2014 Fiscal Year Final Research Report
Detecting climatic changes and volcanic activity records in laminated tufa of Asama volcano
| Project/Area Number |
24700947
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Geography
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| Research Institution | Gifu University |
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Principal Investigator |
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Keywords | トゥファ / 浅間火山 / 炭酸泉 / 年縞 / 方解石 / Mg / Mn / 季節変動 |
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| Outline of Final Research Achievements |
Nigori River is tufa-depositing stream that flow out from carbonic springs in southern foot of Asama volcano, central Japan. We conducted bi-monthly observations and analyses for the water and tufa during about 3 years from 2011 to 2014. The Nigori River tufa has annually laminated textures which are characterized by repeated layers of dense summer acicular crystals alternating with porous winter fine particles. The constituent materials of these two layers are calcites. But the chemical compositions of calcite are Mg-rich in summer and Mn-rich in winter which reflect seasonal changes in physical properties (water temperature, alkalinity, PWP-rate, etc) and water chemistry (Ca2+, Mn2+, dissolved oxygen, etc). Survey of Jabori River in Asama volcano which have a similar springs to Nigori River, revealed that an important factor of tufa-formation in an active volcanic area is an alkalinity of carbonic springs.
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| Free Research Field |
地球環境システム学
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