Earth Planets Space, Vol. 57 (No. 6), pp. 533-538, 2005LETTER
K. Kamae1,T.Ikeda2, and S. Miwa2
1Research Reactor Institute, Kyoto University, Osaka 590-0494, Japan
2Technical Research Institute, Tobishima Corp., Chiba 270-0222, Japan
(Received February 12, 2005; Revised April 28, 2005; Accepted May 2, 2005)
A preliminary source model composed of asperities for the 2004 Mid Niigata Prefecture, Japan, earthquake (MJMA =6.8) was estimated by the empirical Green's function method. The source parameters for two asperities located on the fault plane were determined from the comparisons of the synthesized broad-band ground motions with the observed ones at several stations including near source. Furthermore, we performed the preliminary nonlinear analysis of the sedimentary soils to reproduce the observed ground motions at NIG019 of K-NET. Resultantly, we pointed out the need of more asperity in northern part on the fault plane and the importance of the quantitative analysis of the nonlinearity of the sedimentary soils at K-NET stations.
Key words: Source model, asperity, forward modeling, empirical Green's function method, nonlinear analysis.