SOURCE MODEING OF THE 2009 SURUGA BAY EARTHQUAKE USING SPECTRAL INVERSION AND EMPIRICAL GREEN'S FUNCTION METHOD

Abstract

The Q value and short period source spectra of the 2009 Suruga bay earthquake (M_J6.5) and its aftershocks are estimated using spectral inversion method. Then the source model composed of two strong motion generation areas (SMGAs) are estimated using the empirical Green's function method. The estimated Q value near the source region is modeled as 30ƒ^0.64, that is, ƒ is frequency. The short period source spectrum of the main shock is the largest among previous intraslab earthquakes occurred in the Philippine Sea plate and larger than the average value for intraslab earthquakes occurred in the Pacific Sea plate. The stress drop and the total area of SMGAs are estimated to be 751 bar and 18 km², respectively. The stress drop of SMGAs is larger than the empirical scaling law for crustal earthquakes and big intraslab earthquakes in the Philippine Sea plate. The total area SMGAs is smaller than the empirical scaling law for crustal earthquakes.