| Budget Amount *help |
¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2013: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2012: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2011: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
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| Research Abstract |
Volcano is one of the most heterogeneous field in the Earth's crust, and the understanding of such inhomogeneity in volcanoes may provide us important information on the various volcanic processes.
In this study, I systematically estimate the scattering properties of high-frequency seismic waves using the records of active seismic experiments at active volcanoes in Japan, and reveal that the mean free paths of S wave are as short as about 1km for 8-16Hz band at most of the volcanoes. I further conducted numerical simulation of wave scattering in strongly heterogeneous media, and suggest that fluid-filled cavities concentrated at the shallow portion of volcanic edifice are possible cause of the observed short mean free path.
These results suggest that the mode conversion and multiple scattering have an indispensable effect in the modeling and analysis of seismic wave propagation in heterogeneous volcanic environments.
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