2011 Fiscal Year Final Research Report
A proposal of new isotope geothermometer from lake sediments
| Project/Area Number |
23651013
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | Nagoya University |
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Principal Investigator |
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| Project Period (FY) |
2011
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| Keywords | 気候変動 / 安定同位体 / アジア / 湖沼堆積物 / 酸素同位体 / セルロース / 珪藻 / 気候プロキシ |
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| Research Abstract |
The past climate change is recorded on lake sediments. However, the records obtained from the lake sediments are subject to the influence of two or more environmental factors. The data interpretation is not easy task. In this research, a new approach was proposed and examined for quantitative reconstruction of lake water temperature. The isotope thermometer are based on the premise that aquatic celluloseδ^<18> O serves as a direct proxy for lake waterδ^<18> O, thereby allowing resolution of temperature signals inδ^<18> O records from co-existing diatom silica frustules which are influenced by lake water temperature and lake waterδ^<18> O The diatom. cellulose isotope-thermometer was applied to the sediments from Lake Biwa(central Japan) and a marr lake in Inner Mongolia on a trial basis. Although our current data set cannot support more accurate scaling of developed isotope-thermometers, the difference in the presumed temperature was in agreement with the growth season temperature difference of two areas. It was confirmed that this novel multi-isotope approach clearly has much to offer the information of climate changes in continental environments.
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