2014 Fiscal Year Final Research Report
Study on water circulation system of crater lakes using radioactive cesium as a hydrological tracer
Project/Area Number |
24654156
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Research Category |
Grant-in-Aid for Challenging Exploratory Research
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Allocation Type | Multi-year Fund |
Research Field |
Meteorology/Physical oceanography/Hydrology
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Research Institution | Sophia University |
Principal Investigator |
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Project Period (FY) |
2012-04-01 – 2015-03-31
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Keywords | 草津白根山 / 活火山 / 火口湖 / 物質収支 / 物質循環 / 水文学的トレーサー / 放射性セシウム / 福島第一原子力発電所事故 |
Outline of Final Research Achievements |
The Kusatsu-Shirane volcano is one of the active volcanoes in Japan. In Yugama, one of its four crater lakes, a part of the lake water always flows out from the lake bed, and volcanic fluid always flows into the lake from the bottom. I considered radioactive isotopes of cesium derived from the Fukushima Daiichi Nuclear Power Plant accident could be utilized as a hydrological tracer for the study on the lake water circulation system, and started measuring their concentrations in the lake water samples collected periodically. The time series data of the concentrations of radioactive cesium are a good indicator of the water circulation in the crater lakes of the Kusatsu-Shirane volcano. It was estimated that, in Yugama, 0.1% of the lake water leaks out per day, based on the decreasing rate of the dissolved radioactive cesium.
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Free Research Field |
火山化学・環境分析化学
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