past atmospheric ^<14>C concentration therefore provides the possibility to detect change of global carbon cycle. However, since the atmospheric ^<14>CO_2 concentration is sensitive to changes in the ^<14>C production rate, we need to verify the past production rate from the independent data. In this study, we focused on a cosmogenic radionuclide, ^<10>Be, as a trace of.pastproduction changes.
In this study, we aimed to investigate the past carbon cycle by the comparison of ^<14>C concentration with ^<10>Be abundance. In general, the past ^<10>Be reconstructions have carried out from ice core analyses. We had an approach to reconstruct the ^<10>Be change from the terrestrial deposition such as lake sediment and peat depositions with higher sedimentation rate. As research marches on 10Be analysis of the lake sediments, it became very obvious that the ^<10>Be concentration of the lake sediments can be strongly influenced by the ^<10>Be cycle on the earth's surface ; supply of the material form atmosphere and river. Based on the this fact, we here complete following interpretation into a report ; developed method of ^<10>Be concentration of the terrestrial sediments, extended wiggle matching method to determine the sedimentation rate, ^<10>Be on the earth's surface based on the analysis of a core from the lake Biwa.
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