2010 Fiscal Year Final Research Report

Study of scattering property in the crust using the autocorrelation function of ambient seismic noises

Research Project

Project/Area Number	20540409
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Solid earth and planetary physics
Research Institution	Nagoya University
Principal Investigator	FURUMOTO Muneyoshi Nagoya University, 環境学研究科, 教授 (80109264)
Co-Investigator(Renkei-kenkyūsha)	HIRAMATSU Yoshihiro 金沢大学, 大学院・自然科学研究科, 准教授 (80283092) ITO Takeo 名古屋大学, 大学院・環境学研究科, 助教 (40377982)
Project Period (FY)	2008 – 2010
Keywords	地震 / 地球・惑星内部構造 / 固体地球物理学 / 散乱 / 地殻・マントル物質
Research Abstract	Scattered seismic waves provide much information about a subterranean heterogeneous structure. If we can obtain waves which are radiated from a source, back scattered, and come back to the location of the source, they should be invaluable for the study. Equivalent signals can be retrieved by the autocorrelation function of ambient ground noise. We estimated quality factors Q_<ACF> of the signals derived from the noises for 26 stations in Izu-Oshima volcanic island, Japan. It is found that the signals mainly consist of back scattered surface waves. The resultant spatio-temporal distribution of Q_<ACF> of the island in a period, Aug. 2008-Jun. 2009, demonstrates that Q_<ACF> is a useful parameter to study the shallow heterogeneous structure in the crust.

(4 results)