| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2015: ¥260,000 (Direct Cost: ¥200,000、Indirect Cost: ¥60,000)
Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2013: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
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| Outline of Final Research Achievements |
Volcanic activity of the Nakadake 1st crater of Aso volcano has increased since 2013 immediately after this project was started. Volcanic lake at the crater has been disappeared and then new active vent was opened inside the crater in January 2014. On 25 November 2014, magmatic eruptions started after c.a. 20 years dormancy. So as to satisfy an extreme objective of this project - understanding and evaluating of future phreatic explosions - several kinds of analysis on seismo-acoustic signals were investigated. From the analysis of high-frequency continuous tremor, final section of the pathway of volcanic fluids toward crater bottom was revealed. Monochromatic infrasound tremor with the ~0.5 Hz peak was identified by a new network of infrasound sensors. Source process of this signal was considered as the Helmholtz resonance inside the conduit.
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