| Budget Amount *help |
¥17,680,000 (Direct Cost: ¥13,600,000、Indirect Cost: ¥4,080,000)
Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2016: ¥6,110,000 (Direct Cost: ¥4,700,000、Indirect Cost: ¥1,410,000)
Fiscal Year 2015: ¥10,530,000 (Direct Cost: ¥8,100,000、Indirect Cost: ¥2,430,000)
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| Outline of Final Research Achievements |
Crystal-rich magmas with high viscosity often cause explosive volcanism. To ascend rapidly to the surface, the magma must be lubricated during the eruption. We performed decompression experiments for bubble- and crystal-bearing magmas to simulate magma ascent process. We also measured the viscosity of magmas with gas bubbles and crystals. Based on these experiments, we found that crystal-rich magma can lubricate due to the breakage of crystal network with gas bubble formation under high decompression rates. In contrast, gas bubbles escaped under low decompression rates. Thus, we infer that explosive volcanism by crystal-rich magmas can cause when high decompression rate is achieved by some mechanisms such as large overpressure in a magma reservoir.
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