2013 Fiscal Year Final Research Report
Seismological study on the small-scale heterogeneity beneath active volcanoes
| Project/Area Number |
23740327
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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 |
Solid earth and planetary physics
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| Research Institution | Tohoku University |
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Principal Investigator |
YAMAMOTO Mare 東北大学, 理学(系)研究科(研究院), 助教 (30400229)
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| Project Period (FY) |
2011 – 2013
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| Keywords | 火山 / 短波長不均質構造 / 火山構造探査 / 波動 / 散乱 |
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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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