Study on seismic wave propagation through the heterogeneous structure and the Green function retrieval from the noise cross correlation

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540448
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Solid earth and planetary physics
• Research Institution: Tohoku University
• Principal Investigator: SATO Haruo 東北大学, 理学(系)研究科(研究院), 名誉教授 (80225987)
• Co-Investigator(Kenkyū-buntansha): NISHIMURA Takeshi 東北大学, 大学院理学研究科, 教授 (40222187)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 地震波動 / 散乱 / 不均質構造 / 地殻 / リソスフェア / 火山 / ランダム媒質

Outline of Final Research Achievements

In order to describe the propagation of seismic wave-energy through random heterogeneities of the solid earth medium, we have improved the radiative transfer theory. If we imagine a fractal distribution of scatterers, we can explain the power-law decay of the maximum amplitude and coda amplitude with lapse time increasing. Since low-velocity bodies including melt/or water are expected beneath volcanoes, we have developed the radiative transfer theory which deals with the trap and release of wave energy due to resonant scattering. For the Green function retrieval from the cross-correlation function of ambient noise for the existence of an obstacle (heterogeneity) of arbitrary shape, we have theoretically shown that the generalized optical theorem as the necessary condition.

Free Research Field

固体地球物理学および地震学